## What changed
Add the turn's `root_turn_id` to `_codex_apps` request metadata for host-owned Apps MCP calls. Remove any tool-supplied value before populating it from turn metadata, and omit the field for user-configured or extension-owned Apps servers.
## Testing
Extend unit coverage to verify that host-owned Apps calls replace an untrusted `root_turn_id` and user-configured Apps calls omit it. Update integration assertions for default and explicitly supplied root turn IDs, including approval flows, and verify that extension-owned calls omit the field.
GitOrigin-RevId: 754a642c2fff36a866b8cffa9fb3e161f232de08
## Why
Tool lifecycle observers need visibility into calls rejected before execution starts and timing that remains available on cancellation, independently of tracing settings.
## What changed
- Add `on_tool_dispatch` and `on_tool_timing` callbacks to `ToolLifecycleContributor`, with thread, turn, and call IDs for correlation.
- Report direct calls before readiness, dispatch waiting, and hooks. Report handler duration when dispatch completes or is dropped, excluding readiness and gate waiting and returning zero if the call never passes the gate.
- Expose code-mode host durations as a separate `HostOperation` timing boundary. Exclude nested code-mode calls from dispatch and handler timing observations to avoid double counting.
## Testing
Add tests for callback ordering on completed and rejected calls, timing on cancellation, zero handler duration before gate admission without tracing, and code-mode host timing without nested dispatch or handler timing observations.
GitOrigin-RevId: 97998b5094564c13cb2cfad089bb0a9d6615eb5c
## What changed
Add `ToolLifecycleContributor::on_command_start` with `CommandStartInput` carrying the resolved command, working directory, selected executor's filesystem, and lifecycle context. Await contributors after command hooks and environment resolution so they can prepare the filesystem before `exec_command` runs, including calls from code mode.
Reserve process IDs only after preparation completes so cancelled preparation does not consume an ID. Keep deterministic process IDs from being reused after removal.
## Testing
Add tests for direct and code-mode calls that verify callbacks receive hook-rewritten commands and the executor's working directory, filesystem preparation completes before execution, and interrupted preparation prevents execution without consuming a process ID. Add a regression test for deterministic process ID reuse after removal.
GitOrigin-RevId: d10bcafcc583a6e3e8b5924d004806727e3763bb
## Why
Environment-backed stdio MCP servers have no host-local working-directory
fallback, so their test fixtures must provide a workspace explicitly.
## What changed
- Set the fixture workspace as `cwd` for environment-backed MCP servers across
the core integration tests.
- Reuse the same test environment when configuring MCP servers and building
fixtures that need an explicit working directory.
GitOrigin-RevId: e38f2029e01fc1377cdc34d01a392ad310419766
## 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
- Add `ToolLifecycleContributor::on_mcp_tool_result` with access to the
executed MCP tool context, rewritten arguments, extension data stores, and
mutable server result.
- Run contributors before publishing MCP completion and before preparing the
result for the model, so extensions can inspect or replace successful and
error results.
## Testing
- Cover unchanged, replaced, and error results for direct MCP calls, plus
replaced and error results through Code Mode.
- Verify completion waits for result processing and the processed result flows
to both completion events and subsequent model input.
GitOrigin-RevId: ece7acfe9c5eed4778cb78a29c3ffd06a74e1bcf
## Why
Plugin MCP trust decisions must describe the exact host-discovered server
registration. Looking up a plugin again by ID can resolve a different root.
## What changed
- Retain the host plugin root in MCP catalog attribution and connection identity.
- Reconnect an MCP server when its attributed plugin root changes.
- Pass the retained root through tool lifecycle attribution and use it directly
when building trusted tool context.
## Testing
Add coverage for catalog identity, connection reconciliation, lifecycle
attribution, and rejecting a different root associated with the same plugin ID.
GitOrigin-RevId: bc92743dd40ab44065a07c3ea972b4956ef8351f
## What changed
- Add optional `McpToolContext` metadata to `ToolStartInput`, exposing the
model-visible MCP tool details and its source classification without exposing
the executable client.
- Classify MCP calls as connectors, configured servers, plugin servers,
executor-selected plugins, or other registrations based on the prepared call.
- Prepare each MCP call before notifying tool lifecycle contributors and reuse
that same call for execution so the callback describes the call that runs.
## Testing
- Cover host-owned connector calls and extension-owned Apps server calls,
including their distinct provenance and executed tool names.
GitOrigin-RevId: efd23f511b1045ffdd96349d621ad62365569b2b
## Why
External tool events may need to enter thread history without a preceding function call and therefore do not have a `call_id`.
## What changed
- Allow `function_call_output` items to omit `call_id` and carry optional `name` and `namespace` fields.
- Preserve named standalone outputs during history normalization and agent forks while retaining existing pairing behavior for outputs with a `call_id`.
- Accept, persist, and forward these outputs through `thread/inject_items`, and update the app-server schemas and documentation.
## Testing
- Cover paired and standalone JSON round trips, history normalization, agent forks, and injected thread history.
GitOrigin-RevId: a3258163a7dc93777c7c3023116fe204819bdbb0
## What changed
- Remove the legacy `shell_command` handler and runtime, leaving `exec_command`
and `write_stdin` as the shell execution tools.
- Treat legacy `shell_command` model metadata as `unified_exec`, and normalize
legacy user opt-outs so they do not disable command execution. Managed feature
requirements and `shell_tool` can still disable it.
- Preserve shell approvals, sandboxing, zsh-fork support, and output truncation
through the unified execution path.
## Testing
- Cover legacy configuration and model-metadata compatibility.
- Exercise unified shell execution, approvals, truncation, and `apply_patch`
serialization across the app-server and core test suites.
GitOrigin-RevId: 5c2fd6164fc3519cdae4944cb9db276b8467311c
## What changed
- Invoke `ToolLifecycleContributor::on_tool_start` only after pre-tool hooks
have finalized the invocation.
- Pass hook-rewritten arguments and the post-hook conversation snapshot to the
callback.
- Skip the start callback when a hook denies execution or supplies input that
cannot be applied.
## Testing
Add lifecycle tests covering rewritten input, hook-added context, denied tool
calls, and invalid rewritten input.
GitOrigin-RevId: 936efaf4a8c35321f9982ff2a33bb8bece1ebf39
## Why
Guardian V2 needs the requested action and its conversation context to assess
risk; a tool name and call ID alone do not describe what the tool will do.
## What changed
- Expose the original, pre-hook `ToolPayload` to tool lifecycle contributors.
- Build Guardian V2 classifier input from the bounded conversation transcript
and a structured planned-action object containing the tool name and arguments.
- Warn and skip classification if the planned action cannot be serialized.
## Testing
- Verify lifecycle contributors receive tool arguments.
- Verify Guardian V2 sends transcript history and planned-action JSON to the
classifier.
GitOrigin-RevId: 28266ef7c1d2267ba705fcfbd9be4ef48e64e104
## What changed
- Add a shared, read-only `ConversationHistorySnapshot` capability to the extension API.
- Include the snapshot in `ToolStartInput`, preserving conversation order while excluding contextual user messages.
- Avoid acquiring a history snapshot when no tool lifecycle contributors are registered.
## Testing
- Verify snapshots share existing response items, remain stable as history changes, and filter contextual user messages.
- Verify tool-start callbacks receive the history available for successive tool calls.
GitOrigin-RevId: 822cae33781dd876ea628f104be08d8a449a4900
Eddie Chen