## Thinking Path
> - Paperclip manages agent work as issues and pull requests.
> - This change lives in the Codex local adapter path.
> - The host auth flow needs a stable cache per identity.
> - The cache must not change the copy-back path or the default store
overwrite.
> - This pull request adds that cache and keeps the existing flow
intact.
> - The benefit is repeatable host auth with safer identity scoping.
## Linked Issues or Issue Description
**Subsystem affected**
- packages/adapters: Codex local adapter and host auth flow
**Problem or motivation**
- The host auth flow needs one usable credential per identity.
- The current flow does not keep that identity state in a separate
cache.
**Proposed solution**
- Add an identity-keyed host credential cache.
- Keep the cache company scoped.
- Add an opt-in seed mode for the merge decision helper.
- Write the cache at copy-back time without changing the default store
overwrite.
**Alternatives considered**
- Store the cache in the instance-global root.
- Seed the host default store through an environment flag.
- Both choices weaken isolation or caller control, so I did not use
them.
**Roadmap alignment**
- I checked `ROADMAP.md`.
- I found no direct overlap with an active roadmap item.
- The change fits the core auth and secrets direction.
**Additional context**
- Local tests passed before I opened this pull request.
- I found no direct duplicate pull request for this branch.
## What Changed
- Added `codex-auth-cache.ts` for company scoped cache storage and
identity anchored vending.
- Added `codex-auth-merge-decision.cjs` support for a leading
`--seed-if-dest-absent` flag.
- Updated `codex-auth-copyback.ts` to write the cache at teardown under
the merge lock.
- Wired `execute.ts` to use the identity anchored vend before the
managed home seed step.
- Added `CODEX-AUTH-CACHE.md` for the cache rules, directions, state
matrix, off switch, and clear action.
- Added and updated tests for cache behavior, merge decision flow, and
copy-back flow.
## Verification
- `pnpm --filter @paperclipai/adapter-codex-local exec vitest run`.
- `node_modules/.bin/vitest run --project @paperclipai/adapter-utils
workspace-restore-merge`.
- `tsc --noEmit` in `packages/adapters/codex-local`.
- `git log --oneline
origin/master..origin/feat/codex-auth-identity-cache` shows the expected
commits.
## Risks
- This change touches credential storage.
- A mistake in the cache path could break host auth for one identity.
- The tests reduce this risk, but the surface stays sensitive.
## Model Used
- OpenAI Codex, GPT-5, tool use enabled.
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used with version and capability
details
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either linked existing issues with `Fixes:` / `Closes:` /
`Refs:` or described the issue in the pull request body
- [x] I have not referenced internal or instance-local Paperclip issues
or links
- [x] My branch name describes the change and contains no internal
Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
Nicky Leach