diff --git a/packages/adapters/codex-local/src/index.ts b/packages/adapters/codex-local/src/index.ts
index a9c25fc0..8bd1d699 100644
--- a/packages/adapters/codex-local/src/index.ts
+++ b/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.
 `;
diff --git a/packages/adapters/codex-local/src/server/codex-args.test.ts b/packages/adapters/codex-local/src/server/codex-args.test.ts
index 435859b5..feb22574 100644
--- a/packages/adapters/codex-local/src/server/codex-args.test.ts
+++ b/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",
diff --git a/server/src/__tests__/adapter-models.test.ts b/server/src/__tests__/adapter-models.test.ts
index a35efb9d..dc1eba55 100644
--- a/server/src/__tests__/adapter-models.test.ts
+++ b/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();
   });