fix

codex-rs/app-server-protocol/schema/typescript/Compaction.ts

@@ -0,0 +1,5 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+export type Compaction = { encrypted_content: string, };

codex-rs/app-server-protocol/schema/typescript/CustomToolCall.ts

@@ -0,0 +1,5 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+export type CustomToolCall = { status?: string, call_id: string, name: string, input: string, };

codex-rs/app-server-protocol/schema/typescript/CustomToolCallOutput.ts

@@ -0,0 +1,5 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+export type CustomToolCallOutput = { call_id: string, output: string, };

codex-rs/app-server-protocol/schema/typescript/FunctionCall.ts

@@ -0,0 +1,5 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+export type FunctionCall = { name: string, arguments: string, call_id: string, };

codex-rs/app-server-protocol/schema/typescript/FunctionCallOutput.ts

@@ -0,0 +1,6 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { FunctionCallOutputPayload } from "./FunctionCallOutputPayload";
+
+export type FunctionCallOutput = { call_id: string, output: FunctionCallOutputPayload, };

codex-rs/app-server-protocol/schema/typescript/GhostSnapshot.ts

@@ -0,0 +1,6 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { GhostCommit } from "./GhostCommit";
+
+export type GhostSnapshot = { ghost_commit: GhostCommit, };

codex-rs/app-server-protocol/schema/typescript/LocalShellCall.ts

@@ -0,0 +1,11 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { LocalShellAction } from "./LocalShellAction";
+import type { LocalShellStatus } from "./LocalShellStatus";
+
+export type LocalShellCall = { 
+/**
+ * Set when using the Responses API.
+ */
+call_id: string | null, status: LocalShellStatus, action: LocalShellAction, };

codex-rs/app-server-protocol/schema/typescript/Message.ts

@@ -0,0 +1,7 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { ContentItem } from "./ContentItem";
+import type { MessagePhase } from "./MessagePhase";
+
+export type Message = { role: string, content: Array<ContentItem>, end_turn?: boolean, phase?: MessagePhase, };

codex-rs/app-server-protocol/schema/typescript/Reasoning.ts

@@ -0,0 +1,7 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { ReasoningItemContent } from "./ReasoningItemContent";
+import type { ReasoningItemReasoningSummary } from "./ReasoningItemReasoningSummary";
+
+export type Reasoning = { summary: Array<ReasoningItemReasoningSummary>, content?: Array<ReasoningItemContent>, encrypted_content: string | null, };

codex-rs/app-server-protocol/schema/typescript/ResponseItem.ts

@@ -1,18 +1,15 @@
 // GENERATED CODE! DO NOT MODIFY BY HAND!
 
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
-import type { ContentItem } from "./ContentItem";
+import type { Compaction } from "./Compaction";
-import type { FunctionCallOutputPayload } from "./FunctionCallOutputPayload";
+import type { CustomToolCall } from "./CustomToolCall";
-import type { GhostCommit } from "./GhostCommit";
+import type { CustomToolCallOutput } from "./CustomToolCallOutput";
-import type { LocalShellAction } from "./LocalShellAction";
+import type { FunctionCall } from "./FunctionCall";
-import type { LocalShellStatus } from "./LocalShellStatus";
+import type { FunctionCallOutput } from "./FunctionCallOutput";
-import type { MessagePhase } from "./MessagePhase";
+import type { GhostSnapshot } from "./GhostSnapshot";
-import type { ReasoningItemContent } from "./ReasoningItemContent";
+import type { LocalShellCall } from "./LocalShellCall";
-import type { ReasoningItemReasoningSummary } from "./ReasoningItemReasoningSummary";
+import type { Message } from "./Message";
-import type { WebSearchAction } from "./WebSearchAction";
+import type { Reasoning } from "./Reasoning";
+import type { WebSearchCall } from "./WebSearchCall";
 
-export type ResponseItem = { "type": "message", role: string, content: Array<ContentItem>, end_turn?: boolean, phase?: MessagePhase, } | { "type": "reasoning", summary: Array<ReasoningItemReasoningSummary>, content?: Array<ReasoningItemContent>, encrypted_content: string | null, } | { "type": "local_shell_call", 
+export type ResponseItem = { "type": "message" } & Message | { "type": "reasoning" } & Reasoning | { "type": "local_shell_call" } & LocalShellCall | { "type": "function_call" } & FunctionCall | { "type": "function_call_output" } & FunctionCallOutput | { "type": "custom_tool_call" } & CustomToolCall | { "type": "custom_tool_call_output" } & CustomToolCallOutput | { "type": "web_search_call" } & WebSearchCall | { "type": "ghost_snapshot" } & GhostSnapshot | { "type": "compaction" } & Compaction | { "type": "other" };
-/**
- * Set when using the Responses API.
- */
-call_id: string | null, status: LocalShellStatus, action: LocalShellAction, } | { "type": "function_call", name: string, arguments: string, call_id: string, } | { "type": "function_call_output", call_id: string, output: FunctionCallOutputPayload, } | { "type": "custom_tool_call", status?: string, call_id: string, name: string, input: string, } | { "type": "custom_tool_call_output", call_id: string, output: string, } | { "type": "web_search_call", status?: string, action?: WebSearchAction, } | { "type": "ghost_snapshot", ghost_commit: GhostCommit, } | { "type": "compaction", encrypted_content: string, } | { "type": "other" };

codex-rs/app-server-protocol/schema/typescript/WebSearchCall.ts

@@ -0,0 +1,6 @@
+// GENERATED CODE! DO NOT MODIFY BY HAND!
+
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { WebSearchAction } from "./WebSearchAction";
+
+export type WebSearchCall = { status?: string, action?: WebSearchAction, };

codex-rs/app-server-protocol/schema/typescript/index.ts

@@ -43,6 +43,7 @@ export type { CollabWaitingBeginEvent } from "./CollabWaitingBeginEvent";
 export type { CollabWaitingEndEvent } from "./CollabWaitingEndEvent";
 export type { CollaborationMode } from "./CollaborationMode";
 export type { CollaborationModeMask } from "./CollaborationModeMask";
+export type { Compaction } from "./Compaction";
 export type { ContentItem } from "./ContentItem";
 export type { ContextCompactedEvent } from "./ContextCompactedEvent";
 export type { ContextCompactionItem } from "./ContextCompactionItem";
@@ -50,6 +51,8 @@ export type { ConversationGitInfo } from "./ConversationGitInfo";
 export type { ConversationSummary } from "./ConversationSummary";
 export type { CreditsSnapshot } from "./CreditsSnapshot";
 export type { CustomPrompt } from "./CustomPrompt";
+export type { CustomToolCall } from "./CustomToolCall";
+export type { CustomToolCallOutput } from "./CustomToolCallOutput";
 export type { DeprecationNoticeEvent } from "./DeprecationNoticeEvent";
 export type { DynamicToolCallRequest } from "./DynamicToolCallRequest";
 export type { ElicitationRequestEvent } from "./ElicitationRequestEvent";
@@ -71,6 +74,8 @@ export type { FileChange } from "./FileChange";
 export type { ForcedLoginMethod } from "./ForcedLoginMethod";
 export type { ForkConversationParams } from "./ForkConversationParams";
 export type { ForkConversationResponse } from "./ForkConversationResponse";
+export type { FunctionCall } from "./FunctionCall";
+export type { FunctionCallOutput } from "./FunctionCallOutput";
 export type { FunctionCallOutputBody } from "./FunctionCallOutputBody";
 export type { FunctionCallOutputContentItem } from "./FunctionCallOutputContentItem";
 export type { FunctionCallOutputPayload } from "./FunctionCallOutputPayload";
@@ -85,6 +90,7 @@ export type { GetHistoryEntryResponseEvent } from "./GetHistoryEntryResponseEven
 export type { GetUserAgentResponse } from "./GetUserAgentResponse";
 export type { GetUserSavedConfigResponse } from "./GetUserSavedConfigResponse";
 export type { GhostCommit } from "./GhostCommit";
+export type { GhostSnapshot } from "./GhostSnapshot";
 export type { GitDiffToRemoteParams } from "./GitDiffToRemoteParams";
 export type { GitDiffToRemoteResponse } from "./GitDiffToRemoteResponse";
 export type { GitSha } from "./GitSha";
@@ -104,6 +110,7 @@ export type { ListCustomPromptsResponseEvent } from "./ListCustomPromptsResponse
 export type { ListRemoteSkillsResponseEvent } from "./ListRemoteSkillsResponseEvent";
 export type { ListSkillsResponseEvent } from "./ListSkillsResponseEvent";
 export type { LocalShellAction } from "./LocalShellAction";
+export type { LocalShellCall } from "./LocalShellCall";
 export type { LocalShellExecAction } from "./LocalShellExecAction";
 export type { LocalShellStatus } from "./LocalShellStatus";
 export type { LoginApiKeyParams } from "./LoginApiKeyParams";
@@ -120,6 +127,7 @@ export type { McpStartupStatus } from "./McpStartupStatus";
 export type { McpStartupUpdateEvent } from "./McpStartupUpdateEvent";
 export type { McpToolCallBeginEvent } from "./McpToolCallBeginEvent";
 export type { McpToolCallEndEvent } from "./McpToolCallEndEvent";
+export type { Message } from "./Message";
 export type { MessagePhase } from "./MessagePhase";
 export type { ModeKind } from "./ModeKind";
 export type { NetworkAccess } from "./NetworkAccess";
@@ -137,6 +145,7 @@ export type { Profile } from "./Profile";
 export type { RateLimitSnapshot } from "./RateLimitSnapshot";
 export type { RateLimitWindow } from "./RateLimitWindow";
 export type { RawResponseItemEvent } from "./RawResponseItemEvent";
+export type { Reasoning } from "./Reasoning";
 export type { ReasoningContentDeltaEvent } from "./ReasoningContentDeltaEvent";
 export type { ReasoningEffort } from "./ReasoningEffort";
 export type { ReasoningItem } from "./ReasoningItem";
@@ -218,6 +227,7 @@ export type { ViewImageToolCallEvent } from "./ViewImageToolCallEvent";
 export type { WarningEvent } from "./WarningEvent";
 export type { WebSearchAction } from "./WebSearchAction";
 export type { WebSearchBeginEvent } from "./WebSearchBeginEvent";
+export type { WebSearchCall } from "./WebSearchCall";
 export type { WebSearchEndEvent } from "./WebSearchEndEvent";
 export type { WebSearchItem } from "./WebSearchItem";
 export type { WebSearchMode } from "./WebSearchMode";

codex-rs/app-server/tests/suite/list_resume.rs

@@ -301,7 +301,7 @@ async fn test_list_and_resume_conversations() -> Result<()> {
 
     // Resuming with explicit history should succeed even without a stored rollout.
     let fork_history_text = "Hello from history";
-    let history = vec![ResponseItem::Message {
+    let history = vec![ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".to_string(),
         content: vec![ContentItem::InputText {
@@ -309,7 +309,7 @@ async fn test_list_and_resume_conversations() -> Result<()> {
         }],
         end_turn: None,
         phase: None,
-    }];
+    })];
     let resume_with_history_req_id = mcp
         .send_resume_conversation_request(ResumeConversationParams {
             path: None,

codex-rs/app-server/tests/suite/send_message.rs

@@ -445,7 +445,10 @@ async fn read_raw_response_item(mcp: &mut McpProcess, conversation_id: ThreadId)
         // Ghost snapshots are produced concurrently and may arrive before the model reply.
         let event: RawResponseItemEvent =
             serde_json::from_value(msg_value).expect("deserialize raw response item");
-        if !matches!(event.item, ResponseItem::GhostSnapshot { .. }) {
+        if !matches!(
+            event.item,
+            ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. })
+        ) {
             return event.item;
         }
     }
@@ -453,7 +456,7 @@ async fn read_raw_response_item(mcp: &mut McpProcess, conversation_id: ThreadId)
 
 fn assert_instructions_message(item: &ResponseItem) {
     match item {
-        ResponseItem::Message { role, content, .. } => {
+        ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
             assert_eq!(role, "user");
             let texts = content_texts(content);
             let is_instructions = texts
@@ -470,7 +473,7 @@ fn assert_instructions_message(item: &ResponseItem) {
 
 fn assert_permissions_message(item: &ResponseItem) {
     match item {
-        ResponseItem::Message { role, content, .. } => {
+        ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
             assert_eq!(role, "developer");
             let texts = content_texts(content);
             let expected = DeveloperInstructions::from_policy(
@@ -493,7 +496,7 @@ fn assert_permissions_message(item: &ResponseItem) {
 
 fn assert_developer_message(item: &ResponseItem, expected_text: &str) {
     match item {
-        ResponseItem::Message { role, content, .. } => {
+        ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
             assert_eq!(role, "developer");
             let texts = content_texts(content);
             assert_eq!(
@@ -508,7 +511,7 @@ fn assert_developer_message(item: &ResponseItem, expected_text: &str) {
 
 fn assert_environment_message(item: &ResponseItem) {
     match item {
-        ResponseItem::Message { role, content, .. } => {
+        ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
             assert_eq!(role, "user");
             let texts = content_texts(content);
             assert!(
@@ -524,7 +527,7 @@ fn assert_environment_message(item: &ResponseItem) {
 
 fn assert_user_message(item: &ResponseItem, expected_text: &str) {
     match item {
-        ResponseItem::Message { role, content, .. } => {
+        ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
             assert_eq!(role, "user");
             let texts = content_texts(content);
             assert_eq!(texts, vec![expected_text]);
@@ -535,7 +538,7 @@ fn assert_user_message(item: &ResponseItem, expected_text: &str) {
 
 fn assert_assistant_message(item: &ResponseItem, expected_text: &str) {
     match item {
-        ResponseItem::Message { role, content, .. } => {
+        ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
             assert_eq!(role, "assistant");
             let texts = content_texts(content);
             assert_eq!(texts, vec![expected_text]);

codex-rs/app-server/tests/suite/v2/compaction.rs

@@ -123,7 +123,7 @@ async fn auto_compaction_remote_emits_started_and_completed_items() -> Result<()
     let responses_log = responses::mount_sse_sequence(&server, vec![sse1, sse2, sse3]).await;
 
     let compacted_history = vec![
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -131,10 +131,10 @@ async fn auto_compaction_remote_emits_started_and_completed_items() -> Result<()
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Compaction {
+        ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock = responses::mount_compact_json_once(
         &server,

codex-rs/app-server/tests/suite/v2/thread_resume.rs

@@ -392,7 +392,7 @@ async fn thread_resume_supports_history_and_overrides() -> Result<()> {
     let ThreadStartResponse { thread, .. } = to_response::<ThreadStartResponse>(start_resp)?;
 
     let history_text = "Hello from history";
-    let history = vec![ResponseItem::Message {
+    let history = vec![ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".to_string(),
         content: vec![ContentItem::InputText {
@@ -400,7 +400,7 @@ async fn thread_resume_supports_history_and_overrides() -> Result<()> {
         }],
         end_turn: None,
         phase: None,
-    }];
+    })];
 
     // Resume with explicit history and override the model.
     let resume_id = mcp

codex-rs/codex-api/src/endpoint/aggregate.rs

@@ -36,12 +36,15 @@ impl Stream for AggregatedStream {
                 Poll::Ready(Some(Ok(ResponseEvent::OutputItemDone(item)))) => {
                     let is_assistant_message = matches!(
                         &item,
-                        ResponseItem::Message { role, .. } if role == "assistant"
+                        ResponseItem::Message(codex_protocol::models::Message { role, .. }) if role == "assistant"
                     );
 
                     if is_assistant_message {
                         if this.cumulative.is_empty()
-                            && let ResponseItem::Message { content, .. } = &item
+                            && let ResponseItem::Message(codex_protocol::models::Message {
+                                content,
+                                ..
+                            }) = &item
                             && let Some(text) = content.iter().find_map(|c| match c {
                                 ContentItem::OutputText { text } => Some(text),
                                 _ => None,
@@ -70,29 +73,31 @@ impl Stream for AggregatedStream {
                     let mut emitted_any = false;
 
                     if !this.cumulative_reasoning.is_empty() {
-                        let aggregated_reasoning = ResponseItem::Reasoning {
+                        let aggregated_reasoning =
-                            id: String::new(),
+                            ResponseItem::Reasoning(codex_protocol::models::Reasoning {
-                            summary: Vec::new(),
+                                id: String::new(),
-                            content: Some(vec![ReasoningItemContent::ReasoningText {
+                                summary: Vec::new(),
-                                text: std::mem::take(&mut this.cumulative_reasoning),
+                                content: Some(vec![ReasoningItemContent::ReasoningText {
-                            }]),
+                                    text: std::mem::take(&mut this.cumulative_reasoning),
-                            encrypted_content: None,
+                                }]),
-                        };
+                                encrypted_content: None,
+                            });
                         this.pending
                             .push_back(ResponseEvent::OutputItemDone(aggregated_reasoning));
                         emitted_any = true;
                     }
 
                     if !this.cumulative.is_empty() {
-                        let aggregated_message = ResponseItem::Message {
+                        let aggregated_message =
-                            id: None,
+                            ResponseItem::Message(codex_protocol::models::Message {
-                            role: "assistant".to_string(),
+                                id: None,
-                            content: vec![ContentItem::OutputText {
+                                role: "assistant".to_string(),
-                                text: std::mem::take(&mut this.cumulative),
+                                content: vec![ContentItem::OutputText {
-                            }],
+                                    text: std::mem::take(&mut this.cumulative),
-                            end_turn: None,
+                                }],
-                            phase: None,
+                                end_turn: None,
-                        };
+                                phase: None,
+                            });
                         this.pending
                             .push_back(ResponseEvent::OutputItemDone(aggregated_message));
                         emitted_any = true;

codex-rs/codex-api/src/requests/responses.rs

@@ -169,12 +169,24 @@ fn attach_item_ids(payload_json: &mut Value, original_items: &[ResponseItem]) {
     };
 
     for (value, item) in items.iter_mut().zip(original_items.iter()) {
-        if let ResponseItem::Reasoning { id, .. }
+        if let ResponseItem::Reasoning(codex_protocol::models::Reasoning { id, .. })
-        | ResponseItem::Message { id: Some(id), .. }
+        | ResponseItem::Message(codex_protocol::models::Message { id: Some(id), .. })
-        | ResponseItem::WebSearchCall { id: Some(id), .. }
+        | ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall {
-        | ResponseItem::FunctionCall { id: Some(id), .. }
+            id: Some(id),
-        | ResponseItem::LocalShellCall { id: Some(id), .. }
+            ..
-        | ResponseItem::CustomToolCall { id: Some(id), .. } = item
+        })
+        | ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
+            id: Some(id),
+            ..
+        })
+        | ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall {
+            id: Some(id),
+            ..
+        })
+        | ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall {
+            id: Some(id),
+            ..
+        }) = item
         {
             if id.is_empty() {
                 continue;
@@ -217,20 +229,20 @@ mod tests {
     fn azure_default_store_attaches_ids_and_headers() {
         let provider = provider("azure", "https://example.openai.azure.com/v1");
         let input = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: Some("m1".into()),
                 role: "assistant".into(),
                 content: Vec::new(),
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "assistant".into(),
                 content: Vec::new(),
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
 
         let request = ResponsesRequestBuilder::new("gpt-test", "inst", &input)

codex-rs/codex-api/src/sse/responses.rs

@@ -531,16 +531,16 @@ mod tests {
 
         assert_matches!(
             &events[0],
-            Ok(ResponseEvent::OutputItemDone(ResponseItem::Message {
+            Ok(ResponseEvent::OutputItemDone(ResponseItem::Message(codex_protocol::models::Message {
                 role,
                 phase: Some(MessagePhase::Commentary),
                 ..
-            })) if role == "assistant"
+            }))) if role == "assistant"
         );
 
         assert_matches!(
             &events[1],
-            Ok(ResponseEvent::OutputItemDone(ResponseItem::Message { role, .. }))
+            Ok(ResponseEvent::OutputItemDone(ResponseItem::Message(codex_protocol::models::Message { role, .. })))
                 if role == "assistant"
         );
 

codex-rs/codex-api/tests/clients.rs

@@ -255,7 +255,7 @@ async fn streaming_client_retries_on_transport_error() -> Result<()> {
 
     let prompt = codex_api::Prompt {
         instructions: "Say hi".to_string(),
-        input: vec![ResponseItem::Message {
+        input: vec![ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -263,7 +263,7 @@ async fn streaming_client_retries_on_transport_error() -> Result<()> {
             }],
             end_turn: None,
             phase: None,
-        }],
+        })],
         tools: Vec::<Value>::new(),
         parallel_tool_calls: false,
         output_schema: None,

codex-rs/codex-api/tests/sse_end_to_end.rs

@@ -144,14 +144,20 @@ async fn responses_stream_parses_items_and_completed_end_to_end() -> Result<()>
     assert_eq!(events.len(), 3);
 
     match &events[0] {
-        ResponseEvent::OutputItemDone(ResponseItem::Message { role, .. }) => {
+        ResponseEvent::OutputItemDone(ResponseItem::Message(codex_protocol::models::Message {
+            role,
+            ..
+        })) => {
             assert_eq!(role, "assistant");
         }
         other => panic!("unexpected first event: {other:?}"),
     }
 
     match &events[1] {
-        ResponseEvent::OutputItemDone(ResponseItem::Message { role, .. }) => {
+        ResponseEvent::OutputItemDone(ResponseItem::Message(codex_protocol::models::Message {
+            role,
+            ..
+        })) => {
             assert_eq!(role, "assistant");
         }
         other => panic!("unexpected second event: {other:?}"),
@@ -215,7 +221,10 @@ async fn responses_stream_aggregates_output_text_deltas() -> Result<()> {
     assert_eq!(events.len(), 2);
 
     match &events[0] {
-        ResponseEvent::OutputItemDone(ResponseItem::Message { content, .. }) => {
+        ResponseEvent::OutputItemDone(ResponseItem::Message(codex_protocol::models::Message {
+            content,
+            ..
+        })) => {
             let mut aggregated = String::new();
             for item in content {
                 if let ContentItem::OutputText { text } = item {

codex-rs/core/src/client_common.rs

@@ -68,35 +68,45 @@ fn reserialize_shell_outputs(items: &mut [ResponseItem]) {
     let mut shell_call_ids: HashSet<String> = HashSet::new();
 
     items.iter_mut().for_each(|item| match item {
-        ResponseItem::LocalShellCall { call_id, id, .. } => {
+        ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall {
+            call_id,
+            id,
+            ..
+        }) => {
             if let Some(identifier) = call_id.clone().or_else(|| id.clone()) {
                 shell_call_ids.insert(identifier);
             }
         }
-        ResponseItem::CustomToolCall {
+        ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall {
             id: _,
             status: _,
             call_id,
             name,
             input: _,
-        } => {
+        }) => {
             if name == "apply_patch" {
                 shell_call_ids.insert(call_id.clone());
             }
         }
-        ResponseItem::CustomToolCallOutput { call_id, output } => {
+        ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput {
+            call_id,
+            output,
+        }) => {
             if shell_call_ids.remove(call_id)
                 && let Some(structured) = parse_structured_shell_output(output)
             {
                 *output = structured
             }
         }
-        ResponseItem::FunctionCall { name, call_id, .. }
+        ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
-            if is_shell_tool_name(name) || name == "apply_patch" =>
+            name, call_id, ..
-        {
+        }) if is_shell_tool_name(name) || name == "apply_patch" => {
             shell_call_ids.insert(call_id.clone());
         }
-        ResponseItem::FunctionCallOutput { call_id, output } => {
+        ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput {
+            call_id,
+            output,
+        }) => {
             if shell_call_ids.remove(call_id)
                 && let Some(structured) = output
                     .text_content()

codex-rs/core/src/codex.rs

@@ -539,10 +539,7 @@ pub(crate) struct TurnContext {
 }
 impl TurnContext {
     pub(crate) fn model_context_window(&self) -> Option<i64> {
-        let effective_context_window_percent = self.model_info.effective_context_window_percent;
+        effective_model_context_window(&self.model_info)
-        self.model_info.context_window.map(|context_window| {
-            context_window.saturating_mul(effective_context_window_percent) / 100
-        })
     }
 
     pub(crate) fn resolve_path(&self, path: Option<String>) -> PathBuf {
@@ -684,6 +681,13 @@ impl SessionConfiguration {
     }
 }
 
+fn effective_model_context_window(model_info: &ModelInfo) -> Option<i64> {
+    let effective_context_window_percent = model_info.effective_context_window_percent;
+    model_info
+        .context_window
+        .map(|context_window| context_window.saturating_mul(effective_context_window_percent) / 100)
+}
+
 #[derive(Default, Clone)]
 pub(crate) struct SessionSettingsUpdate {
     pub(crate) cwd: Option<PathBuf>,
@@ -1044,7 +1048,15 @@ impl Session {
                 }
             };
         session_configuration.thread_name = thread_name.clone();
-        let state = SessionState::new(session_configuration.clone());
+        let model_info = models_manager
+            .get_model_info(session_configuration.collaboration_mode.model(), &config)
+            .await;
+        let state = SessionState::new(
+            session_configuration.clone(),
+            conversation_id.to_string(),
+            config.codex_home.clone(),
+            effective_model_context_window(&model_info),
+        );
 
         let services = SessionServices {
             mcp_connection_manager: Arc::new(RwLock::new(McpConnectionManager::default())),
@@ -2029,7 +2041,11 @@ impl Session {
         turn_context: &TurnContext,
         rollout_items: &[RolloutItem],
     ) -> Vec<ResponseItem> {
-        let mut history = ContextManager::new();
+        let mut history = ContextManager::new(
+            Arc::new(self.conversation_id.to_string()),
+            Arc::new(turn_context.config.codex_home.clone()),
+            turn_context.model_context_window(),
+        );
         for item in rollout_items {
             match item {
                 RolloutItem::ResponseItem(response_item) => {
@@ -2083,7 +2099,7 @@ impl Session {
         self.services
             .otel_manager
             .counter("codex.model_warning", 1, &[]);
-        let item = ResponseItem::Message {
+        let item = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -2091,7 +2107,7 @@ impl Session {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
 
         self.record_conversation_items(ctx, &[item]).await;
     }
@@ -4475,7 +4491,7 @@ async fn maybe_complete_plan_item_from_message(
     state: &mut PlanModeStreamState,
     item: &ResponseItem,
 ) {
-    if let ResponseItem::Message { role, content, .. } = item
+    if let ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) = item
         && role == "assistant"
     {
         let mut text = String::new();
@@ -4568,7 +4584,7 @@ async fn handle_assistant_item_done_in_plan_mode(
     previously_active_item: Option<&TurnItem>,
     last_agent_message: &mut Option<String>,
 ) -> bool {
-    if let ResponseItem::Message { role, .. } = item
+    if let ResponseItem::Message(codex_protocol::models::Message { role, .. }) = item
         && role == "assistant"
     {
         maybe_complete_plan_item_from_message(sess, turn_context, state, item).await;
@@ -4912,7 +4928,7 @@ async fn try_run_sampling_request(
 
 pub(super) fn get_last_assistant_message_from_turn(responses: &[ResponseItem]) -> Option<String> {
     responses.iter().rev().find_map(|item| {
-        if let ResponseItem::Message { role, content, .. } = item {
+        if let ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) = item {
             if role == "assistant" {
                 content.iter().rev().find_map(|ci| {
                     if let ContentItem::OutputText { text } = ci {
@@ -4994,7 +5010,7 @@ mod tests {
     }
 
     fn user_message(text: &str) -> ResponseItem {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -5002,7 +5018,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 
     fn make_connector(id: &str, name: &str) -> AppInfo {
@@ -5136,7 +5152,7 @@ mod tests {
     #[tokio::test]
     async fn reconstruct_history_uses_replacement_history_verbatim() {
         let (session, turn_context) = make_session_and_context().await;
-        let summary_item = ResponseItem::Message {
+        let summary_item = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -5144,10 +5160,10 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         let replacement_history = vec![
             summary_item.clone(),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -5155,7 +5171,7 @@ mod tests {
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         let rollout_items = vec![RolloutItem::Compacted(CompactedItem {
             message: String::new(),
@@ -5352,7 +5368,7 @@ mod tests {
             .await;
 
         let turn_1 = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -5360,8 +5376,8 @@ mod tests {
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "assistant".to_string(),
                 content: vec![ContentItem::OutputText {
@@ -5369,12 +5385,12 @@ mod tests {
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         sess.record_into_history(&turn_1, tc.as_ref()).await;
 
         let turn_2 = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -5382,8 +5398,8 @@ mod tests {
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "assistant".to_string(),
                 content: vec![ContentItem::OutputText {
@@ -5391,7 +5407,7 @@ mod tests {
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         sess.record_into_history(&turn_2, tc.as_ref()).await;
 
@@ -5416,7 +5432,7 @@ mod tests {
         sess.record_into_history(&initial_context, tc.as_ref())
             .await;
 
-        let turn_1 = vec![ResponseItem::Message {
+        let turn_1 = vec![ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -5424,7 +5440,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        }];
+        })];
         sess.record_into_history(&turn_1, tc.as_ref()).await;
 
         handlers::thread_rollback(&sess, "sub-1".to_string(), 99).await;
@@ -5483,6 +5499,7 @@ mod tests {
         let codex_home = tempfile::tempdir().expect("create temp dir");
         let config = build_test_config(codex_home.path()).await;
         let config = Arc::new(config);
+        let conversation_id = ThreadId::default();
         let model = ModelsManager::get_model_offline(config.model.as_deref());
         let model_info = ModelsManager::construct_model_info_offline(model.as_str(), &config);
         let reasoning_effort = config.model_reasoning_effort;
@@ -5517,7 +5534,12 @@ mod tests {
             dynamic_tools: Vec::new(),
         };
 
-        let mut state = SessionState::new(session_configuration);
+        let mut state = SessionState::new(
+            session_configuration,
+            conversation_id.to_string(),
+            config.codex_home.clone(),
+            effective_model_context_window(&model_info),
+        );
         let initial = RateLimitSnapshot {
             primary: Some(RateLimitWindow {
                 used_percent: 10.0,
@@ -5566,6 +5588,7 @@ mod tests {
         let codex_home = tempfile::tempdir().expect("create temp dir");
         let config = build_test_config(codex_home.path()).await;
         let config = Arc::new(config);
+        let conversation_id = ThreadId::default();
         let model = ModelsManager::get_model_offline(config.model.as_deref());
         let model_info = ModelsManager::construct_model_info_offline(model.as_str(), &config);
         let reasoning_effort = config.model_reasoning_effort;
@@ -5600,7 +5623,12 @@ mod tests {
             dynamic_tools: Vec::new(),
         };
 
-        let mut state = SessionState::new(session_configuration);
+        let mut state = SessionState::new(
+            session_configuration,
+            conversation_id.to_string(),
+            config.codex_home.clone(),
+            effective_model_context_window(&model_info),
+        );
         let initial = RateLimitSnapshot {
             primary: Some(RateLimitWindow {
                 used_percent: 15.0,
@@ -5885,7 +5913,12 @@ mod tests {
             session_configuration.session_source.clone(),
         );
 
-        let mut state = SessionState::new(session_configuration.clone());
+        let mut state = SessionState::new(
+            session_configuration.clone(),
+            conversation_id.to_string(),
+            config.codex_home.clone(),
+            effective_model_context_window(&model_info),
+        );
         mark_state_initial_context_seeded(&mut state);
         let skills_manager = Arc::new(SkillsManager::new(config.codex_home.clone()));
 
@@ -6017,7 +6050,12 @@ mod tests {
             session_configuration.session_source.clone(),
         );
 
-        let mut state = SessionState::new(session_configuration.clone());
+        let mut state = SessionState::new(
+            session_configuration.clone(),
+            conversation_id.to_string(),
+            config.codex_home.clone(),
+            effective_model_context_window(&model_info),
+        );
         mark_state_initial_context_seeded(&mut state);
         let skills_manager = Arc::new(SkillsManager::new(config.codex_home.clone()));
 
@@ -6144,7 +6182,7 @@ mod tests {
         let last = history_items.last().expect("warning recorded");
 
         match last {
-            ResponseItem::Message { role, content, .. } => {
+            ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
                 assert_eq!(role, "user");
                 assert_eq!(
                     content,
@@ -6282,7 +6320,7 @@ mod tests {
         sess.on_task_finished(Arc::clone(&tc), None).await;
 
         let history = sess.clone_history().await;
-        let expected = ResponseItem::Message {
+        let expected = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -6290,7 +6328,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         assert!(
             history.raw_items().iter().any(|item| item == &expected),
             "expected pending input to be persisted into history on turn completion"
@@ -6438,7 +6476,10 @@ mod tests {
         // recorded in history for the model.
         assert!(
             history.raw_items().iter().any(|item| {
-                let ResponseItem::Message { role, content, .. } = item else {
+                let ResponseItem::Message(codex_protocol::models::Message {
+                    role, content, ..
+                }) = item
+                else {
                     return false;
                 };
                 if role != "user" {
@@ -6477,13 +6518,13 @@ mod tests {
             ),
             turn_context.dynamic_tools.as_slice(),
         );
-        let item = ResponseItem::CustomToolCall {
+        let item = ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall {
             id: None,
             status: None,
             call_id: "call-1".to_string(),
             name: "shell".to_string(),
             input: "{}".to_string(),
-        };
+        });
 
         let call = ToolRouter::build_tool_call(session.as_ref(), item.clone())
             .await
@@ -6513,7 +6554,11 @@ mod tests {
         turn_context: &TurnContext,
     ) -> (Vec<RolloutItem>, Vec<ResponseItem>) {
         let mut rollout_items = Vec::new();
-        let mut live_history = ContextManager::new();
+        let mut live_history = ContextManager::new(
+            Arc::new(session.conversation_id.to_string()),
+            Arc::new(turn_context.config.codex_home.clone()),
+            turn_context.model_context_window(),
+        );
 
         let initial_context = session.build_initial_context(turn_context).await;
         for item in &initial_context {
@@ -6521,7 +6566,7 @@ mod tests {
         }
         live_history.record_items(initial_context.iter(), turn_context.truncation_policy);
 
-        let user1 = ResponseItem::Message {
+        let user1 = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -6529,11 +6574,11 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         live_history.record_items(std::iter::once(&user1), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(user1.clone()));
 
-        let assistant1 = ResponseItem::Message {
+        let assistant1 = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -6541,7 +6586,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         live_history.record_items(std::iter::once(&assistant1), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(assistant1.clone()));
 
@@ -6559,7 +6604,7 @@ mod tests {
             replacement_history: None,
         }));
 
-        let user2 = ResponseItem::Message {
+        let user2 = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -6567,11 +6612,11 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         live_history.record_items(std::iter::once(&user2), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(user2.clone()));
 
-        let assistant2 = ResponseItem::Message {
+        let assistant2 = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -6579,7 +6624,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         live_history.record_items(std::iter::once(&assistant2), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(assistant2.clone()));
 
@@ -6597,7 +6642,7 @@ mod tests {
             replacement_history: None,
         }));
 
-        let user3 = ResponseItem::Message {
+        let user3 = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -6605,11 +6650,11 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         live_history.record_items(std::iter::once(&user3), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(user3));
 
-        let assistant3 = ResponseItem::Message {
+        let assistant3 = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -6617,7 +6662,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         live_history.record_items(std::iter::once(&assistant3), turn_context.truncation_policy);
         rollout_items.push(RolloutItem::ResponseItem(assistant3));
 

codex-rs/core/src/codex_delegate.rs

@@ -493,13 +493,13 @@ mod tests {
             .send(Event {
                 id: "evt".to_string(),
                 msg: EventMsg::RawResponseItem(RawResponseItemEvent {
-                    item: ResponseItem::CustomToolCall {
+                    item: ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall {
                         id: None,
                         status: None,
                         call_id: "call-1".to_string(),
                         name: "tool".to_string(),
                         input: "{}".to_string(),
-                    },
+                    }),
                 }),
             })
             .await

codex-rs/core/src/compact.rs

@@ -192,7 +192,12 @@ async fn run_compact_task_inner(
     let mut new_history = build_compacted_history(initial_context, &user_messages, &summary_text);
     let ghost_snapshots: Vec<ResponseItem> = history_items
         .iter()
-        .filter(|item| matches!(item, ResponseItem::GhostSnapshot { .. }))
+        .filter(|item| {
+            matches!(
+                item,
+                ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. })
+            )
+        })
         .cloned()
         .collect();
     new_history.extend(ghost_snapshots);
@@ -293,11 +298,17 @@ pub(crate) fn process_compacted_history(
 /// summary messages because they parse as `TurnItem::UserMessage`.
 fn should_keep_compacted_history_item(item: &ResponseItem) -> bool {
     match item {
-        ResponseItem::Message { role, .. } if role == "developer" => false,
+        ResponseItem::Message(codex_protocol::models::Message { role, .. })
-        ResponseItem::Message { role, .. } if role == "user" => matches!(
+            if role == "developer" =>
-            crate::event_mapping::parse_turn_item(item),
+        {
-            Some(TurnItem::UserMessage(_))
+            false
-        ),
+        }
+        ResponseItem::Message(codex_protocol::models::Message { role, .. }) if role == "user" => {
+            matches!(
+                crate::event_mapping::parse_turn_item(item),
+                Some(TurnItem::UserMessage(_))
+            )
+        }
         _ => true,
     }
 }
@@ -342,7 +353,7 @@ fn build_compacted_history_with_limit(
     }
 
     for message in &selected_messages {
-        history.push(ResponseItem::Message {
+        history.push(ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -350,7 +361,7 @@ fn build_compacted_history_with_limit(
             }],
             end_turn: None,
             phase: None,
-        });
+        }));
     }
 
     let summary_text = if summary_text.is_empty() {
@@ -359,13 +370,13 @@ fn build_compacted_history_with_limit(
         summary_text.to_string()
     };
 
-    history.push(ResponseItem::Message {
+    history.push(ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".to_string(),
         content: vec![ContentItem::InputText { text: summary_text }],
         end_turn: None,
         phase: None,
-    });
+    }));
 
     history
 }
@@ -456,7 +467,7 @@ mod tests {
     #[test]
     fn collect_user_messages_extracts_user_text_only() {
         let items = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: Some("assistant".to_string()),
                 role: "assistant".to_string(),
                 content: vec![ContentItem::OutputText {
@@ -464,8 +475,8 @@ mod tests {
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: Some("user".to_string()),
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -473,7 +484,7 @@ mod tests {
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
             ResponseItem::Other,
         ];
 
@@ -485,7 +496,7 @@ mod tests {
     #[test]
     fn collect_user_messages_filters_session_prefix_entries() {
         let items = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -498,8 +509,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -507,8 +518,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -516,7 +527,7 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
 
         let collected = collect_user_messages(&items);
@@ -541,12 +552,13 @@ do things
         let truncated_message = &history[0];
         let summary_message = &history[1];
 
-        let truncated_text = match truncated_message {
+        let truncated_text =
-            ResponseItem::Message { role, content, .. } if role == "user" => {
+            match truncated_message {
-                content_items_to_text(content).unwrap_or_default()
+                ResponseItem::Message(codex_protocol::models::Message {
-            }
+                    role, content, ..
-            other => panic!("unexpected item in history: {other:?}"),
+                }) if role == "user" => content_items_to_text(content).unwrap_or_default(),
-        };
+                other => panic!("unexpected item in history: {other:?}"),
+            };
 
         assert!(
             truncated_text.contains("tokens truncated"),
@@ -557,12 +569,13 @@ do things
             "truncated user message should not include the full oversized user text"
         );
 
-        let summary_text = match summary_message {
+        let summary_text =
-            ResponseItem::Message { role, content, .. } if role == "user" => {
+            match summary_message {
-                content_items_to_text(content).unwrap_or_default()
+                ResponseItem::Message(codex_protocol::models::Message {
-            }
+                    role, content, ..
-            other => panic!("unexpected item in history: {other:?}"),
+                }) if role == "user" => content_items_to_text(content).unwrap_or_default(),
-        };
+                other => panic!("unexpected item in history: {other:?}"),
+            };
         assert_eq!(summary_text, "SUMMARY");
     }
 
@@ -579,19 +592,20 @@ do things
         );
 
         let last = history.last().expect("history should have a summary entry");
-        let summary = match last {
+        let summary =
-            ResponseItem::Message { role, content, .. } if role == "user" => {
+            match last {
-                content_items_to_text(content).unwrap_or_default()
+                ResponseItem::Message(codex_protocol::models::Message {
-            }
+                    role, content, ..
-            other => panic!("expected summary message, found {other:?}"),
+                }) if role == "user" => content_items_to_text(content).unwrap_or_default(),
-        };
+                other => panic!("expected summary message, found {other:?}"),
+            };
         assert_eq!(summary, summary_text);
     }
 
     #[test]
     fn process_compacted_history_replaces_developer_messages() {
         let compacted_history = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -599,8 +613,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -608,8 +622,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -617,10 +631,10 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         let initial_context = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -628,8 +642,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -641,8 +655,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -650,12 +664,12 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
 
         let refreshed = process_compacted_history(compacted_history, &initial_context);
         let expected = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -663,8 +677,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -676,8 +690,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -685,8 +699,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -694,14 +708,14 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         assert_eq!(refreshed, expected);
     }
 
     #[test]
     fn process_compacted_history_reinjects_full_initial_context() {
-        let compacted_history = vec![ResponseItem::Message {
+        let compacted_history = vec![ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -709,9 +723,9 @@ do things
             }],
             end_turn: None,
             phase: None,
-        }];
+        })];
         let initial_context = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -719,8 +733,8 @@ do things
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -733,8 +747,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -746,8 +760,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -759,12 +773,12 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
 
         let refreshed = process_compacted_history(compacted_history, &initial_context);
         let expected = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -772,8 +786,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -786,8 +800,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -799,8 +813,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -812,8 +826,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -821,7 +835,7 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         assert_eq!(refreshed, expected);
     }
@@ -829,7 +843,7 @@ keep me updated
     #[test]
     fn process_compacted_history_drops_non_user_content_messages() {
         let compacted_history = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -842,8 +856,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -855,8 +869,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -868,8 +882,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -877,8 +891,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -886,9 +900,9 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
-        let initial_context = vec![ResponseItem::Message {
+        let initial_context = vec![ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "developer".to_string(),
             content: vec![ContentItem::InputText {
@@ -896,11 +910,11 @@ keep me updated
             }],
             end_turn: None,
             phase: None,
-        }];
+        })];
 
         let refreshed = process_compacted_history(compacted_history, &initial_context);
         let expected = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -908,8 +922,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -917,7 +931,7 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         assert_eq!(refreshed, expected);
     }
@@ -925,7 +939,7 @@ keep me updated
     #[test]
     fn process_compacted_history_inserts_context_before_last_real_user_message_only() {
         let compacted_history = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -933,8 +947,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -942,8 +956,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -951,9 +965,9 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
-        let initial_context = vec![ResponseItem::Message {
+        let initial_context = vec![ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "developer".to_string(),
             content: vec![ContentItem::InputText {
@@ -961,11 +975,11 @@ keep me updated
             }],
             end_turn: None,
             phase: None,
-        }];
+        })];
 
         let refreshed = process_compacted_history(compacted_history, &initial_context);
         let expected = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -973,8 +987,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -982,8 +996,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "developer".to_string(),
                 content: vec![ContentItem::InputText {
@@ -991,8 +1005,8 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -1000,7 +1014,7 @@ keep me updated
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         ];
         assert_eq!(refreshed, expected);
     }

codex-rs/core/src/compact_remote.rs

@@ -77,7 +77,12 @@ async fn run_remote_compact_task_inner_impl(
     let ghost_snapshots: Vec<ResponseItem> = history
         .raw_items()
         .iter()
-        .filter(|item| matches!(item, ResponseItem::GhostSnapshot { .. }))
+        .filter(|item| {
+            matches!(
+                item,
+                ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. })
+            )
+        })
         .cloned()
         .collect();
 

codex-rs/core/src/context_manager/context_discoverable.rs

@@ -0,0 +1,158 @@
+use crate::truncate::TruncationPolicy;
+use crate::truncate::approx_token_count;
+use crate::truncate::truncate_function_output_items_with_policy;
+use crate::truncate::truncate_text;
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::CustomToolCallOutput;
+use codex_protocol::models::FunctionCallOutput;
+use codex_protocol::models::FunctionCallOutputBody;
+use codex_protocol::models::FunctionCallOutputPayload;
+use codex_protocol::models::Message;
+use codex_protocol::models::ResponseItem;
+use sha2::Digest;
+use sha2::Sha256;
+use std::path::Path;
+
+pub(super) trait ContextDiscoverable {
+    fn discoverable_history_item(
+        &self,
+        policy: TruncationPolicy,
+        codex_home: Option<&Path>,
+        thread_id: Option<&str>,
+        context_window_tokens: Option<i64>,
+        current_usage_tokens: i64,
+    ) -> ResponseItem;
+}
+
+impl ContextDiscoverable for FunctionCallOutput {
+    fn discoverable_history_item(
+        &self,
+        policy: TruncationPolicy,
+        _codex_home: Option<&Path>,
+        _thread_id: Option<&str>,
+        _context_window_tokens: Option<i64>,
+        _current_usage_tokens: i64,
+    ) -> ResponseItem {
+        let body = match &self.output.body {
+            FunctionCallOutputBody::Text(content) => {
+                FunctionCallOutputBody::Text(truncate_text(content, policy))
+            }
+            FunctionCallOutputBody::ContentItems(items) => FunctionCallOutputBody::ContentItems(
+                truncate_function_output_items_with_policy(items, policy),
+            ),
+        };
+
+        ResponseItem::FunctionCallOutput(FunctionCallOutput {
+            call_id: self.call_id.clone(),
+            output: FunctionCallOutputPayload {
+                body,
+                success: self.output.success,
+            },
+        })
+    }
+}
+
+impl ContextDiscoverable for CustomToolCallOutput {
+    fn discoverable_history_item(
+        &self,
+        policy: TruncationPolicy,
+        _codex_home: Option<&Path>,
+        _thread_id: Option<&str>,
+        _context_window_tokens: Option<i64>,
+        _current_usage_tokens: i64,
+    ) -> ResponseItem {
+        ResponseItem::CustomToolCallOutput(CustomToolCallOutput {
+            call_id: self.call_id.clone(),
+            output: truncate_text(&self.output, policy),
+        })
+    }
+}
+
+impl ContextDiscoverable for Message {
+    fn discoverable_history_item(
+        &self,
+        _policy: TruncationPolicy,
+        codex_home: Option<&Path>,
+        thread_id: Option<&str>,
+        context_window_tokens: Option<i64>,
+        current_usage_tokens: i64,
+    ) -> ResponseItem {
+        let (Some(codex_home), Some(thread_id), Some(context_window_tokens)) =
+            (codex_home, thread_id, context_window_tokens)
+        else {
+            return ResponseItem::Message(self.clone());
+        };
+
+        if self.role != "user" {
+            return ResponseItem::Message(self.clone());
+        }
+
+        let Some(user_text) = extract_message_text(&self.content) else {
+            return ResponseItem::Message(self.clone());
+        };
+
+        let estimated_tokens = i64::try_from(approx_token_count(&user_text)).unwrap_or(i64::MAX);
+        if current_usage_tokens.saturating_add(estimated_tokens) <= context_window_tokens {
+            return ResponseItem::Message(self.clone());
+        }
+
+        let checksum = checksum_hex(&user_text);
+        let output_path = codex_home
+            .join("discovarable_items")
+            .join(thread_id)
+            .join("user_message")
+            .join(checksum);
+
+        if let Some(parent) = output_path.parent()
+            && let Err(err) = std::fs::create_dir_all(parent)
+        {
+            tracing::warn!(
+                path = %parent.display(),
+                "failed to create discoverable message directory: {err}"
+            );
+            return ResponseItem::Message(self.clone());
+        }
+
+        if let Err(err) = std::fs::write(&output_path, &user_text) {
+            tracing::warn!(
+                path = %output_path.display(),
+                "failed to write discoverable user message file: {err}"
+            );
+            return ResponseItem::Message(self.clone());
+        }
+
+        let replacement = format!(
+            "User message was too large. Read it from <{}>",
+            output_path.display()
+        );
+        let mut rewritten = self.clone();
+        rewritten.content = vec![ContentItem::InputText { text: replacement }];
+        ResponseItem::Message(rewritten)
+    }
+}
+
+fn extract_message_text(content: &[ContentItem]) -> Option<String> {
+    let parts: Vec<&str> = content
+        .iter()
+        .filter_map(|item| match item {
+            ContentItem::InputText { text } | ContentItem::OutputText { text }
+                if !text.trim().is_empty() =>
+            {
+                Some(text.as_str())
+            }
+            ContentItem::InputText { .. } | ContentItem::OutputText { .. } => None,
+            ContentItem::InputImage { .. } => None,
+        })
+        .collect();
+    if parts.is_empty() {
+        None
+    } else {
+        Some(parts.join("\n\n"))
+    }
+}
+
+fn checksum_hex(content: &str) -> String {
+    let mut hasher = Sha256::new();
+    hasher.update(content.as_bytes());
+    format!("{:x}", hasher.finalize())
+}

codex-rs/core/src/context_manager/history.rs

@@ -1,4 +1,5 @@
 use crate::codex::TurnContext;
+use crate::context_manager::context_discoverable::ContextDiscoverable;
 use crate::context_manager::normalize;
 use crate::instructions::SkillInstructions;
 use crate::instructions::UserInstructions;
@@ -6,32 +7,38 @@ use crate::session_prefix::is_session_prefix;
 use crate::truncate::TruncationPolicy;
 use crate::truncate::approx_token_count;
 use crate::truncate::approx_tokens_from_byte_count;
-use crate::truncate::truncate_function_output_items_with_policy;
-use crate::truncate::truncate_text;
 use crate::user_shell_command::is_user_shell_command_text;
 use codex_protocol::models::BaseInstructions;
 use codex_protocol::models::ContentItem;
-use codex_protocol::models::FunctionCallOutputBody;
 use codex_protocol::models::FunctionCallOutputContentItem;
-use codex_protocol::models::FunctionCallOutputPayload;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::protocol::TokenUsage;
 use codex_protocol::protocol::TokenUsageInfo;
 use std::ops::Deref;
+use std::path::PathBuf;
+use std::sync::Arc;
 
 /// Transcript of thread history
-#[derive(Debug, Clone, Default)]
+#[derive(Debug, Clone)]
 pub(crate) struct ContextManager {
     /// The oldest items are at the beginning of the vector.
     items: Vec<ResponseItem>,
     token_info: Option<TokenUsageInfo>,
+    thread_id: Arc<String>,
+    codex_home: Arc<PathBuf>,
 }
 
 impl ContextManager {
-    pub(crate) fn new() -> Self {
+    pub(crate) fn new(
+        thread_id: Arc<String>,
+        codex_home: Arc<PathBuf>,
+        model_context_window: Option<i64>,
+    ) -> Self {
         Self {
             items: Vec::new(),
-            token_info: TokenUsageInfo::new_or_append(&None, &None, None),
+            token_info: TokenUsageInfo::new_or_append(&None, &None, model_context_window),
+            thread_id,
+            codex_home,
         }
     }
 
@@ -60,7 +67,10 @@ impl ContextManager {
     {
         for item in items {
             let item_ref = item.deref();
-            let is_ghost_snapshot = matches!(item_ref, ResponseItem::GhostSnapshot { .. });
+            let is_ghost_snapshot = matches!(
+                item_ref,
+                ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. })
+            );
             if !is_api_message(item_ref) && !is_ghost_snapshot {
                 continue;
             }
@@ -74,8 +84,12 @@ impl ContextManager {
     /// normalization and drop un-suited items.
     pub(crate) fn for_prompt(mut self) -> Vec<ResponseItem> {
         self.normalize_history();
-        self.items
+        self.items.retain(|item| {
-            .retain(|item| !matches!(item, ResponseItem::GhostSnapshot { .. }));
+            !matches!(
+                item,
+                ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. })
+            )
+        });
         self.items
     }
 
@@ -138,14 +152,17 @@ impl ContextManager {
     /// Returns true when a tool image was replaced, false otherwise.
     pub(crate) fn replace_last_turn_images(&mut self, placeholder: &str) -> bool {
         let Some(index) = self.items.iter().rposition(|item| {
-            matches!(item, ResponseItem::FunctionCallOutput { .. })
+            matches!(item, ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput { .. }))
-                || matches!(item, ResponseItem::Message { role, .. } if role == "user")
+                || matches!(item, ResponseItem::Message(codex_protocol::models::Message { role, .. }) if role == "user")
         }) else {
             return false;
         };
 
         match &mut self.items[index] {
-            ResponseItem::FunctionCallOutput { output, .. } => {
+            ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput {
+                output,
+                ..
+            }) => {
                 let Some(content_items) = output.content_items_mut() else {
                     return false;
                 };
@@ -161,7 +178,11 @@ impl ContextManager {
                 }
                 replaced
             }
-            ResponseItem::Message { role, .. } if role == "user" => false,
+            ResponseItem::Message(codex_protocol::models::Message { role, .. })
+                if role == "user" =>
+            {
+                false
+            }
             _ => false,
         }
     }
@@ -214,7 +235,7 @@ impl ContextManager {
         let Some(last_user_index) = self
             .items
             .iter()
-            .rposition(|item| matches!(item, ResponseItem::Message { role, .. } if role == "user"))
+            .rposition(|item| matches!(item, ResponseItem::Message(codex_protocol::models::Message { role, .. }) if role == "user"))
         else {
             return 0;
         };
@@ -225,10 +246,10 @@ impl ContextManager {
             .filter(|item| {
                 matches!(
                     item,
-                    ResponseItem::Reasoning {
+                    ResponseItem::Reasoning(codex_protocol::models::Reasoning {
                         encrypted_content: Some(_),
                         ..
-                    }
+                    })
                 )
             })
             .fold(0i64, |acc, item| {
@@ -277,46 +298,46 @@ impl ContextManager {
     }
 
     fn process_item(&self, item: &ResponseItem, policy: TruncationPolicy) -> ResponseItem {
+        let used_tokens = self
+            .token_info
+            .as_ref()
+            .map(|info| info.last_token_usage.total_tokens)
+            .unwrap_or(0);
+        let context_window = self
+            .token_info
+            .as_ref()
+            .and_then(|info| info.model_context_window);
         let policy_with_serialization_budget = policy * 1.2;
         match item {
-            ResponseItem::FunctionCallOutput { call_id, output } => {
+            ResponseItem::Reasoning(_)
-                let body = match &output.body {
+            | ResponseItem::LocalShellCall(_)
-                    FunctionCallOutputBody::Text(content) => FunctionCallOutputBody::Text(
+            | ResponseItem::FunctionCall(_)
-                        truncate_text(content, policy_with_serialization_budget),
+            | ResponseItem::CustomToolCall(_)
-                    ),
+            | ResponseItem::WebSearchCall(_)
-                    FunctionCallOutputBody::ContentItems(items) => {
+            | ResponseItem::Compaction(_)
-                        FunctionCallOutputBody::ContentItems(
+            | ResponseItem::GhostSnapshot(_)
-                            truncate_function_output_items_with_policy(
-                                items,
-                                policy_with_serialization_budget,
-                            ),
-                        )
-                    }
-                };
-                ResponseItem::FunctionCallOutput {
-                    call_id: call_id.clone(),
-                    output: FunctionCallOutputPayload {
-                        body,
-                        success: output.success,
-                    },
-                }
-            }
-            ResponseItem::CustomToolCallOutput { call_id, output } => {
-                let truncated = truncate_text(output, policy_with_serialization_budget);
-                ResponseItem::CustomToolCallOutput {
-                    call_id: call_id.clone(),
-                    output: truncated,
-                }
-            }
-            ResponseItem::Message { .. }
-            | ResponseItem::Reasoning { .. }
-            | ResponseItem::LocalShellCall { .. }
-            | ResponseItem::FunctionCall { .. }
-            | ResponseItem::WebSearchCall { .. }
-            | ResponseItem::CustomToolCall { .. }
-            | ResponseItem::Compaction { .. }
-            | ResponseItem::GhostSnapshot { .. }
             | ResponseItem::Other => item.clone(),
+            ResponseItem::FunctionCallOutput(item) => item.discoverable_history_item(
+                policy_with_serialization_budget,
+                Some(self.codex_home.as_path()),
+                Some(self.thread_id.as_str()),
+                context_window,
+                used_tokens,
+            ),
+            ResponseItem::CustomToolCallOutput(item) => item.discoverable_history_item(
+                policy_with_serialization_budget,
+                Some(self.codex_home.as_path()),
+                Some(self.thread_id.as_str()),
+                context_window,
+                used_tokens,
+            ),
+            ResponseItem::Message(item) => item.discoverable_history_item(
+                policy_with_serialization_budget,
+                Some(self.codex_home.as_path()),
+                Some(self.thread_id.as_str()),
+                context_window,
+                used_tokens,
+            ),
         }
     }
 }
@@ -325,16 +346,20 @@ impl ContextManager {
 /// tool calls, tool outputs, shell calls, and web-search calls).
 fn is_api_message(message: &ResponseItem) -> bool {
     match message {
-        ResponseItem::Message { role, .. } => role.as_str() != "system",
+        ResponseItem::Message(codex_protocol::models::Message { role, .. }) => {
-        ResponseItem::FunctionCallOutput { .. }
+            role.as_str() != "system"
-        | ResponseItem::FunctionCall { .. }
+        }
-        | ResponseItem::CustomToolCall { .. }
+        ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput { .. })
-        | ResponseItem::CustomToolCallOutput { .. }
+        | ResponseItem::FunctionCall(codex_protocol::models::FunctionCall { .. })
-        | ResponseItem::LocalShellCall { .. }
+        | ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall { .. })
-        | ResponseItem::Reasoning { .. }
+        | ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput {
-        | ResponseItem::WebSearchCall { .. }
+            ..
-        | ResponseItem::Compaction { .. } => true,
+        })
-        ResponseItem::GhostSnapshot { .. } => false,
+        | ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall { .. })
+        | ResponseItem::Reasoning(codex_protocol::models::Reasoning { .. })
+        | ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall { .. })
+        | ResponseItem::Compaction(codex_protocol::models::Compaction { .. }) => true,
+        ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. }) => false,
         ResponseItem::Other => false,
     }
 }
@@ -349,14 +374,14 @@ fn estimate_reasoning_length(encoded_len: usize) -> usize {
 
 fn estimate_item_token_count(item: &ResponseItem) -> i64 {
     match item {
-        ResponseItem::GhostSnapshot { .. } => 0,
+        ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. }) => 0,
-        ResponseItem::Reasoning {
+        ResponseItem::Reasoning(codex_protocol::models::Reasoning {
             encrypted_content: Some(content),
             ..
-        }
+        })
-        | ResponseItem::Compaction {
+        | ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: content,
-        } => {
+        }) => {
             let reasoning_bytes = estimate_reasoning_length(content.len());
             i64::try_from(approx_tokens_from_byte_count(reasoning_bytes)).unwrap_or(i64::MAX)
         }
@@ -370,12 +395,15 @@ fn estimate_item_token_count(item: &ResponseItem) -> i64 {
 pub(crate) fn is_codex_generated_item(item: &ResponseItem) -> bool {
     matches!(
         item,
-        ResponseItem::FunctionCallOutput { .. } | ResponseItem::CustomToolCallOutput { .. }
+        ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput { .. })
-    ) || matches!(item, ResponseItem::Message { role, .. } if role == "developer")
+            | ResponseItem::CustomToolCallOutput(
+                codex_protocol::models::CustomToolCallOutput { .. }
+            )
+    ) || matches!(item, ResponseItem::Message(codex_protocol::models::Message { role, .. }) if role == "developer")
 }
 
 pub(crate) fn is_user_turn_boundary(item: &ResponseItem) -> bool {
-    let ResponseItem::Message { role, content, .. } = item else {
+    let ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) = item else {
         return false;
     };
 

codex-rs/core/src/context_manager/mod.rs

@@ -1,3 +1,4 @@
+mod context_discoverable;
 mod history;
 mod normalize;
 

codex-rs/core/src/context_manager/normalize.rs

@@ -15,11 +15,15 @@ pub(crate) fn ensure_call_outputs_present(items: &mut Vec<ResponseItem>) {
 
     for (idx, item) in items.iter().enumerate() {
         match item {
-            ResponseItem::FunctionCall { call_id, .. } => {
+            ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
+                call_id, ..
+            }) => {
                 let has_output = items.iter().any(|i| match i {
-                    ResponseItem::FunctionCallOutput {
+                    ResponseItem::FunctionCallOutput(
-                        call_id: existing, ..
+                        codex_protocol::models::FunctionCallOutput {
-                    } => existing == call_id,
+                            call_id: existing, ..
+                        },
+                    ) => existing == call_id,
                     _ => false,
                 });
 
@@ -27,21 +31,28 @@ pub(crate) fn ensure_call_outputs_present(items: &mut Vec<ResponseItem>) {
                     info!("Function call output is missing for call id: {call_id}");
                     missing_outputs_to_insert.push((
                         idx,
-                        ResponseItem::FunctionCallOutput {
+                        ResponseItem::FunctionCallOutput(
-                            call_id: call_id.clone(),
+                            codex_protocol::models::FunctionCallOutput {
-                            output: FunctionCallOutputPayload {
+                                call_id: call_id.clone(),
-                                body: FunctionCallOutputBody::Text("aborted".to_string()),
+                                output: FunctionCallOutputPayload {
-                                ..Default::default()
+                                    body: FunctionCallOutputBody::Text("aborted".to_string()),
+                                    ..Default::default()
+                                },
                             },
-                        },
+                        ),
                     ));
                 }
             }
-            ResponseItem::CustomToolCall { call_id, .. } => {
+            ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall {
+                call_id,
+                ..
+            }) => {
                 let has_output = items.iter().any(|i| match i {
-                    ResponseItem::CustomToolCallOutput {
+                    ResponseItem::CustomToolCallOutput(
-                        call_id: existing, ..
+                        codex_protocol::models::CustomToolCallOutput {
-                    } => existing == call_id,
+                            call_id: existing, ..
+                        },
+                    ) => existing == call_id,
                     _ => false,
                 });
 
@@ -51,20 +62,27 @@ pub(crate) fn ensure_call_outputs_present(items: &mut Vec<ResponseItem>) {
                     ));
                     missing_outputs_to_insert.push((
                         idx,
-                        ResponseItem::CustomToolCallOutput {
+                        ResponseItem::CustomToolCallOutput(
-                            call_id: call_id.clone(),
+                            codex_protocol::models::CustomToolCallOutput {
-                            output: "aborted".to_string(),
+                                call_id: call_id.clone(),
-                        },
+                                output: "aborted".to_string(),
+                            },
+                        ),
                     ));
                 }
             }
             // LocalShellCall is represented in upstream streams by a FunctionCallOutput
-            ResponseItem::LocalShellCall { call_id, .. } => {
+            ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall {
+                call_id,
+                ..
+            }) => {
                 if let Some(call_id) = call_id.as_ref() {
                     let has_output = items.iter().any(|i| match i {
-                        ResponseItem::FunctionCallOutput {
+                        ResponseItem::FunctionCallOutput(
-                            call_id: existing, ..
+                            codex_protocol::models::FunctionCallOutput {
-                        } => existing == call_id,
+                                call_id: existing, ..
+                            },
+                        ) => existing == call_id,
                         _ => false,
                     });
 
@@ -74,13 +92,15 @@ pub(crate) fn ensure_call_outputs_present(items: &mut Vec<ResponseItem>) {
                         ));
                         missing_outputs_to_insert.push((
                             idx,
-                            ResponseItem::FunctionCallOutput {
+                            ResponseItem::FunctionCallOutput(
-                                call_id: call_id.clone(),
+                                codex_protocol::models::FunctionCallOutput {
-                                output: FunctionCallOutputPayload {
+                                    call_id: call_id.clone(),
-                                    body: FunctionCallOutputBody::Text("aborted".to_string()),
+                                    output: FunctionCallOutputPayload {
-                                    ..Default::default()
+                                        body: FunctionCallOutputBody::Text("aborted".to_string()),
+                                        ..Default::default()
+                                    },
                                 },
-                            },
+                            ),
                         ));
                     }
                 }
@@ -99,7 +119,9 @@ pub(crate) fn remove_orphan_outputs(items: &mut Vec<ResponseItem>) {
     let function_call_ids: HashSet<String> = items
         .iter()
         .filter_map(|i| match i {
-            ResponseItem::FunctionCall { call_id, .. } => Some(call_id.clone()),
+            ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
+                call_id, ..
+            }) => Some(call_id.clone()),
             _ => None,
         })
         .collect();
@@ -107,10 +129,10 @@ pub(crate) fn remove_orphan_outputs(items: &mut Vec<ResponseItem>) {
     let local_shell_call_ids: HashSet<String> = items
         .iter()
         .filter_map(|i| match i {
-            ResponseItem::LocalShellCall {
+            ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall {
                 call_id: Some(call_id),
                 ..
-            } => Some(call_id.clone()),
+            }) => Some(call_id.clone()),
             _ => None,
         })
         .collect();
@@ -118,13 +140,19 @@ pub(crate) fn remove_orphan_outputs(items: &mut Vec<ResponseItem>) {
     let custom_tool_call_ids: HashSet<String> = items
         .iter()
         .filter_map(|i| match i {
-            ResponseItem::CustomToolCall { call_id, .. } => Some(call_id.clone()),
+            ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall {
+                call_id,
+                ..
+            }) => Some(call_id.clone()),
             _ => None,
         })
         .collect();
 
     items.retain(|item| match item {
-        ResponseItem::FunctionCallOutput { call_id, .. } => {
+        ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput {
+            call_id,
+            ..
+        }) => {
             let has_match =
                 function_call_ids.contains(call_id) || local_shell_call_ids.contains(call_id);
             if !has_match {
@@ -134,7 +162,10 @@ pub(crate) fn remove_orphan_outputs(items: &mut Vec<ResponseItem>) {
             }
             has_match
         }
-        ResponseItem::CustomToolCallOutput { call_id, .. } => {
+        ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput {
+            call_id,
+            ..
+        }) => {
             let has_match = custom_tool_call_ids.contains(call_id);
             if !has_match {
                 error_or_panic(format!(
@@ -149,53 +180,53 @@ pub(crate) fn remove_orphan_outputs(items: &mut Vec<ResponseItem>) {
 
 pub(crate) fn remove_corresponding_for(items: &mut Vec<ResponseItem>, item: &ResponseItem) {
     match item {
-        ResponseItem::FunctionCall { call_id, .. } => {
+        ResponseItem::FunctionCall(codex_protocol::models::FunctionCall { call_id, .. }) => {
             remove_first_matching(items, |i| {
                 matches!(
                     i,
-                    ResponseItem::FunctionCallOutput {
+                    ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput {
                         call_id: existing, ..
-                    } if existing == call_id
+                    }) if existing == call_id
                 )
             });
         }
-        ResponseItem::FunctionCallOutput { call_id, .. } => {
+        ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput { call_id, .. }) => {
             if let Some(pos) = items.iter().position(|i| {
-                matches!(i, ResponseItem::FunctionCall { call_id: existing, .. } if existing == call_id)
+                matches!(i, ResponseItem::FunctionCall(codex_protocol::models::FunctionCall { call_id: existing, .. }) if existing == call_id)
             }) {
                 items.remove(pos);
             } else if let Some(pos) = items.iter().position(|i| {
-                matches!(i, ResponseItem::LocalShellCall { call_id: Some(existing), .. } if existing == call_id)
+                matches!(i, ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall { call_id: Some(existing), .. }) if existing == call_id)
             }) {
                 items.remove(pos);
             }
         }
-        ResponseItem::CustomToolCall { call_id, .. } => {
+        ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall { call_id, .. }) => {
             remove_first_matching(items, |i| {
                 matches!(
                     i,
-                    ResponseItem::CustomToolCallOutput {
+                    ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput {
                         call_id: existing, ..
-                    } if existing == call_id
+                    }) if existing == call_id
                 )
             });
         }
-        ResponseItem::CustomToolCallOutput { call_id, .. } => {
+        ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput { call_id, .. }) => {
             remove_first_matching(
                 items,
-                |i| matches!(i, ResponseItem::CustomToolCall { call_id: existing, .. } if existing == call_id),
+                |i| matches!(i, ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall { call_id: existing, .. }) if existing == call_id),
             );
         }
-        ResponseItem::LocalShellCall {
+        ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall {
             call_id: Some(call_id),
             ..
-        } => {
+        }) => {
             remove_first_matching(items, |i| {
                 matches!(
                     i,
-                    ResponseItem::FunctionCallOutput {
+                    ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput {
                         call_id: existing, ..
-                    } if existing == call_id
+                    }) if existing == call_id
                 )
             });
         }

codex-rs/core/src/environment_context.rs

@@ -125,7 +125,7 @@ impl EnvironmentContext {
 
 impl From<EnvironmentContext> for ResponseItem {
     fn from(ec: EnvironmentContext) -> Self {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -133,7 +133,7 @@ impl From<EnvironmentContext> for ResponseItem {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 }
 

codex-rs/core/src/event_mapping.rs

@@ -95,13 +95,13 @@ fn parse_agent_message(
 
 pub fn parse_turn_item(item: &ResponseItem) -> Option<TurnItem> {
     match item {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             role,
             content,
             id,
             phase,
             ..
-        } => match role.as_str() {
+        }) => match role.as_str() {
             "user" => parse_user_message(content).map(TurnItem::UserMessage),
             "assistant" => Some(TurnItem::AgentMessage(parse_agent_message(
                 id.as_ref(),
@@ -111,12 +111,12 @@ pub fn parse_turn_item(item: &ResponseItem) -> Option<TurnItem> {
             "system" => None,
             _ => None,
         },
-        ResponseItem::Reasoning {
+        ResponseItem::Reasoning(codex_protocol::models::Reasoning {
             id,
             summary,
             content,
             ..
-        } => {
+        }) => {
             let summary_text = summary
                 .iter()
                 .map(|entry| match entry {
@@ -138,7 +138,9 @@ pub fn parse_turn_item(item: &ResponseItem) -> Option<TurnItem> {
                 raw_content,
             }))
         }
-        ResponseItem::WebSearchCall { id, action, .. } => {
+        ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall {
+            id, action, ..
+        }) => {
             let (action, query) = match action {
                 Some(action) => (action.clone(), web_search_action_detail(action)),
                 None => (WebSearchAction::Other, String::new()),
@@ -172,7 +174,7 @@ mod tests {
         let img1 = "https://example.com/one.png".to_string();
         let img2 = "https://example.com/two.jpg".to_string();
 
-        let item = ResponseItem::Message {
+        let item = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![
@@ -188,7 +190,7 @@ mod tests {
             ],
             end_turn: None,
             phase: None,
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected user message turn item");
 
@@ -214,7 +216,7 @@ mod tests {
         let label = codex_protocol::models::local_image_open_tag_text(1);
         let user_text = "Please review this image.".to_string();
 
-        let item = ResponseItem::Message {
+        let item = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![
@@ -231,7 +233,7 @@ mod tests {
             ],
             end_turn: None,
             phase: None,
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected user message turn item");
 
@@ -256,7 +258,7 @@ mod tests {
         let label = codex_protocol::models::image_open_tag_text();
         let user_text = "Please review this image.".to_string();
 
-        let item = ResponseItem::Message {
+        let item = ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![
@@ -273,7 +275,7 @@ mod tests {
             ],
             end_turn: None,
             phase: None,
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected user message turn item");
 
@@ -295,7 +297,7 @@ mod tests {
     #[test]
     fn skips_user_instructions_and_env() {
         let items = vec![
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -303,8 +305,8 @@ mod tests {
                 }],
                 end_turn: None,
             phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -312,8 +314,8 @@ mod tests {
                 }],
                 end_turn: None,
             phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -321,8 +323,8 @@ mod tests {
                 }],
                 end_turn: None,
             phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -331,8 +333,8 @@ mod tests {
                 }],
                 end_turn: None,
             phase: None,
-            },
+            }),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -340,7 +342,7 @@ mod tests {
                 }],
                 end_turn: None,
             phase: None,
-            },
+            }),
         ];
 
         for item in items {
@@ -351,7 +353,7 @@ mod tests {
 
     #[test]
     fn parses_agent_message() {
-        let item = ResponseItem::Message {
+        let item = ResponseItem::Message(codex_protocol::models::Message {
             id: Some("msg-1".to_string()),
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -359,7 +361,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected agent message turn item");
 
@@ -376,7 +378,7 @@ mod tests {
 
     #[test]
     fn parses_reasoning_summary_and_raw_content() {
-        let item = ResponseItem::Reasoning {
+        let item = ResponseItem::Reasoning(codex_protocol::models::Reasoning {
             id: "reasoning_1".to_string(),
             summary: vec![
                 ReasoningItemReasoningSummary::SummaryText {
@@ -390,7 +392,7 @@ mod tests {
                 text: "raw details".to_string(),
             }]),
             encrypted_content: None,
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected reasoning turn item");
 
@@ -408,7 +410,7 @@ mod tests {
 
     #[test]
     fn parses_reasoning_including_raw_content() {
-        let item = ResponseItem::Reasoning {
+        let item = ResponseItem::Reasoning(codex_protocol::models::Reasoning {
             id: "reasoning_2".to_string(),
             summary: vec![ReasoningItemReasoningSummary::SummaryText {
                 text: "Summarized step".to_string(),
@@ -422,7 +424,7 @@ mod tests {
                 },
             ]),
             encrypted_content: None,
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected reasoning turn item");
 
@@ -440,14 +442,14 @@ mod tests {
 
     #[test]
     fn parses_web_search_call() {
-        let item = ResponseItem::WebSearchCall {
+        let item = ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall {
             id: Some("ws_1".to_string()),
             status: Some("completed".to_string()),
             action: Some(WebSearchAction::Search {
                 query: Some("weather".to_string()),
                 queries: None,
             }),
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected web search turn item");
 
@@ -469,13 +471,13 @@ mod tests {
 
     #[test]
     fn parses_web_search_open_page_call() {
-        let item = ResponseItem::WebSearchCall {
+        let item = ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall {
             id: Some("ws_open".to_string()),
             status: Some("completed".to_string()),
             action: Some(WebSearchAction::OpenPage {
                 url: Some("https://example.com".to_string()),
             }),
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected web search turn item");
 
@@ -496,14 +498,14 @@ mod tests {
 
     #[test]
     fn parses_web_search_find_in_page_call() {
-        let item = ResponseItem::WebSearchCall {
+        let item = ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall {
             id: Some("ws_find".to_string()),
             status: Some("completed".to_string()),
             action: Some(WebSearchAction::FindInPage {
                 url: Some("https://example.com".to_string()),
                 pattern: Some("needle".to_string()),
             }),
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected web search turn item");
 
@@ -525,11 +527,11 @@ mod tests {
 
     #[test]
     fn parses_partial_web_search_call_without_action_as_other() {
-        let item = ResponseItem::WebSearchCall {
+        let item = ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall {
             id: Some("ws_partial".to_string()),
             status: Some("in_progress".to_string()),
             action: None,
-        };
+        });
 
         let turn_item = parse_turn_item(&item).expect("expected web search turn item");
         match turn_item {

codex-rs/core/src/instructions/user_instructions.rs

@@ -28,7 +28,7 @@ impl UserInstructions {
 
 impl From<UserInstructions> for ResponseItem {
     fn from(ui: UserInstructions) -> Self {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -40,7 +40,7 @@ impl From<UserInstructions> for ResponseItem {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 }
 
@@ -64,7 +64,7 @@ impl SkillInstructions {
 
 impl From<SkillInstructions> for ResponseItem {
     fn from(si: SkillInstructions) -> Self {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -75,7 +75,7 @@ impl From<SkillInstructions> for ResponseItem {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 }
 
@@ -92,7 +92,9 @@ mod tests {
         };
         let response_item: ResponseItem = user_instructions.into();
 
-        let ResponseItem::Message { role, content, .. } = response_item else {
+        let ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) =
+            response_item
+        else {
             panic!("expected ResponseItem::Message");
         };
 
@@ -136,7 +138,9 @@ mod tests {
         };
         let response_item: ResponseItem = skill_instructions.into();
 
-        let ResponseItem::Message { role, content, .. } = response_item else {
+        let ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) =
+            response_item
+        else {
             panic!("expected ResponseItem::Message");
         };
 

codex-rs/core/src/rollout/tests.rs

@@ -1141,15 +1141,17 @@ async fn test_updated_at_uses_file_mtime() -> Result<()> {
     for idx in 0..total_messages {
         let response_line = RolloutLine {
             timestamp: format!("{ts}-{idx:02}"),
-            item: RolloutItem::ResponseItem(ResponseItem::Message {
+            item: RolloutItem::ResponseItem(ResponseItem::Message(
-                id: None,
+                codex_protocol::models::Message {
-                role: "assistant".into(),
+                    id: None,
-                content: vec![ContentItem::OutputText {
+                    role: "assistant".into(),
-                    text: format!("reply-{idx}"),
+                    content: vec![ContentItem::OutputText {
-                }],
+                        text: format!("reply-{idx}"),
-                end_turn: None,
+                    }],
-                phase: None,
+                    end_turn: None,
-            }),
+                    phase: None,
+                },
+            )),
         };
         writeln!(file, "{}", serde_json::to_string(&response_line)?)?;
     }

codex-rs/core/src/rollout/truncation.rs

@@ -11,7 +11,7 @@ use codex_protocol::protocol::RolloutItem;
 
 /// Return the indices of user message boundaries in a rollout.
 ///
-/// A user message boundary is a `RolloutItem::ResponseItem(ResponseItem::Message { .. })`
+/// A user message boundary is a `RolloutItem::ResponseItem(ResponseItem::Message(codex_protocol::models::Message { .. }))`
 /// whose parsed turn item is `TurnItem::UserMessage`.
 ///
 /// Rollouts can contain `ThreadRolledBack` markers. Those markers indicate that the
@@ -21,11 +21,12 @@ pub(crate) fn user_message_positions_in_rollout(items: &[RolloutItem]) -> Vec<us
     let mut user_positions = Vec::new();
     for (idx, item) in items.iter().enumerate() {
         match item {
-            RolloutItem::ResponseItem(item @ ResponseItem::Message { .. })
+            RolloutItem::ResponseItem(
-                if matches!(
+                item @ ResponseItem::Message(codex_protocol::models::Message { .. }),
-                    event_mapping::parse_turn_item(item),
+            ) if matches!(
-                    Some(TurnItem::UserMessage(_))
+                event_mapping::parse_turn_item(item),
-                ) =>
+                Some(TurnItem::UserMessage(_))
+            ) =>
             {
                 user_positions.push(idx);
             }
@@ -79,7 +80,7 @@ mod tests {
     use pretty_assertions::assert_eq;
 
     fn user_msg(text: &str) -> ResponseItem {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::OutputText {
@@ -87,11 +88,11 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 
     fn assistant_msg(text: &str) -> ResponseItem {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -99,7 +100,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 
     #[test]
@@ -110,20 +111,20 @@ mod tests {
             assistant_msg("a2"),
             user_msg("u2"),
             assistant_msg("a3"),
-            ResponseItem::Reasoning {
+            ResponseItem::Reasoning(codex_protocol::models::Reasoning {
                 id: "r1".to_string(),
                 summary: vec![ReasoningItemReasoningSummary::SummaryText {
                     text: "s".to_string(),
                 }],
                 content: None,
                 encrypted_content: None,
-            },
+            }),
-            ResponseItem::FunctionCall {
+            ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
                 id: None,
                 name: "tool".to_string(),
                 arguments: "{}".to_string(),
                 call_id: "c1".to_string(),
-            },
+            }),
             assistant_msg("a4"),
         ];
 

codex-rs/core/src/state/session.rs

@@ -3,6 +3,8 @@
 use codex_protocol::models::ResponseItem;
 use std::collections::HashMap;
 use std::collections::HashSet;
+use std::path::PathBuf;
+use std::sync::Arc;
 
 use crate::codex::SessionConfiguration;
 use crate::context_manager::ContextManager;
@@ -30,8 +32,17 @@ pub(crate) struct SessionState {
 
 impl SessionState {
     /// Create a new session state mirroring previous `State::default()` semantics.
-    pub(crate) fn new(session_configuration: SessionConfiguration) -> Self {
+    pub(crate) fn new(
-        let history = ContextManager::new();
+        session_configuration: SessionConfiguration,
+        thread_id: String,
+        codex_home: PathBuf,
+        model_context_window: Option<i64>,
+    ) -> Self {
+        let history = ContextManager::new(
+            Arc::new(thread_id),
+            Arc::new(codex_home),
+            model_context_window,
+        );
         Self {
             session_configuration,
             history,

codex-rs/core/src/stream_events_utils.rs

@@ -165,9 +165,9 @@ pub(crate) async fn handle_non_tool_response_item(
     debug!(?item, "Output item");
 
     match item {
-        ResponseItem::Message { .. }
+        ResponseItem::Message(codex_protocol::models::Message { .. })
-        | ResponseItem::Reasoning { .. }
+        | ResponseItem::Reasoning(codex_protocol::models::Reasoning { .. })
-        | ResponseItem::WebSearchCall { .. } => {
+        | ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall { .. }) => {
             let mut turn_item = parse_turn_item(item)?;
             if plan_mode && let TurnItem::AgentMessage(agent_message) = &mut turn_item {
                 let combined = agent_message
@@ -183,7 +183,10 @@ pub(crate) async fn handle_non_tool_response_item(
             }
             Some(turn_item)
         }
-        ResponseItem::FunctionCallOutput { .. } | ResponseItem::CustomToolCallOutput { .. } => {
+        ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput { .. })
+        | ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput {
+            ..
+        }) => {
             debug!("unexpected tool output from stream");
             None
         }
@@ -195,7 +198,7 @@ pub(crate) fn last_assistant_message_from_item(
     item: &ResponseItem,
     plan_mode: bool,
 ) -> Option<String> {
-    if let ResponseItem::Message { role, content, .. } = item
+    if let ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) = item
         && role == "assistant"
     {
         let combined = content
@@ -220,18 +223,18 @@ pub(crate) fn last_assistant_message_from_item(
 
 pub(crate) fn response_input_to_response_item(input: &ResponseInputItem) -> Option<ResponseItem> {
     match input {
-        ResponseInputItem::FunctionCallOutput { call_id, output } => {
+        ResponseInputItem::FunctionCallOutput { call_id, output } => Some(
-            Some(ResponseItem::FunctionCallOutput {
+            ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput {
                 call_id: call_id.clone(),
                 output: output.clone(),
-            })
+            }),
-        }
+        ),
-        ResponseInputItem::CustomToolCallOutput { call_id, output } => {
+        ResponseInputItem::CustomToolCallOutput { call_id, output } => Some(
-            Some(ResponseItem::CustomToolCallOutput {
+            ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput {
                 call_id: call_id.clone(),
                 output: output.clone(),
-            })
+            }),
-        }
+        ),
         ResponseInputItem::McpToolCallOutput { call_id, result } => {
             let output = match result {
                 Ok(call_tool_result) => FunctionCallOutputPayload::from(call_tool_result),
@@ -240,10 +243,12 @@ pub(crate) fn response_input_to_response_item(input: &ResponseInputItem) -> Opti
                     success: Some(false),
                 },
             };
-            Some(ResponseItem::FunctionCallOutput {
+            Some(ResponseItem::FunctionCallOutput(
-                call_id: call_id.clone(),
+                codex_protocol::models::FunctionCallOutput {
-                output,
+                    call_id: call_id.clone(),
-            })
+                    output,
+                },
+            ))
         }
         _ => None,
     }

codex-rs/core/src/tasks/ghost_snapshot.rs

@@ -106,9 +106,9 @@ impl SessionTask for GhostSnapshotTask {
                             }
                             session
                                 .session
-                                .record_conversation_items(&ctx, &[ResponseItem::GhostSnapshot {
+                                .record_conversation_items(&ctx, &[ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot {
                                     ghost_commit: ghost_commit.clone(),
-                                }])
+                                })])
                                 .await;
                             info!("ghost commit captured: {}", ghost_commit.id());
                         }

codex-rs/core/src/tasks/mod.rs

@@ -270,7 +270,7 @@ impl Session {
             .await;
 
         if reason == TurnAbortReason::Interrupted {
-            let marker = ResponseItem::Message {
+            let marker = ResponseItem::Message(codex_protocol::models::Message {
                 id: None,
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText {
@@ -280,7 +280,7 @@ impl Session {
                 }],
                 end_turn: None,
                 phase: None,
-            };
+            });
             self.record_into_history(std::slice::from_ref(&marker), task.turn_context.as_ref())
                 .await;
             self.persist_rollout_items(&[RolloutItem::ResponseItem(marker)])

codex-rs/core/src/tasks/review.rs

@@ -231,13 +231,13 @@ pub(crate) async fn exit_review_mode(
     session
         .record_conversation_items(
             &ctx,
-            &[ResponseItem::Message {
+            &[ResponseItem::Message(codex_protocol::models::Message {
                 id: Some(REVIEW_USER_MESSAGE_ID.to_string()),
                 role: "user".to_string(),
                 content: vec![ContentItem::InputText { text: user_message }],
                 end_turn: None,
                 phase: None,
-            }],
+            })],
         )
         .await;
 
@@ -250,7 +250,7 @@ pub(crate) async fn exit_review_mode(
     session
         .record_response_item_and_emit_turn_item(
             ctx.as_ref(),
-            ResponseItem::Message {
+            ResponseItem::Message(codex_protocol::models::Message {
                 id: Some(REVIEW_ASSISTANT_MESSAGE_ID.to_string()),
                 role: "assistant".to_string(),
                 content: vec![ContentItem::OutputText {
@@ -258,7 +258,7 @@ pub(crate) async fn exit_review_mode(
                 }],
                 end_turn: None,
                 phase: None,
-            },
+            }),
         )
         .await;
 

codex-rs/core/src/tasks/undo.rs

@@ -77,9 +77,9 @@ impl SessionTask for UndoTask {
                 .enumerate()
                 .rev()
                 .find_map(|(idx, item)| match item {
-                    ResponseItem::GhostSnapshot { ghost_commit } => {
+                    ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot {
-                        Some((idx, ghost_commit.clone()))
+                        ghost_commit,
-                    }
+                    }) => Some((idx, ghost_commit.clone())),
                     _ => None,
                 })
         else {

codex-rs/core/src/tasks/user_shell.rs

@@ -298,7 +298,9 @@ async fn persist_user_shell_output(
     }
 
     let response_input_item = match output_item {
-        ResponseItem::Message { role, content, .. } => ResponseInputItem::Message { role, content },
+        ResponseItem::Message(codex_protocol::models::Message { role, content, .. }) => {
+            ResponseInputItem::Message { role, content }
+        }
         _ => unreachable!("user shell command output record should always be a message"),
     };
 

codex-rs/core/src/thread_manager.rs

@@ -530,7 +530,7 @@ mod tests {
     use pretty_assertions::assert_eq;
 
     fn user_msg(text: &str) -> ResponseItem {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::OutputText {
@@ -538,10 +538,10 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
     fn assistant_msg(text: &str) -> ResponseItem {
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -549,7 +549,7 @@ mod tests {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 
     #[test]
@@ -560,20 +560,20 @@ mod tests {
             assistant_msg("a2"),
             user_msg("u2"),
             assistant_msg("a3"),
-            ResponseItem::Reasoning {
+            ResponseItem::Reasoning(codex_protocol::models::Reasoning {
                 id: "r1".to_string(),
                 summary: vec![ReasoningItemReasoningSummary::SummaryText {
                     text: "s".to_string(),
                 }],
                 content: None,
                 encrypted_content: None,
-            },
+            }),
-            ResponseItem::FunctionCall {
+            ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
                 id: None,
                 call_id: "c1".to_string(),
                 name: "tool".to_string(),
                 arguments: "{}".to_string(),
-            },
+            }),
             assistant_msg("a4"),
         ];
 

codex-rs/core/src/tools/handlers/collab.rs

@@ -1150,15 +1150,17 @@ mod tests {
         let thread = manager
             .resume_thread_with_history(
                 config,
-                InitialHistory::Forked(vec![RolloutItem::ResponseItem(ResponseItem::Message {
+                InitialHistory::Forked(vec![RolloutItem::ResponseItem(ResponseItem::Message(
-                    id: None,
+                    codex_protocol::models::Message {
-                    role: "user".to_string(),
+                        id: None,
-                    content: vec![ContentItem::InputText {
+                        role: "user".to_string(),
-                        text: "materialized".to_string(),
+                        content: vec![ContentItem::InputText {
-                    }],
+                            text: "materialized".to_string(),
-                    end_turn: None,
+                        }],
-                    phase: None,
+                        end_turn: None,
-                })]),
+                        phase: None,
+                    },
+                ))]),
                 AuthManager::from_auth_for_testing(CodexAuth::from_api_key("dummy")),
             )
             .await

codex-rs/core/src/tools/router.rs

@@ -65,12 +65,12 @@ impl ToolRouter {
         item: ResponseItem,
     ) -> Result<Option<ToolCall>, FunctionCallError> {
         match item {
-            ResponseItem::FunctionCall {
+            ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
                 name,
                 arguments,
                 call_id,
                 ..
-            } => {
+            }) => {
                 if let Some((server, tool)) = session.parse_mcp_tool_name(&name).await {
                     Ok(Some(ToolCall {
                         tool_name: name,
@@ -89,22 +89,22 @@ impl ToolRouter {
                     }))
                 }
             }
-            ResponseItem::CustomToolCall {
+            ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall {
                 name,
                 input,
                 call_id,
                 ..
-            } => Ok(Some(ToolCall {
+            }) => Ok(Some(ToolCall {
                 tool_name: name,
                 call_id,
                 payload: ToolPayload::Custom { input },
             })),
-            ResponseItem::LocalShellCall {
+            ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall {
                 id,
                 call_id,
                 action,
                 ..
-            } => {
+            }) => {
                 let call_id = call_id
                     .or(id)
                     .ok_or(FunctionCallError::MissingLocalShellCallId)?;

codex-rs/core/src/user_shell_command.rs

@@ -56,7 +56,7 @@ pub fn user_shell_command_record_item(
     exec_output: &ExecToolCallOutput,
     turn_context: &TurnContext,
 ) -> ResponseItem {
-    ResponseItem::Message {
+    ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".to_string(),
         content: vec![ContentItem::InputText {
@@ -64,7 +64,7 @@ pub fn user_shell_command_record_item(
         }],
         end_turn: None,
         phase: None,
-    }
+    })
 }
 
 #[cfg(test)]
@@ -94,7 +94,7 @@ mod tests {
         };
         let (_, turn_context) = make_session_and_context().await;
         let item = user_shell_command_record_item("echo hi", &exec_output, &turn_context);
-        let ResponseItem::Message { content, .. } = item else {
+        let ResponseItem::Message(codex_protocol::models::Message { content, .. }) = item else {
             panic!("expected message");
         };
         let [ContentItem::InputText { text }] = content.as_slice() else {

codex-rs/core/tests/responses_headers.rs

@@ -101,7 +101,7 @@ async fn responses_stream_includes_subagent_header_on_review() {
     let mut client_session = client.new_session();
 
     let mut prompt = Prompt::default();
-    prompt.input = vec![ResponseItem::Message {
+    prompt.input = vec![ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".into(),
         content: vec![ContentItem::InputText {
@@ -109,7 +109,7 @@ async fn responses_stream_includes_subagent_header_on_review() {
         }],
         end_turn: None,
         phase: None,
-    }];
+    })];
 
     let mut stream = client_session
         .stream(&prompt, &model_info, &otel_manager, effort, summary, None)
@@ -205,7 +205,7 @@ async fn responses_stream_includes_subagent_header_on_other() {
     let mut client_session = client.new_session();
 
     let mut prompt = Prompt::default();
-    prompt.input = vec![ResponseItem::Message {
+    prompt.input = vec![ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".into(),
         content: vec![ContentItem::InputText {
@@ -213,7 +213,7 @@ async fn responses_stream_includes_subagent_header_on_other() {
         }],
         end_turn: None,
         phase: None,
-    }];
+    })];
 
     let mut stream = client_session
         .stream(&prompt, &model_info, &otel_manager, effort, summary, None)
@@ -308,7 +308,7 @@ async fn responses_respects_model_info_overrides_from_config() {
     let mut client_session = client.new_session();
 
     let mut prompt = Prompt::default();
-    prompt.input = vec![ResponseItem::Message {
+    prompt.input = vec![ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".into(),
         content: vec![ContentItem::InputText {
@@ -316,7 +316,7 @@ async fn responses_respects_model_info_overrides_from_config() {
         }],
         end_turn: None,
         phase: None,
-    }];
+    })];
 
     let mut stream = client_session
         .stream(&prompt, &model_info, &otel_manager, effort, summary, None)

codex-rs/core/tests/suite/client.rs

@@ -187,15 +187,16 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
     .unwrap();
 
     // Prior item: user message (should be delivered)
-    let prior_user = codex_protocol::models::ResponseItem::Message {
+    let prior_user =
-        id: None,
+        codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
-        role: "user".to_string(),
+            id: None,
-        content: vec![codex_protocol::models::ContentItem::InputText {
+            role: "user".to_string(),
-            text: "resumed user message".to_string(),
+            content: vec![codex_protocol::models::ContentItem::InputText {
-        }],
+                text: "resumed user message".to_string(),
-        end_turn: None,
+            }],
-        phase: None,
+            end_turn: None,
-    };
+            phase: None,
+        });
     let prior_user_json = serde_json::to_value(&prior_user).unwrap();
     writeln!(
         f,
@@ -209,15 +210,16 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
     .unwrap();
 
     // Prior item: system message (excluded from API history)
-    let prior_system = codex_protocol::models::ResponseItem::Message {
+    let prior_system =
-        id: None,
+        codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
-        role: "system".to_string(),
+            id: None,
-        content: vec![codex_protocol::models::ContentItem::OutputText {
+            role: "system".to_string(),
-            text: "resumed system instruction".to_string(),
+            content: vec![codex_protocol::models::ContentItem::OutputText {
-        }],
+                text: "resumed system instruction".to_string(),
-        end_turn: None,
+            }],
-        phase: None,
+            end_turn: None,
-    };
+            phase: None,
+        });
     let prior_system_json = serde_json::to_value(&prior_system).unwrap();
     writeln!(
         f,
@@ -231,15 +233,16 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
     .unwrap();
 
     // Prior item: assistant message
-    let prior_item = codex_protocol::models::ResponseItem::Message {
+    let prior_item =
-        id: None,
+        codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
-        role: "assistant".to_string(),
+            id: None,
-        content: vec![codex_protocol::models::ContentItem::OutputText {
+            role: "assistant".to_string(),
-            text: "resumed assistant message".to_string(),
+            content: vec![codex_protocol::models::ContentItem::OutputText {
-        }],
+                text: "resumed assistant message".to_string(),
-        end_turn: None,
+            }],
-        phase: Some(MessagePhase::Commentary),
+            end_turn: None,
-    };
+            phase: Some(MessagePhase::Commentary),
+        });
     let prior_item_json = serde_json::to_value(&prior_item).unwrap();
     writeln!(
         f,
@@ -1280,66 +1283,82 @@ async fn azure_responses_request_includes_store_and_reasoning_ids() {
     let mut client_session = client.new_session();
 
     let mut prompt = Prompt::default();
-    prompt.input.push(ResponseItem::Reasoning {
+    prompt
-        id: "reasoning-id".into(),
+        .input
-        summary: vec![ReasoningItemReasoningSummary::SummaryText {
+        .push(ResponseItem::Reasoning(codex_protocol::models::Reasoning {
-            text: "summary".into(),
+            id: "reasoning-id".into(),
-        }],
+            summary: vec![ReasoningItemReasoningSummary::SummaryText {
-        content: Some(vec![ReasoningItemContent::ReasoningText {
+                text: "summary".into(),
-            text: "content".into(),
+            }],
-        }]),
+            content: Some(vec![ReasoningItemContent::ReasoningText {
-        encrypted_content: None,
+                text: "content".into(),
-    });
+            }]),
-    prompt.input.push(ResponseItem::Message {
+            encrypted_content: None,
-        id: Some("message-id".into()),
+        }));
-        role: "assistant".into(),
+    prompt
-        content: vec![ContentItem::OutputText {
+        .input
-            text: "message".into(),
+        .push(ResponseItem::Message(codex_protocol::models::Message {
-        }],
+            id: Some("message-id".into()),
-        end_turn: None,
+            role: "assistant".into(),
-        phase: None,
+            content: vec![ContentItem::OutputText {
-    });
+                text: "message".into(),
-    prompt.input.push(ResponseItem::WebSearchCall {
+            }],
-        id: Some("web-search-id".into()),
+            end_turn: None,
-        status: Some("completed".into()),
+            phase: None,
-        action: Some(WebSearchAction::Search {
+        }));
-            query: Some("weather".into()),
+    prompt.input.push(ResponseItem::WebSearchCall(
-            queries: None,
+        codex_protocol::models::WebSearchCall {
-        }),
+            id: Some("web-search-id".into()),
-    });
+            status: Some("completed".into()),
-    prompt.input.push(ResponseItem::FunctionCall {
+            action: Some(WebSearchAction::Search {
-        id: Some("function-id".into()),
+                query: Some("weather".into()),
-        name: "do_thing".into(),
+                queries: None,
-        arguments: "{}".into(),
+            }),
-        call_id: "function-call-id".into(),
+        },
-    });
+    ));
-    prompt.input.push(ResponseItem::FunctionCallOutput {
+    prompt.input.push(ResponseItem::FunctionCall(
-        call_id: "function-call-id".into(),
+        codex_protocol::models::FunctionCall {
-        output: FunctionCallOutputPayload::from_text("ok".into()),
+            id: Some("function-id".into()),
-    });
+            name: "do_thing".into(),
-    prompt.input.push(ResponseItem::LocalShellCall {
+            arguments: "{}".into(),
-        id: Some("local-shell-id".into()),
+            call_id: "function-call-id".into(),
-        call_id: Some("local-shell-call-id".into()),
+        },
-        status: LocalShellStatus::Completed,
+    ));
-        action: LocalShellAction::Exec(LocalShellExecAction {
+    prompt.input.push(ResponseItem::FunctionCallOutput(
-            command: vec!["echo".into(), "hello".into()],
+        codex_protocol::models::FunctionCallOutput {
-            timeout_ms: None,
+            call_id: "function-call-id".into(),
-            working_directory: None,
+            output: FunctionCallOutputPayload::from_text("ok".into()),
-            env: None,
+        },
-            user: None,
+    ));
-        }),
+    prompt.input.push(ResponseItem::LocalShellCall(
-    });
+        codex_protocol::models::LocalShellCall {
-    prompt.input.push(ResponseItem::CustomToolCall {
+            id: Some("local-shell-id".into()),
-        id: Some("custom-tool-id".into()),
+            call_id: Some("local-shell-call-id".into()),
-        status: Some("completed".into()),
+            status: LocalShellStatus::Completed,
-        call_id: "custom-tool-call-id".into(),
+            action: LocalShellAction::Exec(LocalShellExecAction {
-        name: "custom_tool".into(),
+                command: vec!["echo".into(), "hello".into()],
-        input: "{}".into(),
+                timeout_ms: None,
-    });
+                working_directory: None,
-    prompt.input.push(ResponseItem::CustomToolCallOutput {
+                env: None,
-        call_id: "custom-tool-call-id".into(),
+                user: None,
-        output: "ok".into(),
+            }),
-    });
+        },
+    ));
+    prompt.input.push(ResponseItem::CustomToolCall(
+        codex_protocol::models::CustomToolCall {
+            id: Some("custom-tool-id".into()),
+            status: Some("completed".into()),
+            call_id: "custom-tool-call-id".into(),
+            name: "custom_tool".into(),
+            input: "{}".into(),
+        },
+    ));
+    prompt.input.push(ResponseItem::CustomToolCallOutput(
+        codex_protocol::models::CustomToolCallOutput {
+            call_id: "custom-tool-call-id".into(),
+            output: "ok".into(),
+        },
+    ));
 
     let mut stream = client_session
         .stream(&prompt, &model_info, &otel_manager, effort, summary, None)

codex-rs/core/tests/suite/client_websockets.rs

@@ -622,13 +622,13 @@ async fn responses_websocket_v2_sets_openai_beta_header() {
 }
 
 fn message_item(text: &str) -> ResponseItem {
-    ResponseItem::Message {
+    ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".into(),
         content: vec![ContentItem::InputText { text: text.into() }],
         end_turn: None,
         phase: None,
-    }
+    })
 }
 
 fn prompt_with_input(input: Vec<ResponseItem>) -> Prompt {

codex-rs/core/tests/suite/compact.rs

@@ -1444,7 +1444,7 @@ async fn auto_compact_runs_after_resume_when_token_usage_is_over_limit() {
     let remote_summary = "REMOTE_COMPACT_SUMMARY";
 
     let compacted_history = vec![
-        codex_protocol::models::ResponseItem::Message {
+        codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![codex_protocol::models::ContentItem::OutputText {
@@ -1452,10 +1452,10 @@ async fn auto_compact_runs_after_resume_when_token_usage_is_over_limit() {
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        codex_protocol::models::ResponseItem::Compaction {
+        codex_protocol::models::ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock =
         mount_compact_json_once(&server, serde_json::json!({ "output": compacted_history })).await;
@@ -2266,7 +2266,7 @@ async fn auto_compact_counts_encrypted_reasoning_before_last_user() {
     .await;
 
     let compacted_history = vec![
-        codex_protocol::models::ResponseItem::Message {
+        codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![codex_protocol::models::ContentItem::OutputText {
@@ -2274,10 +2274,10 @@ async fn auto_compact_counts_encrypted_reasoning_before_last_user() {
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        codex_protocol::models::ResponseItem::Compaction {
+        codex_protocol::models::ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock =
         mount_compact_json_once(&server, serde_json::json!({ "output": compacted_history })).await;
@@ -2386,7 +2386,7 @@ async fn auto_compact_runs_when_reasoning_header_clears_between_turns() {
     mount_response_sequence(&server, responses).await;
 
     let compacted_history = vec![
-        codex_protocol::models::ResponseItem::Message {
+        codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![codex_protocol::models::ContentItem::OutputText {
@@ -2394,10 +2394,10 @@ async fn auto_compact_runs_when_reasoning_header_clears_between_turns() {
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        codex_protocol::models::ResponseItem::Compaction {
+        codex_protocol::models::ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock =
         mount_compact_json_once(&server, serde_json::json!({ "output": compacted_history })).await;

codex-rs/core/tests/suite/compact_remote.rs

@@ -65,7 +65,7 @@ async fn remote_compact_replaces_history_for_followups() -> Result<()> {
     .await;
 
     let compacted_history = vec![
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -73,10 +73,10 @@ async fn remote_compact_replaces_history_for_followups() -> Result<()> {
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Compaction {
+        ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock = responses::mount_compact_json_once(
         harness.server(),
@@ -184,7 +184,7 @@ async fn remote_compact_runs_automatically() -> Result<()> {
     .await;
 
     let compacted_history = vec![
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -192,10 +192,10 @@ async fn remote_compact_runs_automatically() -> Result<()> {
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Compaction {
+        ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock = responses::mount_compact_json_once(
         harness.server(),
@@ -783,7 +783,7 @@ async fn remote_manual_compact_emits_context_compaction_items() -> Result<()> {
     .await;
 
     let compacted_history = vec![
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -791,10 +791,10 @@ async fn remote_manual_compact_emits_context_compaction_items() -> Result<()> {
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Compaction {
+        ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock = responses::mount_compact_json_once(
         harness.server(),
@@ -881,7 +881,7 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
     .await;
 
     let compacted_history = vec![
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -889,11 +889,11 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Compaction {
+        ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -901,7 +901,7 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
     ];
     let compact_mock = responses::mount_compact_json_once(
         harness.server(),
@@ -946,7 +946,7 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
             let has_compacted_user_summary = replacement_history.iter().any(|item| {
                 matches!(
                     item,
-                    ResponseItem::Message { role, content, .. }
+                    ResponseItem::Message(codex_protocol::models::Message { role, content, .. })
                         if role == "user"
                             && content.iter().any(|part| matches!(
                                 part,
@@ -957,14 +957,14 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
             let has_compaction_item = replacement_history.iter().any(|item| {
                 matches!(
                     item,
-                    ResponseItem::Compaction { encrypted_content }
+                    ResponseItem::Compaction(codex_protocol::models::Compaction { encrypted_content })
                         if encrypted_content == "ENCRYPTED_COMPACTION_SUMMARY"
                 )
             });
             let has_compacted_assistant_note = replacement_history.iter().any(|item| {
                 matches!(
                     item,
-                    ResponseItem::Message { role, content, .. }
+                    ResponseItem::Message(codex_protocol::models::Message { role, content, .. })
                         if role == "assistant"
                             && content.iter().any(|part| matches!(
                                 part,
@@ -975,7 +975,7 @@ async fn remote_compact_persists_replacement_history_in_rollout() -> Result<()>
             let has_permissions_developer_message = replacement_history.iter().any(|item| {
                 matches!(
                     item,
-                    ResponseItem::Message { role, content, .. }
+                    ResponseItem::Message(codex_protocol::models::Message { role, content, .. })
                         if role == "developer"
                             && content.iter().any(|part| matches!(
                                 part,
@@ -1041,7 +1041,7 @@ async fn remote_compact_and_resume_refresh_stale_developer_instructions() -> Res
     .await;
 
     let compacted_history = vec![
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -1049,8 +1049,8 @@ async fn remote_compact_and_resume_refresh_stale_developer_instructions() -> Res
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "developer".to_string(),
             content: vec![ContentItem::InputText {
@@ -1058,10 +1058,10 @@ async fn remote_compact_and_resume_refresh_stale_developer_instructions() -> Res
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Compaction {
+        ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock = responses::mount_compact_json_once(
         &server,
@@ -1182,7 +1182,7 @@ async fn remote_compact_refreshes_stale_developer_instructions_without_resume()
     .await;
 
     let compacted_history = vec![
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![ContentItem::InputText {
@@ -1190,8 +1190,8 @@ async fn remote_compact_refreshes_stale_developer_instructions_without_resume()
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Message {
+        ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "developer".to_string(),
             content: vec![ContentItem::InputText {
@@ -1199,10 +1199,10 @@ async fn remote_compact_refreshes_stale_developer_instructions_without_resume()
             }],
             end_turn: None,
             phase: None,
-        },
+        }),
-        ResponseItem::Compaction {
+        ResponseItem::Compaction(codex_protocol::models::Compaction {
             encrypted_content: "ENCRYPTED_COMPACTION_SUMMARY".to_string(),
-        },
+        }),
     ];
     let compact_mock = responses::mount_compact_json_once(
         &server,

codex-rs/core/tests/suite/discoverable_history.rs

@@ -0,0 +1,73 @@
+#![cfg(not(target_os = "windows"))]
+
+use anyhow::Context;
+use anyhow::Result;
+use codex_core::protocol::EventMsg;
+use codex_protocol::user_input::UserInput;
+use core_test_support::responses::ev_completed;
+use core_test_support::responses::ev_response_created;
+use core_test_support::responses::mount_sse_once;
+use core_test_support::responses::sse;
+use core_test_support::responses::start_mock_server;
+use core_test_support::skip_if_no_network;
+use core_test_support::test_codex::test_codex;
+use core_test_support::wait_for_event;
+use sha2::Digest;
+use sha2::Sha256;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn oversized_user_message_is_stored_as_discoverable_item() -> Result<()> {
+    skip_if_no_network!(Ok(()));
+
+    let server = start_mock_server().await;
+    let request_log = mount_sse_once(
+        &server,
+        sse(vec![ev_response_created("resp-1"), ev_completed("resp-1")]),
+    )
+    .await;
+
+    let mut builder = test_codex().with_config(|config| {
+        config.model_context_window = Some(100);
+    });
+    let test = builder.build(&server).await?;
+
+    let large_prompt = "oversized user prompt ".repeat(800);
+    test.codex
+        .submit(codex_core::protocol::Op::UserInput {
+            items: vec![UserInput::Text {
+                text: large_prompt.clone(),
+                text_elements: Vec::new(),
+            }],
+            final_output_json_schema: None,
+        })
+        .await?;
+
+    wait_for_event(&test.codex, |ev| matches!(ev, EventMsg::TurnComplete(_))).await;
+
+    let request = request_log.single_request();
+    let mut hasher = Sha256::new();
+    hasher.update(large_prompt.as_bytes());
+    let expected_checksum = format!("{:x}", hasher.finalize());
+    let discoverable_root = test.codex_home_path().join("discovarable_items");
+    let expected_path = std::fs::read_dir(&discoverable_root)
+        .context("read discoverable_items dir")?
+        .filter_map(|entry| entry.ok())
+        .map(|entry| entry.path().join("user_message").join(&expected_checksum))
+        .find(|candidate| candidate.is_file())
+        .context("expected discoverable file was not created")?;
+    assert!(expected_path.is_file(), "discoverable file should exist");
+
+    let expected = format!(
+        "User message was too large. Read it from <{}>",
+        expected_path.display()
+    );
+    let actual = request
+        .message_input_texts("user")
+        .into_iter()
+        .find(|text| text.contains(&expected_checksum))
+        .context("missing discoverable replacement text in user input")?;
+
+    assert_eq!(actual, expected);
+
+    Ok(())
+}

codex-rs/core/tests/suite/image_rollout.rs

@@ -35,8 +35,11 @@ fn find_user_message_with_image(text: &str) -> Option<ResponseItem> {
             Ok(rollout) => rollout,
             Err(_) => continue,
         };
-        if let RolloutItem::ResponseItem(ResponseItem::Message { role, content, .. }) =
+        if let RolloutItem::ResponseItem(ResponseItem::Message(codex_protocol::models::Message {
-            &rollout.item
+            role,
+            content,
+            ..
+        })) = &rollout.item
             && role == "user"
             && content
                 .iter()
@@ -51,10 +54,12 @@ fn find_user_message_with_image(text: &str) -> Option<ResponseItem> {
 
 fn extract_image_url(item: &ResponseItem) -> Option<String> {
     match item {
-        ResponseItem::Message { content, .. } => content.iter().find_map(|span| match span {
+        ResponseItem::Message(codex_protocol::models::Message { content, .. }) => {
-            ContentItem::InputImage { image_url } => Some(image_url.clone()),
+            content.iter().find_map(|span| match span {
-            _ => None,
+                ContentItem::InputImage { image_url } => Some(image_url.clone()),
-        }),
+                _ => None,
+            })
+        }
         _ => None,
     }
 }
@@ -142,7 +147,7 @@ async fn copy_paste_local_image_persists_rollout_request_shape() -> anyhow::Resu
         .expect("expected user message with input image in rollout");
 
     let image_url = extract_image_url(&actual).expect("expected image url in rollout");
-    let expected = ResponseItem::Message {
+    let expected = ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".to_string(),
         content: vec![
@@ -159,7 +164,7 @@ async fn copy_paste_local_image_persists_rollout_request_shape() -> anyhow::Resu
         ],
         end_turn: None,
         phase: None,
-    };
+    });
 
     assert_eq!(actual, expected);
 
@@ -224,7 +229,7 @@ async fn drag_drop_image_persists_rollout_request_shape() -> anyhow::Result<()>
         .expect("expected user message with input image in rollout");
 
     let image_url = extract_image_url(&actual).expect("expected image url in rollout");
-    let expected = ResponseItem::Message {
+    let expected = ResponseItem::Message(codex_protocol::models::Message {
         id: None,
         role: "user".to_string(),
         content: vec![
@@ -241,7 +246,7 @@ async fn drag_drop_image_persists_rollout_request_shape() -> anyhow::Result<()>
         ],
         end_turn: None,
         phase: None,
-    };
+    });
 
     assert_eq!(actual, expected);
 

codex-rs/core/tests/suite/mod.rs

@@ -70,6 +70,7 @@ mod compact;
 mod compact_remote;
 mod compact_resume_fork;
 mod deprecation_notice;
+mod discoverable_history;
 mod exec;
 mod exec_policy;
 mod fork_thread;

codex-rs/core/tests/suite/override_updates.rs

@@ -61,7 +61,7 @@ fn rollout_developer_texts(text: &str) -> Vec<String> {
             Ok(rollout) => rollout,
             Err(_) => continue,
         };
-        if let RolloutItem::ResponseItem(ResponseItem::Message { role, content, .. }) =
+        if let RolloutItem::ResponseItem(ResponseItem::Message(codex_protocol::models::Message { role, content, .. })) =
             rollout.item
             && role == "developer"
         {
@@ -86,7 +86,7 @@ fn rollout_environment_texts(text: &str) -> Vec<String> {
             Ok(rollout) => rollout,
             Err(_) => continue,
         };
-        if let RolloutItem::ResponseItem(ResponseItem::Message { role, content, .. }) =
+        if let RolloutItem::ResponseItem(ResponseItem::Message(codex_protocol::models::Message { role, content, .. })) =
             rollout.item
             && role == "user"
         {

codex-rs/core/tests/suite/review.rs

@@ -130,7 +130,12 @@ async fn review_op_emits_lifecycle_and_review_output() {
         }
         let v: serde_json::Value = serde_json::from_str(line).expect("jsonl line");
         let rl: RolloutLine = serde_json::from_value(v).expect("rollout line");
-        if let RolloutItem::ResponseItem(ResponseItem::Message { role, content, .. }) = rl.item {
+        if let RolloutItem::ResponseItem(ResponseItem::Message(codex_protocol::models::Message {
+            role,
+            content,
+            ..
+        })) = rl.item
+        {
             if role == "user" {
                 for c in content {
                     if let ContentItem::InputText { text } = c {
@@ -523,7 +528,7 @@ async fn review_input_isolated_from_parent_history() {
             .unwrap();
 
         // Prior user message (enveloped response_item)
-        let user = codex_protocol::models::ResponseItem::Message {
+        let user = codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
             id: None,
             role: "user".to_string(),
             content: vec![codex_protocol::models::ContentItem::InputText {
@@ -531,7 +536,7 @@ async fn review_input_isolated_from_parent_history() {
             }],
             end_turn: None,
             phase: None,
-        };
+        });
         let user_json = serde_json::to_value(&user).unwrap();
         let user_line = serde_json::json!({
             "timestamp": "2024-01-01T00:00:01.000Z",
@@ -543,15 +548,16 @@ async fn review_input_isolated_from_parent_history() {
             .unwrap();
 
         // Prior assistant message (enveloped response_item)
-        let assistant = codex_protocol::models::ResponseItem::Message {
+        let assistant =
-            id: None,
+            codex_protocol::models::ResponseItem::Message(codex_protocol::models::Message {
-            role: "assistant".to_string(),
+                id: None,
-            content: vec![codex_protocol::models::ContentItem::OutputText {
+                role: "assistant".to_string(),
-                text: "parent: assistant reply".to_string(),
+                content: vec![codex_protocol::models::ContentItem::OutputText {
-            }],
+                    text: "parent: assistant reply".to_string(),
-            end_turn: None,
+                }],
-            phase: None,
+                end_turn: None,
-        };
+                phase: None,
+            });
         let assistant_json = serde_json::to_value(&assistant).unwrap();
         let assistant_line = serde_json::json!({
             "timestamp": "2024-01-01T00:00:02.000Z",
@@ -636,7 +642,11 @@ async fn review_input_isolated_from_parent_history() {
         }
         let v: serde_json::Value = serde_json::from_str(line).expect("jsonl line");
         let rl: RolloutLine = serde_json::from_value(v).expect("rollout line");
-        if let RolloutItem::ResponseItem(ResponseItem::Message { role, content, .. }) = rl.item
+        if let RolloutItem::ResponseItem(ResponseItem::Message(codex_protocol::models::Message {
+            role,
+            content,
+            ..
+        })) = rl.item
             && role == "user"
         {
             for c in content {

codex-rs/otel/src/traces/otel_manager.rs

@@ -102,13 +102,21 @@ impl OtelManager {
         match event {
             ResponseEvent::OutputItemDone(item) => {
                 handle_responses_span.record("from", "output_item_done");
-                if let ResponseItem::FunctionCall { name, .. } = &item {
+                if let ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
+                    name,
+                    ..
+                }) = &item
+                {
                     handle_responses_span.record("tool_name", name.as_str());
                 }
             }
             ResponseEvent::OutputItemAdded(item) => {
                 handle_responses_span.record("from", "output_item_added");
-                if let ResponseItem::FunctionCall { name, .. } = &item {
+                if let ResponseItem::FunctionCall(codex_protocol::models::FunctionCall {
+                    name,
+                    ..
+                }) = &item
+                {
                     handle_responses_span.record("tool_name", name.as_str());
                 }
             }
@@ -755,16 +763,34 @@ impl OtelManager {
 
     fn responses_item_type(item: &ResponseItem) -> String {
         match item {
-            ResponseItem::Message { role, .. } => format!("message_from_{role}"),
+            ResponseItem::Message(codex_protocol::models::Message { role, .. }) => {
-            ResponseItem::Reasoning { .. } => "reasoning".into(),
+                format!("message_from_{role}")
-            ResponseItem::LocalShellCall { .. } => "local_shell_call".into(),
+            }
-            ResponseItem::FunctionCall { .. } => "function_call".into(),
+            ResponseItem::Reasoning(codex_protocol::models::Reasoning { .. }) => "reasoning".into(),
-            ResponseItem::FunctionCallOutput { .. } => "function_call_output".into(),
+            ResponseItem::LocalShellCall(codex_protocol::models::LocalShellCall { .. }) => {
-            ResponseItem::CustomToolCall { .. } => "custom_tool_call".into(),
+                "local_shell_call".into()
-            ResponseItem::CustomToolCallOutput { .. } => "custom_tool_call_output".into(),
+            }
-            ResponseItem::WebSearchCall { .. } => "web_search_call".into(),
+            ResponseItem::FunctionCall(codex_protocol::models::FunctionCall { .. }) => {
-            ResponseItem::GhostSnapshot { .. } => "ghost_snapshot".into(),
+                "function_call".into()
-            ResponseItem::Compaction { .. } => "compaction".into(),
+            }
+            ResponseItem::FunctionCallOutput(codex_protocol::models::FunctionCallOutput {
+                ..
+            }) => "function_call_output".into(),
+            ResponseItem::CustomToolCall(codex_protocol::models::CustomToolCall { .. }) => {
+                "custom_tool_call".into()
+            }
+            ResponseItem::CustomToolCallOutput(codex_protocol::models::CustomToolCallOutput {
+                ..
+            }) => "custom_tool_call_output".into(),
+            ResponseItem::WebSearchCall(codex_protocol::models::WebSearchCall { .. }) => {
+                "web_search_call".into()
+            }
+            ResponseItem::GhostSnapshot(codex_protocol::models::GhostSnapshot { .. }) => {
+                "ghost_snapshot".into()
+            }
+            ResponseItem::Compaction(codex_protocol::models::Compaction { .. }) => {
+                "compaction".into()
+            }
             ResponseItem::Other => "other".into(),
         }
     }

codex-rs/protocol/src/models.rs

@@ -88,82 +88,125 @@ pub enum MessagePhase {
     FinalAnswer,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct Message {
+    #[serde(default, skip_serializing)]
+    #[ts(skip)]
+    pub id: Option<String>,
+    pub role: String,
+    pub content: Vec<ContentItem>,
+    // Do not use directly, no available consistently across all providers.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub end_turn: Option<bool>,
+    // Optional output-message phase (for example: "commentary", "final_answer").
+    // Availability varies by provider/model, so downstream consumers must
+    // preserve fallback behavior when this is absent.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub phase: Option<MessagePhase>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct Reasoning {
+    #[serde(default, skip_serializing)]
+    #[ts(skip)]
+    pub id: String,
+    pub summary: Vec<ReasoningItemReasoningSummary>,
+    #[serde(default, skip_serializing_if = "should_serialize_reasoning_content")]
+    #[ts(optional)]
+    pub content: Option<Vec<ReasoningItemContent>>,
+    pub encrypted_content: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct LocalShellCall {
+    /// Legacy id field retained for compatibility with older payloads.
+    #[serde(default, skip_serializing)]
+    #[ts(skip)]
+    pub id: Option<String>,
+    /// Set when using the Responses API.
+    pub call_id: Option<String>,
+    pub status: LocalShellStatus,
+    pub action: LocalShellAction,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct FunctionCall {
+    #[serde(default, skip_serializing)]
+    #[ts(skip)]
+    pub id: Option<String>,
+    // The Responses API returns the function call arguments as a *string* that contains
+    // JSON, not as an already‑parsed object. We keep it as a raw string here and let
+    // Session::handle_function_call parse it into a Value.
+    pub name: String,
+    pub arguments: String,
+    pub call_id: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct FunctionCallOutput {
+    pub call_id: String,
+    pub output: FunctionCallOutputPayload,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct CustomToolCall {
+    #[serde(default, skip_serializing)]
+    #[ts(skip)]
+    pub id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub status: Option<String>,
+    pub call_id: String,
+    pub name: String,
+    pub input: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct CustomToolCallOutput {
+    pub call_id: String,
+    pub output: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct WebSearchCall {
+    #[serde(default, skip_serializing)]
+    #[ts(skip)]
+    pub id: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub status: Option<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub action: Option<WebSearchAction>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct GhostSnapshot {
+    pub ghost_commit: GhostCommit,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
+pub struct Compaction {
+    pub encrypted_content: String,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema, TS)]
 #[serde(tag = "type", rename_all = "snake_case")]
 pub enum ResponseItem {
-    Message {
+    Message(Message),
-        #[serde(default, skip_serializing)]
+    Reasoning(Reasoning),
-        #[ts(skip)]
+    LocalShellCall(LocalShellCall),
-        id: Option<String>,
+    FunctionCall(FunctionCall),
-        role: String,
-        content: Vec<ContentItem>,
-        // Do not use directly, no available consistently across all providers.
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        #[ts(optional)]
-        end_turn: Option<bool>,
-        // Optional output-message phase (for example: "commentary", "final_answer").
-        // Availability varies by provider/model, so downstream consumers must
-        // preserve fallback behavior when this is absent.
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        #[ts(optional)]
-        phase: Option<MessagePhase>,
-    },
-    Reasoning {
-        #[serde(default, skip_serializing)]
-        #[ts(skip)]
-        id: String,
-        summary: Vec<ReasoningItemReasoningSummary>,
-        #[serde(default, skip_serializing_if = "should_serialize_reasoning_content")]
-        #[ts(optional)]
-        content: Option<Vec<ReasoningItemContent>>,
-        encrypted_content: Option<String>,
-    },
-    LocalShellCall {
-        /// Legacy id field retained for compatibility with older payloads.
-        #[serde(default, skip_serializing)]
-        #[ts(skip)]
-        id: Option<String>,
-        /// Set when using the Responses API.
-        call_id: Option<String>,
-        status: LocalShellStatus,
-        action: LocalShellAction,
-    },
-    FunctionCall {
-        #[serde(default, skip_serializing)]
-        #[ts(skip)]
-        id: Option<String>,
-        name: String,
-        // The Responses API returns the function call arguments as a *string* that contains
-        // JSON, not as an already‑parsed object. We keep it as a raw string here and let
-        // Session::handle_function_call parse it into a Value.
-        arguments: String,
-        call_id: String,
-    },
     // NOTE: The `output` field for `function_call_output` uses a dedicated payload type with
     // custom serialization. On the wire it is either:
     //   - a plain string (`content`)
     //   - an array of structured content items (`content_items`)
     // We keep this behavior centralized in `FunctionCallOutputPayload`.
-    FunctionCallOutput {
+    FunctionCallOutput(FunctionCallOutput),
-        call_id: String,
+    CustomToolCall(CustomToolCall),
-        output: FunctionCallOutputPayload,
+    CustomToolCallOutput(CustomToolCallOutput),
-    },
-    CustomToolCall {
-        #[serde(default, skip_serializing)]
-        #[ts(skip)]
-        id: Option<String>,
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        #[ts(optional)]
-        status: Option<String>,
-
-        call_id: String,
-        name: String,
-        input: String,
-    },
-    CustomToolCallOutput {
-        call_id: String,
-        output: String,
-    },
     // Emitted by the Responses API when the agent triggers a web search.
     // Example payload (from SSE `response.output_item.done`):
     // {
@@ -172,25 +215,11 @@ pub enum ResponseItem {
     //   "status":"completed",
     //   "action": {"type":"search","query":"weather: San Francisco, CA"}
     // }
-    WebSearchCall {
+    WebSearchCall(WebSearchCall),
-        #[serde(default, skip_serializing)]
-        #[ts(skip)]
-        id: Option<String>,
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        #[ts(optional)]
-        status: Option<String>,
-        #[serde(default, skip_serializing_if = "Option::is_none")]
-        #[ts(optional)]
-        action: Option<WebSearchAction>,
-    },
     // Generated by the harness but considered exactly as a model response.
-    GhostSnapshot {
+    GhostSnapshot(GhostSnapshot),
-        ghost_commit: GhostCommit,
-    },
     #[serde(alias = "compaction_summary")]
-    Compaction {
+    Compaction(Compaction),
-        encrypted_content: String,
-    },
     #[serde(other)]
     Other,
 }
@@ -459,7 +488,7 @@ fn render_command_prefix(prefix: &[String]) -> String {
 
 impl From<DeveloperInstructions> for ResponseItem {
     fn from(di: DeveloperInstructions) -> Self {
-        ResponseItem::Message {
+        ResponseItem::Message(Message {
             id: None,
             role: "developer".to_string(),
             content: vec![ContentItem::InputText {
@@ -467,7 +496,7 @@ impl From<DeveloperInstructions> for ResponseItem {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 }
 
@@ -619,15 +648,15 @@ pub fn local_image_content_items_with_label_number(
 impl From<ResponseInputItem> for ResponseItem {
     fn from(item: ResponseInputItem) -> Self {
         match item {
-            ResponseInputItem::Message { role, content } => Self::Message {
+            ResponseInputItem::Message { role, content } => Self::Message(Message {
                 role,
                 content,
                 id: None,
                 end_turn: None,
                 phase: None,
-            },
+            }),
             ResponseInputItem::FunctionCallOutput { call_id, output } => {
-                Self::FunctionCallOutput { call_id, output }
+                Self::FunctionCallOutput(FunctionCallOutput { call_id, output })
             }
             ResponseInputItem::McpToolCallOutput { call_id, result } => {
                 let output = match result {
@@ -637,10 +666,10 @@ impl From<ResponseInputItem> for ResponseItem {
                         success: Some(false),
                     },
                 };
-                Self::FunctionCallOutput { call_id, output }
+                Self::FunctionCallOutput(FunctionCallOutput { call_id, output })
             }
             ResponseInputItem::CustomToolCallOutput { call_id, output } => {
-                Self::CustomToolCallOutput { call_id, output }
+                Self::CustomToolCallOutput(CustomToolCallOutput { call_id, output })
             }
         }
     }
@@ -1462,9 +1491,9 @@ mod tests {
 
         assert_eq!(
             item,
-            ResponseItem::Compaction {
+            ResponseItem::Compaction(crate::models::Compaction {
                 encrypted_content: "abc".into(),
-            }
+            })
         );
         Ok(())
     }
@@ -1540,11 +1569,11 @@ mod tests {
         for (json_literal, expected_id, expected_action, expected_status, expect_roundtrip) in cases
         {
             let parsed: ResponseItem = serde_json::from_str(json_literal)?;
-            let expected = ResponseItem::WebSearchCall {
+            let expected = ResponseItem::WebSearchCall(crate::models::WebSearchCall {
                 id: expected_id.clone(),
                 status: expected_status.clone(),
                 action: expected_action.clone(),
-            };
+            });
             assert_eq!(parsed, expected);
 
             let serialized = serde_json::to_value(&parsed)?;

codex-rs/protocol/src/protocol.rs

@@ -1720,7 +1720,7 @@ pub struct CompactedItem {
 
 impl From<CompactedItem> for ResponseItem {
     fn from(value: CompactedItem) -> Self {
-        ResponseItem::Message {
+        ResponseItem::Message(crate::models::Message {
             id: None,
             role: "assistant".to_string(),
             content: vec![ContentItem::OutputText {
@@ -1728,7 +1728,7 @@ impl From<CompactedItem> for ResponseItem {
             }],
             end_turn: None,
             phase: None,
-        }
+        })
     }
 }
 

codex-rs/state/src/extract.rs

@@ -137,15 +137,16 @@ mod tests {
     #[test]
     fn response_item_user_messages_do_not_set_title_or_first_user_message() {
         let mut metadata = metadata_for_test();
-        let item = RolloutItem::ResponseItem(ResponseItem::Message {
+        let item =
-            id: None,
+            RolloutItem::ResponseItem(ResponseItem::Message(codex_protocol::models::Message {
-            role: "user".to_string(),
+                id: None,
-            content: vec![ContentItem::InputText {
+                role: "user".to_string(),
-                text: "hello from response item".to_string(),
+                content: vec![ContentItem::InputText {
-            }],
+                    text: "hello from response item".to_string(),
-            end_turn: None,
+                }],
-            phase: None,
+                end_turn: None,
-        });
+                phase: None,
+            }));
 
         apply_rollout_item(&mut metadata, &item, "test-provider");