diff --git a/apps/server/src/provider/CodexProvider.ts b/apps/server/src/provider/CodexProvider.ts
index 9ed238bf5d2ceb9981dcdc970612708b4d6f96bd..7d4bbfdf5d0fad1cc1f6f20aa882e62760fb2a2d 100644
--- a/apps/server/src/provider/CodexProvider.ts
+++ b/apps/server/src/provider/CodexProvider.ts
@@ -32,7 +32,6 @@ import {
   codexModelFamily,
   createModelCapabilities,
   formatCodexModelName,
-  readCustomModelEntries,
 } from "@t3tools/shared/model";
 import { resolveSpawnCommand } from "@t3tools/shared/shell";
 import { codexAppServerArgs, resolveCodexLaunchArgs } from "./codexLaunchArgs.ts";
@@ -40,6 +39,7 @@ import {
   AUTH_PROBE_TIMEOUT_MS,
   buildServerProvider,
   COMPACT_SLASH_COMMAND,
+  providerModelsFromSettings,
   type ServerProviderDraft,
 } from "@t3tools/provider-core/server/snapshotProbe";
 import { expandHomePath } from "@t3tools/provider-core/server/pathExpansion";
@@ -277,26 +277,8 @@ function appendCustomCodexModels(
   models: ReadonlyArray<ServerProviderModel>,
   customModels: ReadonlyArray<CustomModelSetting>,
 ): ReadonlyArray<ServerProviderModel> {
-  if (customModels.length === 0) {
-    return models;
-  }
-
-  const seen = new Set(models.map((model) => model.slug));
   const fallbackCapabilities = models.find((model) => model.capabilities)?.capabilities ?? null;
-  const customEntries: ServerProviderModel[] = [];
-  for (const entry of readCustomModelEntries(customModels)) {
-    if (seen.has(entry.slug)) {
-      continue;
-    }
-    seen.add(entry.slug);
-    customEntries.push({
-      slug: entry.slug,
-      name: entry.name,
-      isCustom: true,
-      capabilities: entry.capabilities ?? fallbackCapabilities,
-    });
-  }
-  return customEntries.length === 0 ? models : [...models, ...customEntries];
+  return providerModelsFromSettings(models, customModels, fallbackCapabilities);
 }
 
 function parseCodexSkillsListResponse(
diff --git a/apps/web/src/components/settings/ProviderInstanceCard.tsx b/apps/web/src/components/settings/ProviderInstanceCard.tsx
index b9f2a4569b0c24b298983a875ea4115bf1c23a90..53b6cbc2783f7af544330b11d7da95b62ba92cb8 100644
--- a/apps/web/src/components/settings/ProviderInstanceCard.tsx
+++ b/apps/web/src/components/settings/ProviderInstanceCard.tsx
@@ -181,13 +181,22 @@ export function deriveProviderModelsForDisplay(input: {
     ),
   );
   const serverModels = input.liveModels?.filter((model) => !model.isCustom) ?? [];
-  const customModels = input.customModels.map((entry) => ({
-    slug: entry.slug,
-    name: entry.name,
-    isCustom: true,
-    capabilities:
-      entry.capabilities ?? liveCustomModelsBySlug.get(entry.slug)?.capabilities ?? null,
-  }));
+  const serverSlugs = new Set(serverModels.map((model) => model.slug));
+  // A custom entry with a built-in slug only renames that built-in on the
+  // server, so the built-in row already shows it.
+  const customModels = input.customModels.flatMap((entry) =>
+    serverSlugs.has(entry.slug)
+      ? []
+      : [
+          {
+            slug: entry.slug,
+            name: entry.name,
+            isCustom: true,
+            capabilities:
+              entry.capabilities ?? liveCustomModelsBySlug.get(entry.slug)?.capabilities ?? null,
+          },
+        ],
+  );
   return [...serverModels, ...customModels];
 }
 
diff --git a/docs/user/composer.md b/docs/user/composer.md
index 831a8ac9792d14b22a8f53d3ece08ce02677af1d..9fe7cb28d8c276721fdcc9134ae03633b0ad0a28 100644
--- a/docs/user/composer.md
+++ b/docs/user/composer.md
@@ -85,6 +85,21 @@ On web and desktop, use Settings → Providers → **Models** to add an unlisted
 name and options. Only options supported by the provider integration affect turns. Antigravity
 uses its account catalog and does not support custom models.
 
+To rename a built-in model on every client, edit the server's `settings.json` in its `userdata`
+directory. Add a custom model entry with the built-in model ID and a new name under that provider
+instance:
+
+```json
+{
+  "providerInstances": {
+    "codex": {
+      "driver": "codex",
+      "config": { "customModels": [{ "slug": "gpt-5.5", "name": "Team GPT" }] }
+    }
+  }
+}
+```
+
 ## Model defaults
 
 T3 Code remembers your provider, model, and model options for new threads. A
diff --git a/packages/provider-core/src/server/snapshotProbe.test.ts b/packages/provider-core/src/server/snapshotProbe.test.ts
index fc207f90f340930c572cb3b9ff73efa8c2dd49dd..29ba4c9cd9d603cf9688ad5849f5b3d05e4f7b27 100644
--- a/packages/provider-core/src/server/snapshotProbe.test.ts
+++ b/packages/provider-core/src/server/snapshotProbe.test.ts
@@ -75,6 +75,25 @@ describe("providerModelsFromSettings", () => {
     ]);
   });
 
+  it("renames a built-in model when a named entry uses its slug", () => {
+    const capabilities = createModelCapabilities({ optionDescriptors: [] });
+    const models = providerModelsFromSettings(
+      [
+        {
+          slug: "gpt-5.5",
+          name: "GPT-5.5",
+          shortName: "5.5",
+          isCustom: false,
+          capabilities,
+        },
+      ],
+      [{ slug: "gpt-5.5", name: "Team GPT" }],
+      capabilities,
+    );
+
+    expect(models).toEqual([{ slug: "gpt-5.5", name: "Team GPT", isCustom: false, capabilities }]);
+  });
+
   it("preserves a custom slug that collides with a provider alias", () => {
     const capabilities = createModelCapabilities({ optionDescriptors: [] });
     const models = providerModelsFromSettings(
diff --git a/packages/provider-core/src/server/snapshotProbe.ts b/packages/provider-core/src/server/snapshotProbe.ts
index 071d9fd5ae07e3ee0cd79380eb4486dbdc3c9943..7ca44770f2673ef2d780656a7fc812cf247cbf56 100644
--- a/packages/provider-core/src/server/snapshotProbe.ts
+++ b/packages/provider-core/src/server/snapshotProbe.ts
@@ -146,18 +146,32 @@ export function parseGenericCliVersion(output: string): string | null {
 /**
  * Append the user's custom models after the built-ins. A custom entry that
  * declares its own capabilities keeps them; a bare slug gets the driver's
- * default set. Slugs that collide with a built-in are dropped.
+ * default set. A named entry whose slug matches a built-in renames that
+ * built-in instead (for example `{ "slug": "gpt-5.5", "name": "GPT" }` in
+ * `settings.json`); other fields on such an entry are ignored.
  */
 export function providerModelsFromSettings(
   builtInModels: ReadonlyArray<ServerProviderModel>,
   customModels: ReadonlyArray<CustomModelSetting>,
-  customModelCapabilities: ModelCapabilities,
+  customModelCapabilities: ModelCapabilities | null,
 ): ReadonlyArray<ServerProviderModel> {
-  const resolvedBuiltInModels = [...builtInModels];
+  const entries = readCustomModelEntries(customModels);
+  if (entries.length === 0) return builtInModels;
+
+  const nameOverrides = new Map(
+    entries.filter((entry) => entry.name !== entry.slug).map((entry) => [entry.slug, entry.name]),
+  );
+  const resolvedBuiltInModels = builtInModels.map((model) => {
+    const name = nameOverrides.get(model.slug);
+    if (!name) return model;
+    // The built-in short name would undo the override in compact UI.
+    const { shortName: _shortName, ...rest } = model;
+    return { ...rest, name };
+  });
   const seen = new Set(resolvedBuiltInModels.map((model) => model.slug));
   const customEntries: ServerProviderModel[] = [];
 
-  for (const entry of readCustomModelEntries(customModels)) {
+  for (const entry of entries) {
     if (seen.has(entry.slug)) {
       continue;
     }