Add GPT-5.5 to Codex local model options (#5575)

## Related work

This PR is the cleanest "add `gpt-5.5` to the codex-local catalog"
change open against master. Several other PRs propose the same
catalog/fast-mode update; they should close as duplicates once this
lands:

- #4646 — Add Codex gpt-5.5 model option
- #6044 — feat(codex-local): add gpt-5.5 to model catalog, default
reasoning to medium, cheap profile xhigh
- #6045 — feat(codex-local): add gpt-5.5 to model catalog, default
medium reasoning, xhigh cheap profile
- #6595 — feat(adapters): add new Codex models (gpt-5.5, gpt-5.4-mini,
gpt-5.3-codex, gpt-5.2)

Related issues this enables (catalog-level surface area):

- #5371 — codex_local default model selection persists `gpt-5.3-codex`
instead of adapter default. This PR makes `gpt-5.5` selectable in the
dropdown; a separate follow-up changes the *default* behavior so users
who don't pick a model are subscription-compatible.
- #5132 — opencode-local: hire-time default model fails on ChatGPT-OAuth
accounts. Sibling adapter, same problem shape; not fixed here but worth
tracking as a parallel for the opencode side.

---

## Thinking Path

> - Paperclip orchestrates AI agents through adapter-backed local and
remote runtimes.
> - The `codex_local` adapter declares built-in model options that feed
the server model list and, in turn, the agent configuration UI dropdown.
> - GPT-5.5 is available in newer Codex environments but was missing
from Paperclip's fallback `codex_local` model list.
> - Operators could still type a manual model ID, but the default
dropdown made the supported path look unavailable.
> - Codex fast mode support is declared separately, so adding GPT-5.5 to
the visible list should also include it in the supported fast-mode set.
> - This pull request adds GPT-5.5 to the built-in Codex local model
options and updates focused tests around argument generation and adapter
model listing.
> - The benefit is a clearer default setup path for agents using GPT-5.5
without changing existing defaults or migrations.

## What Changed

- Added `gpt-5.5` to the `codex_local` fallback model list.
- Added `gpt-5.5` to `CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS`.
- Updated Codex argument tests to cover GPT-5.5 fast mode and preserve
manual-model fast mode behavior.
- Updated adapter model listing tests to assert the Codex fallback list
includes GPT-5.5.

## Verification

- `pnpm exec vitest run
packages/adapters/codex-local/src/server/codex-args.test.ts
server/src/__tests__/adapter-models.test.ts`
- `git diff --check`
- UI note: this is a dropdown data-source change rather than a
layout/component change; the adapter model listing test covers the list
consumed by the UI.

## Risks

- Low risk. This only extends a static fallback model list and fast-mode
allowlist.
- Existing defaults remain unchanged (`gpt-5.3-codex`).
- If a local Codex CLI does not support `gpt-5.5`, selecting it will
still fail at execution time the same way any unavailable manual model
would.

> 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 desktop coding agent, GPT-5-family model. The exact
backing model ID was not exposed by the local runtime; the session used
shell, Git, test execution, and GitHub CLI tool access.


## 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 run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots
- [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: apple <apple@appledeMacBook-Pro.local>
Co-authored-by: Paperclip <noreply@paperclip.ing>
Co-authored-by: Devin Foley <devin@paperclip.ing>

packages/adapters/codex-local/src/index.ts

@@ -7,7 +7,7 @@ export const SANDBOX_INSTALL_COMMAND = "npm install -g @openai/codex";
 
 export const DEFAULT_CODEX_LOCAL_MODEL = "gpt-5.3-codex";
 export const DEFAULT_CODEX_LOCAL_BYPASS_APPROVALS_AND_SANDBOX = true;
-export const CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS = ["gpt-5.4"] as const;
+export const CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS = ["gpt-5.5", "gpt-5.4"] as const;
 
 function normalizeModelId(model: string | null | undefined): string {
   return typeof model === "string" ? model.trim() : "";
@@ -33,6 +33,7 @@ export function isCodexLocalFastModeSupported(model: string | null | undefined):
 }
 
 export const models = [
+  { id: "gpt-5.5", label: "gpt-5.5" },
   { id: "gpt-5.4", label: "gpt-5.4" },
   { id: DEFAULT_CODEX_LOCAL_MODEL, label: DEFAULT_CODEX_LOCAL_MODEL },
   { id: "gpt-5.3-codex-spark", label: "gpt-5.3-codex-spark" },
@@ -70,7 +71,7 @@ Core fields:
 - modelReasoningEffort (string, optional): reasoning effort override (minimal|low|medium|high|xhigh) passed via -c model_reasoning_effort=...
 - promptTemplate (string, optional): run prompt template
 - search (boolean, optional): run codex with --search
-- fastMode (boolean, optional): enable Codex Fast mode; supported on GPT-5.4 and passed through for manual model IDs
+- fastMode (boolean, optional): enable Codex Fast mode; supported on GPT-5.5, GPT-5.4 and passed through for manual model IDs
 - dangerouslyBypassApprovalsAndSandbox (boolean, optional): run with bypass flag
 - command (string, optional): defaults to "codex"
 - extraArgs (string[], optional): additional CLI args
@@ -89,6 +90,6 @@ Notes:
 - Paperclip injects desired local skills into the effective CODEX_HOME/skills/ directory at execution time so Codex can discover "$paperclip" and related skills without polluting the project working directory. In managed-home mode (the default) this is ~/.paperclip/instances/<id>/companies/<companyId>/codex-home/skills/; when CODEX_HOME is explicitly overridden in adapter config, that override is used instead.
 - Unless explicitly overridden in adapter config, Paperclip runs Codex with a per-company managed CODEX_HOME under the active Paperclip instance and seeds auth/config from the shared Codex home (the CODEX_HOME env var, when set, or ~/.codex).
 - Some model/tool combinations reject certain effort levels (for example minimal with web search enabled).
-- Fast mode is supported on GPT-5.4 and manual model IDs. When enabled for those models, Paperclip applies \`service_tier="fast"\` and \`features.fast_mode=true\`.
+- Fast mode is supported on GPT-5.5, GPT-5.4 and manual model IDs. When enabled for those models, Paperclip applies \`service_tier="fast"\` and \`features.fast_mode=true\`.
 - When Paperclip realizes a workspace/runtime for a run, it injects PAPERCLIP_WORKSPACE_* and PAPERCLIP_RUNTIME_* env vars for agent-side tooling.
 `;

packages/adapters/codex-local/src/server/codex-args.test.ts

@@ -26,7 +26,7 @@ describe("buildCodexExecArgs", () => {
     ]);
   });
 
-  it("enables Codex fast mode overrides for manual models", () => {
+  it("enables Codex fast mode overrides for GPT-5.5", () => {
     const result = buildCodexExecArgs({
       model: "gpt-5.5",
       fastMode: true,
@@ -48,6 +48,28 @@ describe("buildCodexExecArgs", () => {
     ]);
   });
 
+  it("enables Codex fast mode overrides for manual models", () => {
+    const result = buildCodexExecArgs({
+      model: "future-codex-model",
+      fastMode: true,
+    });
+
+    expect(result.fastModeRequested).toBe(true);
+    expect(result.fastModeApplied).toBe(true);
+    expect(result.fastModeIgnoredReason).toBeNull();
+    expect(result.args).toEqual([
+      "exec",
+      "--json",
+      "--model",
+      "future-codex-model",
+      "-c",
+      'service_tier="fast"',
+      "-c",
+      "features.fast_mode=true",
+      "-",
+    ]);
+  });
+
   it("ignores fast mode for unsupported models", () => {
     const result = buildCodexExecArgs({
       model: "gpt-5.3-codex",
@@ -57,7 +79,7 @@ describe("buildCodexExecArgs", () => {
     expect(result.fastModeRequested).toBe(true);
     expect(result.fastModeApplied).toBe(false);
     expect(result.fastModeIgnoredReason).toContain(
-      "currently only supported on gpt-5.4 or manually configured model IDs",
+      "currently only supported on gpt-5.5, gpt-5.4 or manually configured model IDs",
     );
     expect(result.args).toEqual([
       "exec",

server/src/__tests__/adapter-models.test.ts

@@ -49,6 +49,7 @@ describe("adapter model listing", () => {
     const models = await listAdapterModels("codex_local");
 
     expect(models).toEqual(codexFallbackModels);
+    expect(models.some((model) => model.id === "gpt-5.5")).toBe(true);
     expect(fetchSpy).not.toHaveBeenCalled();
   });