Allow Codex fast mode for manual models

Co-Authored-By: Paperclip <noreply@paperclip.ing>

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

@@ -4,7 +4,23 @@ 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;
 
+function normalizeModelId(model: string | null | undefined): string {
+  return typeof model === "string" ? model.trim() : "";
+}
+
+export function isCodexLocalKnownModel(model: string | null | undefined): boolean {
+  const normalizedModel = normalizeModelId(model);
+  if (!normalizedModel) return false;
+  return models.some((entry) => entry.id === normalizedModel);
+}
+
+export function isCodexLocalManualModel(model: string | null | undefined): boolean {
+  const normalizedModel = normalizeModelId(model);
+  return Boolean(normalizedModel) && !isCodexLocalKnownModel(normalizedModel);
+}
+
 export function isCodexLocalFastModeSupported(model: string | null | undefined): boolean {
+  if (isCodexLocalManualModel(model)) return true;
   const normalizedModel = typeof model === "string" ? model.trim() : "";
   return CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS.includes(
     normalizedModel as (typeof CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS)[number],
@@ -35,7 +51,7 @@ 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; currently supported on GPT-5.4 only and consumes credits faster
+- fastMode (boolean, optional): enable Codex Fast mode; supported on 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
@@ -54,6 +70,6 @@ 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 currently supported on GPT-5.4 only. When enabled, Paperclip applies \`service_tier="fast"\` and \`features.fast_mode=true\`.
+- 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\`.
 - 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

@@ -26,6 +26,28 @@ describe("buildCodexExecArgs", () => {
     ]);
   });
 
+  it("enables Codex fast mode overrides for manual models", () => {
+    const result = buildCodexExecArgs({
+      model: "gpt-5.5",
+      fastMode: true,
+    });
+
+    expect(result.fastModeRequested).toBe(true);
+    expect(result.fastModeApplied).toBe(true);
+    expect(result.fastModeIgnoredReason).toBeNull();
+    expect(result.args).toEqual([
+      "exec",
+      "--json",
+      "--model",
+      "gpt-5.5",
+      "-c",
+      'service_tier="fast"',
+      "-c",
+      "features.fast_mode=true",
+      "-",
+    ]);
+  });
+
   it("ignores fast mode for unsupported models", () => {
     const result = buildCodexExecArgs({
       model: "gpt-5.3-codex",
@@ -34,7 +56,9 @@ describe("buildCodexExecArgs", () => {
 
     expect(result.fastModeRequested).toBe(true);
     expect(result.fastModeApplied).toBe(false);
-    expect(result.fastModeIgnoredReason).toContain("currently only supported on gpt-5.4");
+    expect(result.fastModeIgnoredReason).toContain(
+      "currently only supported on gpt-5.4 or manually configured model IDs",
+    );
     expect(result.args).toEqual([
       "exec",
       "--json",

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

@@ -25,7 +25,7 @@ function asRecord(value: unknown): Record<string, unknown> {
 }
 
 function formatFastModeSupportedModels(): string {
-  return CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS.join(", ");
+  return `${CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS.join(", ")} or manually configured model IDs`;
 }
 
 export function buildCodexExecArgs(

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

@@ -146,7 +146,7 @@ export async function testEnvironment(
           code: "codex_fast_mode_unsupported_model",
           level: "warn",
           message: execArgs.fastModeIgnoredReason,
-          hint: "Switch the agent model to GPT-5.4 to enable Codex Fast mode.",
+          hint: "Switch the agent model to GPT-5.4 or enter a manual model ID to enable Codex Fast mode.",
         });
       }
 

ui/src/adapters/codex-local/config-fields.tsx

@@ -10,6 +10,7 @@ import { LocalWorkspaceRuntimeFields } from "../local-workspace-runtime-fields";
 import {
   CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS,
   isCodexLocalFastModeSupported,
+  isCodexLocalManualModel,
 } from "@paperclipai/adapter-codex-local";
 
 const inputClass =
@@ -37,8 +38,14 @@ export function CodexLocalConfigFields({
   const currentModel = isCreate
     ? String(values!.model ?? "")
     : eff("adapterConfig", "model", String(config.model ?? ""));
+  const fastModeManualModel = isCodexLocalManualModel(currentModel);
   const fastModeSupported = isCodexLocalFastModeSupported(currentModel);
   const supportedModelsLabel = CODEX_LOCAL_FAST_MODE_SUPPORTED_MODELS.join(", ");
+  const fastModeMessage = fastModeManualModel
+    ? "Fast mode will be passed through for this manual model. If Codex rejects it, turn the toggle off."
+    : fastModeSupported
+      ? "Fast mode consumes credits/tokens much faster than standard Codex runs."
+      : `Fast mode currently only works on ${supportedModelsLabel} or manual model IDs. Paperclip will ignore this toggle until the model is switched.`;
 
   return (
     <>
@@ -112,9 +119,7 @@ export function CodexLocalConfigFields({
       />
       {fastModeEnabled && (
         <div className="rounded-md border border-amber-300/70 bg-amber-50/80 px-3 py-2 text-sm text-amber-900 dark:border-amber-500/40 dark:bg-amber-500/10 dark:text-amber-100">
-          {fastModeSupported
-            ? "Fast mode consumes credits/tokens much faster than standard Codex runs."
-            : `Fast mode currently only works on ${supportedModelsLabel}. Paperclip will ignore this toggle until the model is switched.`}
+          {fastModeMessage}
         </div>
       )}
       <LocalWorkspaceRuntimeFields

ui/src/components/agent-config-primitives.tsx

@@ -34,7 +34,7 @@ export const help: Record<string, string> = {
   dangerouslySkipPermissions: "Run unattended by auto-approving adapter permission prompts when supported.",
   dangerouslyBypassSandbox: "Run Codex without sandbox restrictions. Required for filesystem/network access.",
   search: "Enable Codex web search capability during runs.",
-  fastMode: "Enable Codex Fast mode. This burns credits/tokens much faster and is currently supported on GPT-5.4 only.",
+  fastMode: "Enable Codex Fast mode. This burns credits/tokens much faster and is supported on GPT-5.4 and manual Codex model IDs.",
   workspaceStrategy: "How Paperclip should realize an execution workspace for this agent. Keep project_primary for normal cwd execution, or use git_worktree for issue-scoped isolated checkouts.",
   workspaceBaseRef: "Base git ref used when creating a worktree branch. Leave blank to use the resolved workspace ref or HEAD.",
   workspaceBranchTemplate: "Template for naming derived branches. Supports {{issue.identifier}}, {{issue.title}}, {{agent.name}}, {{project.id}}, {{workspace.repoRef}}, and {{slug}}.",