## What changed
- Separate native child spawn preparation from submission and move forked-history loading and filtering into `agent::history`.
- Group resolved session startup dependencies in `ThreadStartupContext` and extract helpers for effective spawn configuration and inherited environment requests.
- Share loaded-recipient message submission and capture only the content needed for communication logging, avoiding a clone of the full message.
GitOrigin-RevId: 4417ba6ca35e9f293064600f0a54932de514636f
## Why
Local administrators need to require managed configuration from a specific customer-hosted server before a session can start.
## What changed
- Add a local managed `config_server` requirement with an HTTPS base URL and optional OAuth settings. Validate endpoints and derive the bundle route as `codex/config/bundle` beneath the base URL.
- Replace the entire `config_server` block when a higher-priority requirements layer supplies one, keeping the endpoint and OAuth settings together. Reject this setting in fetched policy.
- Track the applied server through configuration snapshots, role overrides, and refreshes. Reject session startup and managed refreshes when the applied server does not match the requirement; user refreshes retain the session's managed configuration.
## Testing
Add coverage for missing, mismatched, and matching server configuration at session startup, whole-block replacement, rejection of server settings in fetched policy, and preservation across role overrides and refreshes.
GitOrigin-RevId: 51e8a1738dabdb117ae858120f6fb09ae2ff1261
## What changed
Store `RolloutItem::SessionMeta` and `RolloutItem::Compacted` payloads in `Box` values and update their producers, consumers, and test fixtures. Preserve the existing serialized rollout format.
GitOrigin-RevId: 59fcc4beb47d23160872dcb6e95ace9b142d3d11
## What changed
Add `MessageLifecycleContributor` hooks to capture extension state when local agent control publishes a message and notify contributors when the recipient commits it to history, before sampling.
Carry shared delivery state through submissions, input queues, and mailbox eviction with `PendingAgentMessage`. Notify consumption at most once per delivery, release captured state when consumed or abandoned, and drop pending mail outside queue locks. Preserve the serialized message format without republishing restored history.
## Testing
Extend the mailbox eviction test to verify that publication state survives eviction and retained messages are consumed before the first resumed model sample.
GitOrigin-RevId: 9a1f6832bd48ec646a3fd179485c095e8dcc72cc
## What changed
Expose `PromptCacheKey` through `StartThreadOptions` with three policies: retain the default session-derived key, send a custom key, or omit `prompt_cache_key` from model requests. Keep session identity headers independent of this policy.
Propagate the policy to child agents, delegated sessions, and guardian review sessions. Hosts must reapply the policy when resuming a thread from storage.
## Testing
Add coverage for all three policies across turns, including unchanged session and thread headers. Extend subagent coverage to verify inheritance of the default and omitted-key policies.
GitOrigin-RevId: f9e8ab31fcf568636f9712726760e4e9a4672428
## 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
## Why
Temporary environment attachments for a parent turn should not become a
subagent's persistent environments. Children also need to retain their
configured executor bindings when their runtime is evicted and reloaded.
## What changed
- Add the disabled-by-default `subagent_thread_environments` feature flag.
When enabled, both subagent implementations inherit configured thread
environments captured with the invoking step, excluding turn-only attachments.
- Track configured bindings separately from active turn attachments, preserving
pending configuration ownership and sharing completed executor startup.
- Retain configured selections and bindings across idle eviction. Reload children
using retained bindings when the parent changes workspace, while continuing to
validate current parent roots and permissions for matching workspaces.
## Testing
Extend regression coverage for configured, empty, forked, pending, and legacy
inheritance; temporary attachment removal across eviction; and reload behavior
with changed workspaces, deferred startup, and restricted permissions.
GitOrigin-RevId: 15692ecd99deb38002014b44fd859d793bd54373
## What changed
- Remove `subagent_thread_environments` and the separate configured environment bindings. Spawned agents inherit the invoking step's environment snapshot.
- Retain environment selections across child eviction without retaining executor bindings. Reload V2 children against the parent's captured environments, requiring matching environment IDs, working directories, and workspace roots while preserving permission validation.
GitOrigin-RevId: d820c63ea20f5834ed88071d16c60683f2545406
## Why
Temporary environment attachments for a parent's turn should not become a child's persistent environment configuration or survive child eviction.
## What changed
- Add the default-disabled `subagent_thread_environments` feature flag. When enabled, subagents inherit configured thread environments captured with the spawning step instead of active turn selections.
- Track configured bindings separately from turn attachments, preserving pending configuration ownership when turn selections change.
- Retain configured bindings across child eviction and reload, excluding temporary attachments. Preserve the child's workspace when the parent switches workspaces, while enforcing current roots and permissions when the parent still configures the same workspace.
## Testing
Extend coverage for both multi-agent versions, forked children, empty configured environments, pending configuration, and legacy inheritance. Add eviction and reload cases covering temporary attachments, workspace changes, deferred executor startup, and permission validation.
GitOrigin-RevId: 4533645503d5f863a9ccc064386ed7ca169d98b7
## Why
Configuration loading can finish before a pending startup is visible to the thread manager. Reloads need a cancellation scope that also covers these configuration snapshots.
## What changed
- Capture an enterprise managed authentication (EMA) cancellation token before loading configuration and carry it through config layers, role overrides, runtime refreshes, and `McpConfig`.
- Cancel the previous scope on MCP or user configuration reloads and cloud config loader changes, then create a fresh scope for subsequent loads.
- Cancel the session's token when enterprise MCP authentication is disabled or a refresh leaves it unavailable.
## Testing
Extend the MCP reload test to verify that existing thread and pending startup tokens are cancelled while a fresh startup receives an uncancelled token.
GitOrigin-RevId: 5fc0658b74c360e7dc9ab3488339fcf19bfe9fae
## Why
Cloning `ResponseItem::AdditionalTools` deep-copies its tool declarations for history and request copies.
## What changed
Store `tools` in an `Arc<[serde_json::Value]>` so clones share immutable declarations. Update constructors and existing test fixtures to use the shared representation.
GitOrigin-RevId: eb8831774afb45fe8431a796f34ae9d1243e884a
## 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 `ThreadStoreError::Retryable` for transient failures known to be safe to retry and `ThreadStoreError::OutcomeUnknown` for writes that may already have committed. Recovery remains the operation owner's responsibility; neither category automatically triggers retries.
Preserve existing app-server error mappings and fatal session startup behavior, and report the new categories in shutdown diagnostics without exposing raw error payloads.
## Testing
Add coverage for conservative SQLx error classification, mutation error mappings, session initialization categories, and shutdown diagnostics that omit raw error payloads.
GitOrigin-RevId: 259a9bfaa6ff3cbfa2ee61a01a1f1e744c90f118
## What changed
Recognize `codex_app.create_thread` deliveries when capturing sender context so Guardian receives the sender's recent user messages and assistant context for delegated tasks.
## Testing
Extend the sender-context integration test to cover `create_thread`, including reviewer-only context and clearing the snapshot on a subsequent delivery without sender provenance.
GitOrigin-RevId: 7a47c3ac5b9c9405e6728010c494529274b7b73d
## What changed
Replace duplicated content-kind strings with constants shared by fragment producers and consumers, including authorization checks, forked-history filtering, and memory instructions. Share the compaction summary kind between core and Guardian's transcript filter.
## Testing
Add a regression test verifying that Guardian excludes compaction summaries while retaining surrounding user messages, including a user message with identical text.
GitOrigin-RevId: 36dbdf0f82c61b52d2571ac1c392fb151c98151b
## Why
Incremental-tool windows recorded base instructions only at setup, so a catalog refresh for the same model could leave active instructions stale. Instruction changes need to reach the model without rewriting the existing history prefix.
## What changed
- Track model identity and instruction content independently, appending a `model_instructions` developer message when either changes. Explicitly mark replacement or removal of base instructions, and avoid repeating unchanged updates.
- Start new windows after compaction with the latest model instructions while preserving custom base instructions.
- Preserve the recorded window base during local compaction retries, including empty instructions, and rebuild current model instructions when reconstructing child context.
## Testing
Add integration tests and request snapshots for catalog refreshes, instruction removal, model switches, compaction, restart, and forks. Extend regression coverage for legacy snapshots and local compaction retries.
GitOrigin-RevId: eeca69067b4d9cd91c817732d79b4d5c1faa18b9
## Why
Message roles and content classifications do not identify who supplied each context part. Source attribution needs to survive prompt assembly and history truncation, including messages that combine text from different producers.
## What changed
- Add per-part `ContentItemMetadata` for user input, developer instructions, `AGENTS.md`, skills, harness context, command hooks, and tool context with optional callable namespaces.
- Carry attribution alongside content and classifications through contextual fragments, extension prompts, hook output, and agent messages. Keep tool-provided context-window hints separate from harness text.
- Preserve the source of retained text slices during compaction and attribute generated truncation notices to the harness. Default missing historical attribution to unknown.
- Attribute host MCP calls using cached tool namespaces only when catalog revisions remain stable, without starting servers or refreshing catalogs for attribution.
- Send the new metadata to Responses Lite and strip it from requests to endpoints that do not support it.
## Testing
Extend compaction tests to cover mixed sources, missing or extra metadata entries, and discarded media. Update Responses Lite request assertions to verify endpoint-specific attribution handling.
GitOrigin-RevId: b0ebc929b7c60f3ec49d1affbf897312d63edcc8
## Why
Cancellation after initial input admission could leave a child registered even though the spawn caller had not received its result.
## What changed
Resolve the child's status and configuration before committing reservations and releasing provisional ownership. This keeps cancellation cleanup active through the final awaits and lets the spawn result return without yielding after commitment. Cancellation after the result returns does not retract the accepted child.
## Testing
Add a regression test that cancels spawn during the final status lookup after input admission and verifies that the child is unregistered, terminated, and unloaded, and that shutdown completes. Extend the provisional-child cancellation test to cover both native V1 and V2 callers.
GitOrigin-RevId: 028b873ad4c1fac2c4b5d1dc823b4561ff19e6bf
## What changed
- Add the disabled-by-default `output_token_replay` feature to request `output.encrypted_content` from OpenAI providers.
- Preserve encrypted message and tool-call output, message and function-call status, and output-text `annotations` and `logprobs` through history and replay. Update the generated protocol schemas and SDK types.
- Strip output ciphertext from requests to other providers while retaining it in stored history, including after replay is disabled. Remove encrypted content from memory extraction inputs.
## Testing
Add integration coverage for the feature/provider combinations, metadata replay across follow-up requests, and history preservation when resuming with replay disabled.
GitOrigin-RevId: 77729a021b6771933402aebe74ece8eb39c057e2
## What changed
Add `model_messages.tools.incremental_tools` overrides for the update hint, tool and namespace removal headers, and namespace instruction update and clearing messages. Missing, null, or over-512-byte values fall back to bundled wording; empty strings omit static text while retaining runtime names and instructions.
Substitute `{name}` in namespace message templates and append runtime instructions verbatim. Wording changes alone do not trigger tool catalog updates.
## Testing
Extend unit tests and MCP request-history snapshots to cover custom wording, empty notices, tool removal and restoration, and namespace instruction changes and clearing without repeating unchanged tools or notices.
GitOrigin-RevId: 22dea0a6fb4cfcd646f5e65346424834c8b7d5a2
## What changed
Add the disabled-by-default `subagent_default_context_limits` feature and expose it in the configuration schema. When enabled, shared configuration for spawning and resuming subagents clears inherited `model_context_window` and `model_auto_compact_token_limit` overrides so subagents use their model's default context window and auto-compaction threshold.
GitOrigin-RevId: 5168ae2b4fbe72c533d8c6152922a8bceb2c5cbd
## What changed
Add `preserve_fork_prefix` to the multi-agent v2 configuration, defaulting to `false`. When enabled, full forks retain the parent's model-visible history, including commentary and tool records, and append the child's instructions. Legacy compaction without a reusable context baseline still rebuilds the child context.
Mark copied history as inherited, complete unfinished tool calls in the fork snapshot, and exclude inherited manual approvals from authorization review while retaining them in model context.
## Testing
Add coverage for preserved request prefixes, child instructions, legacy and paginated histories, Code Mode, missing inherited tool outputs, compaction fallback, and approval isolation across checkpoint replay. Update the noisy helper failure test to read its response before starting cleanup.
GitOrigin-RevId: ce9235dfa111c88d6ce66cb93d564fb63b326489
## What changed
- Remove `ContentItemMetadata`, provenance and namespace types, and the `content_item_metadata` protocol field while retaining `content_item_kinds` classifications.
- Simplify context fragments, extension contributions, and hook output to carry content without source attribution. Return MCP tool results directly without an attribution wrapper.
- Render context-window hints together in a single text fragment.
## Testing
Update Responses and Responses Lite request assertions to expect content-kind classifications without per-content attribution, and adapt context, hook, and extension tests to the simplified types.
GitOrigin-RevId: 201894cd4c93c6d4b4c41c845e7a9af1dd3c95ca
## What changed
Move incremental tool guidance out of namespace descriptions and into a developer message preceding each namespace declaration batch after the initial catalog. The notice covers newly added namespaces as well as changed ones, explaining that earlier tools remain available unless explicitly removed and that newer definitions replace earlier ones.
Retain the notice alongside tool declarations in full-history agent forks, and discard it when legacy compaction forks rebuild those declarations.
## Testing
Add unit coverage for multiple new namespaces sharing one notice. Update request-history snapshots for tool changes, removals and restoration, and regular Responses requests. Extend resume and fork tests to cover notice preservation without duplication and removal when rebuilding declarations.
GitOrigin-RevId: 05f79f5eb378a355cf935eabf63951015a9b454b
## Why
Subagents should retain the spawning turn's selected skills and plugin choices whether `fork_turns` is `none` or `all`. Capability selection should not depend on copied conversation metadata.
## What changed
- Use a shared child startup path for fresh and history-forked agents, inheriting selected capability roots from the spawning environment snapshot.
- Pass the spawning turn's `disabled_plugin_ids` through both spawn handlers. When omitted, inherit the parent's current choices; explicit lists, including an empty list, override them.
- Resolve the parent before startup so inherited client MCP settings apply even when only the session source identifies the parent.
- Carry plugin choices into delegates with inherited isolation and preserve saved capability roots when resuming a child.
## Testing
Add regression coverage for executor skill listing and reading, plugin MCP registration with both history modes, plugin overrides, capability-root precedence and isolation, and restoring saved child settings after parent settings change.
GitOrigin-RevId: 2a6891a9bc6372fd2d1f30add2b5611f96b60594
## What changed
- Add `ContentItemMetadata` to distinguish user input, developer instructions, `AGENTS.md`, skills, harness context, and tool-supplied context independently of message role and content classification.
- Keep attribution attached to content through prompt assembly, history processing, and hook-output spilling. Distinguish command hooks from MCP hooks and retain tool namespaces when known.
- Treat missing historical attribution as unknown and send per-content metadata only to Responses Lite.
## Testing
Update request and history assertions to cover attribution persistence and Responses Lite metadata handling.
GitOrigin-RevId: 24e56005f5bdb98bf82f2b3943f29c4c81f3d587
## What changed
- Use the standard shell executor and remove the zsh fork escalation runtime, `codex-execve-wrapper`, and `shell-escalation` crate.
- Ignore `shell_zsh_fork` and `unified_exec_zsh_fork`, emit migration notices for legacy configuration, and warn when ignoring managed requirements for these flags.
- Keep the active session's `apply_patch` alias directory readable under restricted filesystem permissions.
## Testing
Add coverage for legacy configuration startup and shell execution, migration notice rendering, active alias directory selection, and nested `apply_patch` execution while other files in `CODEX_HOME` remain unreadable.
GitOrigin-RevId: 43af461fea32b4980550ee7237effd2bc0646ed8
## What changed
Add `cancelled_v2_send_finishes_reload_registration` to verify that cancelling a multi-agent V2 send during an evicted child's reload does not cancel registration. The test checks that the thread-created notification arrives and evicted-environment state is cleared.
Evict and reload the child again with only one child slot available to catch leaked residency pins or reservations, and verify that only the subsequent follow-up message is delivered.
GitOrigin-RevId: ce6ed90d0049245370f26d8dbb35b9f1cd0b3063
## What changed
- Route app-server idle unloading of multi-agent v2 children through local eviction that preserves unread mail and environment selections for reload.
- Hold residency pins through input submission so newly reloaded children cannot be evicted before receiving their work.
- Guard listener cleanup against replacement runtimes and subscriptions, and reject local eviction of host-controlled threads.
## Testing
Add coverage for unsubscribe-driven eviction followed by `followup_task`, verifying restored conversation context and exactly-once delivery of queued mail. Extend tests to check that residency pins block eviction and that rejected host eviction preserves the thread and mailbox.
GitOrigin-RevId: e36723730af683d2081e495e637f0e6d23548b8d
## Why
Guardian cannot capture sender instructions from another host when the sender thread is absent from the receiver's local runtime.
## What changed
Fall back to the authenticated thread store to reconstruct sender history without resuming the sender. Respect compaction and rollback, and label persisted evidence to indicate that newer unpersisted messages may be missing.
Limit storage reads to five seconds and capture sender context before acquiring the active-turn lock. Bind the captured evidence to the turn that accepts the delivery, allowing an existing turn to finish while the read is pending.
## Testing
Add cross-host scenarios for legacy and paginated history that verify sender evidence reaches only Guardian and excludes rolled-back permissions. Add a gated storage-read test that verifies turn completion remains unblocked and evidence is bound to the newly accepted turn.
GitOrigin-RevId: fe896f4e82fe3e32017fe4884846f3fa90a87949
## Why
Agent tree shutdown previously returned a generic error without identifying which operation or thread failed, making cleanup failures difficult to diagnose.
## What changed
- Add `AgentTreeShutdown::wait_detailed()` and public report types while preserving the existing `wait()` result and error message.
- Record operation, optional thread ID, and either an abandoned teardown guard or a failed phase with a payload-free error category across session cleanup, child spawn cleanup, and resident eviction.
- Give each tree a correlation ID, log each failure, and retain up to 64 failures with a count of additional failures omitted. Record failures before releasing tree membership so all completed waiters observe the same report.
## Testing
Add unit coverage for aborted and completed teardown, cloned guard context, concurrent and repeated waiters, omitted failure counts, and report formatting without raw error payloads. Extend integration coverage for successful tree shutdown and persistence writer failures, including compatibility with `wait()`.
GitOrigin-RevId: 68784af28b63e875b00a55d78729f0cc5b01ac15
## Why
Capability discovery needs the roots captured with each environment snapshot. Threads sharing an executor can select different roots, and changing environment order must preserve executor skill aliases.
## What changed
- Attach the receiving thread's capability roots when constructing `TurnEnvironmentSelection` at startup and settings updates, including roots loaded from saved history.
- Resolve capability roots from environment snapshots while preserving their original order. Retain startup roots so deselecting and reselecting an environment restores its capabilities.
- Match inherited configuration by environment and workspace so differences in capability root metadata do not interrupt configuration propagation.
## Testing
Add regression coverage for root ordering across environment states and configuration changes, independent root selections on a shared executor, reselection with startup or saved roots, active turn updates, and pending configuration failures reaching child and grandchild threads.
GitOrigin-RevId: 4f2e4bb414d27195a6752406117a6050718a1198
## Why
Changing the incremental tools setting on resume should not move tool declarations and base instructions within an existing context window.
## What changed
- Determine the current window's tool declaration mode from its history, and apply the incremental tools setting when building a new window after compaction or a context reset.
- Use that mode consistently for sampling, remote compaction, startup prewarm, prompt debugging, and Guardian input budgeting.
- Preserve tool declarations alongside their comparison baseline in full-history agent forks, including compacted histories; remove them together when rebuilding context.
## Testing
Add request snapshots covering legacy resume, migration after remote compaction or a context reset, disabling incremental tools, and tool updates after restart. Extend agent fork and WebSocket startup prewarm tests to cover retained declarations and incremental tools.
GitOrigin-RevId: 7c46849a1788027a8435082e4d1f7e7f48d2700c
## 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
## Why
Clients starting delegated work need to attribute descendant turns to the original turn and retain that attribution through completion and history reads.
## What changed
- Accept optional `parentTurnId` and `rootTurnId` in `turn/start`, and expose `rootTurnId` on returned turns and lifecycle notifications.
- Default new turns to their own root when none is supplied. Preserve the active turn's root when steering, ignoring incoming lineage fields.
- Carry root IDs through completion, interruption, recovery, and fork boundaries, and persist them for paginated history reads. Leave unknown roots null in older history.
- Update protocol schemas and generated TypeScript and Python bindings.
## Testing
Extend coverage for default and explicit roots, steering without changing lineage, interrupted and recovered turns, history reads after restart in both history modes, nested fork pagination, and compatibility with older database writers.
GitOrigin-RevId: f1a570a12bd11742929fd2e8b017e5d35aa07dcb
## Why
Recovering an interrupted turn replaced its original trigger with `retry` and restored only its root lineage from model context. Turns suspended before that context was written could lose their attribution entirely.
## What changed
- Persist regular-turn attribution in `TurnStartedEvent` and compaction resume metadata, including the trigger, parent and root turn IDs, and initiating agent path.
- Restore matching attribution during recovery, keep unknown triggers absent, and retain the model-context root fallback for older records.
- Reconstruct attribution from surviving turns across rollback and late completion or abort events, and clear inherited attribution when spawning a forked agent.
## Testing
Add coverage for repeated cold recovery, suspension before context persistence, legacy rollouts, fresh attribution on subsequent turns, compaction checkpoints, rollback, and late terminal events.
GitOrigin-RevId: 85b5763e8fbd48a1ea2c07cfda8196e63c2cd33a
## Why
Spawn failures can share an error kind and message despite different causes, such as execution and residency capacity limits. Telemetry needs enough detail to distinguish these failures without using error messages or correlation IDs as metric labels.
## What changed
- Add `AgentErrorContext` annotations for capacity limits, registry rejections, runtime availability, and spawn stages. Preserve the first annotation so outer stages retain the more precise failure origin.
- Add bounded `detail` and `error_kind` labels to spawn failure metrics, using `unknown` when no context is available.
- Emit spawn failure trace events with these classifications and the call and turn IDs for both multi-agent versions.
## Testing
Add tests for distinct capacity and registry failure contexts, preservation of manager, fork, and shutdown errors, and metric aggregation across different error messages and correlation IDs. Verify that annotations preserve existing error kinds and user-visible messages.
GitOrigin-RevId: 5bbe3d32f6ce408622f38e559fddeab05b8ccb65
## What changed
Increment `codex.multi_agent.result_delivery` when sending a terminal child result to its parent, with `outcome=queued` for queue acceptance and `outcome=failed` for delivery errors.
GitOrigin-RevId: 7571f66c2c2d2baea1a54dce3741f6393e809b66
## 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
Fast mode previously gated both Fast and Ultra Fast, preventing policies from allowing one while disabling the other.
## What changed
- Add the default-enabled `features.ultrafast_mode` flag and enforce it independently of `features.fast_mode` in service-tier selection, requests, and agent prewarming.
- Filter TUI service-tier commands and selections by the corresponding policy and model catalog support.
- Report `supportsIndependentSpeedModes: true` from `configRequirements/read` and update the protocol schemas and generated bindings. Retain the shared Fast gate when connecting to older servers that omit this capability.
- Preserve legacy cloud speed denials by translating `rbac-fast-mode` fragments with `fast_mode = false` into a denial of both modes, while retaining higher-priority enterprise overrides.
## Testing
Add coverage for all four Fast/Ultra Fast policy combinations in requirements responses and request routing, agent prewarm inheritance, TUI command visibility and saved selections, and legacy cloud denial normalization and override precedence.
GitOrigin-RevId: 147e08524c4b228ea9d46b25a9f8aa64c359e169
## Why
Partial answers contain answer fragments while a turn is still in progress. Treating them as final answers defers mailbox delivery and can count empty fragments as empty final responses; filtering them from forked histories and guardian transcripts loses answer content.
## What changed
- Allow mailbox preemption after `partial_answer` messages and keep mailbox delivery open.
- Preserve partial answers in forked agent histories and include them as protected assistant entries in guardian transcripts.
- Exclude empty partial answers from empty-final-response accounting for goals.
## Testing
Add regression coverage for partial-answer phases in live events, sampling continuations, follow-up requests, and forked child requests, plus mailbox preemption, goal accounting, and guardian transcript inclusion.
GitOrigin-RevId: 208c8933e211b42b6c2d0bec6952527b8c9c120e
## What changed
Introduce `TurnEnvironmentRequest` for caller-supplied environment input and construct `TurnEnvironmentSelection` at session startup and app-server settings boundaries. Update thread startup, default environments, and inherited environment handoffs to use requests, with explicit conversions when reusing runtime selections.
Move the environment types into `protocol::environment` while retaining their `protocol` re-exports. Update test fixtures and existing tests to build request inputs separately from runtime selections.
GitOrigin-RevId: 12e7daaece95aae136afae8b055b4dbaebdffc75
## Why
Reloaded subagent threads did not emit initialization analytics, and subagent initialization events always reported `new`.
## What changed
Emit initialization events for resumed spawned subagents before notifying thread listeners. Inherit parent client metadata before reserving a residency slot can evict the parent, preserve the thread's original `created_at`, and report `initialization_mode` as `resumed`. Refresh stored analytics metadata when a subagent resumes; newly created subagents continue to report `new`.
## Testing
Extend the cold-resume integration test to verify a single worker initialization event with the expected session, parent, source, resume mode, and original creation timestamp. Update serialization and session tests to check initialization modes.
GitOrigin-RevId: e78b0c4d88b6ddbe993ca7e1fe7717b6f74bf3d9
## Why
Reloading an unloaded root from a surviving child can supply the shared instruction wrapper already registered for that root. Replacing its underlying provider with that same wrapper makes instruction loading recurse into itself.
## What changed
Reuse the existing wrapper without replacing its provider when both are the same `Arc`. Continue to accept distinct replacement providers.
## Testing
Extend regression coverage to reload the root from a surviving child and verify that shared instructions still update. Check wrapper reuse, replacement with a distinct shared provider, and freezing the shared snapshot when switching to a provider that does not share with subagents.
GitOrigin-RevId: 7b6b2f9031f206e203f6fa14e1478a36b305ec39
## Why
Unread queue-only messages prevented idle agents from unloading, and sending a
message to an evicted agent reloaded its session. Pending mail should not require
an idle recipient to occupy a loaded thread slot.
## What changed
- Retain queue-only mail in an in-memory runtime mailbox when a session unloads.
Queue new messages for locally evicted agents without reloading them or
starting a turn.
- Add `AgentControl::take_mailbox` and `AgentControl::watch_mailbox` so sessions
can consume retained mail and react to host mailbox notifications.
- Preserve message order across eviction, reload, and subsequent follow-ups.
Keep agents with outstanding durable sleep or turn-triggering mail loaded,
and discard retained mail when an agent is removed or its tree shuts down.
## Testing
Add integration coverage for retaining mail across eviction, sending while
unloaded, and ordering messages around a follow-up after reload. Add a host
controller test verifying that mailbox notifications wake `wait_agent` and
that the message is delivered exactly once.
GitOrigin-RevId: 4b55647f9ee9d1aaf3753f0688863bda81617327
## Why
Subagents spawned without forked history do not receive their parent's client-defined dynamic tools, preventing them from using those tools for delegated work.
## What changed
Add the disabled-by-default `multi_agent_v2_dynamic_tools` feature flag. When enabled, fresh V2 subagents inherit the parent's dynamic tool definitions and persist them in session metadata.
## Testing
Add coverage for V1 and V2 feature gating, tool persistence, and a fresh V2 subagent calling an inherited tool and receiving its result without inheriting parent history. Update TUI assertions and a snapshot to reflect blank-line separation and question text in recovered answers.
GitOrigin-RevId: a17a16bf5570f54ce922c1521cffb883022354f2
## Why
A user restriction such as “Cancel the deployment” can fall outside the recent-message window after unrelated status questions. Guardian reviews need that restriction when assessing delegated actions.
## What changed
- Preserve root user messages during handoff relevance filtering, subject to the existing shared message cap.
- Apply handoff filtering during heartbeats while retaining saved heartbeat instructions and the active turn's trusted skills.
- Mark assistant context as incomplete when handoff filtering omits it, so ordinary user replies are not interpreted without their missing context.
## Testing
Add regression coverage for restrictions followed by status questions, bounded user history, omitted assistant questions, and trusted skills across first and repeated heartbeats. Update the delegation request-history snapshot.
GitOrigin-RevId: 67f77313572dc54225713cd7cdb90f06b0fbe030
## Why
Short sender replies such as `👍` need preceding assistant context to be understood during a delegation review. User messages alone omit that context.
## What changed
- Capture preceding assistant context alongside up to three recent sender user messages at delivery, for Guardian only. Label assistant messages as untrusted context rather than authorization or verified questions.
- Share the existing 900-byte budget per exchange, prioritize user evidence, and report unavailable assistant context.
- Recognize `cloud_threads.send_message` deliveries and accept both compact and indented delegation envelopes.
## Testing
Expand integration coverage for app, TUI, and cloud-thread deliveries, contextual replies, and budget-driven omissions. Assert that sender user and assistant context stays out of the delegated agent's prompt.
GitOrigin-RevId: 4eca369cbb30241635273f729dec81b78ea57faf
## What changed
Expose `ThreadManager::request_agent_tree_shutdown` and an `AgentTreeShutdown::wait` handle. Requests reject new starts in the shared runtime, cancel pending startup, and signal every session in that tree, including delegates outside the thread registry. Waiting covers admitted operations and session teardown, and reports cleanup or persistence writer failures. Other root trees remain unaffected; registry removal and persistence handoff remain caller responsibilities.
Retain tree membership through startup, cancelled spawn cleanup, residency eviction, and completion watchers. Release persistence resources before returning startup failures, and stop completion watchers during tree shutdown without reporting shutdown as a child result.
## Testing
Add coverage for tree isolation, children removed from the registry, delegate teardown, cancellation during required MCP initialization, aborted teardown, persistence writer failures, and successful retry after a failed resume releases its writer.
GitOrigin-RevId: a109e25adf23d20baf7595891099947050c6b6b5
ioanbudea-OAI