## What changed
Add experimental `deferOutput.mcpToolCall` support to `thread/items/list` requests scoped to a `turnId`. Successful, completed MCP calls with nonempty, unannotated plain-text results can return empty `result.content` with `outputDeferred: true`. Clients can retrieve the saved output through `thread/items/read`; connector identity remains on the listed item.
Keep rich results, JSON or fenced text, app UI results, and built-in `codex_app` results inline. Preserve plain-text output when creating bounded previews of oversized MCP results so those previews remain eligible for deferral. Reads return the saved preview when output exceeds the 64 KiB history limit.
## Testing
Extend thread history integration coverage for independent and combined command/MCP deferral, experimental capability gating, excluded result types, connector identity, oversized previews, and retrieval of deferred items.
GitOrigin-RevId: 5c160b30a4eac2a9b70e3fa65b6dbd83e935338b
## What changed
Add `exchange_ema_auth_token` to discover and validate the MCP resource's authorization server before resolving enterprise identity credentials and performing the ID-JAG token exchange. Keep the lower-level exchange primitive private.
- Probe `server/discover` with the enterprise-managed authorization extension, support recognized legacy discovery rejections, and follow protected-resource metadata challenges or well-known fallbacks.
- Match configured resource and issuer constraints, require advertised public-client JWT bearer support, and validate token endpoint metadata without requiring an authorization endpoint.
- Bound discovery with a shared timeout, redirect and authorization-server limits, reject cross-origin metadata redirects, and restrict private authorization-server destinations while allowing local loopback discovery.
## Testing
Add tests covering resource and issuer mismatches before identity access, metadata capability validation, query preservation, modern challenges, JSON and SSE legacy fallback behavior, cross-origin redirect rejection, and private or malformed issuer destinations.
GitOrigin-RevId: 9a55233a20ff42c293f9bd8175e01141ac2d8576
## Why
The `attribution_error` status does not explain why MCP attribution is incomplete. Preserve a diagnostic reason so callers can distinguish history and recorder errors from request serialization failures.
## What changed
- Add optional `error_reason` diagnostics to `McpAttribution`, retaining the first recorder error through checkpoints, compaction, resume, and fork.
- Identify missing or invalid checkpoints, conflicting sources, invalid sources, and poisoned recorder state. Use `restored_error_unknown` for older error checkpoints without a reason.
- Distinguish `payload_too_large` from `serialization_failed` in request metadata fallbacks.
- Tolerate missing, unknown, or malformed diagnostic reasons when reading history, without letting diagnostics determine attribution status.
## Testing
Add coverage for reason preservation, recorder poisoning, backward-compatible checkpoint decoding, resume and cold-fork restoration, and request metadata serialization, including oversized payloads.
GitOrigin-RevId: 389b9446fae119f793978f3e7e4a926677e84d8c
## Why
The Browser connector on `codex_apps` needs the computer-use policies and review handling already applied to `node_repl` and `cua_repl`.
## What changed
- Classify `connector_openai_browser` using registered tool metadata and preserve its computer-use scope through Guardian review.
- Extend confirmation-policy forwarding, review evidence capture, JavaScript execution tracking, and initial-call approval handling to the Browser connector.
- Correlate Browser elicitations with live invocations so nested actions retain their own review identity while assessments are attributed to the originating call. Require verified Browser identity for strict nested review.
- Include the Browser connector in computer-use policy prompts and bundled model messages.
## Testing
Add integration coverage for ordinary and strict Browser nested reviews, including policy injection and action attribution. Verify strict review declines requests with missing or unknown invocation correlation or a non-Browser registration.
GitOrigin-RevId: b04af6fb9db1bac2203dc4265913d210746df90b
## What changed
- Record each MCP source and its first turn, including connector and plugin identifiers when available. Cover direct and Code Mode calls, including returned errors and results that are not printed.
- Persist cumulative attribution checkpoints and restore them across compaction, resume, and forks, including forks limited to recent turns.
- Attach fresh attribution to Responses API `client_metadata` under `mcp_attribution`, outside model-visible content. Restrict transmission to allowed OpenAI HTTPS destinations for both HTTP and WebSocket requests.
- Report `attribution_error` for legacy history without checkpoints, malformed or conflicting attribution, and serialized attribution exceeding 16 KiB.
## Testing
Add coverage for source deduplication, checkpoint persistence and restoration, recent-turn forks, direct and Code Mode calls, destination filtering, and the serialized size limit.
GitOrigin-RevId: fd285e152ca9e24bfa000debb20013709d67a86e
## What changed
- Advertise `openai/elicitation` form support when the client declares an
object-valued `form` capability, without deriving it from the legacy
`openai/form` capability.
- Handle `openai/elicitation/create` requests in `form` mode and forward their
metadata and opaque schema through app-server as `openaiForm`, preserving
`x-openai-*` annotations.
- Keep legacy form handling independent and have the TUI automatically decline
the new form requests it cannot render.
## Testing
- Add an app-server round-trip test for capability negotiation, request
forwarding, and accepted responses.
- Extend MCP capability filtering coverage for `openai/elicitation.form`.
GitOrigin-RevId: 88f39257bffafe4ee98a9c910e38507843cd7eeb
## What changed
- Add optional Browser Use and Computer Use confirmation-policy Markdown to model catalog messages.
- Send the configured documents verbatim in `openai/confirmation_policies` metadata for `node_repl` and `cua_repl` tool calls. Send an empty object when the issuing model has no policies so runtime defaults are cleared.
- Use the issuing step's model snapshot across approval waits, and omit the metadata for other MCP servers and Guardian sessions.
## Testing
- Cover policy serialization, configuration overrides, model changes, approval waits, partial or empty policies, eligible server filtering, and Guardian exclusion.
GitOrigin-RevId: 038c4c262a31fc71986e4a2a947fe9bcbd407acc
## What changed
- Recognize `cua_repl` alongside `node_repl` when collecting Guardian review evidence, applying computer-use policy, and capturing transcript images.
- Render `cua_repl.js` results with the compact REPL history and transcript views.
- Preserve failed MCP call status and result content when replaying app-server history.
## Testing
- Cover both REPL server names across Guardian policy, evidence, image capture, history rendering, and failed-call replay tests.
GitOrigin-RevId: 8c13a721f718add403b07e727c1634b59203c51a
## Why
MCP inventory can be cached or collected separately from a thread's live
connections, so tool availability alone does not describe the current runtime
state.
## What changed
- Add a nullable `runtimeStatus` to `mcpServerStatus/list` for thread-scoped
requests, covering not-started, starting, connected, authentication-required,
failed, cancelled, and disabled connections.
- Observe published connection state without starting or reconnecting servers,
and return an unknown status when no thread is supplied or the active
configuration no longer matches the published registration.
- Show connection state and tool counts in the compact `/mcp` view while
retaining the detailed inventory in `/mcp verbose` and compatibility with
servers that omit `runtimeStatus`.
## Testing
- Cover runtime status transitions, deferred and disabled servers, closed
transports, configuration changes, protocol compatibility, and TUI rendering.
GitOrigin-RevId: e3bb6efe652f0fa8b3c97d5c53e4729b3a87cd91
## Why
Compaction can remove the tool-call events that associate an MCP app widget with
the tool, account, and URI needed to authorize later resource reads.
## What changed
- Store a bounded MCP resource-origin checkpoint with each compacted rollout.
- Restore the checkpoint when resuming a session so existing widgets remain
readable after compaction and restart.
- Discard saved origins when rollback rewrites history across the compaction
boundary, and reject oversized or invalid checkpoints during restoration.
## Testing
- Extend the app-server MCP resource-origin test to compact a paginated thread,
continue the conversation, and read the original widgets before and after a
restart.
- Verify rollback clears provenance that no longer matches retained history.
GitOrigin-RevId: 7f91c6202fe8d9be21c78dda42fa205937c44263
## Why
Standard MCP forms can require user-entered values even when tool permissions are
otherwise auto-approved in full-access sessions.
## What changed
- Recognize the `openai/standard-form-input` client extension and surface
non-approval forms in full-access, user-initiated root threads.
- Keep approval forms, automation and subagent threads, headless sessions, and
clients without the capability on their existing decline or review paths.
- Treat the capability as client-only so it is not advertised to MCP servers,
and enable it after session startup so required servers cannot block startup
waiting for form input.
## Testing
Add unit and app-server coverage for accepted form round trips, declined cases,
approval metadata safeguards, resumed threads, and extension filtering.
GitOrigin-RevId: 053bfe397a5c79eceef90a81d13e2aca6353af43
## 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
We started working with MCP in Codex before
https://crates.io/crates/rmcp was mature, so we had our own crate for
MCP types that was generated from the MCP schema:
https://github.com/openai/codex/blob/8b95d3e082376f4cb23e92641705a22afb28a9da/codex-rs/mcp-types/README.md
Now that `rmcp` is more mature, it makes more sense to use their MCP
types in Rust, as they handle details (like the `_meta` field) that our
custom version ignored. Though one advantage that our custom types had
is that our generated types implemented `JsonSchema` and `ts_rs::TS`,
whereas the types in `rmcp` do not. As such, part of the work of this PR
is leveraging the adapters between `rmcp` types and the serializable
types that are API for us (app server and MCP) introduced in #10356.
Note this PR results in a number of changes to
`codex-rs/app-server-protocol/schema`, which merit special attention
during review. We must ensure that these changes are still
backwards-compatible, which is possible because we have:
```diff
- export type CallToolResult = { content: Array<ContentBlock>, isError?: boolean, structuredContent?: JsonValue, };
+ export type CallToolResult = { content: Array<JsonValue>, structuredContent?: JsonValue, isError?: boolean, _meta?: JsonValue, };
```
so `ContentBlock` has been replaced with the more general `JsonValue`.
Note that `ContentBlock` was defined as:
```typescript
export type ContentBlock = TextContent | ImageContent | AudioContent | ResourceLink | EmbeddedResource;
```
so the deletion of those individual variants should not be a cause of
great concern.
Similarly, we have the following change in
`codex-rs/app-server-protocol/schema/typescript/Tool.ts`:
```
- export type Tool = { annotations?: ToolAnnotations, description?: string, inputSchema: ToolInputSchema, name: string, outputSchema?: ToolOutputSchema, title?: string, };
+ export type Tool = { name: string, title?: string, description?: string, inputSchema: JsonValue, outputSchema?: JsonValue, annotations?: JsonValue, icons?: Array<JsonValue>, _meta?: JsonValue, };
```
so:
- `annotations?: ToolAnnotations` ➡️ `JsonValue`
- `inputSchema: ToolInputSchema` ➡️ `JsonValue`
- `outputSchema?: ToolOutputSchema` ➡️ `JsonValue`
and two new fields: `icons?: Array<JsonValue>, _meta?: JsonValue`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/10349).
* #10357
* __->__ #10349
* #10356
Brent Traut