## Summary
This PR adds `CodexAuth::AgentIdentity` as an explicit auth mode.
An AgentIdentity auth record is a standalone `auth.json` mode. When
`AuthManager::auth().await` loads that mode, it registers one
process-scoped task and stores it in runtime-only state on the auth
value. Header creation stays synchronous after that because the task is
initialized before callers receive the auth object.
This PR also removes the old feature flag path. AgentIdentity is
selected by explicit auth mode, not by a hidden flag or lazy mutation of
ChatGPT auth records.
Reference old stack: https://github.com/openai/codex/pull/17387/changes
## Design Decisions
- AgentIdentity is a real auth enum variant because it can be the only
credential in `auth.json`.
- The process task is ephemeral runtime state. It is not serialized and
is not stored in rollout/session data.
- Account/user metadata needed by existing Codex backend checks lives on
the AgentIdentity record for now.
- `is_chatgpt_auth()` remains token-specific.
- `uses_codex_backend()` is the broader predicate for ChatGPT-token auth
and AgentIdentity auth.
## Stack
1. https://github.com/openai/codex/pull/18757: full revert
2. https://github.com/openai/codex/pull/18871: isolated Agent Identity
crate
3. This PR: explicit AgentIdentity auth mode and startup task allocation
4. https://github.com/openai/codex/pull/18811: migrate Codex backend
auth callsites through AuthProvider
5. https://github.com/openai/codex/pull/18904: accept AgentIdentity JWTs
and load `CODEX_AGENT_IDENTITY`
## Testing
Tests: targeted Rust checks, cargo-shear, Bazel lock check, and CI.
## Summary
This PR fully reverts the previously merged Agent Identity runtime
integration from the old stack:
https://github.com/openai/codex/pull/17387/changes
It removes the Codex-side task lifecycle wiring, rollout/session
persistence, feature flag plumbing, lazy `auth.json` mutation,
background task auth paths, and request callsite changes introduced by
that stack.
This leaves the repo in a clean pre-AgentIdentity integration state so
the follow-up PRs can reintroduce the pieces in smaller reviewable
layers.
## Stack
1. This PR: full revert
2. https://github.com/openai/codex/pull/18871: move Agent Identity
business logic into a crate
3. https://github.com/openai/codex/pull/18785: add explicit
AgentIdentity auth mode and startup task allocation
4. https://github.com/openai/codex/pull/18811: migrate auth callsites
through AuthProvider
## Testing
Tests: targeted Rust checks, cargo-shear, Bazel lock check, and CI.
## Summary
This changes Codex logout so managed ChatGPT auth is revoked against
AuthAPI before local auth state is removed. CLI logout, TUI `/logout`,
and the app-server account logout path now use the token-revoking logout
flow instead of only deleting `auth.json` / credential store state.
## Root Cause
Logout previously cleared only local auth storage. That removed Codex's
local credentials but did not ask the backend to invalidate the
refresh/access token state associated with a managed ChatGPT login.
## Behavior
For managed ChatGPT auth, logout sends the stored refresh token to
`https://auth.openai.com/oauth/revoke` with `token_type_hint:
refresh_token` and the Codex OAuth client id, then deletes all local
auth stores after revocation succeeds. If only an access token is
available, it falls back to revoking that access token. API key auth and
externally supplied `chatgptAuthTokens` are still only cleared locally
because Codex does not own a refresh token for those modes.
Revocation failures are fail-closed: if Codex cannot load stored auth or
the backend revoke call fails, logout returns an error and leaves local
auth in place so the user can retry instead of silently clearing local
state while backend tokens remain valid.
## Validation
ran local version of `codex-cli` with staging overrides/harness for auth
ran `codex login` then `codex logout`:
saw auth.json clear and backend revocation endpoints were called
```
POST /oauth/revoke
status: 200
revoking access token
should clear auth session
clearing auth session due to token revocation
successfully revoked session and access token
CANONICAL-API-LINE Response: status='200' method='POST' path='/oauth/revoke
```
---------
Co-authored-by: Codex <noreply@openai.com>