analytics: add responses api call schema

codex-rs/analytics/src/analytics_client_tests.rs

@@ -49,6 +49,8 @@ use crate::facts::TurnTokenUsageFact;
 use crate::reducer::AnalyticsReducer;
 use crate::reducer::normalize_path_for_skill_id;
 use crate::reducer::skill_id_for_local_skill;
+use crate::responses_api::CodexResponsesApiCallFact;
+use crate::responses_api::CodexResponsesApiCallStatus;
 use codex_app_server_protocol::ApprovalsReviewer as AppServerApprovalsReviewer;
 use codex_app_server_protocol::AskForApproval as AppServerAskForApproval;
 use codex_app_server_protocol::ClientInfo;
@@ -1050,6 +1052,71 @@ async fn compaction_event_ingests_custom_fact() {
     assert_eq!(payload[0]["event_params"]["status"], "failed");
 }
 
+#[tokio::test]
+async fn responses_api_call_event_ingests_custom_fact() {
+    let mut reducer = AnalyticsReducer::default();
+    let mut events = Vec::new();
+    ingest_turn_prerequisites(
+        &mut reducer,
+        &mut events,
+        /*include_initialize*/ true,
+        /*include_resolved_config*/ true,
+        /*include_started*/ false,
+        /*include_token_usage*/ false,
+    )
+    .await;
+    assert!(events.is_empty());
+
+    reducer
+        .ingest(
+            AnalyticsFact::Custom(CustomAnalyticsFact::ResponsesApiCall(Box::new(
+                CodexResponsesApiCallFact {
+                    thread_id: "thread-2".to_string(),
+                    turn_id: "turn-2".to_string(),
+                    responses_id: Some("resp-1".to_string()),
+                    turn_responses_call_index: 2,
+                    status: CodexResponsesApiCallStatus::Completed,
+                    error: None,
+                    started_at: 100,
+                    completed_at: Some(101),
+                    duration_ms: Some(1200),
+                    input_item_count: 3,
+                    output_item_count: 4,
+                    input_tokens: Some(10),
+                    cached_input_tokens: Some(2),
+                    output_tokens: Some(6),
+                    reasoning_output_tokens: Some(1),
+                    total_tokens: Some(16),
+                    items: Vec::new(),
+                },
+            ))),
+            &mut events,
+        )
+        .await;
+
+    let payload = serde_json::to_value(&events).expect("serialize events");
+    assert_eq!(payload.as_array().expect("events array").len(), 1);
+    assert_eq!(payload[0]["event_type"], "codex_responses_api_call_event");
+    assert_eq!(payload[0]["event_params"]["thread_id"], "thread-2");
+    assert_eq!(payload[0]["event_params"]["turn_id"], "turn-2");
+    assert_eq!(payload[0]["event_params"]["responses_id"], "resp-1");
+    assert_eq!(payload[0]["event_params"]["turn_responses_call_index"], 2);
+    assert_eq!(payload[0]["event_params"]["model"], "gpt-5");
+    assert_eq!(payload[0]["event_params"]["model_provider"], "openai");
+    assert_eq!(payload[0]["event_params"]["status"], "completed");
+    assert_eq!(payload[0]["event_params"]["input_tokens"], 10);
+    assert_eq!(payload[0]["event_params"]["cached_input_tokens"], 2);
+    assert_eq!(payload[0]["event_params"]["output_tokens"], 6);
+    assert_eq!(payload[0]["event_params"]["reasoning_output_tokens"], 1);
+    assert_eq!(payload[0]["event_params"]["total_tokens"], 16);
+    assert_eq!(payload[0]["event_params"]["ephemeral"], false);
+    assert_eq!(payload[0]["event_params"]["thread_source"], "user");
+    assert_eq!(
+        payload[0]["event_params"]["app_server_client"]["product_client_id"],
+        "codex-tui"
+    );
+}
+
 #[test]
 fn subagent_thread_started_review_serializes_expected_shape() {
     let event = TrackEventRequest::ThreadInitialized(subagent_thread_started_event_request(

codex-rs/analytics/src/client.rs

@@ -20,6 +20,7 @@ use crate::facts::TrackEventsContext;
 use crate::facts::TurnResolvedConfigFact;
 use crate::facts::TurnTokenUsageFact;
 use crate::reducer::AnalyticsReducer;
+use crate::responses_api::CodexResponsesApiCallFact;
 use codex_app_server_protocol::ClientRequest;
 use codex_app_server_protocol::ClientResponse;
 use codex_app_server_protocol::InitializeParams;
@@ -214,6 +215,12 @@ impl AnalyticsEventsClient {
         )));
     }
 
+    pub fn track_responses_api_call(&self, event: CodexResponsesApiCallFact) {
+        self.record_fact(AnalyticsFact::Custom(
+            CustomAnalyticsFact::ResponsesApiCall(Box::new(event)),
+        ));
+    }
+
     pub fn track_turn_resolved_config(&self, fact: TurnResolvedConfigFact) {
         self.record_fact(AnalyticsFact::Custom(
             CustomAnalyticsFact::TurnResolvedConfig(Box::new(fact)),

codex-rs/analytics/src/events.rs

@@ -10,6 +10,8 @@ use crate::facts::TurnStatus;
 use crate::facts::TurnSteerRejectionReason;
 use crate::facts::TurnSteerResult;
 use crate::facts::TurnSubmissionType;
+use crate::responses_api::CodexResponsesApiCallStatus;
+use crate::responses_api::CodexResponsesApiItemMetadata;
 use codex_app_server_protocol::CodexErrorInfo;
 use codex_login::default_client::originator;
 use codex_plugin::PluginTelemetryMetadata;
@@ -45,6 +47,7 @@ pub(crate) enum TrackEventRequest {
     AppUsed(CodexAppUsedEventRequest),
     HookRun(CodexHookRunEventRequest),
     Compaction(Box<CodexCompactionEventRequest>),
+    ResponsesApiCall(Box<CodexResponsesApiCallEventRequest>),
     TurnEvent(Box<CodexTurnEventRequest>),
     TurnSteer(CodexTurnSteerEventRequest),
     PluginUsed(CodexPluginUsedEventRequest),
@@ -350,6 +353,43 @@ pub(crate) struct CodexCompactionEventRequest {
     pub(crate) event_params: CodexCompactionEventParams,
 }
 
+#[derive(Serialize)]
+pub(crate) struct CodexResponsesApiCallEventParams {
+    pub(crate) thread_id: String,
+    pub(crate) turn_id: String,
+    pub(crate) ephemeral: bool,
+    pub(crate) thread_source: Option<String>,
+    pub(crate) initialization_mode: ThreadInitializationMode,
+    pub(crate) subagent_source: Option<String>,
+    pub(crate) parent_thread_id: Option<String>,
+    pub(crate) app_server_client: CodexAppServerClientMetadata,
+    pub(crate) runtime: CodexRuntimeMetadata,
+    pub(crate) responses_id: Option<String>,
+    pub(crate) turn_responses_call_index: u64,
+    pub(crate) model: Option<String>,
+    pub(crate) model_provider: Option<String>,
+    pub(crate) reasoning_effort: Option<String>,
+    pub(crate) status: CodexResponsesApiCallStatus,
+    pub(crate) error: Option<String>,
+    pub(crate) started_at: u64,
+    pub(crate) completed_at: Option<u64>,
+    pub(crate) duration_ms: Option<u64>,
+    pub(crate) input_item_count: usize,
+    pub(crate) output_item_count: usize,
+    pub(crate) input_tokens: Option<i64>,
+    pub(crate) cached_input_tokens: Option<i64>,
+    pub(crate) output_tokens: Option<i64>,
+    pub(crate) reasoning_output_tokens: Option<i64>,
+    pub(crate) total_tokens: Option<i64>,
+    pub(crate) items: Vec<CodexResponsesApiItemMetadata>,
+}
+
+#[derive(Serialize)]
+pub(crate) struct CodexResponsesApiCallEventRequest {
+    pub(crate) event_type: &'static str,
+    pub(crate) event_params: CodexResponsesApiCallEventParams,
+}
+
 #[derive(Serialize)]
 pub(crate) struct CodexTurnEventParams {
     pub(crate) thread_id: String,

codex-rs/analytics/src/facts.rs

@@ -1,6 +1,7 @@
 use crate::events::AppServerRpcTransport;
 use crate::events::CodexRuntimeMetadata;
 use crate::events::GuardianReviewEventParams;
+use crate::responses_api::CodexResponsesApiCallFact;
 use codex_app_server_protocol::ClientRequest;
 use codex_app_server_protocol::ClientResponse;
 use codex_app_server_protocol::InitializeParams;
@@ -295,6 +296,7 @@ pub(crate) enum AnalyticsFact {
 pub(crate) enum CustomAnalyticsFact {
     SubAgentThreadStarted(SubAgentThreadStartedInput),
     Compaction(Box<CodexCompactionEvent>),
+    ResponsesApiCall(Box<CodexResponsesApiCallFact>),
     GuardianReview(Box<GuardianReviewEventParams>),
     TurnResolvedConfig(Box<TurnResolvedConfigFact>),
     TurnTokenUsage(Box<TurnTokenUsageFact>),

codex-rs/analytics/src/lib.rs

@@ -2,6 +2,7 @@ mod client;
 mod events;
 mod facts;
 mod reducer;
+mod responses_api;
 
 use std::time::SystemTime;
 use std::time::UNIX_EPOCH;
@@ -43,6 +44,14 @@ pub use facts::TurnSteerRequestError;
 pub use facts::TurnSteerResult;
 pub use facts::TurnTokenUsageFact;
 pub use facts::build_track_events_context;
+pub use responses_api::CodexResponseItemRole;
+pub use responses_api::CodexResponseItemType;
+pub use responses_api::CodexResponseMessagePhase;
+pub use responses_api::CodexResponsesApiCallFact;
+pub use responses_api::CodexResponsesApiCallStatus;
+pub use responses_api::CodexResponsesApiItemMetadata;
+pub use responses_api::CodexResponsesApiItemPhase;
+pub use responses_api::response_items_metadata;
 
 #[cfg(test)]
 mod analytics_client_tests;

codex-rs/analytics/src/reducer.rs

@@ -6,6 +6,8 @@ use crate::events::CodexCompactionEventRequest;
 use crate::events::CodexHookRunEventRequest;
 use crate::events::CodexPluginEventRequest;
 use crate::events::CodexPluginUsedEventRequest;
+use crate::events::CodexResponsesApiCallEventParams;
+use crate::events::CodexResponsesApiCallEventRequest;
 use crate::events::CodexRuntimeMetadata;
 use crate::events::CodexTurnEventParams;
 use crate::events::CodexTurnEventRequest;
@@ -47,6 +49,7 @@ use crate::facts::TurnSteerRejectionReason;
 use crate::facts::TurnSteerResult;
 use crate::facts::TurnTokenUsageFact;
 use crate::now_unix_seconds;
+use crate::responses_api::CodexResponsesApiCallFact;
 use codex_app_server_protocol::ClientRequest;
 use codex_app_server_protocol::ClientResponse;
 use codex_app_server_protocol::CodexErrorInfo;
@@ -202,6 +205,9 @@ impl AnalyticsReducer {
                 CustomAnalyticsFact::Compaction(input) => {
                     self.ingest_compaction(*input, out);
                 }
+                CustomAnalyticsFact::ResponsesApiCall(input) => {
+                    self.ingest_responses_api_call(*input, out);
+                }
                 CustomAnalyticsFact::GuardianReview(input) => {
                     self.ingest_guardian_review(*input, out);
                 }
@@ -739,6 +745,66 @@ impl AnalyticsReducer {
         )));
     }
 
+    fn ingest_responses_api_call(
+        &mut self,
+        input: CodexResponsesApiCallFact,
+        out: &mut Vec<TrackEventRequest>,
+    ) {
+        let Some(connection_id) = self.thread_connections.get(&input.thread_id) else {
+            tracing::warn!(
+                thread_id = %input.thread_id,
+                turn_id = %input.turn_id,
+                "dropping responses API call analytics event: missing thread connection metadata"
+            );
+            return;
+        };
+        let Some(connection_state) = self.connections.get(connection_id) else {
+            tracing::warn!(
+                thread_id = %input.thread_id,
+                turn_id = %input.turn_id,
+                connection_id,
+                "dropping responses API call analytics event: missing connection metadata"
+            );
+            return;
+        };
+        let Some(thread_metadata) = self.thread_metadata.get(&input.thread_id) else {
+            tracing::warn!(
+                thread_id = %input.thread_id,
+                turn_id = %input.turn_id,
+                "dropping responses API call analytics event: missing thread lifecycle metadata"
+            );
+            return;
+        };
+        let Some(turn_state) = self.turns.get(&input.turn_id) else {
+            tracing::warn!(
+                thread_id = %input.thread_id,
+                turn_id = %input.turn_id,
+                "dropping responses API call analytics event: missing turn metadata"
+            );
+            return;
+        };
+        let Some(resolved_config) = turn_state.resolved_config.as_ref() else {
+            tracing::warn!(
+                thread_id = %input.thread_id,
+                turn_id = %input.turn_id,
+                "dropping responses API call analytics event: missing resolved turn config"
+            );
+            return;
+        };
+        out.push(TrackEventRequest::ResponsesApiCall(Box::new(
+            CodexResponsesApiCallEventRequest {
+                event_type: "codex_responses_api_call_event",
+                event_params: codex_responses_api_call_event_params(
+                    input,
+                    connection_state.app_server_client.clone(),
+                    connection_state.runtime.clone(),
+                    thread_metadata,
+                    resolved_config,
+                ),
+            },
+        )));
+    }
+
     fn ingest_turn_steer_response(
         &mut self,
         connection_id: u64,
@@ -859,6 +925,46 @@ impl AnalyticsReducer {
     }
 }
 
+fn codex_responses_api_call_event_params(
+    input: CodexResponsesApiCallFact,
+    app_server_client: CodexAppServerClientMetadata,
+    runtime: CodexRuntimeMetadata,
+    thread_metadata: &ThreadMetadataState,
+    resolved_config: &TurnResolvedConfigFact,
+) -> CodexResponsesApiCallEventParams {
+    CodexResponsesApiCallEventParams {
+        thread_id: input.thread_id,
+        turn_id: input.turn_id,
+        ephemeral: resolved_config.ephemeral,
+        thread_source: thread_metadata.thread_source.map(str::to_string),
+        initialization_mode: thread_metadata.initialization_mode,
+        subagent_source: thread_metadata.subagent_source.clone(),
+        parent_thread_id: thread_metadata.parent_thread_id.clone(),
+        app_server_client,
+        runtime,
+        responses_id: input.responses_id,
+        turn_responses_call_index: input.turn_responses_call_index,
+        model: Some(resolved_config.model.clone()),
+        model_provider: Some(resolved_config.model_provider.clone()),
+        reasoning_effort: resolved_config
+            .reasoning_effort
+            .map(|effort| effort.to_string()),
+        status: input.status,
+        error: input.error,
+        started_at: input.started_at,
+        completed_at: input.completed_at,
+        duration_ms: input.duration_ms,
+        input_item_count: input.input_item_count,
+        output_item_count: input.output_item_count,
+        input_tokens: input.input_tokens,
+        cached_input_tokens: input.cached_input_tokens,
+        output_tokens: input.output_tokens,
+        reasoning_output_tokens: input.reasoning_output_tokens,
+        total_tokens: input.total_tokens,
+        items: input.items,
+    }
+}
+
 fn codex_turn_event_params(
     app_server_client: CodexAppServerClientMetadata,
     runtime: CodexRuntimeMetadata,

codex-rs/analytics/src/responses_api.rs

@@ -0,0 +1,481 @@
+use codex_protocol::models::ContentItem;
+use codex_protocol::models::FunctionCallOutputBody;
+use codex_protocol::models::FunctionCallOutputContentItem;
+use codex_protocol::models::FunctionCallOutputPayload;
+use codex_protocol::models::MessagePhase;
+use codex_protocol::models::ReasoningItemContent;
+use codex_protocol::models::ReasoningItemReasoningSummary;
+use codex_protocol::models::ResponseItem;
+use serde::Serialize;
+
+#[derive(Clone, Copy, Debug, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+pub enum CodexResponsesApiCallStatus {
+    Completed,
+    Failed,
+    Interrupted,
+}
+
+#[derive(Clone, Copy, Debug, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+pub enum CodexResponsesApiItemPhase {
+    Input,
+    Output,
+}
+
+#[derive(Clone, Copy, Debug, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+pub enum CodexResponseItemType {
+    Message,
+    Reasoning,
+    LocalShellCall,
+    FunctionCall,
+    FunctionCallOutput,
+    CustomToolCall,
+    CustomToolCallOutput,
+    ToolSearchCall,
+    ToolSearchOutput,
+    WebSearchCall,
+    ImageGenerationCall,
+    GhostSnapshot,
+    Compaction,
+    Other,
+}
+
+#[derive(Clone, Copy, Debug, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+pub enum CodexResponseItemRole {
+    User,
+    Assistant,
+    System,
+    Developer,
+    Tool,
+}
+
+#[derive(Clone, Copy, Debug, Serialize, PartialEq, Eq)]
+#[serde(rename_all = "snake_case")]
+pub enum CodexResponseMessagePhase {
+    Commentary,
+    FinalAnswer,
+}
+
+#[derive(Clone, Debug, Serialize, PartialEq, Eq)]
+pub struct CodexResponsesApiItemMetadata {
+    pub item_phase: CodexResponsesApiItemPhase,
+    pub item_index: usize,
+    pub response_item_type: CodexResponseItemType,
+    pub role: Option<CodexResponseItemRole>,
+    pub status: Option<String>,
+    pub message_phase: Option<CodexResponseMessagePhase>,
+    pub call_id: Option<String>,
+    pub tool_name: Option<String>,
+    pub content_bytes: Option<i64>,
+    pub arguments_bytes: Option<i64>,
+    pub output_bytes: Option<i64>,
+    pub encrypted_content_bytes: Option<i64>,
+    pub image_generation_revised_prompt_bytes: Option<i64>,
+    pub image_generation_result_bytes: Option<i64>,
+    pub text_part_count: Option<usize>,
+    pub image_part_count: Option<usize>,
+}
+
+#[derive(Clone, Debug)]
+pub struct CodexResponsesApiCallFact {
+    pub thread_id: String,
+    pub turn_id: String,
+    pub responses_id: Option<String>,
+    pub turn_responses_call_index: u64,
+    pub status: CodexResponsesApiCallStatus,
+    pub error: Option<String>,
+    pub started_at: u64,
+    pub completed_at: Option<u64>,
+    pub duration_ms: Option<u64>,
+    pub input_item_count: usize,
+    pub output_item_count: usize,
+    pub input_tokens: Option<i64>,
+    pub cached_input_tokens: Option<i64>,
+    pub output_tokens: Option<i64>,
+    pub reasoning_output_tokens: Option<i64>,
+    pub total_tokens: Option<i64>,
+    pub items: Vec<CodexResponsesApiItemMetadata>,
+}
+
+pub fn response_items_metadata(
+    phase: CodexResponsesApiItemPhase,
+    items: &[ResponseItem],
+) -> Vec<CodexResponsesApiItemMetadata> {
+    items
+        .iter()
+        .enumerate()
+        .map(|(item_index, item)| response_item_metadata(phase, item_index, item))
+        .collect()
+}
+
+fn response_item_metadata(
+    item_phase: CodexResponsesApiItemPhase,
+    item_index: usize,
+    item: &ResponseItem,
+) -> CodexResponsesApiItemMetadata {
+    let mut metadata =
+        CodexResponsesApiItemMetadata::new(item_phase, item_index, response_item_type(item));
+
+    match item {
+        ResponseItem::Message {
+            role,
+            content,
+            phase,
+            ..
+        } => {
+            metadata.role = response_item_role(role);
+            metadata.message_phase = phase.as_ref().and_then(response_message_phase);
+            metadata.content_bytes = nonzero_i64(message_content_text_bytes(content));
+            let (text_part_count, image_part_count) = message_content_part_counts(content);
+            metadata.text_part_count = Some(text_part_count);
+            metadata.image_part_count = Some(image_part_count);
+        }
+        ResponseItem::Reasoning {
+            summary,
+            content,
+            encrypted_content,
+            ..
+        } => {
+            metadata.content_bytes = nonzero_i64(reasoning_content_bytes(summary, content));
+            metadata.encrypted_content_bytes =
+                encrypted_content.as_ref().map(|value| byte_len(value));
+            metadata.text_part_count =
+                Some(summary.len() + content.as_ref().map(std::vec::Vec::len).unwrap_or_default());
+            metadata.image_part_count = Some(0);
+        }
+        ResponseItem::LocalShellCall {
+            call_id,
+            status,
+            action,
+            ..
+        } => {
+            metadata.call_id = call_id.clone();
+            metadata.tool_name = Some("local_shell".to_string());
+            metadata.status = serialized_string(status);
+            metadata.arguments_bytes = serialized_bytes(action);
+        }
+        ResponseItem::FunctionCall {
+            name,
+            arguments,
+            call_id,
+            ..
+        } => {
+            metadata.call_id = Some(call_id.clone());
+            metadata.tool_name = Some(name.clone());
+            metadata.arguments_bytes = Some(byte_len(arguments));
+        }
+        ResponseItem::ToolSearchCall {
+            call_id,
+            status,
+            arguments,
+            ..
+        } => {
+            metadata.call_id = call_id.clone();
+            metadata.tool_name = Some("tool_search".to_string());
+            metadata.status = status.clone();
+            metadata.arguments_bytes = serialized_bytes(arguments);
+        }
+        ResponseItem::FunctionCallOutput { call_id, output } => {
+            metadata.call_id = Some(call_id.clone());
+            metadata.output_bytes = function_call_output_bytes(output);
+            let (text_part_count, image_part_count) = function_call_output_part_counts(output);
+            metadata.text_part_count = text_part_count;
+            metadata.image_part_count = image_part_count;
+        }
+        ResponseItem::CustomToolCall {
+            status,
+            call_id,
+            name,
+            input,
+            ..
+        } => {
+            metadata.call_id = Some(call_id.clone());
+            metadata.tool_name = Some(name.clone());
+            metadata.status = status.clone();
+            metadata.arguments_bytes = Some(byte_len(input));
+        }
+        ResponseItem::CustomToolCallOutput {
+            call_id,
+            name,
+            output,
+        } => {
+            metadata.call_id = Some(call_id.clone());
+            metadata.tool_name = name.clone();
+            metadata.output_bytes = function_call_output_bytes(output);
+            let (text_part_count, image_part_count) = function_call_output_part_counts(output);
+            metadata.text_part_count = text_part_count;
+            metadata.image_part_count = image_part_count;
+        }
+        ResponseItem::ToolSearchOutput {
+            call_id,
+            status,
+            tools,
+            ..
+        } => {
+            metadata.call_id = call_id.clone();
+            metadata.tool_name = Some("tool_search".to_string());
+            metadata.status = Some(status.clone());
+            metadata.output_bytes = serialized_bytes(tools);
+        }
+        ResponseItem::WebSearchCall { status, action, .. } => {
+            metadata.tool_name = Some("web_search".to_string());
+            metadata.status = status.clone();
+            metadata.arguments_bytes = action.as_ref().and_then(serialized_bytes);
+        }
+        ResponseItem::ImageGenerationCall {
+            id,
+            status,
+            revised_prompt,
+            result,
+        } => {
+            metadata.call_id = Some(id.clone());
+            metadata.tool_name = Some("image_generation".to_string());
+            metadata.status = Some(status.clone());
+            metadata.image_generation_revised_prompt_bytes =
+                revised_prompt.as_ref().map(|value| byte_len(value));
+            metadata.image_generation_result_bytes = Some(byte_len(result));
+        }
+        ResponseItem::Compaction { encrypted_content } => {
+            metadata.encrypted_content_bytes = Some(byte_len(encrypted_content));
+        }
+        ResponseItem::GhostSnapshot { .. } | ResponseItem::Other => {}
+    }
+
+    metadata
+}
+
+impl CodexResponsesApiItemMetadata {
+    fn new(
+        item_phase: CodexResponsesApiItemPhase,
+        item_index: usize,
+        response_item_type: CodexResponseItemType,
+    ) -> Self {
+        Self {
+            item_phase,
+            item_index,
+            response_item_type,
+            role: None,
+            status: None,
+            message_phase: None,
+            call_id: None,
+            tool_name: None,
+            content_bytes: None,
+            arguments_bytes: None,
+            output_bytes: None,
+            encrypted_content_bytes: None,
+            image_generation_revised_prompt_bytes: None,
+            image_generation_result_bytes: None,
+            text_part_count: None,
+            image_part_count: None,
+        }
+    }
+}
+
+fn response_item_type(item: &ResponseItem) -> CodexResponseItemType {
+    match item {
+        ResponseItem::Message { .. } => CodexResponseItemType::Message,
+        ResponseItem::Reasoning { .. } => CodexResponseItemType::Reasoning,
+        ResponseItem::LocalShellCall { .. } => CodexResponseItemType::LocalShellCall,
+        ResponseItem::FunctionCall { .. } => CodexResponseItemType::FunctionCall,
+        ResponseItem::ToolSearchCall { .. } => CodexResponseItemType::ToolSearchCall,
+        ResponseItem::FunctionCallOutput { .. } => CodexResponseItemType::FunctionCallOutput,
+        ResponseItem::CustomToolCall { .. } => CodexResponseItemType::CustomToolCall,
+        ResponseItem::CustomToolCallOutput { .. } => CodexResponseItemType::CustomToolCallOutput,
+        ResponseItem::ToolSearchOutput { .. } => CodexResponseItemType::ToolSearchOutput,
+        ResponseItem::WebSearchCall { .. } => CodexResponseItemType::WebSearchCall,
+        ResponseItem::ImageGenerationCall { .. } => CodexResponseItemType::ImageGenerationCall,
+        ResponseItem::GhostSnapshot { .. } => CodexResponseItemType::GhostSnapshot,
+        ResponseItem::Compaction { .. } => CodexResponseItemType::Compaction,
+        ResponseItem::Other => CodexResponseItemType::Other,
+    }
+}
+
+fn response_item_role(role: &str) -> Option<CodexResponseItemRole> {
+    match role {
+        "user" => Some(CodexResponseItemRole::User),
+        "assistant" => Some(CodexResponseItemRole::Assistant),
+        "system" => Some(CodexResponseItemRole::System),
+        "developer" => Some(CodexResponseItemRole::Developer),
+        "tool" => Some(CodexResponseItemRole::Tool),
+        _ => None,
+    }
+}
+
+fn response_message_phase(phase: &MessagePhase) -> Option<CodexResponseMessagePhase> {
+    match phase {
+        MessagePhase::Commentary => Some(CodexResponseMessagePhase::Commentary),
+        MessagePhase::FinalAnswer => Some(CodexResponseMessagePhase::FinalAnswer),
+    }
+}
+
+fn message_content_text_bytes(content: &[ContentItem]) -> i64 {
+    content
+        .iter()
+        .map(|item| match item {
+            ContentItem::InputText { text } | ContentItem::OutputText { text } => byte_len(text),
+            ContentItem::InputImage { .. } => 0,
+        })
+        .sum()
+}
+
+fn message_content_part_counts(content: &[ContentItem]) -> (usize, usize) {
+    let mut text_part_count = 0;
+    let mut image_part_count = 0;
+    for item in content {
+        match item {
+            ContentItem::InputText { .. } | ContentItem::OutputText { .. } => {
+                text_part_count += 1;
+            }
+            ContentItem::InputImage { .. } => {
+                image_part_count += 1;
+            }
+        }
+    }
+    (text_part_count, image_part_count)
+}
+
+fn reasoning_content_bytes(
+    summary: &[ReasoningItemReasoningSummary],
+    content: &Option<Vec<ReasoningItemContent>>,
+) -> i64 {
+    let summary_bytes = summary
+        .iter()
+        .map(|summary| match summary {
+            ReasoningItemReasoningSummary::SummaryText { text } => byte_len(text),
+        })
+        .sum::<i64>();
+    let content_bytes = content
+        .as_ref()
+        .map(|content| {
+            content
+                .iter()
+                .map(|content| match content {
+                    ReasoningItemContent::ReasoningText { text }
+                    | ReasoningItemContent::Text { text } => byte_len(text),
+                })
+                .sum::<i64>()
+        })
+        .unwrap_or_default();
+    summary_bytes + content_bytes
+}
+
+fn function_call_output_bytes(output: &FunctionCallOutputPayload) -> Option<i64> {
+    match &output.body {
+        FunctionCallOutputBody::Text(text) => Some(byte_len(text)),
+        FunctionCallOutputBody::ContentItems(items) => serialized_bytes(items),
+    }
+}
+
+fn function_call_output_part_counts(
+    output: &FunctionCallOutputPayload,
+) -> (Option<usize>, Option<usize>) {
+    let Some(content_items) = output.content_items() else {
+        return (None, None);
+    };
+    let mut text_part_count = 0;
+    let mut image_part_count = 0;
+    for item in content_items {
+        match item {
+            FunctionCallOutputContentItem::InputText { .. } => {
+                text_part_count += 1;
+            }
+            FunctionCallOutputContentItem::InputImage { .. } => {
+                image_part_count += 1;
+            }
+        }
+    }
+    (Some(text_part_count), Some(image_part_count))
+}
+
+fn serialized_string<T: Serialize>(value: &T) -> Option<String> {
+    match serde_json::to_value(value).ok()? {
+        serde_json::Value::String(value) => Some(value),
+        value => Some(value.to_string()),
+    }
+}
+
+fn serialized_bytes<T: Serialize>(value: &T) -> Option<i64> {
+    serde_json::to_string(value)
+        .ok()
+        .map(|value| byte_len(&value))
+}
+
+fn nonzero_i64(value: i64) -> Option<i64> {
+    (value > 0).then_some(value)
+}
+
+fn byte_len(value: &str) -> i64 {
+    i64::try_from(value.len()).unwrap_or(i64::MAX)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use codex_protocol::models::ImageDetail;
+
+    #[test]
+    fn maps_message_metadata() {
+        let items = vec![ResponseItem::Message {
+            id: None,
+            role: "assistant".to_string(),
+            content: vec![
+                ContentItem::OutputText {
+                    text: "hello".to_string(),
+                },
+                ContentItem::InputImage {
+                    image_url: "data:image/png;base64,abc".to_string(),
+                },
+            ],
+            end_turn: None,
+            phase: Some(MessagePhase::FinalAnswer),
+        }];
+
+        let metadata = response_items_metadata(CodexResponsesApiItemPhase::Output, &items);
+
+        assert_eq!(metadata[0].item_phase, CodexResponsesApiItemPhase::Output);
+        assert_eq!(
+            metadata[0].response_item_type,
+            CodexResponseItemType::Message
+        );
+        assert_eq!(metadata[0].role, Some(CodexResponseItemRole::Assistant));
+        assert_eq!(
+            metadata[0].message_phase,
+            Some(CodexResponseMessagePhase::FinalAnswer)
+        );
+        assert_eq!(metadata[0].content_bytes, Some(5));
+        assert_eq!(metadata[0].text_part_count, Some(1));
+        assert_eq!(metadata[0].image_part_count, Some(1));
+    }
+
+    #[test]
+    fn maps_tool_call_output_metadata() {
+        let items = vec![ResponseItem::CustomToolCallOutput {
+            call_id: "call_1".to_string(),
+            name: Some("custom_tool".to_string()),
+            output: FunctionCallOutputPayload::from_content_items(vec![
+                FunctionCallOutputContentItem::InputText {
+                    text: "result".to_string(),
+                },
+                FunctionCallOutputContentItem::InputImage {
+                    image_url: "https://example.test/image.png".to_string(),
+                    detail: Some(ImageDetail::High),
+                },
+            ]),
+        }];
+
+        let metadata = response_items_metadata(CodexResponsesApiItemPhase::Output, &items);
+
+        assert_eq!(
+            metadata[0].response_item_type,
+            CodexResponseItemType::CustomToolCallOutput
+        );
+        assert_eq!(metadata[0].call_id.as_deref(), Some("call_1"));
+        assert_eq!(metadata[0].tool_name.as_deref(), Some("custom_tool"));
+        assert!(metadata[0].output_bytes.unwrap_or_default() > 0);
+        assert_eq!(metadata[0].text_part_count, Some(1));
+        assert_eq!(metadata[0].image_part_count, Some(1));
+    }
+}