## Why
A `503` from an issuer's OAuth metadata endpoint can block discovery even when its OIDC metadata is available, preventing expired OAuth tokens from being refreshed during MCP startup.
## What changed
Try the same issuer's OIDC discovery endpoints when an OAuth authorization-server metadata GET returns `503`. Support issuers with path components and keep all attempts within the original request's timeout.
Reuse existing header, origin, and response-size checks, leave issuer validation to RMCP, and do not follow fallback redirects. Preserve discovery errors when fallback fails instead of enabling legacy endpoint fallback, and propagate terminal HTTP failures.
## Testing
Add tests for OIDC candidate order, malformed metadata, issuer mismatches, header isolation, redirects, terminal failures, unaffected requests, and the shared timeout. Add startup coverage for refreshing expired persisted tokens after OIDC fallback in both legacy and coordinated refresh modes.
GitOrigin-RevId: 6d94fd09e9ba26cb83e029171449e91410a0f6cb
## What changed
- Honor `McpOAuthRefreshMode::Coordinated` for streamable HTTP MCP connections by letting RMCP refresh and persist credentials through the pinned credential store.
- Reread credentials while holding the refresh lock, persist refreshed tokens before retrying requests, and serialize login and logout writes with in-flight refreshes.
- Keep OAuth preparation outside MCP operation and handshake deadlines, and allow refresh persistence to finish if the initiating caller is cancelled.
## Testing
- Cover coordinated startup refresh, concurrent refreshes, `401` retries, credential mutation races, provider timeouts, and caller cancellation.
GitOrigin-RevId: 100ae788048087be23e26bb43f868b1fcebb007a
## What changed
- Add a non-interactive two-step exchange that obtains an ID-JAG from an
enterprise identity provider and trades it for a resource-bound MCP bearer
token.
- Validate trusted endpoint URLs, request inputs, ID-JAG claims, resource and
scope bindings, and token responses before credentials are forwarded or a
bearer token is returned.
- Expose structured authentication failures while redacting credentials and
provider-controlled error details from diagnostics.
## Testing
- Cover successful exchanges, signed scope narrowing, invalid claims and token
responses, request validation, and error redaction.
GitOrigin-RevId: d716e0e1c2dc6b230cecbc0e9cc09afeee81d599
## Why
Interactive MCP OAuth must not trust authorization metadata that could route an
authorization code or PKCE verifier to an unrelated token endpoint.
## What changed
- Require an advertised issuer to match the origin that served authorization
metadata.
- Validate authorization and token endpoint origins before starting both
pre-registered and dynamically registered client flows.
- Allow delegated endpoint origins when the server advertises issuer-bound
authorization responses, while retaining narrow compatibility exceptions for
existing providers.
## Testing
Add coverage for rejected untrusted metadata, accepted issuer-bound delegation,
legacy provider exceptions, and both client registration paths.
GitOrigin-RevId: 43c9f94c9f6ba2d23d7e373576cf9fa26861cfc3
## Why
Executor-owned HTTP MCP servers need to read their bearer credentials from the
selected executor environment instead of the host process.
## What changed
- Preserve `bearer_token_env_var` for executor-owned HTTP MCP configurations and
resolve it when the executor sends each request.
- Extend delegated HTTP headers with executor-local environment references while
rejecting missing, empty, or protected credential variables.
- Keep transport-provided bearer authentication compatible with MCP redirect and
OAuth handling without sending a placeholder authorization value.
## Testing
- Cover authenticated executor-owned MCP requests end to end.
- Cover delegated header resolution and rejection of protected variables.
- Cover parsing executor-owned bearer configuration and transport-provided bearer
behavior.
GitOrigin-RevId: 442bf7382198ffb69eba797eb36d4c74faabda88
## Why
Headers configured for an MCP resource can contain credentials and must not be
forwarded to a different origin during OAuth discovery, registration, or token
exchange.
## What changed
- Apply configured resource headers only to OAuth requests on the MCP resource
origin, while allowing OAuth-generated headers to take precedence.
- Follow credentialed OAuth redirects only when each destination remains on the
resource origin. Preserve redirect method semantics, the overall timeout, the
response size limit, and a maximum of 10 redirects.
- Use the Codex MCP user agent for requests to authorization-server origins.
## Testing
Add coverage for cross-origin header isolation, same-origin dynamic client
registration redirects, OAuth header precedence, token refresh, timeout
accounting, and response size limits.
GitOrigin-RevId: 609d06e2b065e4aa9ca5382b4ae60455f9e26db9
## 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
- Update the Rust MCP SDK from `3.0.0-beta.3` to `3.0.0` and adapt to its renamed metadata and server discovery types.
- Accept discovery responses without server identity metadata, using the configured server name as a fallback, and rely on the SDK's native support for namespaced server identity metadata.
- Preserve typed OAuth HTTP errors so transport failures, cross-origin redirects, and transient HTTP responses are reported instead of being treated as anonymous access.
## Testing
- Cover modern discovery with namespaced or missing server identity over HTTP, SSE, and stdio.
- Cover OAuth discovery error propagation for transport failures, redirects, and transient status codes.
GitOrigin-RevId: 12c1e45136cca89ce4fb15986c2b5df14608682a
## What changed
- Require callers to provide an HTTP client for MCP OAuth discovery and login, removing the separate direct `reqwest` path.
- Use the shared `http` and `url` types throughout the MCP client and drop its direct `reqwest` dependency.
- Preserve configured MCP headers when routing OAuth discovery through the provided client.
## Testing
- Add coverage that routed OAuth discovery forwards configured headers.
GitOrigin-RevId: 1345f56bd794626533133447597a5908e57b9b48
## What changed
- Update the `rmcp` model and transport integrations for `3.0.0-beta.3`.
- Preserve legacy `elicitation/create` form requests, schema defaults, metadata, and wire-format compatibility while adopting the new elicitation types.
- Harden OAuth discovery by using GET-first discovery without starting an MCP session, preventing cross-origin header redirects, validating authorization-server and callback issuers, and retaining compatibility with metadata that omits an issuer.
- Keep stored OAuth credentials readable and avoid requiring reauthorization after transient refresh failures.
## Testing
- Add coverage for legacy elicitation round trips, OAuth discovery variants, callback issuer validation, credential migration, and refresh failures.
GitOrigin-RevId: 756197d26f3fd347c28c400228f6b3d06ed493b7
## Why
MCP authentication checks need to use the same HTTP routing as the MCP
transport so servers reached through configured proxies can be discovered
reliably.
## What changed
- Resolve OAuth discovery and authentication status through each server's
runtime HTTP client for both local and managed environments.
- Keep local discovery capped at five seconds while allowing explicit login
requests to retain their requested timeout.
- Resolve refreshed MCP configuration and its runtime context from the same
snapshot.
## Testing
- Cover OAuth discovery through an environment proxy and macOS system proxy
resolution.
- Cover proxied MCP startup and runtime refresh with updated authorization
headers.
- Verify capped and preserved OAuth discovery timeout policies.
GitOrigin-RevId: 461fb1d4786e547df8b1e6b2215a8ac40438a3aa
## Why
#28522 routes selected-plugin HTTP MCP traffic through the owning
executor, but OAuth bootstrap and refresh still used host-local clients.
Executor-only servers therefore cannot complete discovery or login
through the same network boundary as the MCP connection.
## What changed
- adapt `codex_exec_server::HttpClient` to RMCP 1.8's `OAuthHttpClient`
contract
- let RMCP own discovery, dynamic registration, PKCE, token exchange,
and refresh
- route auth status, persisted-token startup, and app-server login
through the server runtime while preserving the existing local discovery
path
- add optional `threadId` to `mcpServer/oauth/login` and echo it in the
completion notification
- implement RMCP's redirect policy and 1 MiB OAuth response limit over
executor HTTP
- cover selected-thread OAuth discovery and login through an
executor-only route
Depends on #28522.
malsamiri-oai