Add pinned Codex ACP reference harness

[rgarcia]

Summary

• Add an independent Codex preparer using the existing revision manager and connection-owned ACP bridge.
• Pin codex-acp 1.10.0 and native Codex 0.153.3 in both images; map declarative settings and stdio/HTTP MCP to native configuration with credential references.
• Keep native history outside revisions, require optimistic configuration writes, and preserve effective configuration and existing connections on updates/failures.
• Disable native environment snapshots and unpinned plugin catalog sync; force ephemeral auth/session safety settings so credentials are not persisted. Document native modes and supported/unsupported behavior.

Validation

• Passed all non-e2e Go packages with the race detector and go vet ./.... Passed agentproxy/wsproxy again with both installed Pi and Codex runtimes and pinned acpremote.
• Passed four Node native-settings/environment-isolation tests.
• Passed real native HTTP MCP initialize/tools-list with a bound fixture header, no model call, including a project config attempting to enable shell snapshots/plugins. The plugin-sync assertion also fails against an unsafe runtime copy.
• Built and ran the enabled packaged headless image. Small OpenAI gpt-5.4-mini API-key gate passed real turn, independent connections, shared/session stdio MCP, config updates/failures and stale writes, full adapter/native/MCP cleanup, two-page session/list, exact-ID session/load, replayed history and real model recall. Model/mode and native settings preservation asserted; auth.json absent and full managed-state scan found no provider key.
• Pagination padding uses 26 native forks with test-only preview/user-event fixtures in pinned native storage. The original real session/history is never modified by fixture seeding; no extra provider turns for pagination.
• Built the headful agent-runtime stage. Full headful behavior, arm64, HTTP MCP tool invocation, media, mid-tool cancellation and platform gateway/TLS integration are not verified. CI server/image workflows target main, so stacked-PR checks do not run those jobs.

Integration

Based on the Pi reference branch, not main. Shared changes are limited to Config/Handler registration, catalog, both Dockerfiles, CI installation and README links. No changes to other harness adapters, revision manager or transport.

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	npm/​smol-toml@​1.4.2
	npm/​@​openai/​codex@​0.153.3
	npm/​@​agentclientprotocol/​codex-acp@​1.10.0

View full report