## What changed
- Add `mcp_optional_startup_grace_ms` with a default of 1,000 ms to control how long tool catalog capture waits for optional MCP servers.
- Treat a value of `0` as disabling the shared grace, so optional servers use their configured `startup_timeout_sec` instead.
- Apply updated grace values during runtime and MCP configuration refreshes, and reset cached startup deadlines when the configured duration changes.
## Testing
- Cover custom, disabled, refreshed, and shared startup grace behavior in MCP connection and core integration tests.
GitOrigin-RevId: 936196215ed6e0a29c9ec72cfee17663978df8ef
## 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
- Fetch ChatGPT account access and attach `cyber_trusted_access` under
`openai/entitlementContext` when an installed or selected plugin explicitly
requests it from a local, read-only stdio tool with no arguments.
- Reject caller-supplied entitlement context on direct MCP calls, and fall back
to an `unknown` status when access cannot be verified or the account changes
during the lookup.
- Count entitlement lookup time against the MCP tool-call timeout.
## Testing
- Cover eligible calls plus unowned, remote, HTTP, mutable, argument-bearing,
API-key, undeclared, direct, and account-switch cases in core and app-server
integration tests.
GitOrigin-RevId: 303b61585ef4530276c373d914a2d0ccef1f4ac2
## What changed
- Add `TrustedAccessContext` to fetch account-bound cyber verified-access grants and attach them as host-owned `openai/entitlementContext` metadata.
- Replace caller-supplied entitlement metadata and return an `unknown` status when authentication, identity consistency, response validation, size limits, or the lookup deadline cannot be verified.
- Add `HttpResponseBodyStream::from_chunks` for lightweight in-memory streaming clients.
## Testing
- Cover grant mapping, unsupported authentication, account and workspace changes, malformed or oversized responses, duplicate programs, and lookup timeouts.
GitOrigin-RevId: 343b6a6608c98c45a34939ef507c2183516a11c1
## 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
MCP servers attached to executor environments must retain their owner's
permission profile instead of inheriting the thread-wide sandbox authority.
## What changed
- Resolve and capture a permission profile for each enabled MCP server when
publishing the runtime, and reject calls or elicitations when that authority
is unavailable.
- Use the captured server profile for tool approval decisions, elicitation, and
sandbox metadata, including after runtime refreshes.
- Materialize `:workspace_roots` from `PathUri` values so permissions preserve
the path convention of remote executor environments.
- Give threadless app discovery and resource reads an explicit default
permission profile.
## Testing
Added coverage for per-server elicitation authority, unresolved attachments,
runtime refreshes, restricted tool calls, and foreign-platform workspace roots.
GitOrigin-RevId: 6b188d4b08b29e9971ff7aa68a7785a0cdf9e394
## Why
MCP servers can share an OAuth callback URL. Without a validated issuer or a
server-specific callback path, an authorization response could be associated
with the wrong server.
## What changed
- Use stable callbacks when authorization metadata advertises issuer-bound
responses, and validate the returned issuer before exchanging the code.
- Retain server-specific callback IDs for providers without issuer support,
including fallback to the global or default callback for legacy registered
clients.
- Persist registered callback URLs for MCP servers and plugins, and insert the
active listener port into portless loopback redirects.
## Testing
Add coverage for issuer validation, callback-mode discovery, registered and
legacy clients, plugin OAuth, CLI persistence, and loopback listener ports.
GitOrigin-RevId: 2878c92e237fc17fd3def0bd2e1cce3e104a3db8
## Why
Reusing an MCP connection that is still starting after its
`startup_timeout_sec` changes leaves the old startup budget in effect.
## What changed
- Track the effective startup timeout on each MCP connection.
- Reuse a pending startup only when its timeout still matches the current
configuration.
- Continue reusing ready connections when only the startup timeout changes.
## Testing
Added integration coverage that refreshes the timeout while one server is
still initializing and another is ready, verifying that only the pending
startup is replaced.
GitOrigin-RevId: 5ed71a57d3bf0dd6e227aacd16acd3a35bc37ecf
## What changed
- Include the configured authentication mode in the MCP connection identity so
runtime reconciliation replaces connections instead of reusing them after an
authentication-mode change.
- Add a regression test covering a switch from OAuth to ChatGPT authentication
for an executor-owned MCP server.
GitOrigin-RevId: 18cd9df62a9a5ee44594dcde6a844ad7d5e67ee2
## What changed
- Add Windows sandbox mode, private-desktop behavior, and legacy Landlock selection to each `EnvironmentConfig`.
- Centralize sandbox context construction on `TurnEnvironment`, preserving environment-owned permissions, paths, and backend settings while applying additional permission grants.
- Use the environment-derived context for project instructions, capability discovery, file uploads, and filesystem-oriented tools.
## Testing
- Verify capability discovery uses the selected environment's permission profile and sandbox backends when they differ from the thread defaults.
GitOrigin-RevId: 7ae2fed90c8ada950f2e8431e571e9b2c793c291
## 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
## What changed
Propagate canonical denial, timeout, and abort responses from strict MCP
auto-review instead of replacing them with a generic decline. This preserves
the reviewer's action and metadata, including denial rationale, while still
failing closed when no canonical decision is available.
Update the fallback message to direct the agent to request explicit user
approval before proceeding.
## Testing
Add unit and app-server integration coverage for strict auto-review denials
and cancellations.
GitOrigin-RevId: d8126ab223ab546b95e2d984f6e4dd540a324a59
## What changed
- Scope executor-provided stop-hook calls to the MCP server environment that registered the hook, and reject calls when that environment does not match.
- Forward turn metadata with executor stop-hook requests while retaining the hook call's `threadId` metadata.
## Testing
- Cover environment matching for MCP tool calls and verify executor stop hooks receive their environment ID and request metadata.
GitOrigin-RevId: b544ea3a6ca1f61389fb4597978ed7aac27d529a
## Why
Older executors do not support resolving HTTP header values from their own
environment. Sending environment-backed bearer tokens to them can prevent MCP
servers from starting.
## What changed
- Advertise executor support for environment-backed HTTP headers with the
`httpHeaderEnvVars` capability.
- Delegate bearer-token resolution only when the selected executor advertises
that capability; otherwise, resolve tokens available in the host environment.
- Exclude executor-owned MCP servers that require environment-backed bearer
tokens when the executor cannot resolve them, while retaining compatible
host-owned and executor-owned servers.
## Testing
Added protocol and environment-variable coverage plus an end-to-end test that
simulates an older executor and verifies compatible MCP servers remain usable.
GitOrigin-RevId: 43545926f6f7e0f3b1091eb29d34647f6372bc4a
## What changed
- Read `mcp_servers` configuration and requirements from each selected remote
executor and add eligible HTTP servers to the thread's MCP runtime.
- Bind discovered servers to the thread's concrete executor snapshot and apply
environment MCP policy and requirements. Discovery is best effort, and
executor-local servers are not treated as required at startup.
- Ignore unsupported stdio servers and HTTP configurations that depend on
environment-provided headers or header helpers.
## Testing
- Added an app-server integration test covering discovery, authenticated HTTP
tool invocation, requirements enforcement, and exclusion of stdio servers.
GitOrigin-RevId: 6e1cdcebdbb1cc21a5a2285fbc5617d8d5997182
## Why
Remote HTTP MCP connections can source header values from the host environment,
so those variables must remain part of the connection identity even when the MCP
server runs in an executor environment.
## What changed
- Track `env_http_headers` variables for remote HTTP MCP connections.
- Continue tracking `bearer_token_env_var` only for local environments, where the
host resolves the token.
## Testing
Add coverage that verifies remote connections track host header variables without
tracking executor bearer-token variables, while local connections track both.
GitOrigin-RevId: 8fe175c54a101721a27b76495dcd298f0c2bc6a3
## 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
- 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
## Why
The Responses API accepts tool names up to 128 bytes, but MCP tool name
normalization limited model-visible names to 64 bytes.
## What changed
- Preserve MCP tool names up to the 128-byte Responses API limit.
- Continue shortening and hashing names that exceed the limit so generated
names remain bounded and unique.
## Testing
- Cover names at the 128-byte boundary and immediately above it.
- Verify distinct long names remain 128 bytes and code-mode compatible.
GitOrigin-RevId: 75544d00e75dd0e9328b3e2ac763d26f9cc99a48
## What changed
- Add environment-provided MCP restrictions for configured and plugin-provided servers.
- Disable attachment-scoped servers while their environment configuration is pending, failed, or unselected, while preserving selected-plugin access and the controller-owned Apps server.
- Apply the resolved policy to runtime startup, model tool exposure, telemetry, OAuth flows, and skill dependency installation.
## Testing
- Cover policy filtering for configured and plugin servers, environment state transitions, Apps ownership, and managed OAuth rejection.
GitOrigin-RevId: 7ca5d4dda14068e758497f88835d5cba685e159e
## What changed
- Execute hook-triggered MCP calls through the runtime's latest connection set instead of preparing a separate catalog-bound call.
- Keep hook calls from waiting for server startup or reconnecting, and reject disconnected servers immediately.
- Apply the shorter of the hook-requested timeout and the server's configured tool timeout.
## Testing
- Update connection manager tests to cover non-waiting calls and disabled tool filters.
GitOrigin-RevId: 3166b2d1e26d9ae2b8b3a648b4d0897cc260eb93
## What changed
- Execute `mcp_tool` hook handlers through the session's shared MCP runtime, including managed hook configurations.
- Restrict hook calls to already-connected, cataloged, and policy-allowed tools. Unavailable servers fail immediately without starting or reconnecting them.
- Pass session metadata to hook tools, cap hook timeouts by the server timeout, and invoke hooks without model-tool approval or recursive hook dispatch.
- Record handler type and execution mode in hook telemetry, and mark memory as externally influenced after successful or blocking MCP hooks when configured.
## Testing
- Added end-to-end coverage for prompt interpolation, hidden tools, blocking decisions, unavailable servers, thread metadata, approval bypass, and memory-mode handling.
- Added MCP runtime coverage for startup readiness, tool filters, catalog revisions, and managed connector policy.
GitOrigin-RevId: 1647cb801ebc5fa385c7bda9d9c266a389c611b8
## What changed
- Add an optional `connectorId` to `mcpServer/resource/read`.
- Forward the selected connector through `x-codex-turn-metadata` for threaded and threadless resource reads, restricting hosted app resources to that connector.
- Update the generated protocol schemas and app-server documentation.
GitOrigin-RevId: 5cc94d703abbbb6086665910c1c9ed5dc7075210
## 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
App widgets need to read resources using the app and account context of the
tool call that produced them, including after a thread is restored.
## What changed
- Add an optional `originCallId` to `mcpServer/resource/read` requests and
return it on successful scoped reads.
- Track bounded provenance for successful app tool calls in thread history and
use the current tool binding, account link, and app policy when reading the
associated widget resource.
- Reject missing, mismatched, failed, or ambiguous origins, while keeping
app-only tools available for widget reads without exposing them to the model.
## Testing
Add app-server coverage for scoped widget reads across both history modes,
ephemeral and persistent threads, server restarts, app-only visibility, and
invalid origin cases.
GitOrigin-RevId: 11eaefc066b2a3b639599e4cbdef680233d150a2
## What changed
Add `server_kind=openai_codex_apps` to the
`codex.mcp.protocol_discovery` counter and its duration metric when protocol
discovery runs for the Codex Apps MCP server. Other MCP servers retain the
existing `mode` and `outcome` tags.
GitOrigin-RevId: aadbdc54642f2c103a9f1bab39308e962c115f75
## What changed
- Record a counter and duration for MCP client protocol discovery.
- Tag observations with the configured `legacy` or `auto` mode and classify
outcomes as `modern`, `legacy`, or `failure`.
GitOrigin-RevId: f348e0d900b437d5a9fef1c33cdb1314f2421785
## What changed
Keep MCP namespace descriptions when publishing tool definitions to the
process-scoped catalog cache. Cached definitions now expose the server
instructions to the model before a lazily started MCP connection finishes
initializing.
## Testing
Update the cached MCP startup integration test to verify that cached namespace
descriptions retain the originating server instructions.
GitOrigin-RevId: d1b73381852fd43c6b54a7c22a599474c774dc20
## Why
MCP runtime reconciliation can occur while an unchanged server is still
starting, such as when capability roots become available. Reconciliation
should neither wait for that startup nor initialize the same server again.
## What changed
- Reuse an active, uncancelled pending MCP connection when its identity,
catalog limit, and protocol mode still match.
- Publish the shared startup result through the reconciled server view while
applying its updated tool filter.
- Preserve cancellation when a reused pending server is subsequently removed.
## Testing
Added coverage for filtered-tool publication, disabling a reused pending
server, and capability-root reconciliation during Codex Apps startup.
GitOrigin-RevId: 690cf8695e75b341d097d7d22b5da6993b24e787
## What changed
- Add `oauth.callback_port` to MCP server configuration and preserve it when
serializing configuration edits.
- Accept `oauth.callbackPort` from plugin MCP declarations and skill dependency
metadata.
- Prefer the server-specific callback port over `mcp_oauth_callback_port` for
CLI login, app-server, plugin installation, executor, and skill dependency
OAuth flows.
## Testing
- Cover configuration parsing, serialization, and fallback behavior.
- Verify plugin, executor, and skill OAuth registrations use their configured
callback ports instead of the global port.
GitOrigin-RevId: 7f65e5e7869358307e49779f1b75e8672b607736
## Why
Local MCP requests can fail when the platform TLS backend cannot negotiate a
protocol version with an HTTPS endpoint.
## What changed
- Retry replayable local MCP requests once with rustls after a recognized TLS
protocol-version negotiation failure. Keep certificate, timeout, and unrelated
connection failures on the existing error path.
- Remember successful fallback per HTTPS origin and outbound route, while keeping
the platform TLS backend as the default for other destinations.
- Share the fallback-enabled client across local MCP resolution, CLI login, and
OAuth discovery while preserving remote environment HTTP clients.
## Testing
Added coverage for platform-specific error detection, request replay, cached
fallback reuse and isolation, non-replayable requests, redirects, and remote MCP
client selection.
GitOrigin-RevId: 39a2d96fdb2ea0e51df14f652ba2a953d24e69a1
## Why
When an MCP server rejects existing OAuth credentials, reporting that the server
is merely not logged in obscures that the user needs to authenticate again.
## What changed
Pass the MCP startup failure reason into error formatting and report that the
server requires OAuth reauthentication when appropriate. Preserve the existing
recovery hint for either `codex mcp login` or the client's OAuth sign-in flow.
## Testing
Cover the reauthentication message for both login flows and verify it in the
streamable HTTP OAuth round-trip test.
GitOrigin-RevId: 6f6d5fe7519b1a476f8b70d976223b2ea1ec938e
## 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
## Why
Subagents can reuse cached MCP tool definitions without opening another server
connection immediately, but marking a server as required previously forced eager
startup even when its cached tools were available.
## What changed
- Allow required MCP servers with usable cached tools to remain dormant under
the lazy startup policy.
- Treat those cached tools as satisfying required-server validation and tool
catalog capture until the server is needed.
- Preserve eager startup for required servers without cached tools and start a
dormant server when one of its tools is called.
## Testing
Extend the cached HTTP MCP subagent test to cover both optional and required
servers, verifying that the required server stays dormant until its cached tool
is called.
GitOrigin-RevId: 48ea20b9ae447eef27461caee2320ea78465bb6a
## Why
When the event receiver is closed, an MCP elicitation request cannot reach its
consumer. Ignoring that delivery failure leaves the request and its lifecycle
registration pending while waiting for a response that cannot arrive.
## What changed
Return a contextual error when an MCP elicitation event cannot be delivered.
This drops the pending-request guard immediately, removing the responder from
the router and releasing its lifecycle registration.
## Testing
Add a regression test that closes the event channel and verifies the request
fails immediately, the router is empty, and the lifecycle registration is
released.
GitOrigin-RevId: 1067f35a5775d61c5bcd07b4b190d3907d8f219a
## Why
Subagents should be able to use known HTTP MCP tool definitions without opening a connection until a tool is actually called.
## What changed
- Add streamable HTTP configurations to the process-scoped MCP tool catalog cache when their authentication identity can be derived safely.
- Fingerprint transport settings, relevant environment variables, protocol mode, plugin status, and client capabilities so catalogs are reused only across equivalent connections.
- Keep OAuth and other dynamically resolved credential configurations out of the shared cache.
## Testing
- Add an integration test proving that a subagent receives cached HTTP tools without reinitializing the server, then starts its own connection when it calls one.
GitOrigin-RevId: bb2787e29e9b71993def31aafd1f0d8f1b728d26
## 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
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
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
## 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
## What changed
- Add lifecycle-backed gauges for in-flight and queued app requests, pending server requests and mailbox messages, active turns, and live MCP connections.
- Register each gauge on first use and decrement it when the tracked work or resource is dropped.
- Document the new `server/diagnostics` gauge names and account for the diagnostics request itself in the response example and test.
GitOrigin-RevId: 4bb82a3918af0b502d149b5d761ad669b2083f39
## 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
## Why
Subagents can reuse cached MCP tool definitions without starting every optional
server before any of its tools are used.
## What changed
- Defer startup for subagent-owned, optional MCP servers when their cache has at
least one visible, allowed tool, and trigger startup on the first operation
that needs the live client.
- Keep root sessions, required servers, selected plugin servers, and explicit
reconnects eager.
- Exclude empty catalogs from cache eligibility and keep dormant servers out of
the initial startup summary.
## Testing
- Extend MCP tool-cache coverage for eager root startup, unused and filtered
subagent servers, deferred startup status events, and startup that survives an
interrupted first tool call.
GitOrigin-RevId: e7528ff08312583a6747cbc6550ea5b6eabda9a6
## What changed
- Cache an `McpBinding` on each published MCP runtime once server startup has
settled and the tool catalog revision is stable.
- Reuse the cached binding while the catalog revision remains unchanged, and
rebuild it after a runtime publish or catalog change.
- Treat terminal failures from optional servers as stable, while continuing to
wait for required servers and reconnecting Codex Apps servers.
## Testing
- Cover binding reuse within one published runtime and invalidation after a
republish.
- Cover stability checks for pending, failed optional, required, and
reconnected servers.
GitOrigin-RevId: 783a6b04897f6c484a6d56fd9cee542814041759
## 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
- Treat an MCP server as trusted for ChatGPT authentication when its origin
matches the configured HTTPS `chatgpt-staging.com` host or one of its
subdomains.
- Continue trusting the production ChatGPT origin and falling back to OAuth for
other transports and origins.
## Testing
- Cover both the staging apex domain and a staging subdomain.
GitOrigin-RevId: 1b1d06ab214141d39eb38d46de9dfb74e6fedb3e
## 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
- 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 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
## Why
Codex Apps tool catalogs can exceed the standard MCP limit of 2,048 items and
still need to remain available through tool search.
## What changed
- Allow up to 8,192 catalog items for host-owned `codex_apps` registrations.
- Keep the 2,048-item limit for other MCP servers, including extensions that
register the `codex_apps` name.
- Restrict the shared Codex Apps tool cache to host-owned registrations.
## Testing
- Cover large catalogs for built-in and hosted-plugin registrations while
verifying that another extension retains the standard limit.
- Verify that a same-named extension cannot read the host-owned Apps cache.
GitOrigin-RevId: 2265693a460e9be63c4c849169cba7324def4f49