## 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
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
## What changed
- Upgrade `rmcp` and `rmcp-macros` from 3.1.2 to 3.1.3.
- Preserve authentication-required and retryable transport classifications when modern MCP discovery falls back to legacy initialization.
- Prevent unrelated discovery errors from triggering legacy fallback while retaining their diagnostics.
## Testing
- Cover authentication challenges and transient initialization failures during legacy fallback.
- Verify that a failed OAuth issuer check does not consume the pending authorization state.
GitOrigin-RevId: 957c0873fec1148883dd163fbaeb77d7593d8c53
## What changed
- Add experimental `mcpServer/event/stream/start` and `mcpServer/event/stream/stop` requests for hosted apps, plus `mcpServer/event/stream/notification` forwarding.
- Scope subscriptions to the owning app-server connection and subscribed thread, enforce unique IDs and a per-connection limit, and clean them up when the thread is unsubscribed or the connection closes.
- Wait for the MCP active notification before completing startup, retry streams that close immediately, and terminate them when authentication or hosted runtime ownership changes.
## Testing
- Add an app-server integration test covering activation, event forwarding, duplicate subscription rejection, and explicit cancellation.
GitOrigin-RevId: 8a6fc1615adfc5af7e67def3b824fa5909ab3e7b
## What changed
- Add the `shellSnapshotV2` executor capability and an optional shell snapshot request to `ExecParams`.
- Capture and restore Unix shell state and profile exports from an in-memory, attachment-scoped cache for `bash`, `zsh`, and `sh`.
- Apply environment policies, runtime `PATH` entries, sandbox context, and live managed-proxy settings when preparing restored commands.
- Bound snapshot size, capture time, scope length, and cache capacity, and fall back to the original command when capture fails.
## Testing
- Cover local, remote, TTY, sandboxed, and supported-shell execution, plus environment filtering, proxy handling, in-memory reuse, and capture failure fallback.
GitOrigin-RevId: 624f747972c249c88c6f10f42cf0af97b75b5541
## Why
An authorization server discovered for an MCP server can change. A stored refresh token must not be sent to a different issuer than the one that originally granted it.
## What changed
- Persist the discovered authorization server issuer with new OAuth credentials and preserve it across refreshes.
- Validate that issuer against a single pinned metadata snapshot before refreshing or adopting stored refresh credentials.
- Require reauthentication when refresh credentials have no issuer or the issuer changed. An unexpired access token can still be used without exposing its refresh token.
## Testing
Add coverage for issuer persistence, missing and changed issuers, metadata changes during startup, and refresh-token preservation.
GitOrigin-RevId: 07e48ba892f627428a28bbed5cca4ad703e2a5fd
## Why
The fallback file contains OAuth credentials, so it must be private from the
moment it is created and writes must not follow links to another path.
## What changed
- Create the fallback file with mode `0600` on Unix before writing credentials.
- Reject symlinks and other non-regular files on Unix and Windows, including
Windows reparse points.
- Truncate and update an existing regular file through the validated file
handle, restoring private Unix permissions when needed.
## Testing
Added coverage for creation under a permissive umask, updates through an
existing hard link, permission restoration, and symlink rejection.
GitOrigin-RevId: d3e4be52e8f4cebb66c59d496a7f77a952a2d0d9
## What changed
- Cover same-origin redirects for protected-resource and authorization-server metadata.
- Verify that cross-origin redirects are rejected before contacting their targets and that redirect cycles fail within a bounded timeout.
- Exercise issuer validation and resource-header isolation for both direct and redirected metadata across legacy and Agent Plugin discovery modes.
- Reuse the test environment's local HTTP client throughout the discovery tests.
GitOrigin-RevId: bd12ac232c3b020a1c098a413361f8e205699699
## What changed
- Upgrade `rmcp` from 3.0.0 to 3.1.2.
- Use `rmcp`'s native JSON-RPC decoding and remove the local compatibility layer for multi-round-trip tool results.
- Preserve response metadata on `input_required` SSE results.
- Support OAuth protected-resource metadata discovery and include the discovered resource audience when refreshing tokens.
## Testing
- Add coverage for metadata preservation on modern SSE `input_required` responses.
- Add an OAuth startup scenario that discovers protected-resource metadata and verifies the refresh-token resource audience.
GitOrigin-RevId: 689f009b4a33552b640304111b74585b4009eeb8
## Why
MCP requests can contain sensitive headers and tool-call bodies. Following a
cross-origin redirect could disclose them to another server.
## What changed
- Follow redirects only when every hop remains on the configured server's
origin, and require HTTPS for redirects on non-loopback hostnames.
- Preserve standard redirect method and body handling while sharing the
original timeout and enforcing a 10-hop limit.
- Avoid replaying plaintext proxy credentials across redirects, while leaving
OAuth requests that stop at redirects unchanged.
## Testing
Add coverage for same-origin and cross-origin redirects, redirect methods,
headers and bodies, proxy credentials, timeouts, hop limits, and legacy MCP
tool calls.
GitOrigin-RevId: 3e267911a1665ad8c2fc63825099a758770f4d68
## 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
- Preserve valid image content from completed `node_repl` Code Mode responses alongside text evidence for Guardian reviews.
- Enable multimodal evidence for models that require automatic `node_repl` review, or when both `guardian_enhanced_node_repl_transcripts` and `guardian_node_repl_transcript_images` are enabled.
- Bound retained and rendered evidence, deduplicate images already present in review history, and fall back to text-only evidence when the reviewer lacks image support or prompt capacity.
- Keep review evidence out of the parent turn input.
## Testing
- Cover feature gating, mixed text and image ordering, truncation and eviction, unsupported reviewers, prompt pressure, image detail normalization, and reused review sessions.
GitOrigin-RevId: a3e482402f7b3484401b231dadc662e6e3504fdf
## What changed
- Capture accepted, successful `node_repl` results from Code Mode and include them as bounded, untrusted evidence in Guardian review prompts.
- Enable the enhanced transcript through `guardian_enhanced_node_repl_transcripts` or when the selected model requires automatic Node REPL review.
- Keep this evidence out of the parent model history, exclude encrypted and failed results, and avoid resending admitted evidence when a Guardian session is reused.
- Clear retained evidence and invalidate review sessions when a thread is rolled back.
## Testing
- Add unit coverage for evidence ordering, escaping, truncation, and empty responses.
- Add an integration test covering feature-disabled, feature-enabled, and model-required behavior, including filtering and review-session reuse.
GitOrigin-RevId: edc3dca5d5b88d472a492f35531ec46889a89d72
## What changed
- Add `http_headers_helper` configuration for local streamable HTTP MCP servers. The configured shell command runs once per connection and returns a JSON object of headers that is cached across requests.
- Apply helper headers to MCP startup and OAuth flows while restricting them to the server origin, stopping redirects, rejecting reserved or duplicate headers, and enforcing output and execution limits.
- Reject helpers for remote or managed-disabled servers, use the local environment working directory, and redact helper commands from `codex mcp list` and `codex mcp get` output.
## Testing
- Cover configuration validation, helper lifecycle and output parsing, origin isolation, OAuth discovery and token refresh, managed requirements, environment selection, and CLI redaction.
GitOrigin-RevId: 84e0e26ce75520b0869d37c72b1678e033bd6818
## What changed
- Make automatic MCP OAuth registration prefer Client ID Metadata Documents
(CIMD) when the authorization server advertises support for public clients and
Codex is using its native loopback callback. Fall back to advertised Dynamic
Client Registration (DCR) otherwise.
- Add explicit `cimd` and `dcr` registration overrides to the CLI and app-server
OAuth login API. Validate CIMD metadata and callback URLs before starting the
authorization flow.
- Use a callback-specific Codex client metadata URL for CIMD and retain the
exact redirect URI through authorization and token exchange.
## Testing
- Cover automatic and forced CIMD selection, DCR fallback, invalid metadata and
redirects, token refresh, authenticated MCP requests, and conformance
regression checks.
GitOrigin-RevId: 4238372ca53b0f38e781e141ab5da97e0a6ddf45
## What changed
- Add `--oauth-client-registration` with `auto` and `dcr` choices to `codex mcp add` and `codex mcp login`.
- Add the equivalent optional `clientRegistration` field to `mcpServer/oauth/login` and the generated protocol schemas.
- Keep automatic dynamic client registration as the default, prefer a configured OAuth client ID when present, and apply the selection only to the current login without persisting it in MCP configuration.
## Testing
- Cover dynamic registration and configured-client OAuth flows through the app server.
- Verify the CLI does not persist the per-login registration choice.
GitOrigin-RevId: 653a4a1054ff43c2c5d52ae863b6a96d21692a53
## Why
Local stdio MCP servers may start in a different working directory from Codex,
so inherited relative CA bundle paths can otherwise resolve to the wrong file.
## What changed
- Forward the supported custom CA environment variables to local stdio MCP
servers, convert inherited non-empty paths to absolute paths, and let explicit
MCP environment overrides take precedence.
- Match CA variable names and `PATH` case-insensitively where required, avoiding
duplicate environment entries and preserving executable discovery on Windows.
## Testing
- Add an end-to-end stdio MCP test covering relative inherited CA paths, empty
values, explicit overrides, alternate key casing, and a different server
working directory.
- Exercise executable resolution with Windows-style `Path` casing.
GitOrigin-RevId: ea1bc0ae63bc0dc780acb8363b2ed102120f282e
## What changed
- Cover non-blocking credential probes when the file or secrets store is locked, including retaining only a matching prior credential snapshot and recovering after the lock is released.
- Extend the streamable HTTP OAuth round trip to verify that user turns continue during store contention, newly discovered servers recover after contention, and logged-out servers do not reuse authenticated connections.
- Cover reconciliation of authentication failures and effective `Authorization` headers.
GitOrigin-RevId: 8e377644001bd0be04dc9f79841080094d09d199
## Why
Refreshing MCP connection identities should not stall the async executor while another process holds the OAuth credential-store lock.
## What changed
- Probe file and secrets credential stores without waiting during runtime refreshes, retaining the last known credentials when the store is contended.
- Reuse unchanged authentication failures while credentials are temporarily unavailable instead of restarting the connection.
- Run blocking credential loads on a blocking worker during MCP client construction.
- Allow OAuth fallback when a configured authorization header is missing, empty, or invalid.
GitOrigin-RevId: 38dad5606da9a1ceb30fe945000ec9151a5058fa
## Why
Concurrent MCP startup and status checks should not serialize when they only read the shared credential store. Repeated reads of the encrypted MCP OAuth store also needlessly decrypted unchanged contents.
## What changed
- Use shared locks for `File` and `Secrets` credential reads while keeping saves and deletes exclusive.
- Cache decrypted MCP OAuth secrets by store path, ciphertext, and passphrase, and invalidate the cache after writes.
## Testing
- Cover concurrent readers, reader/writer exclusion, shared credential loads, and cache invalidation after updates and deletes.
GitOrigin-RevId: f13512e6404d4919879ba5ba77a3e34e52b35640
## Why
Model-reachable child processes should not inherit Codex launch context.
## What changed
- Treat `OPENAI_FEDERATION_RULE_ID` and `OPENAI_IDENTITY_TOKEN_FILE` as non-inheritable environment variables, with case-insensitive matching.
- Remove them after shell environment policy overrides and before spawning commands across execution, MCP, hooks, Git helpers, and remote helper processes.
## Testing
- Cover inherited and explicitly configured variants, including mixed-case names.
- Verify the variables are absent from real child environments and app-server command and process execution.
GitOrigin-RevId: 2535527893985fef0995617f4c5b2462bea7c136
## What changed
- Expose hosted Plugin Runtime event definitions through `McpResourceClient::list_events`.
- Add cancellable `events/stream` subscriptions that route lifecycle notifications to the matching request and cancel when the stream is dropped.
- Bound event notification and queue sizes, time out stalled response headers, and close streamable HTTP responses locally on cancellation.
## Testing
- Add streamable HTTP integration coverage for isolated concurrent subscriptions, local cancellation, and stalled response-header timeouts.
GitOrigin-RevId: 98c6fffa8f004eb2638c1b0705f659222cbbdfdb
## Why
A local stdio MCP server can exit while its descendants remain alive. Cleaning up
only the server process can therefore leak processes after client shutdown.
## What changed
- Contain locally launched MCP servers in non-breakaway Windows job objects and
terminate the job during shutdown so descendants exit with the server.
- Preserve compatibility when job creation or assignment is unavailable by
retrying without containment and terminating an owned process handle instead.
- Use the process-group member fallback when terminating piped processes on
macOS.
## Testing
- Cover descendant cleanup and breakaway prevention for both local MCP protocol
modes on Windows.
- Cover the Windows nested-job assignment fallback and verify the suspended
process resumes before handle-based termination.
GitOrigin-RevId: 33d3cc122de8f7ce0ae69a649b12ea0ff64b7c6f
## Why
An OAuth-backed Streamable HTTP MCP server can fail startup when its stored credentials are rejected. If a client then completes OAuth sign-in and replaces those credentials, the failed server needs to become available without restarting the Codex session.
## What changed
- Track the credential store and OAuth tokens used for each MCP connection, and detect replacements after authentication failures.
- Refresh affected MCP servers before the next turn and include their recovered tools in the model request.
- Classify HTTP authentication challenges and rejected refresh tokens as requiring reauthentication, with sign-in guidance appropriate to local and client-managed environments.
## Testing
- Cover recovery from expired credentials through an externally written replacement token.
- Cover authentication-error classification, startup messaging, and `Auto` store migration from file credentials to the keyring.
GitOrigin-RevId: 9b090089d4e7a44ffc182f4e25da20a18e97b70f
## What changed
Extend the executor-backed Streamable HTTP timeout test to cover both legacy
`initialize` and MCP 2026 `server/discover` requests. Verify that each stalled
handshake times out and releases the serial executor for subsequent requests.
GitOrigin-RevId: 3493904433c95265b9f645813723e890b7610abb
## Why
A streamable HTTP MCP handshake could time out while its executor-backed HTTP
request continued running, leaving the serial executor blocked for later
requests.
## What changed
- Track the remaining initialization deadline for streamable HTTP transports.
- Apply it to `initialize`, `notifications/initialized`, and discovery HTTP
requests, then clear it when the handshake finishes.
## Testing
- Added a regression test that stalls the remote MCP endpoint, waits for the
handshake timeout, and verifies that a subsequent executor request completes.
GitOrigin-RevId: d4980a332e898309c885cbaa4fdd598924b440e1
## Why
Signaling an MCP server's process group can fail with `EPERM` on macOS,
preventing owned descendants from being terminated.
## What changed
- When a group signal is denied, enumerate the group's processes and signal
members that still belong to the expected process group.
- Apply the fallback to both `SIGTERM` and `SIGKILL` during MCP stdio server
cleanup, while retaining the existing group signaling behavior elsewhere.
- Reject invalid process group IDs and avoid signaling processes that have
moved to another group.
## Testing
Added macOS tests covering cleanup with a live or exited group leader,
`SIGTERM`-resistant descendants, escalation to `SIGKILL`, and unsafe group IDs.
GitOrigin-RevId: db722475b94dece74244ce8109b3e92f6cfb202a
## 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
- Add `parse_agent_plugin_mcp_config` to translate Agent Plugins v1 `mcp.json` files into Codex MCP server configuration.
- Normalize `stdio` and streamable HTTP transports, including `PLUGIN_ROOT` and `PLUGIN_DATA` expansion, contained plugin paths, secure endpoint validation, and filtering of client-owned HTTP headers.
- Keep valid sibling servers when another server is invalid, while returning per-server parse errors.
- Preserve UTF-8 HTTP header values when forwarding streamable HTTP protocol headers.
## Testing
- Cover transport mapping, placeholder expansion, path containment, schema and field validation, per-server errors, platform-specific environment handling, and UTF-8 headers.
GitOrigin-RevId: ed4ab0fcf495afbb381ce48beb93989629444c56
## Why
MCP servers running in an executor must not reuse host-owned OAuth credentials,
even when they have the same configured server name and URL.
## What changed
- Derive environment-scoped credential names for executor-owned MCP servers and
use them consistently for login, logout, authentication, and connection setup.
- Mark executor-owned entries in the file credential store and fail closed when
loading or saving an entry could cross the host/executor boundary.
- Preserve compatibility with existing local OAuth credentials, including local
server names that overlap the new reserved prefixes.
## Testing
- Extend the executor MCP integration test to verify that executor requests use
the executor token, never send the host token, and persist both credentials
separately.
GitOrigin-RevId: 4fc92d0533b0fe2e0df34f6d47b81e3d20d07807
## Why
OAuth discovery failures do not establish that an MCP server lacks OAuth
support. Reporting those failures as `unsupported` conflates an inconclusive
check with a confirmed result.
## What changed
- Add an `unknown` MCP authentication status across the protocol, app server,
CLI, and TUI.
- Preserve OAuth discovery errors so callers can report `unknown`, while
retaining `unsupported` for servers known not to support OAuth.
- Document the distinction in the app server API.
## Testing
- Verify transient HTTP discovery errors are preserved.
- Verify `codex mcp list --json` reports `unknown` when discovery is rate
limited.
GitOrigin-RevId: e4562985971606740538e542ec7eeee502111964
## Why
MCP catalog discovery must not allow a server to keep pagination running or
growing without bounds.
## What changed
- Apply the shared pagination collector to tool, resource, and resource-template
discovery.
- Limit each catalog to 100 pages and 1,024 items, and reject pagination cursors
larger than 64 KiB or any repeated cursor.
- Bound the entire pagination operation by the configured tool timeout, falling
back to 30 seconds when no timeout is configured.
## Testing
Add unit coverage for every limit and an end-to-end MCP test that preserves
valid multi-page tools while excluding a server that returns an oversized
cursor.
GitOrigin-RevId: 961a1bfa5fe8a265daf56e342a919c980cd720fa
## 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
- Limit model-facing MCP namespace descriptions to 1,000 bytes without splitting UTF-8 characters or mutating the stored server metadata.
- Cap the aggregate source-description list in `tool_search` at 4 KiB while retaining source names and discovery instructions.
- Cover direct and deferred MCP tool exposure, including multibyte descriptions and tool visibility.
GitOrigin-RevId: 92736ec39475a1d6b3b03f5e3063e28225d8a5f6
## Why
Some legacy MCP servers reject `server/discover` before creating a session and
return a null-ID JSON-RPC error with a non-JSON content type or without echoing
the rejected protocol version. These responses prevented the client from
falling back to legacy initialization.
## What changed
- Parse HTTP 400 discovery errors without a session ID regardless of their
declared content type.
- Fall back to `initialize` when error code `-32000` reports a missing session
or advertises only known legacy protocol versions, including supported
versions other than `2025-06-18`.
- Continue rejecting unrelated error codes, correlated responses, non-400
statuses, malformed version lists, and lists containing modern or unknown
versions.
## Testing
Added MCP discovery coverage for legacy error variants, server-selected legacy
protocol versions, non-JSON content types, and non-legacy rejection cases.
GitOrigin-RevId: 4d3ee2d7d852ce0d0ab3f486da23cb653a7ff5ca
## 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
- Drive multi-round `tools/call` and `resources/read` requests through
`input_required` responses, preserving opaque request state and elicitation
metadata across JSON, SSE, and stdio transports.
- Decode modern discovery and elicitation result shapes while retaining legacy
initialization, elicitation defaults, and discovery fallback behavior.
- Apply the 8 MiB modern-protocol response limit to JSON, SSE events, and stdio
messages, and reject executor stream recovery when output sequence gaps would
corrupt the protocol stream.
## Testing
Added integration coverage for discovery, multi-round requests, legacy
fallbacks, message limits, stdio launchers, SSE responses, session recovery,
and executor output recovery.
GitOrigin-RevId: d26a08883a2825e8ce2408ac498114b33859225e
## What changed
- Add an opt-in `mcp_2026_07_28` protocol mode while preserving the legacy
lifecycle by default.
- Negotiate the new protocol over streamable HTTP with `server/discover`,
including bounded responses, redirect protection, and fallback only when a
response establishes that the endpoint is legacy-only.
- Require stdio servers to opt in with
`CODEX_MCP_PROTOCOL_VERSION=2026-07-28`, and add a bounded local stdio
transport for the modern lifecycle.
- Consume paginated tool, resource, and resource-template catalogs in modern
mode, reject repeated cursors, and retain discovered server identity.
- Reconnect reusable MCP clients when their selected protocol mode changes.
## Testing
- Cover HTTP JSON and SSE discovery, legacy fallback and rejection cases,
redirects, retries, response limits, and pagination.
- Cover local and executor stdio discovery, protocol markers, message limits,
and legacy compatibility.
GitOrigin-RevId: f6a78816e127d2a482292d63b91c8384f1595903
## 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
## What changed
- Rename `ReqwestHttpClient` to `RouteAwareHttpClient` to reflect that delegated HTTP uses Codex's shared route-aware transport.
- Use `codex_http_client` response and error types plus transport-neutral `http` and `url` types, removing the exec server's direct `reqwest` dependency.
## Testing
- Cover fragment stripping and Unicode hostname normalization for delegated HTTP requests.
GitOrigin-RevId: 8b0fc60a76004feb57198bfb4afb1371c9ceb1bd
## Why
Remote environment connections need to honor Codex's effective outbound proxy policy, including when a rendezvous connection reconnects.
## What changed
- Pass the configured `HttpClientFactory` into remote environment transports and use `WebSocketConnector` for exec-server and rendezvous WebSockets.
- Resolve proxy routes asynchronously so these connections can use the configured system proxy.
- Add connector options that preserve Tungstenite's default TLS behavior and enable `TCP_NODELAY` for latency-sensitive rendezvous traffic.
## Testing
- Verify prepared remote environments connect through a configured system proxy.
- Verify initial and reconnected encrypted relay peers use the system proxy.
- Cover default TLS selection and opt-in `TCP_NODELAY` behavior in the WebSocket client.
GitOrigin-RevId: 8a8da2116e37cb3a891269d0c0b037986fecdd3c
## Why
Delegated HTTP requests need to honor the same outbound proxy policy as the
Codex process that starts the exec server.
## What changed
- Pass the configured `HttpClientFactory` through local and remote exec-server
startup and use route-aware client pools for delegated HTTP and local MCP
requests.
- Preserve per-request timeouts and follow-or-stop redirect behavior while
keeping request URLs and sensitive response headers out of diagnostics.
## Testing
- Cover configured system-proxy routing across the exec-server transport.
- Cover both redirect policies and verify that success and failure logs do not
expose request or response secrets.
GitOrigin-RevId: 4af6aec1d265c4db62dfcb6e1fb076fb31736137
## Why
MCP connection reconciliation can otherwise reuse a client after its service or
underlying transport has stopped.
## What changed
- Add `RmcpClient::is_closed` to report closed client, service, and transport
states.
- Exclude closed clients when selecting a reusable MCP connection so
reconciliation starts a replacement.
## Testing
- Add a reconciliation test that disconnects an in-process MCP transport and
verifies that its connection is replaced.
GitOrigin-RevId: 366a85c9959dbe1763923d7e33a4ecf52d9c3c6a
## Why
Refreshing MCP runtime state should not restart an unchanged, ready server or
relist its tools.
## What changed
- Reconcile refreshed MCP configuration against the published connection set
and reuse connections whose transport, environment, authentication, OAuth
credentials, and client capabilities are unchanged.
- Keep tool filters, timeouts, metadata, and plugin provenance in the published
server view so those settings can change without reconnecting.
- Update elicitation authority in place for reused connections, and reconnect
when connection-defining inputs or live OAuth credentials change.
## Testing
Added coverage for unchanged-server reuse, view-only and elicitation-policy
updates, connection identity changes, OAuth credential changes, and avoiding
redundant tool listing.
GitOrigin-RevId: f04f5db5fbdde127b6a14f6aa9673112c0b557e7
## What changed
- Send `codex-mcp-client/<version>` as the default user agent for streamable HTTP and OAuth requests.
- Preserve user agents supplied through configured HTTP headers.
## Testing
- Verify the default user agent on OAuth discovery, token refresh, and MCP initialization requests.
- Verify that a configured user agent overrides the default.
GitOrigin-RevId: 659ef8f126df97b3c1b4d01e9e542a673b5ef42b
## Why
Remote executions need managed-network proxy listeners in the executor so their
loopback proxy addresses are reachable by the launched process.
## What changed
- Add a capability-gated exec-server protocol field for executor-local proxy
launch configuration, including network policy, audit metadata, and execution
attribution.
- Start the proxy while preparing a remote process, replace inherited proxy
environment variables with its local addresses, and derive the sandbox
context from its listeners.
- Keep the proxy alive until inherited output streams close, then shut it down.
- Reject unsupported remote settings such as MITM and credential injection.
## Testing
- Cover configuration round trips and rejection of unsupported settings.
- Verify executor-local startup, blocked-domain enforcement, protocol
compatibility, and proxy lifetime through process closure.
GitOrigin-RevId: c984f54e3e600aa9ebcbf8cf4574046e2c199d11
## What changed
- Convert MCP text content marked with `_meta["codex/encryptedContent"] = true`
into `encrypted_content` function call output items.
- Prefer the content-item payload whenever encrypted content is present so that
`structured_content` does not replace the encrypted output.
## Testing
- Add a stdio MCP integration test that round-trips mixed plaintext and
encrypted tool output.
GitOrigin-RevId: c3997a16b06ad38ff22b21016ede35b97974d9ec
