diff --git a/config/base-codex.settings.json b/config/base-codex.settings.json
index 5dae2d86..d3a5ecd4 100644
--- a/config/base-codex.settings.json
+++ b/config/base-codex.settings.json
@@ -2,9 +2,9 @@
   "env": {
     "ANTHROPIC_BASE_URL": "http://127.0.0.1:8317/api/provider/codex",
     "ANTHROPIC_AUTH_TOKEN": "ccs-internal-managed",
-    "ANTHROPIC_MODEL": "gpt-5-codex",
-    "ANTHROPIC_DEFAULT_OPUS_MODEL": "gpt-5-codex",
-    "ANTHROPIC_DEFAULT_SONNET_MODEL": "gpt-5-codex",
-    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "gpt-5-codex-mini"
+    "ANTHROPIC_MODEL": "gpt-5.4",
+    "ANTHROPIC_DEFAULT_OPUS_MODEL": "gpt-5.4",
+    "ANTHROPIC_DEFAULT_SONNET_MODEL": "gpt-5.4",
+    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "gpt-5.4-mini"
   }
 }
diff --git a/src/cliproxy/codex-plan-compatibility.ts b/src/cliproxy/codex-plan-compatibility.ts
index 95506089..5276f970 100644
--- a/src/cliproxy/codex-plan-compatibility.ts
+++ b/src/cliproxy/codex-plan-compatibility.ts
@@ -1,5 +1,6 @@
 import { getDefaultAccount } from './account-manager';
 import { getProviderCatalog } from './model-catalog';
+import { normalizeModelIdForProvider } from './model-id-normalizer';
 import { fetchCodexQuota } from './quota-fetcher-codex';
 import { getCachedQuota, setCachedQuota } from './quota-response-cache';
 import type { CodexQuotaResult } from './quota-types';
@@ -7,8 +8,8 @@ import { info, warn } from '../utils/ui';
 
 export type CodexPlanType = CodexQuotaResult['planType'];
 
-const FREE_SAFE_DEFAULT_MODEL = 'gpt-5-codex';
-const FREE_SAFE_FAST_MODEL = 'gpt-5-codex-mini';
+const FREE_SAFE_DEFAULT_MODEL = 'gpt-5.4';
+const FREE_SAFE_FAST_MODEL = 'gpt-5.4-mini';
 const CODEX_EFFORT_SUFFIX_REGEX = /-(xhigh|high|medium)$/i;
 const CODEX_PAREN_SUFFIX_REGEX = /\((xhigh|high|medium)\)$/i;
 const EXTENDED_CONTEXT_SUFFIX_REGEX = /\[1m\]$/i;
@@ -19,7 +20,6 @@ const KNOWN_CODEX_MODELS = new Set(
 const FREE_PLAN_FALLBACKS = new Map<string, string>([
   ['gpt-5.3-codex', FREE_SAFE_DEFAULT_MODEL],
   ['gpt-5.3-codex-spark', FREE_SAFE_FAST_MODEL],
-  ['gpt-5.4', FREE_SAFE_DEFAULT_MODEL],
 ]);
 
 export interface CodexRuntimeFallbackModelMap {
@@ -52,13 +52,13 @@ function isKnownCodexModel(model: string): boolean {
 }
 
 export function normalizeCodexModelId(model: string): string {
-  return model
+  const stripped = model
     .trim()
     .replace(EXTENDED_CONTEXT_SUFFIX_REGEX, '')
     .replace(CODEX_PAREN_SUFFIX_REGEX, '')
     .replace(CODEX_EFFORT_SUFFIX_REGEX, '')
-    .trim()
-    .toLowerCase();
+    .trim();
+  return normalizeModelIdForProvider(stripped, 'codex').trim().toLowerCase();
 }
 
 export function getDefaultCodexModel(): string {
diff --git a/src/cliproxy/model-catalog.ts b/src/cliproxy/model-catalog.ts
index 8a4e4564..f4187873 100644
--- a/src/cliproxy/model-catalog.ts
+++ b/src/cliproxy/model-catalog.ts
@@ -186,56 +186,12 @@ export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> =
   codex: {
     provider: 'codex',
     displayName: 'Copilot Codex',
-    defaultModel: 'gpt-5-codex',
+    defaultModel: 'gpt-5.4',
     models: [
       {
-        id: 'gpt-5-codex',
-        name: 'GPT-5 Codex',
-        description: 'Cross-plan safe Codex default',
-        thinking: {
-          type: 'levels',
-          levels: ['low', 'medium', 'high'],
-          maxLevel: 'high',
-          dynamicAllowed: false,
-        },
-      },
-      {
-        id: 'gpt-5-codex-mini',
-        name: 'GPT-5 Codex Mini',
-        description: 'Faster and cheaper Codex option',
-        thinking: {
-          type: 'levels',
-          levels: ['low', 'medium', 'high'],
-          maxLevel: 'high',
-          dynamicAllowed: false,
-        },
-      },
-      {
-        id: 'gpt-5-mini',
-        name: 'GPT-5 Mini',
-        description: 'Legacy mini model ID kept for backwards compatibility',
-        thinking: {
-          type: 'levels',
-          levels: ['low', 'medium', 'high'],
-          maxLevel: 'high',
-          dynamicAllowed: false,
-        },
-      },
-      {
-        id: 'gpt-5.1-codex-mini',
-        name: 'GPT-5.1 Codex Mini',
-        description: 'Legacy fast Codex mini model',
-        thinking: {
-          type: 'levels',
-          levels: ['low', 'medium', 'high'],
-          maxLevel: 'high',
-          dynamicAllowed: false,
-        },
-      },
-      {
-        id: 'gpt-5.1-codex-max',
-        name: 'GPT-5.1 Codex Max',
-        description: 'Higher-effort Codex model with xhigh support',
+        id: 'gpt-5.4',
+        name: 'GPT-5.4',
+        description: 'Recommended Codex default for most coding and agentic tasks',
         thinking: {
           type: 'levels',
           levels: ['low', 'medium', 'high', 'xhigh'],
@@ -244,13 +200,13 @@ export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> =
         },
       },
       {
-        id: 'gpt-5.2-codex',
-        name: 'GPT-5.2 Codex',
-        description: 'Cross-plan Codex model with xhigh support',
+        id: 'gpt-5.4-mini',
+        name: 'GPT-5.4 Mini',
+        description: 'Fast, lower-cost Codex option for lighter tasks and haiku-tier routing',
         thinking: {
           type: 'levels',
-          levels: ['low', 'medium', 'high', 'xhigh'],
-          maxLevel: 'xhigh',
+          levels: ['low', 'medium', 'high'],
+          maxLevel: 'high',
           dynamicAllowed: false,
         },
       },
@@ -258,7 +214,7 @@ export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> =
         id: 'gpt-5.3-codex',
         name: 'GPT-5.3 Codex',
         tier: 'pro',
-        description: 'Paid Codex plans only',
+        description: 'Previous flagship coding model whose capabilities now power GPT-5.4',
         thinking: {
           type: 'levels',
           levels: ['low', 'medium', 'high', 'xhigh'],
@@ -270,7 +226,8 @@ export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> =
         id: 'gpt-5.3-codex-spark',
         name: 'GPT-5.3 Codex Spark',
         tier: 'pro',
-        description: 'Paid Codex plans only, ultra-fast coding model',
+        description:
+          'Research preview model for ChatGPT Pro subscribers, optimized for near-instant coding iteration',
         thinking: {
           type: 'levels',
           levels: ['low', 'medium', 'high', 'xhigh'],
@@ -279,10 +236,9 @@ export const MODEL_CATALOG: Partial<Record<CLIProxyProvider, ProviderCatalog>> =
         },
       },
       {
-        id: 'gpt-5.4',
-        name: 'GPT-5.4',
-        tier: 'pro',
-        description: 'Paid Codex plans only, latest GPT-5 family model',
+        id: 'gpt-5.2',
+        name: 'GPT-5.2',
+        description: 'Previous general-purpose Codex model',
         thinking: {
           type: 'levels',
           levels: ['low', 'medium', 'high', 'xhigh'],
diff --git a/src/cliproxy/model-id-normalizer.ts b/src/cliproxy/model-id-normalizer.ts
index d2719d2c..192a369f 100644
--- a/src/cliproxy/model-id-normalizer.ts
+++ b/src/cliproxy/model-id-normalizer.ts
@@ -27,6 +27,16 @@ const DENIED_ANTIGRAVITY_SONNET_45_REGEX =
   /claude-sonnet-4(?:[.-])5(?:-thinking)?(?=(?:$|[^a-z0-9]))/gi;
 const CANONICAL_ANTIGRAVITY_OPUS_46_MODEL = 'claude-opus-4-6-thinking';
 const CODEX_EFFORT_SUFFIX_REGEX = /-(xhigh|high|medium)$/i;
+const CODEX_LEGACY_MODEL_ALIASES: Readonly<Record<string, string>> = Object.freeze({
+  'gpt-5-codex': 'gpt-5.4',
+  'gpt-5-codex-mini': 'gpt-5.4-mini',
+  'gpt-5-mini': 'gpt-5.4-mini',
+  'gpt-5.1-codex': 'gpt-5.2',
+  'gpt-5.1-codex-mini': 'gpt-5.4-mini',
+  'gpt-5.1-codex-max': 'gpt-5.4',
+  'gpt-5.2-codex': 'gpt-5.2',
+  'gpt-5.2-codex-mini': 'gpt-5.4-mini',
+});
 const IFLOW_LEGACY_MODEL_ALIASES: Readonly<Record<string, string>> = Object.freeze({
   'iflow-default': 'qwen3-coder-plus',
   'kimi-k2.5': 'kimi-k2',
@@ -92,6 +102,17 @@ export function stripCodexEffortSuffix(model: string): string {
   return model.replace(CODEX_EFFORT_SUFFIX_REGEX, '');
 }
 
+/** Normalize legacy Codex aliases to the current public Codex model IDs. */
+export function normalizeCodexLegacyModelAliases(model: string): string {
+  const trimmed = trimModelId(model);
+  const { baseModel, suffix } = splitBaseModelAndSuffix(trimmed);
+  const replacement = CODEX_LEGACY_MODEL_ALIASES[baseModel.trim().toLowerCase()];
+  if (!replacement) {
+    return trimmed;
+  }
+  return `${replacement}${suffix}`;
+}
+
 /**
  * Normalize known legacy iFlow model aliases to current upstream model IDs.
  * Preserves suffixes such as (budget) and [1m].
@@ -186,6 +207,9 @@ export function normalizeModelIdForProvider(model: string, provider: ProviderLik
   if (isIFlowProvider(provider)) {
     return normalizeIFlowLegacyModelAliases(trimmedModel);
   }
+  if (isCodexProvider(provider)) {
+    return normalizeCodexLegacyModelAliases(trimmedModel);
+  }
   if (!isAntigravityProvider(provider)) return trimmedModel;
   const normalizedDottedVersion = normalizeClaudeDottedMajorMinor(trimmedModel);
   return normalizeDeprecatedAntigravityModelAliases(normalizedDottedVersion);
diff --git a/tests/unit/cliproxy/codex-plan-compatibility-reconcile.test.ts b/tests/unit/cliproxy/codex-plan-compatibility-reconcile.test.ts
index 4cdca89f..1f004389 100644
--- a/tests/unit/cliproxy/codex-plan-compatibility-reconcile.test.ts
+++ b/tests/unit/cliproxy/codex-plan-compatibility-reconcile.test.ts
@@ -9,7 +9,7 @@ afterEach(() => {
   mock.restore();
 });
 
-function createCodexSettingsFixture(haikuModel: string = 'gpt-5-codex-mini'): {
+function createCodexSettingsFixture(haikuModel: string = 'gpt-5.4-mini'): {
   tmpDir: string;
   settingsPath: string;
 } {
@@ -80,7 +80,7 @@ describe('codex plan compatibility reconcile', () => {
       expect(repaired.env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex');
       expect(repaired.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.3-codex-spark');
       expect(errorSpy).toHaveBeenCalledWith(
-        'Codex free plan detected. Keeping saved model "gpt-5.3-codex" in settings; runtime requests will fall back to "gpt-5-codex" when needed.'
+        'Codex free plan detected. Keeping saved model "gpt-5.3-codex" in settings; runtime requests will fall back to "gpt-5.4" when needed.'
       );
     } finally {
       fs.rmSync(tmpDir, { recursive: true, force: true });
@@ -115,7 +115,7 @@ describe('codex plan compatibility reconcile', () => {
       };
       expect(settings.env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
       expect(errorSpy).toHaveBeenCalledWith(
-        'Configured Codex model "gpt-5.3-codex" may require a paid Codex plan. If startup fails, switch to "gpt-5-codex" with "ccs codex --config".'
+        'Configured Codex model "gpt-5.3-codex" may require a paid Codex plan. If startup fails, switch to "gpt-5.4" with "ccs codex --config".'
       );
     } finally {
       fs.rmSync(tmpDir, { recursive: true, force: true });
@@ -195,7 +195,7 @@ describe('codex plan compatibility reconcile', () => {
       };
       expect(settings.env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
       expect(errorSpy).toHaveBeenCalledWith(
-        'Could not verify Codex plan for model "gpt-5.3-codex". If startup fails with model_not_supported, switch to "gpt-5-codex" via "ccs codex --config".'
+        'Could not verify Codex plan for model "gpt-5.3-codex". If startup fails with model_not_supported, switch to "gpt-5.4" via "ccs codex --config".'
       );
     } finally {
       fs.rmSync(tmpDir, { recursive: true, force: true });
@@ -234,9 +234,9 @@ describe('codex plan compatibility reconcile', () => {
         env: Record<string, string>;
       };
       expect(settings.env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
-      expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-codex-mini');
+      expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
       expect(errorSpy).toHaveBeenCalledWith(
-        'Could not verify Codex plan for model "gpt-5.3-codex". If startup fails with model_not_supported, switch to "gpt-5-codex" via "ccs codex --config".'
+        'Could not verify Codex plan for model "gpt-5.3-codex". If startup fails with model_not_supported, switch to "gpt-5.4" via "ccs codex --config".'
       );
     } finally {
       fs.rmSync(tmpDir, { recursive: true, force: true });
diff --git a/tests/unit/cliproxy/codex-plan-compatibility.test.ts b/tests/unit/cliproxy/codex-plan-compatibility.test.ts
index 23bb7bc9..2fc1266a 100644
--- a/tests/unit/cliproxy/codex-plan-compatibility.test.ts
+++ b/tests/unit/cliproxy/codex-plan-compatibility.test.ts
@@ -9,22 +9,21 @@ import {
 
 describe('codex plan compatibility', () => {
   it('uses a cross-plan safe Codex default', () => {
-    expect(getDefaultCodexModel()).toBe('gpt-5-codex');
-    expect(getProviderCatalog('codex')?.defaultModel).toBe('gpt-5-codex');
+    expect(getDefaultCodexModel()).toBe('gpt-5.4');
+    expect(getProviderCatalog('codex')?.defaultModel).toBe('gpt-5.4');
   });
 
   it('maps paid-only free-plan models to safe fallbacks', () => {
-    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex')).toBe('gpt-5-codex');
-    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex-xhigh')).toBe('gpt-5-codex');
-    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex(high)')).toBe('gpt-5-codex');
-    expect(getFreePlanFallbackCodexModel('gpt-5.4')).toBe('gpt-5-codex');
-    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex-spark')).toBe('gpt-5-codex-mini');
+    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex')).toBe('gpt-5.4');
+    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex-xhigh')).toBe('gpt-5.4');
+    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex(high)')).toBe('gpt-5.4');
+    expect(getFreePlanFallbackCodexModel('gpt-5.3-codex-spark')).toBe('gpt-5.4-mini');
   });
 
   it('does not rewrite cross-plan or already-safe Codex models', () => {
-    expect(getFreePlanFallbackCodexModel('gpt-5-codex')).toBeNull();
-    expect(getFreePlanFallbackCodexModel('gpt-5.2-codex')).toBeNull();
-    expect(getFreePlanFallbackCodexModel('gpt-5.1-codex-mini')).toBeNull();
+    expect(getFreePlanFallbackCodexModel('gpt-5.4')).toBeNull();
+    expect(getFreePlanFallbackCodexModel('gpt-5.4-mini')).toBeNull();
+    expect(getFreePlanFallbackCodexModel('gpt-5.2')).toBeNull();
   });
 
   it('detects upstream Codex model_not_supported responses', () => {
@@ -54,25 +53,27 @@ describe('codex plan compatibility', () => {
   it('resolves runtime fallbacks without retrying the rejected model again', () => {
     expect(
       resolveRuntimeCodexFallbackModel({
-        requestedModel: 'gpt-5.4',
-        modelMap: { defaultModel: 'gpt-5-codex' },
+        requestedModel: 'gpt-5.3-codex',
+        modelMap: { defaultModel: 'gpt-5.4' },
       })
-    ).toBe('gpt-5-codex');
+    ).toBe('gpt-5.4');
 
     expect(
       resolveRuntimeCodexFallbackModel({
-        requestedModel: 'gpt-5.4',
+        requestedModel: 'gpt-5.3-codex',
         modelMap: {
           defaultModel: 'gpt-5.4',
-          haikuModel: 'gpt-5-codex-mini',
+          haikuModel: 'gpt-5.4-mini',
         },
-        excludeModels: ['gpt-5-codex'],
+        excludeModels: ['gpt-5.4'],
       })
-    ).toBe('gpt-5-codex-mini');
+    ).toBe('gpt-5.4-mini');
   });
 
-  it('tracks Codex thinking caps for current safe defaults and paid models', () => {
-    expect(getModelMaxLevel('codex', 'gpt-5-codex')).toBe('high');
+  it('tracks Codex thinking caps for current safe defaults, paid models, and legacy aliases', () => {
+    expect(getModelMaxLevel('codex', 'gpt-5.4')).toBe('xhigh');
+    expect(getModelMaxLevel('codex', 'gpt-5.4-mini')).toBe('high');
+    expect(getModelMaxLevel('codex', 'gpt-5-codex')).toBe('xhigh');
     expect(getModelMaxLevel('codex', 'gpt-5-codex-mini')).toBe('high');
     expect(getModelMaxLevel('codex', 'gpt-5.2-codex')).toBe('xhigh');
     expect(getModelMaxLevel('codex', 'gpt-5.3-codex')).toBe('xhigh');
diff --git a/tests/unit/cliproxy/codex-reasoning-proxy-extended-context.test.ts b/tests/unit/cliproxy/codex-reasoning-proxy-extended-context.test.ts
index 5a6dc3a2..569b9dc3 100644
--- a/tests/unit/cliproxy/codex-reasoning-proxy-extended-context.test.ts
+++ b/tests/unit/cliproxy/codex-reasoning-proxy-extended-context.test.ts
@@ -306,11 +306,11 @@ describe('CodexReasoningProxy extended-context compatibility', () => {
 
     expect(firstResponse.statusCode).toBe(200);
     expect(secondResponse.statusCode).toBe(200);
-    expect(firstResponse.body.model).toBe('gpt-5-codex');
+    expect(firstResponse.body.model).toBe('gpt-5.4-mini');
     expect(firstResponse.body.effort).toBe('high');
-    expect(secondResponse.body.model).toBe('gpt-5-codex');
+    expect(secondResponse.body.model).toBe('gpt-5.4-mini');
     expect(secondResponse.body.effort).toBe('high');
-    expect(capturedModels).toEqual(['gpt-5.4', 'gpt-5-codex', 'gpt-5-codex']);
+    expect(capturedModels).toEqual(['gpt-5.4', 'gpt-5.4-mini', 'gpt-5.4-mini']);
     expect(capturedEfforts).toEqual(['xhigh', 'high', 'high']);
   });
 
diff --git a/tests/unit/cliproxy/composite-env-routing.test.ts b/tests/unit/cliproxy/composite-env-routing.test.ts
index 0ef51fc7..3bd86e6c 100644
--- a/tests/unit/cliproxy/composite-env-routing.test.ts
+++ b/tests/unit/cliproxy/composite-env-routing.test.ts
@@ -8,7 +8,7 @@ import { buildClaudeEnvironment } from '../../../src/cliproxy/executor/env-resol
 const tiers = {
   opus: { provider: 'agy' as const, model: 'claude-opus-4-6-thinking' },
   sonnet: { provider: 'gemini' as const, model: 'gemini-2.5-pro' },
-  haiku: { provider: 'codex' as const, model: 'gpt-5.1-codex-mini' },
+  haiku: { provider: 'codex' as const, model: 'gpt-5.4-mini' },
 };
 
 describe('buildClaudeEnvironment - composite remote routing', () => {
@@ -82,7 +82,7 @@ describe('buildClaudeEnvironment - composite remote routing', () => {
       compositeTiers: {
         opus: { provider: 'agy', model: 'claude-opus-4.6-thinking' },
         sonnet: { provider: 'gemini', model: 'gemini-2.5-pro' },
-        haiku: { provider: 'codex', model: 'gpt-5.1-codex-mini' },
+        haiku: { provider: 'codex', model: 'gpt-5.4-mini' },
       },
       compositeDefaultTier: 'opus',
     });
@@ -90,6 +90,6 @@ describe('buildClaudeEnvironment - composite remote routing', () => {
     expect(env.ANTHROPIC_MODEL).toMatch(/^claude-opus-4-6-thinking(\([^)]+\))?$/);
     expect(env.ANTHROPIC_DEFAULT_OPUS_MODEL).toMatch(/^claude-opus-4-6-thinking(\([^)]+\))?$/);
     expect(env.ANTHROPIC_DEFAULT_SONNET_MODEL).toMatch(/^gemini-2.5-pro(\([^)]+\))?$/);
-    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toMatch(/^gpt-5.1-codex-mini(?:-medium)?$/);
+    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toMatch(/^gpt-5.4-mini(?:-medium)?$/);
   });
 });
diff --git a/tests/unit/cliproxy/env-builder-provider-url.test.ts b/tests/unit/cliproxy/env-builder-provider-url.test.ts
index bc7b71e1..7f96cde9 100644
--- a/tests/unit/cliproxy/env-builder-provider-url.test.ts
+++ b/tests/unit/cliproxy/env-builder-provider-url.test.ts
@@ -47,7 +47,7 @@ describe('getEffectiveEnvVars local provider URL normalization', () => {
       ANTHROPIC_MODEL: 'gpt-5.3-codex-xhigh',
       ANTHROPIC_DEFAULT_OPUS_MODEL: 'gpt-5.3-codex-xhigh',
       ANTHROPIC_DEFAULT_SONNET_MODEL: 'gpt-5.3-codex-high',
-      ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5-mini-medium',
+      ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5.4-mini-medium',
     });
 
     const env = getEffectiveEnvVars('codex', 8317, settingsPath);
@@ -55,7 +55,7 @@ describe('getEffectiveEnvVars local provider URL normalization', () => {
     expect(env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
     expect(env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex');
     expect(env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex');
-    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-mini');
+    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
 
     const persisted = JSON.parse(fs.readFileSync(settingsPath, 'utf-8')) as {
       env: Record<string, string>;
@@ -63,7 +63,7 @@ describe('getEffectiveEnvVars local provider URL normalization', () => {
     expect(persisted.env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
     expect(persisted.env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex');
     expect(persisted.env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex');
-    expect(persisted.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-mini');
+    expect(persisted.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
   });
 
   it('rewrites wrong local provider path to the requested provider', () => {
@@ -73,7 +73,7 @@ describe('getEffectiveEnvVars local provider URL normalization', () => {
       ANTHROPIC_MODEL: 'gpt-5.3-codex-xhigh',
       ANTHROPIC_DEFAULT_OPUS_MODEL: 'gpt-5.3-codex-xhigh',
       ANTHROPIC_DEFAULT_SONNET_MODEL: 'gpt-5.3-codex-high',
-      ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5-mini-medium',
+      ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5.4-mini-medium',
     });
 
     const env = getEffectiveEnvVars('codex', 8317, settingsPath);
@@ -438,7 +438,7 @@ describe('getEffectiveEnvVars local provider URL normalization', () => {
             ANTHROPIC_MODEL: ' gpt-5.3-codex-xhigh ',
             ANTHROPIC_DEFAULT_OPUS_MODEL: 'gpt-5.3-codex-xhigh',
             ANTHROPIC_DEFAULT_SONNET_MODEL: 'gpt-5.3-codex-high',
-            ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5-mini-medium',
+            ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5.4-mini-medium',
           },
           presets: [
             {
@@ -446,7 +446,7 @@ describe('getEffectiveEnvVars local provider URL normalization', () => {
               default: 'gpt-5.3-codex-xhigh',
               opus: 'gpt-5.3-codex-xhigh',
               sonnet: 'gpt-5.3-codex-high',
-              haiku: 'gpt-5-mini-medium',
+              haiku: 'gpt-5.4-mini-medium',
             },
           ],
         },
@@ -464,11 +464,11 @@ describe('getEffectiveEnvVars local provider URL normalization', () => {
     expect(repaired.env?.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
     expect(repaired.env?.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex');
     expect(repaired.env?.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex');
-    expect(repaired.env?.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-mini');
+    expect(repaired.env?.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
     expect(repaired.presets?.[0]?.default).toBe('gpt-5.3-codex');
     expect(repaired.presets?.[0]?.opus).toBe('gpt-5.3-codex');
     expect(repaired.presets?.[0]?.sonnet).toBe('gpt-5.3-codex');
-    expect(repaired.presets?.[0]?.haiku).toBe('gpt-5-mini');
+    expect(repaired.presets?.[0]?.haiku).toBe('gpt-5.4-mini');
   });
 
   it('recovers malformed provider settings files by writing defaults and backup copy', () => {
diff --git a/tests/unit/cliproxy/env-resolver-codex-fallback.test.ts b/tests/unit/cliproxy/env-resolver-codex-fallback.test.ts
index 36036cfd..39ee4e6d 100644
--- a/tests/unit/cliproxy/env-resolver-codex-fallback.test.ts
+++ b/tests/unit/cliproxy/env-resolver-codex-fallback.test.ts
@@ -87,7 +87,7 @@ describe('buildClaudeEnvironment codex fallback normalization', () => {
       defaultModel: 'gpt-5.3-codex-high',
       opusModel: 'gpt-5.3-codex-xhigh',
       sonnetModel: 'gpt-5.3-codex-high',
-      haikuModel: 'gpt-5-mini-medium',
+      haikuModel: 'gpt-5.4-mini-medium',
     });
 
     const env = buildClaudeEnvironment({
@@ -101,7 +101,7 @@ describe('buildClaudeEnvironment codex fallback normalization', () => {
     expect(env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex(high)');
     expect(env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex(xhigh)');
     expect(env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex(high)');
-    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-mini(medium)');
+    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini(medium)');
   });
 
   it('keeps codex effort aliases when reasoning proxy is active', () => {
@@ -109,7 +109,7 @@ describe('buildClaudeEnvironment codex fallback normalization', () => {
       defaultModel: 'gpt-5.3-codex-high',
       opusModel: 'gpt-5.3-codex-xhigh',
       sonnetModel: 'gpt-5.3-codex-high',
-      haikuModel: 'gpt-5-mini-medium',
+      haikuModel: 'gpt-5.4-mini-medium',
     });
 
     const env = buildClaudeEnvironment({
@@ -124,7 +124,7 @@ describe('buildClaudeEnvironment codex fallback normalization', () => {
     expect(env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex-high');
     expect(env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex-xhigh');
     expect(env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex-high');
-    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-mini-medium');
+    expect(env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini-medium');
     expect(env.ANTHROPIC_BASE_URL).toBe('http://127.0.0.1:9444/api/provider/codex');
   });
 
diff --git a/tests/unit/cliproxy/model-catalog.test.js b/tests/unit/cliproxy/model-catalog.test.js
index 17068475..3e8f3751 100644
--- a/tests/unit/cliproxy/model-catalog.test.js
+++ b/tests/unit/cliproxy/model-catalog.test.js
@@ -186,6 +186,25 @@ describe('Model Catalog', () => {
     });
   });
 
+  describe('Codex models', () => {
+    it('has correct default model', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      assert.strictEqual(MODEL_CATALOG.codex.defaultModel, 'gpt-5.4');
+    });
+
+    it('advertises the current official Codex model set', () => {
+      const { MODEL_CATALOG } = modelCatalog;
+      const ids = MODEL_CATALOG.codex.models.map((m) => m.id);
+      assert.deepStrictEqual(ids, [
+        'gpt-5.4',
+        'gpt-5.4-mini',
+        'gpt-5.3-codex',
+        'gpt-5.3-codex-spark',
+        'gpt-5.2',
+      ]);
+    });
+  });
+
   describe('supportsModelConfig', () => {
     it('returns true for agy', () => {
       const { supportsModelConfig } = modelCatalog;
diff --git a/tests/unit/cliproxy/model-id-normalizer.test.ts b/tests/unit/cliproxy/model-id-normalizer.test.ts
index 6d4cc361..d7e969cf 100644
--- a/tests/unit/cliproxy/model-id-normalizer.test.ts
+++ b/tests/unit/cliproxy/model-id-normalizer.test.ts
@@ -8,6 +8,7 @@ import {
   migrateDeniedAntigravityModelAliases,
   normalizeClaudeDottedMajorMinor,
   normalizeClaudeDottedThinkingMajorMinor,
+  normalizeCodexLegacyModelAliases,
   normalizeModelIdForProvider,
   normalizeModelIdForRouting,
   normalizeModelEnvVarsForProvider,
@@ -115,6 +116,14 @@ describe('model-id-normalizer', () => {
       expect(canonicalizeModelIdForProvider('minimax-m2.5', 'iflow')).toBe('qwen3-coder-plus');
       expect(canonicalizeModelIdForProvider('kimi-k2.5', 'gemini')).toBe('kimi-k2.5');
     });
+
+    it('normalizes legacy codex aliases to the current supported model IDs', () => {
+      expect(normalizeCodexLegacyModelAliases('gpt-5-codex')).toBe('gpt-5.4');
+      expect(normalizeCodexLegacyModelAliases('gpt-5-codex-mini[1m]')).toBe('gpt-5.4-mini[1m]');
+      expect(normalizeModelIdForProvider('gpt-5.2-codex', 'codex')).toBe('gpt-5.2');
+      expect(normalizeModelIdForProvider('gpt-5.1-codex-mini', 'codex')).toBe('gpt-5.4-mini');
+      expect(canonicalizeModelIdForProvider('gpt-5-codex-high', 'codex')).toBe('gpt-5.4');
+    });
   });
 
   describe('env normalization', () => {
diff --git a/tests/unit/cliproxy/variant-update-service.test.ts b/tests/unit/cliproxy/variant-update-service.test.ts
index fe63fb7d..7e98a4ff 100644
--- a/tests/unit/cliproxy/variant-update-service.test.ts
+++ b/tests/unit/cliproxy/variant-update-service.test.ts
@@ -100,7 +100,7 @@ cliproxy:
 
     expect(result.success).toBe(true);
     expect(result.variant?.provider).toBe('codex');
-    expect(result.variant?.model).toBe('gpt-5.1-codex-mini');
+    expect(result.variant?.model).toBe('gpt-5.4-mini');
 
     const settingsPath = path.join(tmpDir, 'gemini-demo.settings.json');
     const settings = JSON.parse(fs.readFileSync(settingsPath, 'utf-8')) as {
@@ -109,10 +109,10 @@ cliproxy:
     };
 
     expect(settings.env.ANTHROPIC_BASE_URL).toContain('/api/provider/codex');
-    expect(settings.env.ANTHROPIC_MODEL).toBe('gpt-5.1-codex-mini');
-    expect(settings.env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.1-codex-mini');
-    expect(settings.env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.1-codex-mini');
-    expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-codex-mini');
+    expect(settings.env.ANTHROPIC_MODEL).toBe('gpt-5.4-mini');
+    expect(settings.env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.4-mini');
+    expect(settings.env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.4-mini');
+    expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
     expect(settings.env.CUSTOM_FLAG).toBe('keep-me');
     expect(settings.hooks.PreToolUse.length).toBe(1);
 
@@ -134,7 +134,7 @@ cliproxy:
     expect(settings.env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
     expect(settings.env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex');
     expect(settings.env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex');
-    expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-codex-mini');
+    expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
 
     const modelOnly = updateVariant('demo', { model: 'gpt-5.3-codex' });
     expect(modelOnly.success).toBe(true);
@@ -145,6 +145,6 @@ cliproxy:
     expect(settings.env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
     expect(settings.env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex');
     expect(settings.env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex');
-    expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-codex-mini');
+    expect(settings.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
   });
 });
diff --git a/tests/unit/web-server/cliproxy-stats-routes-model-update.test.ts b/tests/unit/web-server/cliproxy-stats-routes-model-update.test.ts
index 84cba3c9..538152a4 100644
--- a/tests/unit/web-server/cliproxy-stats-routes-model-update.test.ts
+++ b/tests/unit/web-server/cliproxy-stats-routes-model-update.test.ts
@@ -137,7 +137,7 @@ describe('cliproxy-stats-routes model update canonicalization', () => {
       ANTHROPIC_MODEL: 'gpt-5.3-codex',
       ANTHROPIC_DEFAULT_OPUS_MODEL: 'gpt-5.3-codex',
       ANTHROPIC_DEFAULT_SONNET_MODEL: 'gpt-5.3-codex',
-      ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5-mini',
+      ANTHROPIC_DEFAULT_HAIKU_MODEL: 'gpt-5.4-mini',
     });
 
     const response = await fetch(`${baseUrl}/api/cliproxy/models/codex`, {
@@ -156,7 +156,7 @@ describe('cliproxy-stats-routes model update canonicalization', () => {
     expect(persisted.env.ANTHROPIC_MODEL).toBe('gpt-5.3-codex');
     expect(persisted.env.ANTHROPIC_DEFAULT_OPUS_MODEL).toBe('gpt-5.3-codex');
     expect(persisted.env.ANTHROPIC_DEFAULT_SONNET_MODEL).toBe('gpt-5.3-codex');
-    expect(persisted.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5-mini');
+    expect(persisted.env.ANTHROPIC_DEFAULT_HAIKU_MODEL).toBe('gpt-5.4-mini');
   });
 
   it('canonicalizes legacy iflow model IDs to supported upstream IDs', async () => {