## What changed
- Preserve executor-native working directories, workspace roots, and permission profiles when preparing remote `exec_command` requests instead of resolving them through the host platform.
- Send sandbox intent to the remote executor, including a restricted-token default for Windows executors and `-NoProfile` for elevated PowerShell commands.
- Reject intercepted cross-platform `apply_patch` commands when filesystem writes are restricted, while continuing to allow them for unsandboxed or full-disk-write profiles.
## Testing
Extended remote unified-exec coverage for foreign Windows workspaces, elevated PowerShell, sandbox metadata, and restricted and unrestricted intercepted patches.
GitOrigin-RevId: 9fd328879fa2c15594fd58e40b6b32e8ba0847e7
## Why
Persisted base instructions need to retain whether they were explicitly customized or generated from a model template. Without that distinction, forks and config-lock replays can treat model-generated instructions as custom and keep the wrong template after a model or personality change.
## What changed
- Record custom or model provenance with base instructions in rollouts and config locks.
- Preserve custom instructions across model changes, while allowing model-generated instructions to follow the selected model and personality.
- Keep legacy rollouts without provenance compatible and propagate provenance through forks and spawned agents.
## Testing
- Cover provenance serialization and legacy rollout decoding.
- Cover role personality changes, forked model changes, config-lock replay, and multi-agent configuration.
GitOrigin-RevId: 801c26559835f558027ce5112700c0cd31fcb21b
## What changed
- Inject the host skill loader into `PluginsManager` so plugin discovery and agent turns use the same loading and product-policy behavior.
- Share plugin skill snapshots across those paths, preserving a consistent view of skills across workspaces.
- Apply migrated-command precedence after product filtering, allowing an eligible migrated command to replace a filtered native skill with the same name.
## Testing
- Add coverage for product-restricted plugin skills, native-versus-migrated command precedence, and the skills exposed to agent turns.
GitOrigin-RevId: f5ef0d0766ebeeb30d73ffaf044d003c2906ea4d
## What changed
- Clamp `wait_agent` timeout requests below `min_wait_timeout_ms` instead of rejecting them.
- Include the timeout adjustment in the wait result message and document it in the tool output schema.
## Testing
- Update the handler test to verify the configured minimum is honored and the adjustment is reported.
- Update the schema test for the expanded result message.
GitOrigin-RevId: 2b4a770ed6d1e9c45b351b479f5ae50c9a3d5388
## What changed
- Add `features.code_mode.default_exec_yield_time_ms`, defaulting to 30 seconds.
- Apply the configured default to code-mode `exec` calls that omit `yield_time_ms` and reflect it in the tool description.
- Remove the `code_mode_buffered_exec` compatibility feature flag.
## Testing
- Cover config loading and tool descriptions for both default and custom yield timeouts.
GitOrigin-RevId: 581ffc737b04721c7b5fc81260b1da1cf7d87523
## Why
Checking the tool search cache currently rebuilds search metadata for every deferred tool, even when an immutable tool runtime has not changed.
## What changed
- Track immutable deferred tools by runtime identity and dynamic tools by their current search metadata.
- Rebuild the search handler when the deferred registry, dynamic metadata, or source-listing mode changes.
- Keep only weak references to immutable runtimes in the cache.
## Testing
Added unit coverage for immutable handler reuse, registry and exposure changes, source-listing changes, and refreshed dynamic tool metadata.
GitOrigin-RevId: 024c6f4498d431e7bbfaecde420f77fcf8c0dba7
## 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
## Why
Multi-agent v2 rejected `agent_type` when `fork_turns` was `all`, forcing callers to choose between a configured role and the parent's full conversation context.
## What changed
- Apply an explicitly selected role to full-history forks, including its model and developer instructions.
- Preserve the parent's developer instructions when the selected role does not define its own.
- Keep the inherited conversation history and model-switch context intact.
- Update the `spawn_agent` schema to clarify that roles apply independently of history inheritance.
## Testing
- Cover full-history role overrides and developer-instruction precedence in multi-agent v2 tests.
GitOrigin-RevId: cd4f35e31d75f56289760f245bff38dd0233abe6
## What changed
- Add the gated `unified_image_budget` feature for models that support original image detail or Responses Lite.
- Apply one 6,000-pixel, 10,000-patch preprocessing limit regardless of legacy image detail hints.
- Hide detail controls from `view_image` and code mode while continuing to accept existing hints for compatibility.
- Preserve detail-based resizing and tool contracts for unsupported models.
## Testing
- Cover unified resizing limits, Responses Lite, legacy detail hints, unsupported models, and `view_image` integration in code mode.
GitOrigin-RevId: cb07bff1669a96599fdfd076b3d9ec80f2b6fff7
## Why
Resumed sessions need the current multi-agent usage instructions when configuration changes or the saved history predates usage-hint tracking.
## What changed
- Store multi-agent usage hints in world state and refresh changed or previously untracked hints before re-emitting the active multi-agent mode.
- Present `wait_agent` polling guidance in the overridable developer instructions only when the tool is enabled, instead of embedding it in the tool schema.
## Testing
- Cover cold resumes, changes to `wait_agent` availability, custom usage hints, message ordering, and tool-schema behavior.
GitOrigin-RevId: a9c6798d5dc2dedc8dadc49e0a80ff50a757ab83
## What changed
- Remove namespace tools named `tool_search` before registering the built-in
search tool, preventing them from sharing its model-visible surface.
- Record removed namespace tools as collisions so strict collision handling
reports their qualified tool names.
## Testing
- Cover direct and deferred MCP tools that use the reserved namespace.
- Cover strict collision errors for both direct and deferred conflicts.
GitOrigin-RevId: 28fff918b4358a67b167467d92728fa545b951d7
## What changed
- Add `transparentBackground` to image-generation items and legacy completion events.
- Map Images API backgrounds to `true` for transparent, `false` for opaque, and `null` for automatic or unavailable values.
- Preserve the metadata in live notifications and persisted or resumed thread history while continuing to deserialize older items that omit it.
## Testing
- Cover transparent, opaque, and automatic backgrounds, including image edits and thread read/resume flows.
- Verify the stable JSON shape and optional TypeScript field.
GitOrigin-RevId: 08527f37f23431df45fab1ed34eb82b2139b49d7
## What changed
- Move permission hooks, reviewer routing, approval caching, and user approval requests into the session-level approval flow.
- Have shell, unified exec, and apply-patch runtimes describe requests as `ApprovalAction` values, which now provide their hook payloads and cache keys.
- Pass a shared `ApprovalContext` through initial and retry approvals so telemetry and approval reasons are handled consistently.
GitOrigin-RevId: 5bfa61daa97e4427f3a648f6cf9d1c27f1551942
## Why
The 4 KiB aggregate limit can truncate source metadata before it reaches the
model through the tool search description.
## What changed
Raise the aggregate source-description limit to 512 KiB while retaining the
existing character-boundary-safe truncation and bounded output.
## Testing
Expand unit and RMCP round-trip coverage to verify that substantially longer
Unicode descriptions remain complete within the new limit.
GitOrigin-RevId: 002760cdd2e8741e531b45f75f8624ef84334d24
## What changed
- Propagate the optional `modelSpecialty` field through the model catalog and
app-server `model/list` response.
- When a newly selected model has the `cyber` specialty, default an active TUI
thread to workspace-write permissions with on-request approval. Use auto
review when available, otherwise keep the user as reviewer, while respecting
configured permission requirements.
- Show a notice when auto review is applied and strengthen the full-access
warning for cyber models.
- Preserve explicitly selected permissions when only reasoning settings change.
## Testing
- Cover auto-review defaults, requirement-aware fallback behavior, permission
preservation across reasoning changes, and the new warning notice.
GitOrigin-RevId: 8f25b0082d3051d9ff91f7355921236d0f82f758
## What changed
- Treat different non-empty descriptions for the same tool namespace as a
collision when `error_on_tool_collisions` is enabled, including deferred
tools.
- Continue allowing multiple tools to share a namespace when their descriptions
match or are empty.
- Preserve the first non-empty namespace description when strict collision
checking is disabled.
## Testing
- Cover strict collisions across direct and deferred tools, valid shared
namespaces, relaxed description merging, and failure before model sampling.
GitOrigin-RevId: 788a2ae0eccb64c97995af7a208d9abb79edf2d0
## What changed
- Derive sandboxing, approval, and permission-profile environment variables from the selected turn environment for shell, unified exec, `apply_patch`, image viewing, and network approval flows.
- Materialize project-root permissions against every workspace root in that environment, allowing `apply_patch` to write to secondary workspace roots while preserving protected paths.
- Carry the selected environment's permission profile into spawned or resumed agents and Guardian permission context.
## Testing
- Add an integration test covering `apply_patch` writes in a secondary workspace root.
- Extend tool, Guardian, and multi-agent tests to distinguish environment permissions from thread-level permissions.
GitOrigin-RevId: e22da8974bcd3de1e724978b1a7790307a51e4bc
## What changed
- Expect tool collisions to report names canonicalized into the default
`functions` namespace.
- Remove the obsolete test that allowed an explicitly namespaced
`functions.shell_command` external tool.
GitOrigin-RevId: 9a517f49c027ffe5b811f6668dca91246f4925a6
## What changed
- Include the current permission profile in each turn environment's configuration.
- Refresh retained environment configurations when session settings change, while preserving the configuration already captured by active turns.
- Keep environment connection and shell snapshot resolution reusable across configuration updates.
## Testing
- Cover permission profile updates applied through both session settings updates and per-turn updates.
- Verify that pending environment resolutions use the configuration captured by their turn and that configuration-only updates do not retry failed environments.
GitOrigin-RevId: 923694f0729b87a118d7635ade3a8ca9bcd4e7b1
## What changed
- Track Agent Plugin manifests through plugin, skill, and MCP loading so their capabilities use format-specific behavior without changing legacy plugins.
- Discover only direct-child skills, exclude app and hook capabilities, isolate MCP data, and reject MCP configuration files that are non-regular or resolve outside the plugin root.
- Bound model-visible skill instructions, plugin instructions, MCP descriptions, schemas, individual tools, and the aggregate Agent Plugin MCP tool set.
- Stop MCP and OAuth redirects when Agent Plugins send configured or authorization headers, while retaining existing redirect behavior for legacy MCP servers.
## Testing
- Add coverage for capability filtering, skill discovery, isolated MCP data and reserved-path expansion, unsafe MCP configuration files, context limits, and redirect handling.
GitOrigin-RevId: c9af66b051269f3226628ca280a58d32c808c38f
## What changed
- Group top-level function and custom tool definitions into a single `functions` namespace for Responses Lite providers that support namespaced tools.
- Normalize missing, empty, and explicit `functions` namespaces to the same tool identity across registration, routing, lifecycle hooks, configuration, and tool search.
- Keep default tool names unprefixed in code mode, display output, and dispatch traces while preserving explicit non-default namespaces.
## Testing
- Add coverage for Responses Lite serialization, tool search results, namespace normalization and collision handling, routing, lifecycle events, and code-mode namespace policies.
GitOrigin-RevId: d48414005b5d22d39b11a198e19c47814d3a19f2
## 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
- Remove the hidden `PairProgramming` and `Execute` variants from `ModeKind`.
- Delete their unused prompt templates and simplify mode handling to cover only `Default` and `Plan`.
GitOrigin-RevId: 8d24e3f562a09e3071b2decae275d2b3871a1e9c
## What changed
- Add the stable, default-enabled `features.view_image` flag.
- Omit the native `view_image` tool when the flag is disabled, including for fresh-context subagents and guardian reviewer turns.
- Keep unrelated execution and MCP tools available when the viewer is disabled.
## Testing
- Add app-server coverage for disabled viewer inheritance in fresh-context subagents and guardian reviewer turns.
GitOrigin-RevId: 42b1311010fbde9f064129b17b425820861c6d91
## Why
Guardian reviews received sandbox retry reasons, but not the execution-policy reason that triggered an initial approval request.
## What changed
- Propagate approval and retry reasons through the tool approval flow and include the applicable reason in the Guardian prompt.
- Prefer a sandbox retry reason when both are available.
- Truncate approval context to 512 tokens while preserving the start and end of the reason.
## Testing
Added prompt and integration coverage for policy reasons, retry precedence, and truncation.
GitOrigin-RevId: 5b0f4e1c40b792b031bc8f7b31685a61d12b8d92
## Why
Amazon Bedrock supports hosted text web search, but it rejects the
`search_content_types` field used for multimodal search and does not support
external live or indexed web access.
## What changed
- Advertise hosted web search for Amazon Bedrock while marking external web
access as unsupported.
- Resolve unsupported live and indexed modes to cached search, or disable the
tool when cached search is prohibited by managed requirements.
- Normalize built-in and configured Bedrock model catalogs to text-only web
search, and retain the runtime provider in session configuration so turn
setup can apply its capabilities.
## Testing
- Cover cached fallback, managed-mode restrictions, text-only tool payloads,
provider capabilities, and catalog normalization.
GitOrigin-RevId: 310473849257401654388a4ebb42920e03aa3228
## What changed
- Remove the cached permission profile from `TurnContext` and derive the
effective profile, filesystem policy, network policy, and legacy sandbox
policy from `config.permissions`.
- Update sandbox consumers and tests to use the current turn configuration.
- Verify that role-based agent spawning reapplies runtime permissions and that
cold-resumed agents retain their disabled permission profile.
GitOrigin-RevId: d67c5d2bcbe6dc76f15b56defb485b155fd1f138
## 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
## Why
App-server clients need to advertise structured MCP extension settings, including supported MCP App UI MIME types, rather than only opting into OpenAI form elicitation with a boolean.
## What changed
- Add an `extensions` map to initialize capabilities and preserve `mcpServerOpenaiFormElicitation` as a legacy alias for `openai/form`.
- Capture the declared extension profile when a thread is started, resumed, or forked, propagate it to subagents, and advertise it to downstream MCP servers during initialization.
- Keep the profile stable for the lifetime of the loaded session instead of changing it on later turns or direct tool calls.
## Testing
- Cover extension conversion, downstream MCP initialization, session isolation, legacy form support, and subagent inheritance.
GitOrigin-RevId: fbcedbb74ce788e574b0f884a4c45c4cedb9de54
## 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
- 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
- Keep complete MCP namespace descriptions in tool-search source metadata.
- Raise the namespace tool-spec description limit from 1,000 bytes to 512 KiB,
truncating at a UTF-8 character boundary only when the new limit is exceeded.
## Testing
- Cover descriptions beyond the former limit and multibyte truncation at 512 KiB.
- Update SSE and stdio MCP tests to verify that complete server instructions are
preserved without hiding tools.
GitOrigin-RevId: 000bfcafb3df348065ae451685bfbf978a0e3248
## What changed
- Allow namespace tool specs to contain custom freeform tools alongside function tools.
- Include namespaced custom tools in deferred tool search and expose them to code mode with names such as `editor__apply_patch`.
- Route custom payloads to matching extension tools while preserving function-only payload validation.
## Testing
- Add serialization, tool search, code-mode definition, and end-to-end dispatch coverage for namespaced custom tools.
GitOrigin-RevId: be64d35f6ae54685c5a9fcf45a732320742ea7e5
## What changed
- Add optional `defer_loading` support to freeform Responses API tool definitions.
- Omit the field when it is unset so existing eager tool definitions retain their wire shape.
## Testing
- Verify legacy freeform tool deserialization and eager and deferred serialization shapes.
GitOrigin-RevId: 50e8658a54ac5b6ae0c1dbfe65f7bb62efef561d
## What changed
Add the tool name to `ApprovalCtx` and use the context's call ID and session
telemetry when recording approval decisions. This removes redundant `ToolCtx`
and telemetry parameters from `resolve_tool_approval`.
GitOrigin-RevId: 238a6f708f83993d64606bfaa74df344b0b46178
Rename `resolve_tool_apporval` to `resolve_tool_approval` and update its
call sites in the tool orchestrator.
GitOrigin-RevId: bc7d9ae675b45dd5b6b5b5643fd75e532f6314ca
## What changed
- Store the effective `allow_login_shell` setting on each turn environment, including inherited environments whose child thread has a different policy.
- Expose the `login` argument for shell tools when any selected environment permits login shells.
- Validate each command against the policy of its selected environment instead of the turn-wide configuration.
## Testing
- Cover tool schema generation for single and multiple environments.
- Cover login-shell rejection by both the command handler and the unified exec integration.
GitOrigin-RevId: 5a93149a5c86f4087f2b92d663ebc33feff8a57c
## What changed
- Add `codex-utils-audio` as a workspace crate for canonicalizing audio inputs
and estimating their token usage.
- Update `codex-core` to consume the new crate while preserving the existing
audio preparation tests.
GitOrigin-RevId: d719ecc08363ef52778aa37f3df0ca14f7778324
## Why
MCP tools can be exposed directly, discovered through tool search, or called
from Code Mode. Servers need to be able to opt out of any of these surfaces
without disabling their tools everywhere.
## What changed
- Add `omit_tools_from` to MCP server configuration, accepting any combination
of `direct`, `deferred`, and `code_mode`.
- Apply the exclusions independently when building direct, deferred, and Code
Mode tool surfaces while keeping omitted tools registered for permitted uses.
- Remove client-private `_meta` fields from MCP results returned to Code Mode.
- Include the new setting in the configuration schema and MCP config
serialization.
## Testing
- Cover every exposure combination across Code Mode, Code-Mode-only sessions,
tool search, direct-only namespaces, and prefixed and unprefixed MCP names.
- Verify direct and nested execution paths, parallel-call support, config
round-tripping, and `_meta` filtering.
GitOrigin-RevId: 12dfcb78bb5c5ecf4d70f38a8b5022792463a27f
## What changed
Derive code-mode tool names directly from registered tool names when checking
eligibility and collisions. Skip unsupported and empty tool specs explicitly,
without serializing schemas or augmenting descriptions that are not used during
executor registration.
GitOrigin-RevId: b439327aafd85ce3745d900301b7e48b56dbd6b4
## What changed
- Route verified patches from both direct tool calls and intercepted shell commands through a shared execution helper.
- Simplify patch safety preparation to return either a runtime invocation or a rejection directly.
- Keep permission resolution, approval handling, event emission, runtime execution, and diff tracking in the common path.
GitOrigin-RevId: e16aae8e91d96b8108aefac7f3fbf2da2cbac016
## What changed
- Share argument normalization, server selection, cursor validation, and pagination setup between `list_mcp_resources` and `list_mcp_resource_templates`.
- Use a generic server-tagged wrapper to build single-server and deterministically sorted all-server payloads for both resources and templates.
## Testing
- Cover shared argument normalization and sorted resource-template payload serialization.
GitOrigin-RevId: 3505e4c1d2b95d8bbbb01f6f930fb914309eb898
## 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
- Add a shared runner for MCP resource operation lifecycle events, output serialization, truncation, timing, and error handling.
- Use it for listing resources, listing resource templates, and reading resources.
GitOrigin-RevId: 84cae2e01a096d5b8ed97ea1cb462f01fe2ed1f9
## What changed
- Reattach recorded `executed_tool_calls` metadata when an output is included in a subsequent prompt.
- Bound retained metadata to 32 KiB, prioritizing recent calls and reporting omitted calls in truncation metadata.
- Drop retained entries after their corresponding outputs leave the prompt history.
## Testing
- Cover metadata replay, cleanup after compaction, bounded retained history, and propagation through later tool requests.
GitOrigin-RevId: 1c23a26123be3b7ad51c61f4ad522139b71bb773
## Why
Clients need to know whether a `request_user_input` request must wait for an
explicit response or may auto-resolve. Using `autoResolutionMs` as that signal
conflated the blocking decision with timeout policy.
## What changed
- Add required `isBlocking` fields to user input protocol and app-server
request payloads. Plan-mode requests are blocking, while requests from other
enabled modes are non-blocking.
- Drive the TUI's auto-resolution behavior from `isBlocking` and remove
`autoResolutionMs` from the model-facing tool schema.
- Deprecate `autoResolutionMs` while retaining it for compatibility, and treat
legacy payloads without `isBlocking` as blocking.
## Testing
- Cover mode-derived blocking behavior, legacy deserialization, app-server
forwarding, delegated requests, and TUI auto-resolution.
GitOrigin-RevId: 29aade657ef743065ec264376ba567a9b353d7d7
## Why
`ToolExecutor::exposure()` describes a tool's preferred exposure, while the host
may apply step-specific policy when building a tool plan.
## What changed
- Store each runtime together with its effective exposure in `ToolRegistry`.
- Apply MCP, namespace, and collaboration-tool exposure overrides directly to
registry entries instead of wrapping runtimes.
- Use the registry-owned exposure when building model-visible specs, deferred
tool search, code-mode executors, and parallel-call support.
## Testing
- Cover that a hidden MCP tool remains routable but is not eligible for parallel
tool calls.
GitOrigin-RevId: 1bc2760add8d993f477954269fa13681bfcc2444
## 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
## Why
Threads can configure the same MCP server name with different runtimes. Tool calls
must use the runtime associated with the thread that issued the call.
## What changed
- Route MCP readiness checks and call preparation through the invoking session.
- Add regression coverage that alternates calls between two threads and verifies
that each thread continues using its own MCP server process and configuration.
GitOrigin-RevId: 5735f7b29a579f545351385ab01a575e35ead01e