## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work.
> - Codex local is the adapter subsystem that exposes OpenAI Codex CLI
model choices to agents and issue overrides.
> - OpenAI has GPT-5.6 Codex-capable models that should appear in
Paperclip's built-in Codex model list and refresh behavior.
> - Paperclip's server model listing falls back to the adapter metadata
and merges OpenAI refresh results with known Codex defaults.
> - This pull request updates the Codex default model metadata to
include GPT-5.6 options and adds regression coverage for fallback and
refresh paths.
> - The benefit is that operators can select the new Codex models
without relying on manual model IDs, and refresh behavior keeps known
GPT-5.6 options visible.
## Linked Issues or Issue Description
Refs #9322.
Refs #9342.
Refs #9346.
### Agent or provider
Codex CLI (OpenAI).
### Why this adapter is useful
OpenAI's GPT-5.6 Codex-capable models should be available in Paperclip's
Codex adapter defaults and model refresh path.
### How the agent is invoked
`codex`
## What Changed
- Changed the `codex_local` default model metadata from `gpt-5.5` to
`gpt-5.6`.
- Added `gpt-5.6-sol`, `gpt-5.6-terra`, and `gpt-5.6-luna` to the
built-in Codex adapter model list.
- Updated adapter and server model-listing tests to cover GPT-5.6
fallback and refresh behavior.
- Aligned Codex Fast mode support and helper text with the new `gpt-5.6`
default, while preserving GPT-5.5, GPT-5.4, and manual model ID support.
## Verification
- `git diff --check origin/master...HEAD`
- `pnpm exec vitest run packages/adapters/codex-local/src/index.test.ts
packages/adapters/codex-local/src/server/codex-args.test.ts
server/src/__tests__/adapter-models.test.ts
server/src/__tests__/adapter-model-refresh-routes.test.ts`
- `pnpm check:token-gates`
- `pnpm --filter @paperclipai/adapter-codex-local typecheck`
- `pnpm --filter @paperclipai/server typecheck`
- `pnpm --filter @paperclipai/ui typecheck`
## Risks
Medium risk because changing `DEFAULT_CODEX_LOCAL_MODEL` from `gpt-5.5`
to `gpt-5.6` changes the adapter's default model selection for new blank
configurations. The model-list additions are otherwise low risk and
covered by adapter/server metadata tests. This PR intentionally overlaps
related PRs #9342 and #9346, so reviewers may prefer to close or fold it
into one of those branches.
> 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
OpenAI Codex coding agent based on GPT-5, with shell, git, GitHub CLI,
and repository editing tool use. Exact served model ID and context
window were not exposed by the runtime.
## 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)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
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>
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