## What changed
Add `RuntimeAuthProvider` to resolve request authentication through the runtime auth manager. Support `dual_header` mode, which sends a bearer credential alongside `x-openai-agent-assertion`, and `assertion_only` mode, which uses `Authorization: AgentAssertion …`.
Replace stale authentication headers and sign a fresh assertion for each request attempt. Propagate registration failures without falling back to credential-only authentication, preserving policy errors and classifying transport failures, rate limits, and server errors as transient.
Add the disabled-by-default `features.runtime_agent_instances` configuration with independent `enabled` and `mode` settings, schema support, and structured override merging. Selecting a mode alone does not enable the feature.
## Testing
Add coverage for both modes with API key and ChatGPT credentials, stale header replacement, fresh assertions, credential refresh without runtime replacement, registration failures, and configuration parsing and merging.
GitOrigin-RevId: 9e93d25762600f0ff592c5248fe4c8c2c8182c8d
## What changed
Add `RuntimeAuthManager` to share one registered runtime per credential source and return request-scoped `RuntimeAuth` values that pair the runtime with its credentials and HTTP client factory.
- Preserve registration keys and idempotency IDs across retryable failures and refreshes that retain the credential source.
- Replace the runtime when the credential source changes, preserve existing request snapshots, and reject late registration responses for a previous source.
- Use bounded credential recovery for registration `401` responses and cache `403` denials until the credential source changes.
- Expose authenticated actor and agent host information on `RuntimeAgentInstance`.
## Testing
Add tests for concurrent registration sharing, retry identity preservation, network policy recovery, credential refresh and replacement, bounded recovery, cached denials, and credential changes during registration.
GitOrigin-RevId: ea1e6e10a5939e8c3f7c0c317ccf8a83522c635f
## What changed
Extend `codex-runtime-agent-instance` with a registration client and an in-memory assertion signer. Pending registrations retain their signing key and idempotency key across caller-driven retries; registered runtimes generate fresh versioned assertions with a timestamp and unique ID.
Bound registration requests and responses, reject unsafe endpoints, disable redirects and request logging, and preserve network policy errors. Report server rejections using only the status and recognized error codes.
## Testing
Add HTTP-backed tests for retry stability, assertion signatures and freshness, policy revocation, endpoint and response validation, redirect refusal, and error redaction.
GitOrigin-RevId: a6dab0900459dfb75f72652a0a2ee1e4b65ca322
## What changed
Add `codex-runtime-agent-instance` with serializable registration requests and deserializable responses. Requests support OAuth, personal access tokens, and platform API keys, along with an installation ID, public key, harness metadata, and runtime role. Responses include runtime and host IDs plus ChatGPT or platform actor context.
Use `RedactedString` for credentials to keep secrets out of debug output.
## Testing
Add tests covering request serialization for all three credential types, debug redaction, response decoding for both actor types, and rejection of responses missing required fields.
GitOrigin-RevId: f33bae734fdd1402144dee407e5b868f5eef1d37
cooper-oai