## Why
Code-mode responses show host duration without exposing time spent outside the host, including app-server waiting.
## What changed
- Add `features.code_mode.experimental_show_cell_overhead`, disabled by default, to show handler duration, host duration, and their difference in `exec` and `wait` response headers.
- Reuse the completed handler measurement from tool-call logging, excluding dispatch waiting, and capture it even when logging is disabled.
- Preserve the existing timing format when the option is disabled or host timing is unavailable, and preserve boolean feature toggles when merging nested code-mode configuration.
## Testing
Add coverage for timing headers, zero and missing host measurements, negative rounding differences, content preservation, and configuration merging. Extend app-server tests across gRPC and stdio to verify timing includes post-host elicitation waiting, and add a response snapshot for successful execution and a failed wait.
GitOrigin-RevId: 929b84784d9c6077cf2b5927a90bd2d5f3870078
## Why
Asynchronous score publication updated the risk score, authorization, and tool-call coverage separately. Approval checks could therefore read inconsistent evidence when deciding whether to reuse a cached score.
## What changed
Keep Guardian's cached score and observation state under one lock, and use consistent snapshots for approval checks. Publish successful scores together with their authorization and classified tool-call index. Preserve timestamp ordering, fail-closed precedence on timestamp ties, and per-call oversized-action tracking.
## Testing
Add regression coverage for rejected delayed results and timestamp ties. Add a gated integration test showing that a delayed score becomes stale after intervening tool calls, while a sufficiently fresh score permits cached approval.
GitOrigin-RevId: 8df6fafd5e0ee59aa0f78f541eac562efce3d4d0
## Why
Read-only MCP discovery and invocation need a consistent policy across requests, connection reuse, and tool catalogs. Reusing an unrestricted connection or cached catalog can bypass filtered discovery.
## What changed
- Thread `requires_read_only_mcp_tools` through MCP configuration and client setup, leaving it disabled by default.
- When enabled, set `openai/readOnly` to `true` in `tools/list` and `tools/call` request metadata, overriding a caller-supplied `false` while preserving other metadata, pagination, and arguments.
- Include the policy in connection identity and bypass shared Apps and persistent tool catalog caches for read-only connections.
## Testing
Add coverage for metadata propagation in legacy and modern protocol modes, preservation through session recovery, and isolation from unrestricted connections and shared Apps catalogs.
GitOrigin-RevId: f4a3a4021a54e302bffd53f08092b080c056246b
## What changed
- Replace dedicated Guardian endpoints with `/responses`, sending `x-codex-guardian: reviewer` or `x-codex-guardian: classifier` for eligible Codex backend requests over HTTP and WebSocket.
- Add model-scoped thread headers, recheck backend authentication on each request attempt, and reconnect WebSockets when the applicable headers change.
- Retain `features.guardianv2.free_guardian` for configuration compatibility while removing its routing gate; the backend now controls Guardian billing.
## Testing
Update tests for reviewer and classifier headers, model and authentication scoping, HTTP fallback, WebSocket reuse, and parent-response metadata across retries.
GitOrigin-RevId: 1c2b3c458ab77fb40aae4ee6784f6d827c60e76c
## What changed
- Record `auth_or_link` for Codex app calls with trusted connector authentication failure metadata, capturing it before result callbacks or model-facing rewrites. Propagate the classification to MCP tool-call and app-usage analytics.
- Record `approval` when a dispatched approval request is denied, times out, or aborts, covering both MCP elicitation and legacy user-input approvals.
## Testing
Add unit and turn-level coverage for authentication failures, metadata removal by callbacks, successful and rejected approvals, and closed approval response channels. Verify event counts, classification, and exclusion of sensitive test values and authentication URLs from analytics payloads.
GitOrigin-RevId: 493df2a2923f346a0f644f1f26ab8b6b9b8888e0
## What changed
- Use cancellation guards to tie reusable reviewers and temporary forks to their lifetimes, including when a review future is dropped. Replace cancelled reusable reviewers before reuse.
- Share `ReviewerTasks` between the pool and `ThreadManager`, and wait for tracked cleanup during pool shutdown. Remove the separate session shutdown protocol.
- Move denial cleanup from core task handling into Guardian's turn start, stop, and abort hooks. Expose `install_reviewer` to register both thread and turn lifecycle contributors together.
## Testing
Add an integration test that exercises stale denial cleanup at turn start, completion, and interruption, including starting another turn after interruption.
GitOrigin-RevId: 85badb235309c1e1576547d1746f7ee9fc66d545
## What changed
Replace `AttachmentStore::persist` with `upload` and `resolve`. Uploads return inline bytes or a file ID; resolution returns optional file metadata and a download URL only when a minimum URL lifetime is requested. Add image dimensions, digest, size, MIME type, and categorized errors to the API.
Make `InlineAttachmentStore` return the original bytes and report `NotFound` when resolving file IDs. Redact attachment bytes and file URLs in debug output.
Pass the configured image store from the thread manager into sessions and inherit it in delegated sessions. Allow `TestCodexBuilder` to accept a custom image store.
## Testing
Update unit coverage for preserving PNG and JPEG bytes, redacting bytes and URLs in debug output, and rejecting file resolution in the inline store.
GitOrigin-RevId: f313e0048925998d84394c7e5a278e0d39d86a45
## Why
Inline delegates have no entry in the thread registry, so reviewer creation cannot depend on looking up the parent or waiting for its thread-ready notification.
## What changed
- Capture parent identity, authentication, shared agent control, originator, and inherited instructions in `StartThreadOptions` so `ThreadManager` can start a child without a registered parent.
- Route Guardian reviewer creation through this path, remove the standalone fallback and readiness gate, and require a Guardian extension host.
- Install explicit reviewer hosts in unit tests and the Guardian reviewer extension in the integration test harness, using `ExtensionRegistry::to_builder()` to preserve existing contributors.
## Testing
Extend the thread-manager regression test to remove the parent from the registry before starting a child, then verify inherited lineage, originator, session identity, and authentication, and exclusion from the public thread list.
GitOrigin-RevId: 468ded6fdce7520cb39d55c1a884dcfa5aaea2d9
## Why
Persisting user input received during an active turn currently blocks the next model request. Stores that support background persistence can overlap this checkpoint with inference.
## What changed
- Add `PersistContext::SteeredUserInput` and `allows_background_persistence()` so stores may enqueue these checkpoints, with durability and error reporting enforced by later flush or shutdown operations.
- Use the new context for accepted steered user input and apply the same metadata handling as turn-start persistence.
- Keep tool outputs synchronous, including in mixed input batches, and allow stores to retain synchronous persistence for all contexts.
## Testing
Add gated-store integration tests covering background user-input persistence, synchronous stores, and synchronous tool-output checkpoints. Verify that the next request includes the steered input and waits for persistence when required.
GitOrigin-RevId: c60b7b6c9b483245fd3169306bcf0de248ccdf35
## Why
Running code-mode cells can request Guardian review while the next response is in flight. Clearing the response ID before that response emits `response.created` leaves those reviews without a `parent_response_id`.
## What changed
Keep the latest response ID received in the turn until a later `response.created` replaces it, including across sampling retries.
## Testing
Add regression coverage for reviews before and after a response handoff and for a fresh turn that must not inherit the previous turn's ID. Update retry coverage to expect the last known parent when the retry supplies no response ID.
GitOrigin-RevId: af0a08de09edad59e1a7ade7904a42d616b05679
## What changed
- Use the same text rendering for model instructions in request settings and Responses Lite developer content.
- Make `rewrite_known_segments` emit plain tags for recognized guidance, including collaboration and multi-agent instructions. Check message roles and complete tag boundaries so lookalike user or tool content stays visible, and retain generated compaction summaries.
- Normalize working-directory, workspace-root, and temporary paths in permission guidance while preserving policy differences.
- Separate text clipping from normalization and retain eight lines at each end of long sections, with fingerprints for omitted content. Update affected snapshots.
## Testing
Add regression coverage for instruction rendering across transports, literal and rewritten guidance, malformed and lookalike tags, compaction summary preservation, and permission path normalization that keeps policy changes detectable.
GitOrigin-RevId: 33b052911323c73b0387d650478f9cc3370fd001
## What changed
- Add a multi-turn scenario covering `request_user_input_async`, continued work while awaiting an answer, and delivery of the answer into the active turn.
- Add a scenario covering plugin configuration reload in an existing thread, including discovery and use of newly installed skills and MCP tools across turns.
- Render explicit tool output names and namespaces in context snapshots, with a regression test ensuring outputs do not inherit metadata from their calls.
GitOrigin-RevId: 64fca8cb51a3a697fa84bf444ce55b8408961ab5
## What changed
- Use one renderer for captured requests, raw request bodies, and input items. Show only appended items when inputs extend the previous request and settings match; start a new snapshot window otherwise and explain the boundary.
- Add optional request settings and tool inventory deltas. Normalize volatile values with stable labels, preserve multiline content, and fingerprint omitted content so changes remain visible.
- Migrate existing context snapshots and expand compaction snapshots to include request history.
## Testing
Add focused tests for window boundaries, cache key changes, tool deltas, shared item rendering, stable normalization, and fingerprints. Assert that the follow-up request after pre-turn compaction includes the working directory override.
GitOrigin-RevId: 6445b014081208ea432b1f3e2ac835c5e4955cb0
## What changed
- Expose `ThreadInstructionsProvider` through `StartThreadOptions`. Load its snapshot at startup and model-request boundaries, composing it after global instructions and before repository instructions. Empty or blank output clears only the thread contribution.
- Reject thread instructions exceeding 10,000 estimated tokens independently of the repository instruction budget. Allow host-provided instructions without a filesystem source and rename the shared future type to `LoadInstructionsFuture`.
- Retain the provider across warm resumes; require hosts to supply it again for cold resumes and offline forks. Live forks and subagents inherit applied snapshots without inheriting the source thread's provider, including when the parent is unloaded during setup or reload.
- Include thread instructions in guardian reviewer inheritance and reuse decisions.
## Testing
Add coverage for composition and clearing, refresh within an active turn, size rejection before sampling, cancellation-safe refresh, fork and resume behavior, parent eviction, and reviewer reuse invalidation.
GitOrigin-RevId: 7be9a523cbbfd67704067dfd526188dad89a3c88
## Why
An enabled shared analytics client could override a thread's explicit opt-out.
Delegated threads also emitted initialization events through the parent's client,
bypassing the child's analytics setting.
## What changed
- Use a disabled analytics client when `config.analytics_enabled` is `Some(false)`,
without disabling analytics for sibling threads or overriding a disabled host client.
- Emit delegated thread initialization events through the child's analytics client.
- Expose the effective analytics state through `CodexThread::analytics_enabled()`.
## Testing
Add regression tests for explicit and unset thread settings with enabled, disabled,
and absent shared clients, plus delegated child opt-outs with an enabled parent.
Update compaction and rollout-budget rollback tests to wait for thread idle after
turn completion and fail immediately on rollback errors.
GitOrigin-RevId: 547852909af1a6822b95c0bcd2336b0d6bc7aad1
## Why
Remote compaction already uses the normal Responses API, leaving the legacy `/responses/compact` runner unused.
## What changed
- Remove the legacy runner, endpoint client, request types, analytics variant, and obsolete test helpers and snapshots.
- Move tool-output trimming and its metadata tests into `compact_remote_history` for reuse by remote compaction v2.
- Consolidate retained-history filtering in the v2 implementation and remove redundant `RemoteCompactionV2` settings from tests.
## Testing
Extend the retained-history unit test to explicitly check that hook prompts survive compaction.
GitOrigin-RevId: 999bb1391aa22c3c281d6a96f98817d6c9e46ed9
## Why
Saved model selections can outlive their bundled catalog entries and still need migration guidance.
## What changed
- Remove `gpt-5.2` and `gpt-5.4-mini` from the bundled model catalog.
- Preserve migration from saved `gpt-5.4-mini` selections to `gpt-5.6-luna` when the old model is absent, while respecting catalog-provided migration metadata.
- Update tests and snapshots to use current models or explicit test fixtures, and remove the obsolete prompt fixture.
## Testing
Extend migration tests to cover catalog metadata precedence, saved selections, replacement model and reasoning-effort persistence, acknowledged prompts, and missing or hidden migration targets.
GitOrigin-RevId: 82beea504cc4a15699677c28a61ec0939af3069c
## What changed
Pass `StartThreadOptions` through rollout, loaded-history, and prepared forks instead of separate configuration and startup arguments. Replace `options.initial_history` with the fork snapshot while preserving the other supplied startup options, and update app-server and test callers.
Box the app-server's `thread_fork_inner` future to keep the large fork future out of the shared request dispatcher's stack frame.
GitOrigin-RevId: d54eb8b212dedabaf2c5d99d155637cefd7deb7a
## Why
When no healthy pooled WebSocket is available, classification waits for a new connection to open and can stall on its handshake.
## What changed
- Use HTTP streaming when no healthy idle WebSocket is ready, and replenish the pool in the background with a five-minute cooldown after connection timeouts.
- Share concurrency limits and the sampling retry budget across both transports, and bound the wait for HTTP response headers.
- Cancel superseded requests while awaiting response headers and stop SSE polling when the consumer closes.
## Testing
Add coverage for HTTP fallback and recovery after cooldown, shared transport capacity, stalled response headers, and cancellation before headers or during body draining. Update sampler and extension tests to cover fallback after socket expiry, authentication changes, and transient failures.
GitOrigin-RevId: 0b23ccc1bfb2dfdbc8d2791d097706cd4dd44f39
## Why
Clients need a per-thread Daybreak toggle that survives restarts and can be
restored on resume without changing the access program of an active or future
turn.
## What changed
- Add experimental `daybreakEnabled` support to `thread/metadata/update` and
expose the saved value on thread responses.
- Store the preference in SQLite, including for threads without a first turn,
and preserve it through reads, resumes, reconciliation, and restarts.
- Copy the preference when forking a thread while keeping subsequent updates
independent.
- Keep `daybreakEnabled` separate from the per-turn `cyberAccessProgram` field;
app-server does not derive one from the other.
## Testing
- Cover persistence across restarts, cold reads, reconciliation, and forks.
- Verify metadata updates do not alter the access program of active or later
turns.
GitOrigin-RevId: bcf987a9fcd7b0ac8a88b1c8f0df06b33ed8ad6e
## What changed
- Add the `codex-attachment-store` crate with storage-neutral attachment metadata, references, errors, and an asynchronous persistence interface.
- Provide an inline implementation that preserves attachment bytes as media-typed base64 data URLs.
- Inject the store into `ThreadManager`, expose it to consumers, and retain inline storage as the default for existing entry points.
## Testing
- Verify inline storage round-trips binary, text, PNG, and JPEG data.
- Verify attachment debug output redacts URLs while retaining file IDs.
GitOrigin-RevId: 7688dcd3c89d7540ed2398f3e7c63881fbfcda97
## Why
Test fixture setup can take more than five seconds on loaded CI workers, and
failures returned from setup can be obscured when downstream mocks verify their
expectations during teardown.
## What changed
- Add a shared `expect_startup` helper with a 30-second timeout that panics on
either timeout or setup failure before mock teardown runs.
- Use the helper for remote-environment and unified-exec fixture setup, and
allow the same startup window for the initial exec-server requests.
## Testing
Add paused-time tests covering successful startup after five seconds, timeout
reporting, and propagation of setup errors in the presence of unmet mocks.
GitOrigin-RevId: 39db69bde2983acd023a1911a6fad106674e169a
## Why
Guardian tests could continue after a WebSocket handshake but before the
connection entered the idle pool. The shared request waiter could also miss a
notification delivered between checking the request log and registering its
wait.
## What changed
- Wait for Guardian prewarming to populate the idle connection pool instead of
treating completed handshakes as sufficient.
- Use two initial Guardian connections in tests while retaining eight in
non-test builds.
- Register for request-log notifications before inspecting the log to avoid a
lost wakeup.
GitOrigin-RevId: 88f6a22c5401e03c24e6e114f2563fc641bfef80
## What changed
- Allow `start_or_steer_turn` to accept named `function_call_output` items without a `call_id`, starting a turn when idle or steering the active turn.
- Preserve standalone outputs as pending input, assign response item IDs, and record them in conversation history without treating them as user prompts.
## Testing
- Cover starting a turn with a standalone output and steering an active turn with one.
- Verify passive response items do not signal pending steering activity.
GitOrigin-RevId: e32b292106b3c5a5f03577b8ebf67d2d7dee4e5d
## What changed
- Add the opt-in `features.guardianv2.free_guardian` setting to route eligible
Guardian reviews to `/guardian` and asynchronous classifications to
`/guardian-classifier`.
- Support endpoint selection for both HTTP and WebSocket Responses clients,
including endpoint-aware connection reuse.
- Keep `/responses` for API-key authentication, custom provider URLs,
non-Guardian models, and configurations where the option is disabled.
- Omit routing hints and `service_tier` from requests sent to the dedicated
Guardian endpoints.
## Testing
- Cover route selection across authentication modes, provider URLs, HTTP
fallback, WebSocket review sessions, and classifier sampling.
GitOrigin-RevId: 9c88673c710d009e0239559b9245a4e6c4f4befc
## What changed
- Add a `TestCodexBuilder` entry point that accepts an explicit `TestEnv`.
- Teach the exec-server test fixture to dispatch filesystem-helper invocations.
- Allow the fixture to receive the Linux sandbox executable through
`CODEX_TEST_LINUX_SANDBOX_EXE` and run the server on a multithreaded Tokio
runtime.
GitOrigin-RevId: cb9c27e9db0363d4022a084bc186ccc749e25a95
## What changed
Mark `content_item_kinds` as stable and enable it by default. Remove the
test harness override that previously enabled the feature explicitly.
GitOrigin-RevId: 86b0c3f295c4de3b8900981bfdd8830f275073f5
## What changed
- Add the under-development `content_item_kinds` feature, disabled by default.
- Strip content item classifications from Responses input when the feature is
disabled while preserving other passthrough metadata.
## Testing
- Add coverage that disables the feature and verifies requests omit content item
kinds without removing the turn ID.
GitOrigin-RevId: f938feb2895d766d979b1666fc7b97fd128fe8a7
## What changed
- Preserve each contextual fragment's `ContentItemKind` when converting it to a response message.
- Classify user text, image, and audio content as `user.text`, `user.image`, and `user.audio` in their original order.
- Give additional context key-specific `additional_content.<key>` kinds and retain annotations on generated messages such as image resize notices and interrupted-turn markers.
## Testing
- Expand request-level coverage to verify content-kind annotations across mixed-modality turns, additional context, reminders, budgets, skills, model switching, subagents, and image resizing.
GitOrigin-RevId: 671e4545f39b335525c60d2a5df4608e8068cafc
## What changed
Reuse the shared `build_zsh_fork_test` helper in the unified exec approval
suite and remove its identical suite-specific wrapper.
GitOrigin-RevId: 0593f0e1a56737eba1d491872a44d14e9171dbfb
## What changed
- Use `exec_command` and `write_stdin` as the shell tool surface.
- Treat legacy `default`, `local`, and `shell_command` model metadata as `unified_exec`.
- Remove obsolete shell-selection configuration and runtime paths while preserving the feature and policy gates for zsh fork execution.
GitOrigin-RevId: d743cbe598630d73052f1fecad680c4cde17977d
## What changed
- Remove the legacy `shell_command` handler and runtime, leaving `exec_command`
and `write_stdin` as the shell execution tools.
- Treat legacy `shell_command` model metadata as `unified_exec`, and normalize
legacy user opt-outs so they do not disable command execution. Managed feature
requirements and `shell_tool` can still disable it.
- Preserve shell approvals, sandboxing, zsh-fork support, and output truncation
through the unified execution path.
## Testing
- Cover legacy configuration and model-metadata compatibility.
- Exercise unified shell execution, approvals, truncation, and `apply_patch`
serialization across the app-server and core test suites.
GitOrigin-RevId: 5c2fd6164fc3519cdae4944cb9db276b8467311c
## Why
An `apply_patch` path can be replaced with a symlink after verification, allowing an unsandboxed patch operation to reach a different file than the one that was approved.
## What changed
- Add `follow_symlinks` options to executor filesystem reads, writes, metadata lookups, directory creation, and removal, including the corresponding `followSymlinks` protocol fields.
- Implement no-follow filesystem operations on Unix and Windows that reject links in any path component and restrict file access to regular files.
- Run `apply_patch` with symlink traversal disabled when an otherwise-required sandbox is bypassed, while retaining the existing follow-symlink default for standalone callers.
## Testing
- Cover leaf and ancestor symlinks across patch add, update, delete, and move operations, including a path swap after verification.
- Exercise local and remote no-follow filesystem behavior, concurrent directory creation, special-file rejection, and Windows reparse points.
GitOrigin-RevId: 43fd479084891493ce13564fbd894b98f329c6dd
## What changed
- Give `PluginsManager` a shared `AuthManager` instead of a separately mutable authentication-mode snapshot.
- Read the current authentication mode and credentials from that shared manager for plugin discovery, startup tasks, CLI commands, MCP setup, and external-agent migration.
- Update test helpers and coverage to exercise plugin projections and curated marketplace selection as authentication changes.
GitOrigin-RevId: 600c94de5130eda2da5727e1a0b4d39083fefc56
## Why
Filesystem permission paths can use a convention that differs from the host
running Codex. Converting them immediately to native absolute paths can change
the meaning of ambiguous paths such as `/C:/secret` or Windows UNC paths.
## What changed
- Store literal filesystem permission paths as `PathUri` values through the
runtime policy and execution protocol.
- Keep legacy string-based serialization at explicit protocol boundaries and
reject conversions that cannot be represented losslessly.
- Encode native paths as opaque URIs when a normal file URI would imply the
wrong path convention.
## Testing
Added coverage for cross-platform and ambiguous path round trips, UNC path
variants, permission-profile serialization, and deny-policy enforcement.
GitOrigin-RevId: 5247713796d1f2bb4e02f94eb9fc82d4698060f0
## Why
Callers need to associate host-owned state with a thread before Core starts it.
## What changed
- Add `ThreadManager::reserve_thread_id` and allow new threads to start with the reserved ID. Reject reserved IDs when resuming an existing thread.
- Let thread stores stage metadata for a reserved ID. The local store merges staged values into the first successful metadata update and then removes them.
- Clear staged metadata when an unmaterialized thread shuts down or is discarded, and require the state database for staging.
## Testing
- Cover reserved ID generation and resume validation.
- Cover metadata persistence, merging, rollout-compatible updates, cleanup, and invalid staging requests.
GitOrigin-RevId: 3f9bc48f0f7764011cc90ea01349e497dda0a9e3
## What changed
- Add `EnvironmentConfigState` to `TurnEnvironmentSelection` so each environment attachment can inherit thread configuration or carry ready configuration for its login-shell policy and selected capability roots.
- Apply ready configuration during thread creation and thread-settings updates while reusing the existing environment connection.
- Validate selection configuration before applying settings, rejecting unsupported pending state and invalid capability roots.
## Testing
- Cover attachment-scoped capability roots, ready configuration at thread startup and turn updates, and rejection of invalid selections without changing existing settings.
GitOrigin-RevId: 86cf8f2148fdaa746ea0dd12890ab7b1577d7587
## What changed
- Add `TurnInputRequest` and typed submission results for atomically starting a turn, steering the active turn, or declining input with a specific reason.
- Expose `start_or_steer_turn`, `start_turn_if_idle`, and `steer_turn` on `CodexThread`, and migrate Core consumers to these APIs.
- Make app-server `turn/start` steer an active regular turn and return that turn's ID. Reject incompatible output schemas and non-steerable turns without applying settings or enqueueing input.
## Testing
- Cover concurrent start-or-steer submissions, accepted and rejected settings updates, output-schema compatibility, idle-start rejection, and app-server steering.
GitOrigin-RevId: dd9b5528d76ec650c019e97af420bc13190ea86a
## Why
`parent_turn_id` identifies the immediate caller of a nested request, but not the
top-level turn that initiated a multi-level chain of work.
## What changed
- Add `root_turn_id` to turn state, submissions, and Responses API metadata.
- Propagate the root through spawned agents, delegated work, review sessions, and
turn-triggering inter-agent messages.
- Omit the root when background work has no user turn or combined input makes the
root ambiguous.
## Testing
Added coverage for nested agent resumes, reviews, mailbox delivery, steered input,
and reserved metadata handling.
GitOrigin-RevId: 60057db2ee81f4efefa946a9f63c74ff98b93929
## What changed
- Add the public asynchronous `ModelsCache` contract and cache entry/error types.
- Let model providers and `OpenAiModelsManager` accept caller-provided cache implementations while retaining the existing file-backed cache by default.
- Treat cache read failures as misses, keep cache write failures non-fatal, and support refreshing an entry's TTL after ETag revalidation.
- Continue to prefer an explicitly configured static model catalog over an injected cache.
## Testing
- Cover injected cache hits, read and write failures, TTL refreshes, and end-to-end model selection.
- Verify that the file-backed implementation satisfies the new cache contract and does not serve expired entries before revalidation.
GitOrigin-RevId: eef957a317910b8502a0c20f8fc112f689d5e389
## Why
App-server clients need to advertise structured MCP extension settings, including supported MCP App UI MIME types, rather than only opting into OpenAI form elicitation with a boolean.
## What changed
- Add an `extensions` map to initialize capabilities and preserve `mcpServerOpenaiFormElicitation` as a legacy alias for `openai/form`.
- Capture the declared extension profile when a thread is started, resumed, or forked, propagate it to subagents, and advertise it to downstream MCP servers during initialization.
- Keep the profile stable for the lifetime of the loaded session instead of changing it on later turns or direct tool calls.
## Testing
- Cover extension conversion, downstream MCP initialization, session isolation, legacy form support, and subagent inheritance.
GitOrigin-RevId: fbcedbb74ce788e574b0f884a4c45c4cedb9de54
## Why
Legacy thread histories did not use the cross-process writer ownership guard already applied to paginated histories.
## What changed
- Acquire and retain a writer lock whenever a legacy or paginated thread is created or resumed.
- Apply the same ownership checks when archiving or deleting either history mode.
- Release ownership when initialization fails or the active thread shuts down, allowing another process to resume it.
## Testing
- Cover competing create and resume operations for both history modes.
- Cover archive and deletion conflicts for legacy and paginated descendants.
GitOrigin-RevId: 1be79b01966ad2634ed79eb96c0aa0db8eafe2fa
## What changed
- Add optional `default` and `plan` collaboration-mode messages to model catalog metadata.
- Prefer the active mode's catalog message, including an explicit empty value, while falling back to the existing developer instructions when the catalog variant is absent.
- Track the model in collaboration-mode world state so mode and model changes append the appropriate instructions, and clear prior instructions when no current message exists.
- Preserve catalog collaboration messages when instruction overrides remove other model instruction fields.
## Testing
- Cover catalog deserialization, variant selection, fallback and empty-message behavior, legacy snapshot migration, mode changes, and model changes.
GitOrigin-RevId: d4c6c0028423bc50b0e8175e55586f3e7bc1c3a8
## What changed
- Propagate the initiating turn ID through agent spawns, follow-up tasks, reviews, and delegated Codex sessions.
- Add `parent_turn_id` to Responses client and turn metadata while keeping it out of external MCP metadata.
- Preserve parent-turn provenance across queued agent messages when their triggering parent is unambiguous.
## Testing
- Cover spawned, resumed, nested, reviewed, delegated, and WebSocket request metadata.
- Verify queued messages do not claim ambiguous or queue-only parent turns.
GitOrigin-RevId: 481fdebbe7df2031880fe259509273cce50b20a8
## What changed
- Allow `features.code_mode_host` to use a configuration table with
`disable_in_process_fallback`. When enabled, failure to start the standalone
host is returned as tool output instead of falling back to embedded V8.
- Preserve the existing fallback behavior by default and continue accepting the
boolean feature toggle.
- Limit displayed host paths in spawn errors to 512 bytes while retaining the
executable-bearing suffix and valid UTF-8 boundaries.
## Testing
- Cover boolean and table-based feature configuration, fallback-disabled host
failures, and bounded ASCII and UTF-8 error paths.
GitOrigin-RevId: ab3d014e79054c2f8beef9a658915f01cca197b2
## Why
The Apps MCP background retry could complete before the test inspected the
initial sampling request, making the recovery timing nondeterministic.
## What changed
- Add a test-server gate that can hold and explicitly release the next
successful Apps MCP initialization.
- Use a dedicated MCP mock server so the held initialization does not block
model responses or app discovery.
- Assert that recovery uses exactly two initialization attempts and that Apps
guidance and the deferred namespace appear only after the gate is released.
GitOrigin-RevId: deb21d4b41f353c3f84428616769af9faa1a0487
## What changed
- Add the disabled-by-default `deferred_tool_world_state` feature, which exposes deferred tool namespaces and their descriptions to the model in a `<tools>` world-state section.
- Emit added and removed namespace updates as tool availability changes, bound the rendered context size, and persist nonempty state across thread resumes.
- Omit empty tool state while retaining deferred tool discovery through `tool_search`.
## Testing
- Cover initial, unchanged, removed, recovered, empty, and resumed namespace state, along with description truncation and rendered-size limits.
GitOrigin-RevId: 867e599666dc3569eb0789ba78aaa40254253a6f
## What changed
- Make `McpRuntime` own the published MCP configuration, connections, elicitation routing, and selected capability roots for a thread.
- Capture immutable MCP bindings for model steps and tool calls so in-flight work keeps a consistent connection set and approval authority while refreshed state is published atomically.
- Mark MCP state dirty when relevant configuration, plugins, environments, authentication, or elicitation capabilities change, then rebuild it before the next sampling request or out-of-band MCP operation.
- Separate config reloads from server invalidation: `ReloadMcpConfig` applies resolved MCP inputs, while `RefreshMcpServers` requests reinitialization from the thread's latest state.
## Testing
- Cover refreshed state visibility for existing turns, stable step bindings, current approval authority, cancelled refresh retries, resource-client reconciliation, and Apps recovery between sampling requests.
GitOrigin-RevId: 59eabb1aa8dc083426bd18ef4d3630508f376401
## What changed
- Add `StartThreadOptions::new` to provide the standard configuration for a new thread.
- Make `ThreadManager::start_thread` the single thread-start entry point and migrate callers from the previous convenience methods.
- Derive default environment selections when `environments` is `None`, while preserving explicit selections, including an empty list.
GitOrigin-RevId: 8977dc11aed54c5e1215a81eaed2b2cf5fc6087a
## What changed
- Send the streaming SSE request-body drain test through `HttpClientFactory`.
- Replace the test-support crate's direct `reqwest` dependency with
`codex-http-client`.
- Remove `core_test_support` from the temporary direct-`reqwest` exceptions.
GitOrigin-RevId: 16ea4309d0b575592c2e59991eb6dce18d9467ed
