core: bundle settings diff updates into one dev/user envelope (#12417)

## Summary - bundle contextual prompt injection into at most one developer message plus one contextual user message in both: - per-turn settings updates - initial context insertion - preserve `<model_switch>` across compaction by rebuilding it through canonical initial-context injection, instead of relying on strip/reattach hacks - centralize contextual user fragment detection in one shared definition table and reuse it for parsing/compaction logic - keep `AGENTS.md` in its natural serialized format: - `# AGENTS.md instructions for {dirname}` - `<INSTRUCTIONS>...</INSTRUCTIONS>` - simplify related tests/helpers and accept the expected snapshot/layout updates from bundled multi-part messages ## Why The goal is to converge toward a simpler, more intentional prompt shape where contextual updates are consistently represented as one developer envelope plus one contextual user envelope, while keeping parsing and compaction behavior aligned with that representation. ## Notable details - the temporary `SettingsUpdateEnvelope` wrapper was removed; these paths now return `Vec<ResponseItem>` directly - local/remote compaction no longer rely on model-switch strip/restore helpers - contextual user detection is now driven by shared fragment definitions instead of ad hoc matcher assembly - AGENTS/user instructions are still the same logical context; only the synthetic `<user_instructions>` wrapper was replaced by the natural AGENTS text format ## Testing - `just fmt` - `cargo test -p codex-app-server codex_message_processor::tests::extract_conversation_summary_prefers_plain_user_messages -- --exact` - `cargo test -p codex-core compact::tests::collect_user_messages_filters_session_prefix_entries --lib -- --exact` - `cargo test -p codex-core --test all 'suite::compact::snapshot_request_shape_pre_turn_compaction_strips_incoming_model_switch' -- --exact` - `cargo test -p codex-core --test all 'suite::compact_remote::snapshot_request_shape_remote_pre_turn_compaction_strips_incoming_model_switch' -- --exact` - `cargo test -p codex-core --test all 'suite::client::includes_apps_guidance_as_developer_message_when_enabled' -- --exact` - `cargo test -p codex-core --test all 'suite::client::includes_developer_instructions_message_in_request' -- --exact` - `cargo test -p codex-core --test all 'suite::client::includes_user_instructions_message_in_request' -- --exact` - `cargo test -p codex-core --test all 'suite::client::resume_includes_initial_messages_and_sends_prior_items' -- --exact` - `cargo test -p codex-core --test all 'suite::review::review_input_isolated_from_parent_history' -- --exact` - `cargo test -p codex-exec --test all 'suite::resume::exec_resume_last_respects_cwd_filter_and_all_flag' -- --exact` - `cargo test -p core_test_support context_snapshot::tests::full_text_mode_preserves_unredacted_text -- --exact` ## Notes - I also ran several targeted `compact`, `compact_remote`, `prompt_caching`, `model_visible_layout`, and `event_mapping` tests while iterating on prompt-shape changes. - I have not claimed a clean full-workspace `cargo test` from this environment because local sandbox/resource conditions have previously produced unrelated failures in large workspace runs.
2026-04-28 16:45:54 +00:00 · 2026-02-26 00:12:08 -08:00
parent 28bfbb8f2b
commit 07aefffb1f
47 changed files with 966 additions and 813 deletions
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact__manual_compact_with_history_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact__manual_compact_with_history_shapes.snap
@@ -6,16 +6,18 @@ Scenario: Manual /compact with prior user history compacts existing history and

 ## Local Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:first manual turn
-04:message/assistant:FIRST_REPLY
-05:message/user:<SUMMARIZATION_PROMPT>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:first manual turn
+03:message/assistant:FIRST_REPLY
+04:message/user:<SUMMARIZATION_PROMPT>

 ## Local Post-Compaction History Layout
 00:message/user:first manual turn
 01:message/user:<COMPACTION_SUMMARY>\nFIRST_MANUAL_SUMMARY
 02:message/developer:<PERMISSIONS_INSTRUCTIONS>
-03:message/user:<AGENTS_MD>
-04:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-05:message/user:second manual turn
+03:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+04:message/user:second manual turn
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact__manual_compact_without_prev_user_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact__manual_compact_without_prev_user_shapes.snap
@@ -6,13 +6,15 @@ Scenario: Manual /compact with no prior user turn currently still issues a compa

 ## Local Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:<SUMMARIZATION_PROMPT>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:<SUMMARIZATION_PROMPT>

 ## Local Post-Compaction History Layout
 00:message/user:<COMPACTION_SUMMARY>\nMANUAL_EMPTY_SUMMARY
 01:message/developer:<PERMISSIONS_INSTRUCTIONS>
-02:message/user:<AGENTS_MD>
-03:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-04:message/user:AFTER_MANUAL_EMPTY_COMPACT
+02:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+03:message/user:AFTER_MANUAL_EMPTY_COMPACT
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact__mid_turn_compaction_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact__mid_turn_compaction_shapes.snap
@@ -1,22 +1,23 @@
 ---
 source: core/tests/suite/compact.rs
-assertion_line: 2646
 expression: "format_labeled_requests_snapshot(\"True mid-turn continuation compaction after tool output: compact request includes tool artifacts, and the continuation request includes the summary in the same turn.\",\n&[(\"Local Compaction Request\", &auto_compact_mock.single_request()),\n(\"Local Post-Compaction History Layout\",\n&post_auto_compact_mock.single_request()),])"
 ---
 Scenario: True mid-turn continuation compaction after tool output: compact request includes tool artifacts, and the continuation request includes the summary in the same turn.

 ## Local Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:function call limit push
-04:function_call/test_tool
-05:function_call_output:unsupported call: test_tool
-06:message/user:<SUMMARIZATION_PROMPT>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:function call limit push
+03:function_call/test_tool
+04:function_call_output:unsupported call: test_tool
+05:message/user:<SUMMARIZATION_PROMPT>

 ## Local Post-Compaction History Layout
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:function call limit push
-04:message/user:<COMPACTION_SUMMARY>\nAUTO_SUMMARY
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:function call limit push
+03:message/user:<COMPACTION_SUMMARY>\nAUTO_SUMMARY
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_sampling_model_switch_compaction_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_sampling_model_switch_compaction_shapes.snap
@@ -1,30 +1,35 @@
 ---
 source: core/tests/suite/compact.rs
+assertion_line: 1791
 expression: "format_labeled_requests_snapshot(\"Pre-sampling compaction on model switch to a smaller context window: current behavior compacts using prior-turn history only (incoming user message excluded), and the follow-up request carries compacted history plus the new user message.\",\n&[(\"Initial Request (Previous Model)\", &requests[0]),\n(\"Pre-sampling Compaction Request\", &requests[1]),\n(\"Post-Compaction Follow-up Request (Next Model)\", &requests[2]),])"
 ---
 Scenario: Pre-sampling compaction on model switch to a smaller context window: current behavior compacts using prior-turn history only (incoming user message excluded), and the follow-up request carries compacted history plus the new user message.

 ## Initial Request (Previous Model)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:before switch
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
+03:message/user:before switch

 ## Pre-sampling Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:before switch
-05:message/assistant:before switch
-06:message/user:<SUMMARIZATION_PROMPT>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
+03:message/user:before switch
+04:message/assistant:before switch
+05:message/user:<SUMMARIZATION_PROMPT>

 ## Post-Compaction Follow-up Request (Next Model)
 00:message/user:before switch
 01:message/user:<COMPACTION_SUMMARY>\nPRE_SAMPLING_SUMMARY
-02:message/developer:<model_switch>\nThe user was previously using a different model....
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:<AGENTS_MD>
-05:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-06:message/user:after switch
+02:message/developer[2]:
+    [01] <model_switch>\nThe user was previously using a different model....
+    [02] <PERMISSIONS_INSTRUCTIONS>
+03:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+04:message/user:after switch
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_turn_compaction_context_window_exceeded_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_turn_compaction_context_window_exceeded_shapes.snap
@@ -6,8 +6,9 @@ Scenario: Pre-turn auto-compaction context-window failure: compaction request ex

 ## Local Compaction Request (Incoming User Excluded)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
-04:message/assistant:FIRST_REPLY
-05:message/user:<SUMMARIZATION_PROMPT>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
+03:message/assistant:FIRST_REPLY
+04:message/user:<SUMMARIZATION_PROMPT>
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_turn_compaction_including_incoming_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_turn_compaction_including_incoming_shapes.snap
@@ -6,19 +6,25 @@ Scenario: Pre-turn auto-compaction with a context override emits the context dif

 ## Local Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
-04:message/assistant:FIRST_REPLY
-05:message/user:USER_TWO
-06:message/assistant:SECOND_REPLY
-07:message/user:<SUMMARIZATION_PROMPT>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
+03:message/assistant:FIRST_REPLY
+04:message/user:USER_TWO
+05:message/assistant:SECOND_REPLY
+06:message/user:<SUMMARIZATION_PROMPT>

 ## Local Post-Compaction History Layout
 00:message/user:USER_ONE
 01:message/user:USER_TWO
 02:message/user:<COMPACTION_SUMMARY>\nPRE_TURN_SUMMARY
 03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:<AGENTS_MD>
-05:message/user:<ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
-06:message/user:<image> | <input_image:image_url> | </image> | USER_THREE
+04:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
+05:message/user[4]:
+    [01] <image>
+    [02] <input_image:image_url>
+    [03] </image>
+    [04] USER_THREE
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_turn_compaction_strips_incoming_model_switch_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact__pre_turn_compaction_strips_incoming_model_switch_shapes.snap
@@ -1,31 +1,36 @@
 ---
 source: core/tests/suite/compact.rs
+assertion_line: 3188
 expression: "format_labeled_requests_snapshot(\"Pre-turn compaction during model switch (without pre-sampling model-switch compaction): current behavior strips incoming <model_switch> from the compact request and restores it in the post-compaction follow-up request.\",\n&[(\"Initial Request (Previous Model)\", &requests[0]),\n(\"Local Compaction Request\", &requests[1]),\n(\"Local Post-Compaction History Layout\", &requests[2]),])"
 ---
 Scenario: Pre-turn compaction during model switch (without pre-sampling model-switch compaction): current behavior strips incoming <model_switch> from the compact request and restores it in the post-compaction follow-up request.

 ## Initial Request (Previous Model)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:BEFORE_SWITCH_USER
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
+03:message/user:BEFORE_SWITCH_USER

 ## Local Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:BEFORE_SWITCH_USER
-05:message/assistant:BEFORE_SWITCH_REPLY
-06:message/user:<SUMMARIZATION_PROMPT>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
+03:message/user:BEFORE_SWITCH_USER
+04:message/assistant:BEFORE_SWITCH_REPLY
+05:message/user:<SUMMARIZATION_PROMPT>

 ## Local Post-Compaction History Layout
 00:message/user:BEFORE_SWITCH_USER
 01:message/user:<COMPACTION_SUMMARY>\nPRETURN_SWITCH_SUMMARY
-02:message/developer:<model_switch>\nThe user was previously using a different model....
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/developer:<personality_spec> The user has requested a new communication st...
-05:message/user:<AGENTS_MD>
-06:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-07:message/user:AFTER_SWITCH_USER
+02:message/developer[3]:
+    [01] <model_switch>\nThe user was previously using a different model....
+    [02] <PERMISSIONS_INSTRUCTIONS>
+    [03] <personality_spec> The user has requested a new communication st...
+03:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+04:message/user:AFTER_SWITCH_USER
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_manual_compact_with_history_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_manual_compact_with_history_shapes.snap
@@ -6,14 +6,16 @@ Scenario: Remote manual /compact where remote compact output is compaction-only:

 ## Remote Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:hello remote compact
-04:message/assistant:FIRST_REMOTE_REPLY
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:hello remote compact
+03:message/assistant:FIRST_REMOTE_REPLY

 ## Remote Post-Compaction History Layout
 00:compaction:encrypted=true
 01:message/developer:<PERMISSIONS_INSTRUCTIONS>
-02:message/user:<AGENTS_MD>
-03:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-04:message/user:after compact
+02:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+03:message/user:after compact
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_manual_compact_without_prev_user_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_manual_compact_without_prev_user_shapes.snap
@@ -6,11 +6,13 @@ Scenario: Remote manual /compact with no prior user turn still issues a compact

 ## Remote Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>

 ## Remote Post-Compaction History Layout
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_mid_turn_compaction_multi_summary_reinjects_above_last_summary_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_mid_turn_compaction_multi_summary_reinjects_above_last_summary_shapes.snap
@@ -1,6 +1,5 @@
 ---
 source: core/tests/suite/compact_remote.rs
-assertion_line: 1876
 expression: "format_labeled_requests_snapshot(\"After a prior manual /compact produced an older remote compaction item, the next turn hits remote auto-compaction before the next sampling request. The compact request carries forward that earlier compaction item, and the next sampling request shows the latest compaction item with context reinjected before USER_TWO.\",\n&[(\"Remote Compaction Request\", &compact_request),\n(\"Second Turn Request (After Compaction)\", &second_turn_request),])"
 ---
 Scenario: After a prior manual /compact produced an older remote compaction item, the next turn hits remote auto-compaction before the next sampling request. The compact request carries forward that earlier compaction item, and the next sampling request shows the latest compaction item with context reinjected before USER_TWO.
@@ -13,6 +12,7 @@ Scenario: After a prior manual /compact produced an older remote compaction item
 00:message/user:USER_ONE
 01:compaction:encrypted=true
 02:message/developer:<PERMISSIONS_INSTRUCTIONS>
-03:message/user:<AGENTS_MD>
-04:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-05:message/user:USER_TWO
+03:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+04:message/user:USER_TWO
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_mid_turn_compaction_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_mid_turn_compaction_shapes.snap
@@ -6,15 +6,17 @@ Scenario: Remote mid-turn continuation compaction after tool output: compact req

 ## Remote Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
-04:function_call/test_tool
-05:function_call_output:unsupported call: test_tool
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
+03:function_call/test_tool
+04:function_call_output:unsupported call: test_tool

 ## Remote Post-Compaction History Layout
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
-04:compaction:encrypted=true
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
+03:compaction:encrypted=true
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_mid_turn_compaction_summary_only_reinjects_context_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_mid_turn_compaction_summary_only_reinjects_context_shapes.snap
@@ -1,19 +1,21 @@
 ---
 source: core/tests/suite/compact_remote.rs
-expression: "format_labeled_requests_snapshot(\"Remote mid-turn compaction where compact output has only a compaction item: continuation layout reinjects context before that compaction item.\",\n&[(\"Remote Compaction Request\", &compact_request),\n(\"Remote Post-Compaction History Layout\", &requests[1]),])"
+expression: "format_labeled_requests_snapshot(\"Remote mid-turn compaction where compact output has only a compaction item: continuation layout reinjects context before that compaction item.\",\n&[(\"Remote Compaction Request\", &compact_request),\n(\"Remote Post-Compaction History Layout\", &post_compact_turn_request),])"
 ---
 Scenario: Remote mid-turn compaction where compact output has only a compaction item: continuation layout reinjects context before that compaction item.

 ## Remote Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
-04:function_call/test_tool
-05:function_call_output:unsupported call: test_tool
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
+03:function_call/test_tool
+04:function_call_output:unsupported call: test_tool

 ## Remote Post-Compaction History Layout
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:compaction:encrypted=true
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:compaction:encrypted=true
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_context_window_exceeded_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_context_window_exceeded_shapes.snap
@@ -6,7 +6,8 @@ Scenario: Remote pre-turn auto-compaction context-window failure: compaction req

 ## Remote Compaction Request (Incoming User Excluded)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
-04:message/assistant:REMOTE_FIRST_REPLY
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
+03:message/assistant:REMOTE_FIRST_REPLY
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_failure_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_failure_shapes.snap
@@ -6,7 +6,8 @@ Scenario: Remote pre-turn auto-compaction parse failure: compaction request excl

 ## Remote Compaction Request (Incoming User Excluded)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:turn that exceeds token threshold
-04:message/assistant:initial turn complete
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:turn that exceeds token threshold
+03:message/assistant:initial turn complete
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_including_incoming_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_including_incoming_shapes.snap
@@ -6,18 +6,20 @@ Scenario: Remote pre-turn auto-compaction with a context override emits the cont

 ## Remote Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:USER_ONE
-04:message/assistant:REMOTE_FIRST_REPLY
-05:message/user:USER_TWO
-06:message/assistant:REMOTE_SECOND_REPLY
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:USER_ONE
+03:message/assistant:REMOTE_FIRST_REPLY
+04:message/user:USER_TWO
+05:message/assistant:REMOTE_SECOND_REPLY

 ## Remote Post-Compaction History Layout
 00:message/user:USER_ONE
 01:message/user:USER_TWO
 02:compaction:encrypted=true
 03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:<AGENTS_MD>
-05:message/user:<ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
-06:message/user:USER_THREE
+04:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
+05:message/user:USER_THREE
--- a/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_strips_incoming_model_switch_shapes.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitecompact_remote__remote_pre_turn_compaction_strips_incoming_model_switch_shapes.snap
@@ -1,28 +1,33 @@
 ---
 source: core/tests/suite/compact_remote.rs
+assertion_line: 1514
 expression: "format_labeled_requests_snapshot(\"Remote pre-turn compaction during model switch currently excludes incoming user input, strips incoming <model_switch> from the compact request payload, and restores it in the post-compaction follow-up request.\",\n&[(\"Initial Request (Previous Model)\", &initial_turn_request),\n(\"Remote Compaction Request\", &compact_request),\n(\"Remote Post-Compaction History Layout\", &post_compact_turn_request),])"
 ---
 Scenario: Remote pre-turn compaction during model switch currently excludes incoming user input, strips incoming <model_switch> from the compact request payload, and restores it in the post-compaction follow-up request.

 ## Initial Request (Previous Model)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:BEFORE_SWITCH_USER
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:BEFORE_SWITCH_USER

 ## Remote Compaction Request
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:BEFORE_SWITCH_USER
-04:message/assistant:BEFORE_SWITCH_REPLY
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:BEFORE_SWITCH_USER
+03:message/assistant:BEFORE_SWITCH_REPLY

 ## Remote Post-Compaction History Layout
 00:message/user:BEFORE_SWITCH_USER
 01:compaction:encrypted=true
-02:message/developer:<model_switch>\nThe user was previously using a different model....
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/developer:<personality_spec> The user has requested a new communication st...
-05:message/user:<AGENTS_MD>
-06:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-07:message/user:AFTER_SWITCH_USER
+02:message/developer[3]:
+    [01] <model_switch>\nThe user was previously using a different model....
+    [02] <PERMISSIONS_INSTRUCTIONS>
+    [03] <personality_spec> The user has requested a new communication st...
+03:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+04:message/user:AFTER_SWITCH_USER
--- a/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_cwd_change_does_not_refresh_agents.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_cwd_change_does_not_refresh_agents.snap
@@ -6,19 +6,21 @@ Scenario: Second turn changes cwd to a directory with different AGENTS.md; curre

 ## First Request (agents_one)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
 03:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-04:message/developer:<PERMISSIONS_INSTRUCTIONS>
-05:message/user:first turn in agents_one
+04:message/user:first turn in agents_one

 ## Second Request (agents_two cwd)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
 03:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-04:message/developer:<PERMISSIONS_INSTRUCTIONS>
-05:message/user:first turn in agents_one
-06:message/assistant:turn one complete
-07:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-08:message/user:second turn in agents_two
+04:message/user:first turn in agents_one
+05:message/assistant:turn one complete
+06:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
+07:message/user:second turn in agents_two
--- a/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_resume_override_matches_rollout_model.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_resume_override_matches_rollout_model.snap
@@ -1,21 +1,22 @@
 ---
 source: core/tests/suite/model_visible_layout.rs
-assertion_line: 435
 expression: "format_labeled_requests_snapshot(\"First post-resume turn where pre-turn override sets model to rollout model; no model-switch update should appear.\",\n&[(\"Last Request Before Resume\", &initial_request),\n(\"First Request After Resume + Override\", &resumed_request),])"
 ---
 Scenario: First post-resume turn where pre-turn override sets model to rollout model; no model-switch update should appear.

 ## Last Request Before Resume
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:seed resume history
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:seed resume history

 ## First Request After Resume + Override
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:seed resume history
-04:message/assistant:recorded before resume
-05:message/user:<ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
-06:message/user:first resumed turn after model override
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:seed resume history
+03:message/assistant:recorded before resume
+04:message/user:<ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
+05:message/user:first resumed turn after model override
--- a/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_resume_with_personality_change.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_resume_with_personality_change.snap
@@ -1,23 +1,25 @@
 ---
 source: core/tests/suite/model_visible_layout.rs
-assertion_line: 337
 expression: "format_labeled_requests_snapshot(\"First post-resume turn where resumed config model differs from rollout and personality changes.\",\n&[(\"Last Request Before Resume\", &initial_request),\n(\"First Request After Resume\", &resumed_request),])"
 ---
 Scenario: First post-resume turn where resumed config model differs from rollout and personality changes.

 ## Last Request Before Resume
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:seed resume history
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:seed resume history

 ## First Request After Resume
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/user:seed resume history
-04:message/assistant:recorded before resume
-05:message/developer:<model_switch>\nThe user was previously using a different model. Please continue the conversatio...
-06:message/user:<ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
-07:message/developer:<PERMISSIONS_INSTRUCTIONS>
-08:message/user:resume and change personality
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/user:seed resume history
+03:message/assistant:recorded before resume
+04:message/developer[2]:
+    [01] <model_switch>\nThe user was previously using a different model. Please continue the conversatio...
+    [02] <PERMISSIONS_INSTRUCTIONS>
+05:message/user:<ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
+06:message/user:resume and change personality
--- a/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_turn_overrides.snap
+++ b/codex-rs/core/tests/suite/snapshots/allsuitemodel_visible_layout__model_visible_layout_turn_overrides.snap
@@ -6,19 +6,22 @@ Scenario: Second turn changes cwd, approval policy, and personality while keepin

 ## First Request (Baseline)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:first turn
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
+03:message/user:first turn

 ## Second Request (Turn Overrides)
 00:message/developer:<PERMISSIONS_INSTRUCTIONS>
-01:message/user:<AGENTS_MD>
-02:message/user:<ENVIRONMENT_CONTEXT:cwd=<CWD>>
-03:message/developer:<PERMISSIONS_INSTRUCTIONS>
-04:message/user:first turn
-05:message/assistant:turn one complete
+01:message/user[2]:
+    [01] <AGENTS_MD>
+    [02] <ENVIRONMENT_CONTEXT:cwd=<CWD>>
+02:message/developer:<PERMISSIONS_INSTRUCTIONS>
+03:message/user:first turn
+04:message/assistant:turn one complete
+05:message/developer[2]:
+    [01] <PERMISSIONS_INSTRUCTIONS>
+    [02] <personality_spec> The user has requested a new communication style. Future messages should adhe...
 06:message/user:<ENVIRONMENT_CONTEXT:cwd=PRETURN_CONTEXT_DIFF_CWD>
-07:message/developer:<PERMISSIONS_INSTRUCTIONS>
-08:message/developer:<personality_spec> The user has requested a new communication style. Future messages should adhe...
-09:message/user:second turn with context updates
+07:message/user:second turn with context updates