## Why
Hook configurations can mark command handlers as asynchronous, but Codex previously skipped those handlers outside `SessionEnd`.
## What changed
- Run asynchronous command hooks in the background with a per-session concurrency limit, while keeping `SessionEnd` hooks synchronous.
- Prevent asynchronous hooks from blocking, stopping, rewriting, or otherwise controlling the operation that launched them.
- Deliver warnings and additional context at safe turn boundaries: inject results into an active turn after sampling, or buffer them ahead of the next user prompt when the session is idle.
- Preserve in-flight hooks across configuration reloads, scope spilled output to the thread, and abort outstanding work during session shutdown.
## Testing
Add unit and integration coverage for background scheduling, concurrency, output parsing, active and idle result delivery, configuration reloads, and shutdown cleanup.
GitOrigin-RevId: 8094552e4afe7b47b09a61bb575bb20f4e491d8d
## What changed
- Add `HostSkillsSnapshot::load_skill_prompts` so the skills extension owns reading and rendering selected host skills.
- Keep explicit invocation telemetry, unreadable-skill warnings, plugin prompt ordering, and suppression of host prompts superseded by provider prompts.
- Remove the legacy prompt injection and fragment implementation from `codex-core-skills`.
## Testing
- Cover prompt truncation without an installed skills extension, skill/plugin ordering, selective provider supersession, unreadable skills, and contextual fragment detection.
GitOrigin-RevId: 9c8b84ad54b90d174abc287ab49cc5a231e9e1aa
## What changed
- Classify HTTP connection failures separately from other network errors without exposing request URLs.
- For sampling requests, retry connection failures with exponential delays from 5 to 60 seconds and show a `Reconnecting... waiting for network` stream error.
- Preserve the normal stream retry budget while waiting for the provider to become reachable. Keep the existing bounded retry behavior for other retryable errors.
## Testing
- Verify connection errors are classified without leaking URL contents.
- Verify a turn recovers after its provider becomes reachable and still applies the configured retry limit to a subsequent incomplete stream.
GitOrigin-RevId: 646553290c865a1332abd30c4a64ed9266bbfc6f
## Why
Converting each environment's working directory to a host-native path caused
turn-input contributors to omit environments with foreign path formats.
## What changed
- Expose `TurnInputEnvironment.cwd` as a `PathUri`.
- Pass every turn environment to contributors without host-path conversion.
## Testing
Added an integration test that submits a foreign working-directory URI and
verifies the contributor receives the environment unchanged.
GitOrigin-RevId: a122526be47f5331614381e9c6e4b85087a96bed
## Why
Environment readiness can change between sampling requests. Extension turn-input contributors should receive the same refreshed environment snapshot used by the current step.
## What changed
Build `TurnInputContext.environments` from `StepContext` so newly ready environments are included in extension input for the current request.
GitOrigin-RevId: ee4444072162317974cd2bbfd57ffcf9a9445391
## Why
MCP tool handlers and their Code Mode definitions are immutable for the lifetime
of a stable MCP binding, so rebuilding them for every sampling step repeats schema
construction unnecessarily.
## What changed
- Cache MCP handlers per session and reuse them while the same binding remains
active, invalidating the cache when the binding changes.
- Lazily cache schema-free Code Mode definitions on MCP handlers while continuing
to rebuild definitions for step-local tools whose specifications may change.
- Reapply current app enablement, tool policy, exposure, and plugin schema budgets
whenever cached handlers are registered for a step.
## Testing
- Cover handler and Code Mode definition reuse, binding invalidation, changing app
policy, stable continuation schemas, and step-local custom tool updates.
GitOrigin-RevId: 69c5011fb97c08580ac476e7fb2286b1e92e0359
## What changed
- Add a storage-neutral queue extension for listing, adding, editing, reordering, deleting, and explicitly starting queued user messages.
- Dispatch queued messages in FIFO order when a thread becomes idle after a completed turn, while leaving them queued after interruptions or failures.
- Wait for user input to be persisted before removing its queue item, and report hook rejection, task termination, and persistence failures distinctly.
- Snapshot local image and audio attachments into validated data URLs before storing them, enforce input limits, and emit `ThreadQueueChanged` events after mutations.
## Testing
- Cover queue mutations, automatic and explicit dispatch, interruption and failure behavior, hook rejection, invalid records, input limits, and local attachment snapshotting.
GitOrigin-RevId: 14f39d7c8cbaccb767a6da84b82cced0edfcb4b9
## Why
Symlinked skills have a canonical `SKILL.md` path that can differ from the path
under the configured skill root. A catalog entry that advertises the discovery
path must still select the canonical skill.
## What changed
- Track each loaded skill's discovery path alongside its canonical identity.
- Render discovery paths in the skill catalog and accept either form for
structured selections and linked skill mentions.
- Preserve enabled-state checks, deduplication, and product filtering when
resolving discovery paths.
## Testing
Added loader, catalog, mention-resolution, and end-to-end turn coverage for
skills discovered through directory symlinks.
GitOrigin-RevId: bae539b766cc3782c7c121a4276c337699cbb509
## What changed
- Track the first duplicate effective tool name while assembling the tool registry, including collisions introduced by external tools, code mode, and tool search.
- When `[features.tool_registry].error_on_tool_collisions` is enabled, fail the turn with a `duplicate tool: <namespace>.<name>` error before sending a model request.
- Continue allowing identical tool names in different namespaces, and preserve the existing collision behavior when strict checking is disabled.
## Testing
- Cover registry collision tracking, strict tool planning across tool sources, namespace isolation, failure before sampling, and pre-sampling compaction.
GitOrigin-RevId: 4cf83538fb513cec0b9c8b567780caaaadd3243d
## What changed
- Add provider-owned remote compaction capabilities for unsupported, v1, and v2 protocols.
- Mark Amazon Bedrock as v1-only so manual and automatic compaction use `/v1/responses/compact`, even when the v2 feature is enabled.
- Preserve v2 support for OpenAI and Azure Responses providers and local compaction for unsupported providers.
## Testing
- Cover Amazon Bedrock manual and automatic remote compaction, including endpoint selection, authentication headers, model selection, and reuse of the compacted summary.
GitOrigin-RevId: d58093178605d1f8155b93d9a161408177f6ac72
## What changed
- Add `AppToolPolicyEvaluator::apply_app_enabled_state` and use it when
presenting app lists, building plugin context, and deciding whether app
instructions are available.
- Preserve each app's source state unless local or managed configuration
explicitly overrides it.
- Keep connector discovery and post-install refresh checks based on raw
accessibility rather than configured enablement.
## Testing
- Cover default enablement, per-app overrides, managed disablement, and
preservation of unconfigured source state.
GitOrigin-RevId: f1a62d55e7cc48b37113848e3baa0d69d8d9c8a8
## Why
Thread settings can update the approval policy after a turn context is created.
Keeping a separate copy on `TurnContext` could leave tool approval checks using
the previous policy.
## What changed
- Remove the duplicated approval-policy field from `TurnContext`.
- Resolve the policy through the turn's current configuration everywhere it is
needed, including tool execution, Guardian routing, MCP handling, and
permission requests.
## Testing
- Update the shell escalation test to apply a thread-level policy override and
verify that the next turn rejects an escalation using the updated policy.
GitOrigin-RevId: e5966ba08f179d53fd76871ad904762958c0f5ea
## What changed
- Gate Codex Apps MCP tool registration on whether apps are enabled instead of requiring each tool's connector to appear in the accessible connector list.
- Continue enforcing model-visibility and app-tool policy checks, including the requirement for connector metadata.
- Use the merged connector catalog for tool-suggestion discovery.
## Testing
- Cover app-tool registration from catalog metadata, including synthetic links, source ordering, and the apps-disabled case.
GitOrigin-RevId: eef4eb03da9738d3a165dd6cfda0d3c1844d51e7
## What changed
- Store each turn's host skills snapshot in `ExtensionData` and expose it through
`TurnContext::skills_snapshot`.
- Lazily keep implicit skill invocation deduplication state in the same turn-scoped
store.
- Carry the skills snapshot into review turns without a separate
`TurnSkillsContext` field.
GitOrigin-RevId: d71579b5d230bd0b5f3c2ad062861f74d614d88c
## What changed
- Emit dynamic tool-call analytics for code mode `exec` and `wait` calls, including duration and terminal status.
- Associate code-mode cells and their nested tool calls with the originating and subsequent model response IDs.
- Buffer correlated tool events until the next response is known, while flushing pending events when turns, threads, or the analytics queue close.
## Testing
- Add reducer coverage for correlating `exec`, `wait`, and nested tool events across turns.
- Add an app-server test that verifies production analytics include the cell and response IDs for a code-mode `exec` call.
GitOrigin-RevId: 8b34ab59c1ad68ebbd57f9c8a05f19ab04df48a4
## What changed
- Read the frozen MCP tool catalog directly from the step-scoped `McpBinding`
when building tool routers, plugin injections, and connector state.
- Remove the redundant `Vec<ToolInfo>` from `StepContext` and stop returning a
duplicate catalog from `built_tools`.
GitOrigin-RevId: d12d694e1224da3f6ccb1960868491f0d80c6e19
## Why
Tool calls can outlive the sampling request that advertised them, so execution
must retain the finalized tool plan for that specific step.
## What changed
- Resolve tool runtimes, parallelism, cancellation behavior, argument diff
consumers, and dispatch from the `ToolRouter` stored in `StepContext`.
- Remove the separate router parameter from `ToolCallRuntime` and code-mode
worker construction so callers cannot supply a different router.
- Add a test helper for installing a router into a test `StepContext`.
GitOrigin-RevId: 9e476ddd228ca5b1c03ed87863618ba77de6200c
## What changed
- Replace `SessionTaskContext` with `Arc<Session>` in the session task run and abort interfaces.
- Read extension data from `TurnContext` during regular turns instead of storing and forwarding a duplicate reference through the running task.
GitOrigin-RevId: 04bc0d324e5ba781f35ac9c61e811888208b74ae
## Why
The `<current_date>` in environment context could diverge from the clock used by current-time features, especially when a host provides an external clock.
## What changed
- Read the current time from the session's time provider whenever world state is built, and render its local date in environment context.
- Use each session's own thread ID for clock reads, including guardian sessions.
- Propagate clock-read failures through turn error events and stop before model inference.
## Testing
- Cover date updates across turns and app-server requests.
- Verify guardian clock reads use the corresponding root or guardian thread ID and do not run during prewarm.
- Verify clock failures emit an error without sending an inference request.
GitOrigin-RevId: bb7f32ccc0229b7bc6f14d7356db00bcce78066d
## What changed
- Add the opt-in `executed_tool_call_metadata` feature to record model-attempted direct and code-mode tool calls.
- Attach recorded names and arguments to the matching tool output in the next Responses request, preserving the metadata across sampling retries.
- Bound pending calls and argument sizes, and emit truncation metadata when limits are exceeded.
## Testing
- Cover disabled-by-default behavior, namespaced and nested calls, blocked or failed attempts, retry handling, and recorder limits.
GitOrigin-RevId: 5ce917b73e797b0f6904d46477b9d2cf8ea71bf2
## Why
External MCP, extension, and dynamic tools can collide with host-owned tool
names. In particular, a dynamic `tool_search` definition must not replace the
host implementation used to discover and route deferred tools.
## What changed
- Build each turn's tools through a single ordered `ToolRegistry` that retains
the first runtime registered for a name.
- Treat duplicate external tools as skippable collisions while preserving
strict duplicate checks for trusted host tools.
- Reserve host-owned code-mode and `tool_search` runtimes before producing the
model-visible tool list.
- Base hosted web-search fallback behavior on the extension runtime that
actually won registration.
## Testing
- Cover ordered registry mutation and duplicate handling.
- Verify a client-provided `tool_search` cannot shadow the host tool.
- Verify hosted web-search fallback follows the registered browser runtime.
GitOrigin-RevId: acebe360de8ec69ad7da2f684cc2542cbf18a984
## What changed
- Split core tool planning from the assembly of MCP, extension, and dynamic tool runtimes.
- Build `ToolRouter` from a single ordered runtime list plus hosted tool specs.
- Centralize whether each `ToolExposure` variant is available in code mode.
- Preserve core, MCP, extension, and dynamic source ordering and existing name-collision priority.
## Testing
- Add coverage for unified source ordering and collisions, code-mode exposure, and standalone web search alongside MCP and dynamic `web.run` tools.
GitOrigin-RevId: b010c2e9728b92b75a35325ca9b2ec465c3bac12
## 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
## Why
A pending optional MCP server can delay the first model request even when the
turn does not need that server.
## What changed
- Give optional MCP servers a shared one-second startup grace, then omit servers
that are still pending from the captured tool catalog.
- Continue waiting when the turn explicitly requires a server through a plugin,
skill dependency, or `mcp://` mention, and preserve this behavior for input
received between sampling steps.
- Route direct resource requests to the live connection set when a pending
server was omitted from the binding, while keeping all-server resource
discovery non-blocking.
## Testing
- Cover the shared grace period and resource behavior for pending optional
servers.
- Verify plugin, plugin-skill, and direct MCP mentions wait for startup.
- Verify an Apps-enabled turn proceeds without tools from an unrelated pending
optional server.
GitOrigin-RevId: b5f895c5a5362fe73f7d33250367662d4a217e4d
## Why
Turn preparation waited for MCP discovery before requesting endpoint plugin
recommendations, adding their latencies together.
## What changed
- Prepare the MCP runtime and endpoint plugin recommendations concurrently.
- Wait for both results before building tools and starting model sampling.
- Cancel the combined preparation when the turn is interrupted.
## Testing
- Add coverage that gates MCP initialization and verifies recommendation fetching
overlaps it while the final request includes both results.
- Verify interrupting concurrent preparation prevents model sampling.
GitOrigin-RevId: 295ec268331bf05304e6b313925fd2b6c2ae4190
## What changed
- Add an optional `ExtensionMetrics` capability to thread, turn-input, and world-state contributors, backed by session telemetry in the host.
- Record skill counts, omissions, and truncated description characters for extension-rendered catalogs, tagged by the catalog surface.
- Preserve host session attribution on extension metrics, including the effective model for each turn, and prevent extension tags from overriding host metadata.
- Avoid duplicate host-catalog samples by recording world-state metrics only when the section is published or changes.
## Testing
- Cover metric values and surface tags, session metadata preservation, turn-level model changes, and host world-state publication behavior.
GitOrigin-RevId: 9059e521943a8f81df25a38b03692eddbc1d990d
## What changed
- Add executor authority support to `skills.list` and `skills.read` for skills from selected capability roots.
- Allow `skills.read` to load package-relative resources referenced by an executor skill while keeping reads within the selected package.
- Paginate skill listings and resource contents with bounded response sizes and stale-cursor validation.
- Resolve executor filesystems per sampling step so skill tools use the active selected capability roots.
## Testing
- Extend the app-server executor skill test to list an executor skill, read its main `SKILL.md`, and read a paginated reference resource.
- Cover visibility filtering, metadata bounds, pagination, invalid cursors, package boundaries, and resource size limits.
GitOrigin-RevId: 1b5de95d5d1b9f79c34d2879d6e67f24401e9c29
## What changed
- Add `WaitForEnvironmentToolConfig` as thread extension data for overriding the
model-visible tool and `environment_id` descriptions.
- Preserve the default descriptions when no override is provided or when the
configured descriptions exceed the input or serialized tool-spec limits.
- Keep `wait_for_environment` availability gated by the deferred executor
feature independently of whether a host override is present.
## Testing
- Cover default, custom, oversized, and feature-disabled tool configurations.
- Verify the custom descriptions in the deferred-environment integration flow.
GitOrigin-RevId: 6b49a73a434becd99ea5df911be53f3706a17c0a
## What changed
- Wrap `CodexErrorDetails` and an optional retry delay in `CodexErr`, allowing any mapped error to preserve server-provided retry timing.
- Generate the payload-free `CodexErrKind` classification alongside the error details and reuse it for analytics.
- Update error handling sites to inspect `CodexErr::details()` while preserving existing display, debug, protocol mapping, and retryability behavior.
## Testing
- Add coverage for legacy debug formatting, error-specific retryability, and retry-delay propagation through API error mapping.
GitOrigin-RevId: d3ab8a305f2a2ee21d0c0a8c8c388b06dda9c59a
## 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
## Why
Interrupting a turn while MCP tools were still starting could abort before the
submitted user input was recorded in conversation history.
## What changed
- Build and retain the MCP tool list and tool router as part of each step
snapshot, using the turn cancellation token during tool discovery.
- Record turn hooks and submitted input when cancellation occurs during startup
prewarming, pre-sampling compaction, or first-step capture.
- Reuse the captured router for sampling, compaction, and prompt debugging so
advertised and executable tools share the same request-scoped view.
## Testing
Add coverage that interrupts each affected MCP startup phase and verifies that
the user prompt remains in history before the turn-aborted marker.
GitOrigin-RevId: 6e96c6814357a55545d69b580e28f35933cfadf7
## What changed
- Add `compaction_ms` to turn profile facts and turn analytics events.
- Measure manual and automatic compaction as an exclusive profile phase instead of including it in surrounding idle time.
- Complete the profile and total turn duration from the same instant so their elapsed times remain consistent.
## Testing
- Cover compaction phase accounting and profile-duration consistency.
- Update turn event serialization coverage for `compaction_ms`.
GitOrigin-RevId: 50f0e1cf19789a807f9f56c2ef763c620a5d641c
## Why
The post-sampling trace calculated an estimated token count even when only the
always-on diagnostic and state log sinks were listening, adding unnecessary work
after every sample.
## What changed
- Move the estimate to a dedicated trace target and calculate it only when that
event is enabled.
- Disable the target for the always-on diagnostic and state log sinks while
keeping it available to explicitly configured subscribers.
## Testing
- Verify that the combined always-on subscribers do not enable the estimate
event.
GitOrigin-RevId: ea572584597dda313e7719897d0ab1fdf7362745
## What changed
- Remove the step-scoped `ExtensionData` argument from context, turn-input, and tool contributors.
- Pass the host's optional `McpResourceClient` through `ThreadStartInput` so extensions can retain session capabilities explicitly.
- Keep the MCP resource client in skills-owned session state for catalog loading and skill tools.
GitOrigin-RevId: bafa77bcd998aff408d6a396c5fd9ac268c4cce4
## Why
Turn diffs need to render paths from remote environments whose path convention may differ from the Codex host.
## What changed
- Preserve `PathUri` values through applied patch deltas, display-root discovery, and turn-diff tracking.
- Add host-independent relative-path rendering and normalize Windows drive-letter case in `PathUri`.
- Render paths relative to each environment's repository root while keeping Git diff headers slash-separated.
## Testing
- Cover POSIX, Windows, UNC, encoded-separator, and opaque URI relative paths.
- Verify an applied patch in a remote Windows working directory emits a portable unified diff.
GitOrigin-RevId: 526f70ae36a40627de5496d375310d12295b69bb
## What changed
- Assign IDs to client-created response items in every session, including streamed items, forked history, compaction results, and non-OpenAI provider requests.
- Preserve server-provided IDs and stable generated IDs across persisted and resumed conversations while continuing to omit unprefixed server IDs from outbound requests.
- Retire `features.item_ids` as a configurable feature. Existing configuration and CLI toggles remain accepted as compatibility no-ops.
## Testing
- Cover default ID assignment, persistence and resume behavior, remote compaction, provider requests, WebSocket requests, and removed-feature compatibility.
GitOrigin-RevId: 7a09e2d07d2606c2ef1e8e2283d36cb555557eae
## What changed
- Add an `ExtensionData` store to each `StepContext`.
- Pass the step store to context, world-state, turn-input, and tool contributors so extensions can use capabilities bound to the current sampling step.
- Preserve the captured step context when rebuilding initial context during compaction.
GitOrigin-RevId: 51f3105d3a793f60534f122f9be8247c131c2ca5
## Why
Mid-turn auto-compaction queued `SessionStart` hooks but continued sampling
before running them. This delayed hook-provided context and ignored requests to
stop the continuation.
## What changed
Drain pending session-start hooks immediately after successful mid-turn
auto-compaction. End the turn when a hook requests a stop; otherwise include
its additional context in the next sampling request.
## Testing
Added coverage for repeated compactions in one turn, context delivery without
leaking hooks into the next user turn, and stop requests that block sampling.
GitOrigin-RevId: c57708a792fb47d98d95c38d7d91bcd9f235be84
## What changed
Remove the fallback that replaced image content in the latest tool output with
`Invalid image` and retried the model request. Invalid-image responses now use
the existing bad-request error path without modifying conversation history.
GitOrigin-RevId: f4ea782f16c5451feb261694caa73b77f24c3e4e
## What changed
- Stream V3 agent message deltas to `delegation.context.append` at 200 ms intervals instead of waiting for each completed message.
- Send commentary without a prefix and label final or phase-less V1/V3 output with `"Agent Final Message":`.
- Bound streamed output while preserving both its beginning and final tail when truncation is required.
- Remove `codexResponseHandoffPrefix` from `thread/realtime/start`; unknown fields from older clients remain ignored.
## Testing
- Cover incremental V3 commentary and final output, Unicode-safe truncation, V1/V3 phase labeling, and legacy request compatibility.
GitOrigin-RevId: 633c18b5eb9a4f5756a264b63b7bfc185b073951
## Why
Changes to the selected working directory can select different `AGENTS.md`
instructions. These updates need to reach the model even when the deferred
executor feature is disabled.
## What changed
- Refresh environment readiness and `AGENTS.md` before capturing each step.
- Record model-visible world-state changes for every session instead of gating
them on the deferred executor feature.
- Preserve the initial environment context without duplicating it.
## Testing
- Cover `AGENTS.md` replacement after a working-directory change.
- Verify that initial environment context remains unique with the deferred
executor both enabled and disabled.
GitOrigin-RevId: ea5dbe590cc049170259e7eccb6a3346fb2ed8e6
## Why
With deferred execution enabled, rebuilding a step context from the latest
thread environment snapshot could apply a settings update to a turn that was
already in progress.
## What changed
- Preserve each turn's captured environment selections when creating later
step contexts.
- Refresh only the readiness of environments that were already starting, while
retaining their original selection order.
- Apply updated environment selections to the next turn.
## Testing
Add coverage for changing the selected workspace while a turn is paused,
verifying that the active turn keeps its original working directory and the
next turn uses the new one.
GitOrigin-RevId: c6f4388c843384ef045b7abdbc303dcfca11d230
## What changed
- Parse `cache_write_tokens` from response input token details and carry it through token usage aggregation.
- Expose `cache_write_input_tokens` in protocol, app-server, exec, and TypeScript SDK usage events, defaulting it to zero for compatibility with older payloads.
- Report cache-write usage in analytics, metrics, traces, and rollout data alongside existing cache-read usage.
## Testing
- Add coverage for response parsing, usage event output, aggregation, analytics, metrics, and telemetry fields.
GitOrigin-RevId: 634e4fbe3086a8923c0ee13b622573e7d9d221bd
## Why
Queue-only child-agent updates that arrive around a final answer should not
restart sampling, but they must remain available to the next turn. Explicitly
injected response items still need to reopen the current turn.
## What changed
- Defer queue-only inter-agent mail after a final answer without treating it as
same-turn pending input.
- Re-enable current-turn mailbox delivery when the model requests a follow-up,
a stop hook continues the turn, or a response item is explicitly injected.
- Check for turn-triggering mailbox work after clearing the completed active
turn so pending work can start safely.
## Testing
Added coverage that queued child mail waits for the next user turn and that an
injected response item after a final answer triggers a follow-up request.
GitOrigin-RevId: aa81d00707943284b7ab069b60970e547908c895
## Why
Token-budget sessions need a final opportunity to preserve important state before the current context is compacted.
## What changed
- When `auto_compact_fallback_prompt` is configured, reserve `auto_compact_fallback_buffer_tokens` beyond the base auto-compaction limit.
- At the base limit, inject the fallback prompt once as a developer message while keeping the normal tool surface available. Continue reporting zero base-window tokens during this reserve.
- Roll over when the reserve or full model context is exhausted, and skip the fallback when a new context was already requested.
## Testing
Added coverage for using the fallback reserve, rolling over after it is exhausted, and bypassing the fallback for an explicit `new_context` request.
GitOrigin-RevId: 32983ecadc5cb4927e15ecd7b1e896cb52a9ad3b
## What changed
- Track connected and disconnected states across initial remote exec-server connections and reconnection attempts.
- Emit experimental `thread/environment/connected` and `thread/environment/disconnected` app-server notifications for each thread selecting the environment. Each payload identifies the thread and environment; current state is not replayed when a thread starts.
- Stop forwarding connection events when an environment selection is removed or replaced.
## Testing
- Cover connection, disconnection, reconnection, shared-environment notifications, and replacement of a selected environment.
GitOrigin-RevId: 5dd767372363c4a2a8319fc16164be117d5bd20c
## What changed
- Convert filtered MCP tool metadata into `CoreToolRuntime` instances before constructing the tool router.
- Pass those runtimes through the shared tool-planning path instead of maintaining separate direct and deferred MCP tool lists.
- Preserve MCP visibility, app policy filtering, and direct versus deferred exposure behavior.
GitOrigin-RevId: 67f7fbeecc2992318c859e038cd97938833911db
## Why
Clients that account for individual upstream Responses API calls need the exact
usage for each completion rather than accumulated or estimated thread usage.
## What changed
- Add the opt-in `rawResponse/completed` app-server notification with the
`threadId`, `turnId`, `responseId`, and upstream `usage` payload.
- Emit the transient event for normal turns and compaction requests when
`experimentalRawEvents` is enabled. The event is not persisted or replayed,
and `usage` is `null` when the upstream response omits it.
- Export the notification in the app-server schemas and document its behavior.
## Testing
- Cover exact token breakdowns for turn and compaction completions.
GitOrigin-RevId: 49040a060bf1784c1ff1dd62112efb4a778428c4
## Why
`TurnContext` stored model and reasoning settings both as resolved turn fields and inside `CollaborationMode`, requiring the copies to stay synchronized when the model changed.
## What changed
- Store the mode and collaboration-mode developer instructions directly on `TurnContext`.
- Reconstruct `CollaborationMode` from those values plus the turn's current model and reasoning effort when callers need it.
- Read the mode directly for plan-mode checks, lifecycle events, and telemetry.
GitOrigin-RevId: b8fccafdd5d5cbccc84bc70d542588087ddf0093
## What changed
- Add a `ResponseItemId` type that generates item-specific prefixes with UUIDv7 suffixes and use it across response items.
- Keep deserialization permissive for legacy histories, but omit empty or unprefixed item IDs from HTTP and WebSocket requests.
- Export the new type in the generated TypeScript protocol schema.
## Testing
- Cover prefixed ID generation, legacy deserialization, prefix recognition, and outbound request filtering.
GitOrigin-RevId: 0209fe430c826d0ae88bc4648652c4ebf390c4a4
Abhinav