## Thinking Path
> - Paperclip is the open source control plane people use to manage AI
agents for work
> - The `codex_local` adapter runs OpenAI's Codex CLI through direct CLI
and ACP execution lanes
> - The adapter defaulted to the bare `gpt-5.6` alias while the bundled
ACP Codex version lacked GPT-5.6-family metadata
> - Default and legacy-configured runs therefore emitted
fallback-metadata warnings and could use generic context limits
> - This pull request upgrades the bundled Codex ACP dependency, selects
the concrete `gpt-5.6-sol` model, and normalizes the legacy alias in
both execution lanes
> - The benefit is correct model metadata without hiding genuine stderr
or transcript warnings
## Linked Issues or Issue Description
Related public PRs: Refs #9342, Refs #9352, and Refs #9382. This PR is
narrower: it upgrades bundled Codex metadata and normalizes the legacy
bare alias in both execution lanes.
**Bug report**
### What happened
Default `codex_local` runs, and agents still configured with the bare
`gpt-5.6` model, print a model-metadata fallback warning and use generic
context-window limits.
Root cause: the ACP lane bundled a Codex release predating
GPT-5.6-family metadata, while Paperclip's default and advertised model
used the bare `gpt-5.6` alias for which Codex publishes no metadata.
### Expected behavior
A default Codex run resolves to a concrete model slug with published
metadata and does not emit a fallback-metadata warning.
### Deployment mode
Self-hosted/local `codex_local` adapter.
## What Changed
- Upgraded `@agentclientprotocol/codex-acp` from `^1.1.0` to `^1.1.4`
- Changed `DEFAULT_CODEX_LOCAL_MODEL` from `gpt-5.6` to `gpt-5.6-sol`
- Removed the bare alias from advertised models and listed concrete
GPT-5.6 Fast-mode variants
- Added `normalizeCodexModel()` and applied it in both CLI and ACP
execution lanes
- Updated adapter docs, Storybook fixtures, and regression tests
- Preserved warning visibility; no stderr, transcript, or log filtering
changed
## Verification
- `pnpm --filter @paperclipai/adapter-codex-local typecheck`
- `pnpm check:token-gates`
- `cd packages/adapters/codex-local && pnpm exec vitest run` — 205 tests
passed
- `cd server && pnpm exec vitest run
src/__tests__/adapter-models.test.ts` — 17 tests passed
- Confirmed the PR diff excludes `pnpm-lock.yaml` and
`.github/workflows/**` as required by repository policy
- Confirmed `.github/workflows/pr.yml` regenerates and uploads the PR
lockfile artifact before downstream `pnpm install --frozen-lockfile`
steps
## Risks
Low risk. The behavior change is scoped to `codex_local` model
selection. Existing concrete model IDs pass through unchanged; only the
legacy bare `gpt-5.6` alias is rewritten. Dependency resolution may
select a newer compatible `codex-acp` release within the declared range,
so CI remains the final compatibility gate.
> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.
## Model Used
- Original implementation: Anthropic Claude Opus 4.8 (`claude-opus-4-8`,
1M context, tool use and code execution)
- Conflict resolution and PR preparation: OpenAI GPT-5.5 (`gpt-5.5`,
Codex CLI coding agent, high-reasoning tool use and code execution;
host-managed context window)
## 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 (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [ ] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
— branch name is fixed by the assigned execution workspace and cannot be
renamed in-place
- [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>
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