## What changed
Add the disabled-by-default `omit_skill_descriptions` feature flag to omit descriptions from model-visible host, executor, and cloud skill catalogs while retaining names and locators. Adapt catalog introductions, usage instructions, and alias budget accounting to the selected policy.
Persist the description policy in catalog snapshots and refresh usage instructions when it changes. Ignore description-only edits in catalog deltas while descriptions are omitted.
## Testing
Add coverage for alias token budgets, policy changes with older snapshots, and suppressed description-only updates. Extend scenario snapshots to cover plugin visibility and catalog deduplication with descriptions omitted.
GitOrigin-RevId: 5bf1dcee8c04059c7a78998affc1efcdef8ec883
## What changed
- Add the disabled-by-default `skill_catalog_deltas` feature flag to append new and updated skills without repeating unchanged catalog entries.
- Share a cumulative metadata budget across executor, cloud, and host catalogs, preserving usage across turns and resume. Removals emit no update and do not refund budget.
- Rebuild the current catalog and reset its budget after compaction, including any required skill root mappings in updates.
## Testing
Add unit and integration coverage for update costs, shared source budgets, feature rollback, and catalog updates across resume and compaction, with a request-history snapshot.
GitOrigin-RevId: e88b4265d7361498113d43fdc2e0260a9f930bbc
## Why
The context inheritance tests enabled `MultiAgentV2` but invoked `spawn_agent` through the V1 namespace, leaving the V2 path untested.
## What changed
- Share a helper that spawns through the V2 namespace, waits for child completion, and identifies the child's request by its thread ID.
- Assert that the child receives inherited instructions in a `developer` message and its task in an `agent_message` addressed to `/root/worker`.
- Test skill instructions both enabled and disabled for parent and child requests, with an explicit skills extension and discovery isolated to the fixture skill.
GitOrigin-RevId: 193fca57398e950acad1f020382dc1bae6453df4
## What changed
Classify messages from code-mode collaboration calls as `AgentMessage::Plaintext` so they receive the context wrapper for plaintext messages. Apply this to `spawn_agent`, `send_message`, and `followup_task`.
## Testing
Add a regression test that spawns an agent through `exec` and verifies that the child receives the task as plaintext with sender and recipient attribution.
GitOrigin-RevId: 495c70ea13fd2bb06989e5aacab60beed0c19a56
## What changed
Default `features.multi_agent_v2.preserve_fork_prefix` to `true`, so full-history forks retain the parent's model-visible history and append child instructions. Keep `preserve_fork_prefix = false` as an explicit opt-out for instruction filtering, and update the configuration schema documentation.
## Testing
Update coverage to verify inherited prefixes across child and grandchild forks, child instruction ordering after compaction, and explicit filtering opt-outs.
GitOrigin-RevId: f14eae5b924cdeac555d112d0aba3fbbb063b0ea
## What changed
Mark `incremental_tools` as stable and enable it by default. Responses Lite sessions now append tool catalog updates to request history without requiring an explicit feature opt-in.
## Testing
Run the incremental catalog scenario with the default configuration. Update assertions and snapshots for empty Responses Lite prewarm input, tool declarations on the first turn, preserved compaction history, and tool changes across model switches and child agents.
GitOrigin-RevId: 27aa6b8499d76ab12167470748452f47e14dd900
## Why
Contextual fragments and extension-owned world-state sections currently return strings, limiting them to text content.
## What changed
- Return `ContentItem` from fragment bodies and rendering, preserving classification and attribution. Apply text markers only to `InputText`; pass other content through unchanged.
- Allow extension prompt and world-state contributions to carry typed content, and preserve media in context-window hints.
- Hash non-text world-state fragments by their serialized content and role while retaining the existing text hashing behavior.
- Add shared content-to-tool-output conversion that preserves image references, image detail, and audio.
## Testing
Add coverage for typed world-state hashing and preservation of image content and attribution. Expand code-mode output tests to cover input text, output text, file-backed and inline images, and audio.
GitOrigin-RevId: 2ed00d466a3f169b151202f3eef71e667ea64be1
## What changed
Add `model` and `reasoningEffort` to `subAgentActivity` items for multi-agent v2 spawns. Capture startup settings before the child begins its turn and resolve the reported effort against model metadata, including model defaults, while preserving the child's configured effort.
Carry these fields through live notifications, persisted activity, thread history, and legacy rollout migration. Update the JSON schemas and generated TypeScript and Python types. Older records and other activity kinds retain null values.
## Testing
Add coverage for resolved spawn settings matching the child's request across legacy and paginated history, preserving configured effort, forwarding metadata through events and history, and reading and migrating older records without the new fields.
GitOrigin-RevId: a9e4241ae21bb8db1ead293f78ffba8257cca0ae
## What changed
Add `TurnEnvironmentRequests` to carry environment requests together with their fallback working directory. Update thread settings overrides and active turn settings to accept requests, constructing `TurnEnvironmentSelection` values in the receiving thread before validation and runtime use.
Adapt app-server callers, reviewer settings, and existing tests to supply requests or explicitly convert runtime selections back into requests.
GitOrigin-RevId: 8028f804bebe3fde553f57bb450f6dca3970cc4a
## Why
Queue-only agent mail can wake a sleeping session without starting a new task. The wake turn needs to retain the previous turn's attribution so delegated work reports completion to the initiating agent, including after a reload.
## What changed
Capture the previous turn's attribution while reserving the pending-work turn. Reuse its trigger, parent and root turn IDs, and initiating agent path for queue-only wakes. Mail that explicitly starts a new task continues to supply its own attribution.
## Testing
Extend regression coverage for live and reloaded sleep wakes, delegated and unknown attribution, settings changes while asleep, and subsequent task-triggering mail. Verify that a reloaded sleeping worker routes completion to the initiating turn.
GitOrigin-RevId: 28e38474028bdbf35a0538c1202165f056bb3dc3
## What changed
- Limit multi-agent V2 `fork_turns` guidance to `all` and `none`. Accept legacy positive integer strings as full-history forks instead of truncating parent history.
- Remove partial-history fork handling and telemetry, and direct model override usage to `fork_turns: "none"`.
- Strip inherited `multi_agent.role_instructions` and `multi_agent.usage_hint` content by kind, including persisted hints whose wording predates the current bundled instructions.
## Testing
Update regression coverage for legacy `"1"` and `"3"` values inheriting full history, invalid and zero values being rejected, and stale parent hints being removed from compacted history with both marked and unmarked instructions.
GitOrigin-RevId: 8f6017dc66ad8deefd7745399ef76e1bb1435bb2
## Why
A subagent stopped by repeated Guardian denials remained interrupted without notifying its parent. The parent needs guidance to report the stop and wait for explicit user confirmation before continuing the blocked work.
## What changed
Forward `TooManyDenials` interruptions from `MultiAgentV2` children to their parents with Guardian-specific guidance to inform the user and avoid resuming or retrying until the user explicitly confirms. Preserve the child's `Interrupted` status and keep ordinary interruptions silent.
## Testing
Add integration coverage for parent notifications under `CircuitBreakAction::Strict`, silence under `CircuitBreakAction::Default`, and preservation of the child's interrupted status. Add a unit test ensuring long denial messages stay within the notification token limit while retaining the guidance.
GitOrigin-RevId: c9bb90827393068d9c92edaf0443a52e6ff57f9f
## Why
Forked subagent startup serializes history persistence and spawn-edge writes. Cancellation during startup can also leave a provisional child behind.
## What changed
- Defer copied-history durability so it can run alongside spawn-edge persistence, while still awaiting both before submitting the child's initial input.
- Commit agent and residency reservations and notify clients only after initial input is accepted.
- Guard provisional children so cancellation or startup failure removes and shuts them down, discards their stored state, and closes their spawn edge after any pending edge write finishes.
## Testing
Add coverage for cancellation at the child-history durability barrier, checking child termination, removal, and edge closure. Extend fork-context tests in legacy and paginated history modes to verify inherited context can be read from storage after spawn acknowledgment without flushing the live child first.
GitOrigin-RevId: e02dda57efc32b7237bb7af0ce5e5844922890c3
## What changed
Add a V1 spawn regression test that removes the child from the thread manager during startup, before spawn reports its settings. Verify that the completed spawn event retains the role-configured model and reasoning effort, nickname, and role even when the child can no longer be looked up.
Also verify that the child receives its initial input with the effective settings and the parent receives a successful spawn result.
GitOrigin-RevId: 5e94e3ddb0feda0eaaa86e7539ef8c6720176f88
## Why
After a settings update during an active turn, spawned agents could inherit the turn's initial model and reasoning settings. Effort-only overrides could also be validated against the wrong model.
## What changed
Build child configuration from the invoking step's captured model, effective reasoning effort, and reasoning summary in both multi-agent versions. Validate effort-only overrides against that captured model's supported reasoning levels.
## Testing
Add regression coverage for spawning after an active-turn settings update in both multi-agent versions, including effort-only overrides. Update configuration tests to check captured settings and the model's default reasoning effort.
GitOrigin-RevId: 068bdb744149048829cdaa68d254b62e96e6e6af
## Why
Clock provider failures can abort a turn while preparing time context or running clock tools. Allow turns to continue with an explicit indication that the current time is unavailable.
## What changed
- Add `features.nonfatal_clock_read_errors`, disabled by default, to report clock failures to the model without failing the turn.
- Emit a generic `failed to read current time` notice for context reads and tool errors, without exposing provider error details. Deduplicate context notices per turn and compaction window, and remove inherited notices from forked subagent context.
- Omit unavailable environment dates and explicitly clear previously visible dates with `<current_date status="unavailable" />`.
- Return external sleep clock failures to the model when the feature is enabled, preserving sleep item completion notifications.
## Testing
Add coverage for continued inference after clock failures, notice deduplication across compaction, subagent notice filtering, environment date removal and recovery, and sleep failures during initial and polling reads.
GitOrigin-RevId: a39c3723c06a6f786d8ad59d667e8b9f626c973e
## Why
Direct tool-call records need to stay associated with the invocation that produced each output, including when call IDs are reused. Completeness must describe the recorded call inventory, independently of tool success.
## What changed
- Attach direct-call records to outputs before they enter history, and set `tool_calls_complete` when the invocation's arguments are fully recorded.
- Bound pending recordings and retained metadata, release reservations on completion or cancellation, and invalidate pending records when capture is disabled.
- Apply request budgets to direct metadata and strip it from inference and compaction inputs when capture is disabled.
- Remove executed-call metadata from app-server raw response notifications and exclude its size from Guardian history retention budgets.
- Track call IDs that bypass dispatch so their reuse cannot incorrectly establish Code Mode completeness.
## Testing
Add regression coverage for direct-call attribution, malformed calls, metadata budgets, cancellation, configuration changes, compaction, notification filtering, and Guardian context isolation.
GitOrigin-RevId: 2ebd39c7f141d04788736491495109841656b4c0
## Why
Delegated usage should retain the trigger of the turn that initiated it, including composer input and scheduled automation.
## What changed
Propagate `turn_trigger` through agent spawning and follow-up messages in both multi-agent tool implementations. Apply the supplied trigger when pending mailbox work starts a new turn.
## Testing
Extend tests to verify trigger propagation to spawned and nested agents, updated triggers on reused agents and peer follow-ups, and preservation of the active turn's trigger when steering.
GitOrigin-RevId: e8fea208587c633fec7cb3f1c0815ff91d1a44e5
## Why
Forked threads reported `startup`, causing startup hooks to run again even when their context was inherited from the parent. Resuming with supplied history also reported `startup` instead of `resume`.
## What changed
- Add `fork` as a `SessionStart` source and expose it in the hook input schema.
- Report `fork` for histories with a fork parent and `resume` for supplied histories without one.
- Continue dispatching `SubagentStart` for spawned subagents with either fresh or forked context.
## Testing
Add regression coverage for fork hook matching without duplicate startup context, resume hooks with supplied history, and `SubagentStart` context injection for fresh and forked subagents.
GitOrigin-RevId: 5ac1ae4ab8adcbbbceb8cb0ffb9b32b6402c585b
## What changed
- Route manual and automatic remote compaction through the v2 implementation.
- Retire the `remote_compaction_v2` feature toggle while continuing to advertise it in the model client beta features header.
- Migrate compaction tests from `/responses/compact` to streamed `/responses` requests with `compaction_trigger` items and remove legacy parity coverage.
## Testing
Add streamed compaction coverage for tool search output trimming and session base instruction token estimates. Update app-server tests to verify started/completed notifications for both local and streamed remote compaction.
GitOrigin-RevId: cea392a6166a9b116ff83708fd9126d5546476e4
## 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
- Match parent follow-up responses by tool call IDs in the grandchild context baseline test, and assert that the grandchild completes with `done`.
- Drive delayed terminal output with newline-delimited stdin instead of sleeps, keeping the process alive across three `write_stdin` calls and updating the expected stdin events.
GitOrigin-RevId: 433954e5ed5ecce920cf198d1bf1264e58178ba6
## What changed
- Cover the default, explicitly enabled, and explicitly disabled states of
`tools.update_plan.enabled`.
- Verify prompt tool lists remain consistent across requests, including when
custom base and developer instructions are configured.
- Explicitly enable `update_plan` in existing fixtures that depend on the tool.
GitOrigin-RevId: 3be279cb5195dfc5892c2c8ff6a1461fac879309
## What changed
- Treat a surviving full world-state snapshot as a context baseline when a fork removes the associated user message.
- Restore the previous turn settings and reference context from that baseline, without treating the segment as a user turn for rollback.
- Ignore partial snapshots and full snapshots superseded by compaction.
## Testing
- Cover resumed rollout reconstruction with removed task messages, partial snapshots, and compaction.
- Verify nested agents inherit developer instructions and environment context exactly once across history modes and compacted histories.
GitOrigin-RevId: 9f9f6992d7ea8cff9ac82a7fcdf0c8fb764db81c
## What changed
- Add an optional `multi_agent_reasoning_effort` field to model metadata.
- When `Ultra` is selected, use a supported catalog override when present. Otherwise, prefer `max`, then the highest supported non-`ultra` effort, and finally `medium` when the model has no reasoning levels.
- Preserve existing request behavior for other reasoning efforts, including mapping `persistent` to `disabled`.
## Testing
- Cover configured, missing, unsupported, and empty-catalog fallbacks for both parent and spawned-agent requests.
GitOrigin-RevId: b7ef576f32e0ea95ef38bf95c25789ed16aae94e
## Why
Pending user input or agent mail could cause a regular task to restart immediately after a terminal compaction error, retrying the failed turn instead of completing it and preserving the pending input.
## What changed
- Stop the regular-task continuation loop when the turn records a terminal error.
- Allow turn completion to persist pending input so a later explicit request can retry it after the error is resolved.
## Testing
Added coverage for pre-turn and mid-turn compaction failures with steered input, queued agent mail, and mail that triggers a turn.
GitOrigin-RevId: 48c7a2cba44ac2444957556dd94910fb34515f09
## What changed
- Record the initiating agent path when inter-agent communication triggers a turn.
- Emit completed subagent activity to that agent's turn instead of always using the completed agent's parent thread.
- Keep parent-directed completion messages unchanged.
## Testing
Added a multi-agent v2 regression test where one sibling requests follow-up work from another and receives the resulting completion activity on the requesting turn.
GitOrigin-RevId: 949dd1116cccdd461c66a9b213a5bcd554cb3720
## Why
A Multi-Agent V2 child can finish after the parent turn that spawned it, so its
successful completion needs to remain associated with that parent turn in
notifications and history.
## What changed
- Add `completed` to `SubAgentActivityKind` and emit the corresponding started
and completed item events on the spawning parent turn when a child succeeds.
- Persist completed activity as a canonical turn item in both legacy and
paginated history, and expose it through app-server history and schemas.
- Render completed activity as terminal in the TUI without counting it as a
separate tool call or tool-runtime event.
## Testing
- Cover successful completion in legacy and paginated history, late updates to
completed parent turns, TUI rendering, analytics, and rollout tracing.
- Verify that terminal child errors do not emit completed activity.
GitOrigin-RevId: 6c71eb8b10e7327611c6af84f70e294e27d94d02
## What changed
- Add a dedicated contextual fragment for developer instructions that emits the
`generic.developer_instructions` content kind.
- Use the fragment when adding child-specific developer instructions to a
full-history subagent fork, preserving their classification and ensuring they
reach the child exactly once without appearing in the parent request.
## Testing
- Extend full-history subagent coverage to verify the child-only instructions'
annotation, placement, and count.
GitOrigin-RevId: 82589d311535225fed76d500a19458fda72f40f2
## What changed
- Represent compaction summaries and Guardian-approved actions as typed contextual fragments.
- Inject subagent notifications through the same fragment path.
- Annotate the resulting request items with `compaction.summary`, `guardian.approved_action`, and `multi_agent.subagent_notification` content kinds while preserving their existing roles and text.
## Testing
- Verify the content-kind metadata on compacted summaries, approved actions, and subagent notifications.
GitOrigin-RevId: 01c93e7f08b2dc1c1e85ba69e82bfb5f56e6cca5
## Why
Developer-message content and its positional `content_item_kinds` metadata must stay aligned when parent history is prepared for a spawned agent.
## What changed
- Filter and rewrite developer-message content as annotated content so each retained item keeps its matching kind.
- Rebuild both message content and annotation metadata together after removing parent-only instructions and multi-agent usage hints.
## Testing
- Extend forked-history coverage to verify retained annotation kinds.
- Assert that spawned child requests contain the same number of content items and annotation kinds.
GitOrigin-RevId: 59748d9e8c4fc06ef8e5b90389bcf40465589f90
## Why
Guardian reviews were reported with the generic `subagent` thread source, making them indistinguishable from other delegated threads in persisted metadata and analytics.
## What changed
- Add the `guardian_review` thread source to the core protocol and app-server schema.
- Assign it to Guardian reviewer sessions and propagate the configured source through turn metadata, rollouts, and analytics.
- Continue treating Guardian reviews like subagents for paginated history and trusted-provenance checks.
## Testing
- Cover protocol round trips, delegate source selection, emitted analytics, request metadata, and persisted rollout metadata.
GitOrigin-RevId: 07480c122715812874c9d3b48bb39fc5c86b2367
## 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
## Why
Developer messages can contain both inherited agent policy and unrelated context. Full-history forks need to replace the parent policy without dropping the unrelated content that shares its message.
## What changed
- Filter fork-specific developer instructions by content item instead of excluding an entire developer message.
- Remove inherited multi-agent mode instructions before applying the child agent's current mode.
- Preserve unrelated content items and discard developer messages only when filtering leaves them empty.
## Testing
Extend agent-control and subagent notification tests to cover compound compacted messages, multi-agent mode instructions, and proactive-to-explicit mode transitions.
GitOrigin-RevId: 028834e237d8636c13b17a724574bc8eb09a55ba
## What changed
- Add model-catalog messages for root and subagent roles, explicit delegation, and delegation hints.
- Resolve role instructions in config, catalog, then bundled-default order, while preserving empty values as an explicit way to suppress fallback text.
- Refresh catalog-provided role and mode instructions when the model changes, and give full-history forks the selected child model's subagent role without retaining the parent's role guidance.
- Keep existing config overrides and reasoning-effort behavior, including proactive delegation for ultra reasoning effort.
## Testing
- Cover message deserialization and preservation through model overrides.
- Cover precedence, empty overrides, model switches, resumed sessions, and full-history subagent forks.
GitOrigin-RevId: 4625cf7c6a5490176adddfaa0fb99100707daea9
## What changed
- Exclude current-time reminder developer messages when copying parent history into a full-history subagent.
- Keep the child's newly generated reminder, preventing inherited reminders from accumulating while preserving the rest of the forked context.
## Testing
- Extend the full-history V2 spawn test to verify that two reminders in the parent become one fresh reminder in the child request.
GitOrigin-RevId: fb61c72f7f0d61d1068f2c599a8b8caf1788b7e2
## 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 `codex-history` for model-history and persisted-rollout domain types, including `RolloutItem`, `RolloutLine`, `CompactedItem`, and initial/resumed history state.
- Re-export the persisted types from `codex-rollout` and update consumers to use the new crate boundary instead of `codex-protocol`.
- Preserve existing rollout serialization, including legacy numeric compacted-window IDs.
## Testing
- Add `codex-history` tests for rollout JSON round trips, compacted-history compatibility, persisted history modes, and multi-agent version selection.
GitOrigin-RevId: 944daa9297ddd231d3aebbdcb05fff4adf8b4e1b
## Why
Forked subagents can inherit a parent's compacted history, but their context-window metadata needs to identify the child and start a distinct window lineage.
## What changed
- Always identify context windows by agent name and remove the `features.token_budget.mode` setting.
- Persist the agent path in world state and emit context-window metadata as a standalone developer message when the identity changes.
- Reset inherited compaction metadata to the forked subagent's initial context window and restore that window in session state.
## Testing
Extend the full-history subagent test to verify parent and child world-state snapshots, agent identities, distinct window IDs, and the reset child checkpoint.
GitOrigin-RevId: 6584201e57b3d2fba0ce626b89a8b3b0b3c752db
## What changed
- Allow multi-agent v2 parents to spawn any visible model that has not explicitly disabled multi-agent support.
- Expose collaboration tools to child agents only when their selected model supports multi-agent v2, keeping legacy models as leaf workers.
- Preserve a worker's selected model when reloading it into residency.
- Propagate multi-agent capability metadata to Amazon Bedrock model entries so delegation is gated consistently.
## Testing
- Cover model selection, leaf-worker tool visibility, Bedrock capability handling, and model preservation after reload.
GitOrigin-RevId: 1457adb1a09806d1f0621311d5a42a6815b9dd4e
## What changed
- Preserve `encrypted_function_args` on function calls so an empty list can mark plaintext collaboration arguments across request replay.
- Deliver `spawn_agent`, `send_message`, and `followup_task` payloads as structured plaintext agent messages when that marker is present; retain encrypted delivery otherwise.
- Redact plaintext collaboration arguments from tool and communication logs, and omit the metadata when sending requests to non-OpenAI providers.
## Testing
- Cover serialization of empty encrypted-argument metadata and plaintext versus encrypted subagent message delivery.
- Verify plaintext tool arguments are redacted and provider-specific metadata is removed from non-OpenAI requests.
GitOrigin-RevId: 64db98ff0b61a3af2f04ed609292363f2e2362a8
## 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
- 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
- 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
## Why
Agent roles can override the model or reasoning effort after the initial
`spawn_agent` configuration is validated, leaving an unsupported combination
unchecked.
## What changed
- Validate the final reasoning effort against model metadata whenever a role
changes the spawned agent's model settings.
- Preserve independently configured subagent defaults when a role does not
override them.
- Apply the same role validation in both multi-agent spawn implementations.
## Testing
Added coverage for independent model and reasoning defaults, instruction-only
roles, and rejection of a reasoning effort unsupported by a role-selected
model.
GitOrigin-RevId: 1885314e9380f778603f067fc04a6225ee963428
## What changed
- Apply `agents.default_subagent_model` and
`agents.default_subagent_reasoning_effort` when a spawn request does not
provide explicit values, including agent job workers.
- Allow full-history forks to use configured defaults or explicit model and
reasoning-effort overrides while retaining the parent conversation context.
- Preserve the selected model and reasoning effort when an agent role does not
override them.
## Testing
- Cover configured defaults, explicit override precedence, full-history forks,
role application, and agent job workers.
GitOrigin-RevId: b1efa8c9abeee82355088fceef57560433144595
## What changed
- Inherit paginated history mode when spawning or forking a subagent from a paginated parent.
- Load the parent's model context when forking and persist it as an inherited rollout prefix, while excluding that prefix from the child's projected turns, items, and metadata.
- Record the boundary between inherited context and child history, and reject partially initialized paginated subagent rollouts on resume.
- Resume paginated subagents from their stored model context instead of legacy rollout history.
## Testing
Added coverage for fresh and forked paginated subagents, compacted-history forks, model-context resume, inherited-prefix projection, metadata isolation, and incomplete-prefix detection.
GitOrigin-RevId: e57dc37c29aa4aaaf57b052b991be591d730e5ba
## What changed
- Add `supports_reasoning_summary_parameter` to model metadata, defaulting to
`true` for backward compatibility.
- Omit `reasoning.summary` and its summary-delivery stream option when the
selected model does not support the parameter.
- Apply the capability of the final selected model when a spawned agent uses a
different model.
## Testing
- Cover unsupported models in regular requests and spawned-agent model
overrides.
GitOrigin-RevId: 72b783799fc0685cef1501ef2dbf62d1308ceead
Alex Daley