## Why
This PR prepares the stack to enable Clippy await-holding lints that
were left disabled in #18178. The mechanical lock-scope cleanup is
handled separately; this PR is the documentation/configuration layer for
the remaining await-across-guard sites.
Without explicit annotations, reviewers and future maintainers cannot
tell whether an await-holding warning is a real concurrency smell or an
intentional serialization boundary.
## What changed
- Configures `clippy.toml` so `await_holding_invalid_type` also covers
`tokio::sync::{MutexGuard,RwLockReadGuard,RwLockWriteGuard}`.
- Adds targeted `#[expect(clippy::await_holding_invalid_type, reason =
...)]` annotations for intentional async guard lifetimes.
- Documents the main categories of intentional cases: active-turn state
transitions that must remain atomic, session-owned MCP manager accesses,
remote-control websocket serialization, JS REPL kernel/process
serialization, OAuth persistence, external bearer token refresh
serialization, and tests that intentionally serialize shared global or
session-owned state.
- For external bearer token refresh, documents the existing
serialization boundary: holding `cached_token` across the provider
command prevents concurrent cache misses from starting duplicate refresh
commands, and the current behavior is small enough that an explicit
expectation is easier to maintain than adding another synchronization
primitive.
## Verification
- `cargo clippy -p codex-login --all-targets`
- `cargo clippy -p codex-connectors --all-targets`
- `cargo clippy -p codex-core --all-targets`
- The follow-up PR #18698 enables `await_holding_invalid_type` and
`await_holding_lock` as workspace `deny` lints, so any undocumented
remaining offender will fail Clippy.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/18423).
* #18698
* __->__ #18423
Summary
- require `CODEX_HOME` to point to an existing directory before
canonicalizing and surface clear errors otherwise
- share the same helper logic in both `core` and `rmcp-client` and add
unit tests that cover missing, non-directory, valid, and default paths
This addresses #9222
### What
Add JSON Schema generation for `config.toml`, with checked‑in
`docs/config.schema.json`. We can move the schema elsewhere if preferred
(and host it if there's demand).
Add fixture test to prevent drift and `just write-config-schema` to
regenerate on schema changes.
Generate MCP config schema from `RawMcpServerConfig` instead of
`McpServerConfig` because that is the runtime type used for
deserialization.
Populate feature flag values into generated schema so they can be
autocompleted.
### Tests
Added tests + regenerate script to prevent drift. Tested autocompletions
using generated jsonschema locally with Even Better TOML.
https://github.com/user-attachments/assets/5aa7cd39-520c-4a63-96fb-63798183d0bc
Follow-up PR to #5569. Add Keyring Support for Auth Storage in Codex CLI
as well as a hybrid mode (default to persisting in keychain but fall
back to file when unavailable.)
It also refactors out the keyringstore implementation from rmcp-client
[here](https://github.com/openai/codex/blob/main/codex-rs/rmcp-client/src/oauth.rs)
to a new keyring-store crate.
There will be a follow-up that picks the right credential mode depending
on the config, instead of hardcoding `AuthCredentialsStoreMode::File`.
This adds a queryable auth status for MCP servers which is useful:
1. To determine whether a streamable HTTP server supports auth or not
based on whether or not it supports RFC 8414-3.2
2. Allow us to build a better user experience on top of MCP status
This lets users/companies explicitly choose whether to force/disallow
the keyring/fallback file storage for mcp credentials.
People who develop with Codex will want to use this until we sign
binaries or else each ad-hoc debug builds will require keychain access
on every build. I don't love this and am open to other ideas for how to
handle that.
```toml
mcp_oauth_credentials_store = "auto"
mcp_oauth_credentials_store = "file"
mcp_oauth_credentials_store = "keyrung"
```
Defaults to `auto`
This PR adds oauth login support to streamable http servers when
`experimental_use_rmcp_client` is enabled.
This PR is large but represents the minimal amount of work required for
this to work. To keep this PR smaller, login can only be done with
`codex mcp login` and `codex mcp logout` but it doesn't appear in `/mcp`
or `codex mcp list` yet. Fingers crossed that this is the last large MCP
PR and that subsequent PRs can be smaller.
Under the hood, credentials are stored using platform credential
managers using the [keyring crate](https://crates.io/crates/keyring).
When the keyring isn't available, it falls back to storing credentials
in `CODEX_HOME/.credentials.json` which is consistent with how other
coding agents handle authentication.
I tested this on macOS, Windows, WSL (ubuntu), and Linux. I wasn't able
to test the dbus store on linux but did verify that the fallback works.
One quirk is that if you have credentials, during development, every
build will have its own ad-hoc binary so the keyring won't recognize the
reader as being the same as the write so it may ask for the user's
password. I may add an override to disable this or allow
users/enterprises to opt-out of the keyring storage if it causes issues.
<img width="5064" height="686" alt="CleanShot 2025-09-30 at 19 31 40"
src="https://github.com/user-attachments/assets/9573f9b4-07f1-4160-83b8-2920db287e2d"
/>
<img width="745" height="486" alt="image"
src="https://github.com/user-attachments/assets/9562649b-ea5f-4f22-ace2-d0cb438b143e"
/>
Michael Bolin