diff --git a/README.md b/README.md
index ddeafd8..e838e49 100644
--- a/README.md
+++ b/README.md
@@ -156,12 +156,13 @@ manual refresh via `mmx auth refresh`.
 Useful for CI/CD (`mmx auth login --api-key sk-xxxxx`), or pass per-command via `--api-key`.
 
 OAuth and API key are mutually exclusive — logging in with one clears the other.
-Credential priority: `--api-key` flag > OAuth (config) > `api_key` (config).
+Credential priority: `--api-key` flag > `MINIMAX_API_KEY` > OAuth (config) > `api_key` (config).
 
 ### Environment variables
 
 | Variable | Description |
 |---|---|
+| `MINIMAX_API_KEY` | API key for non-interactive use. Overridden by `--api-key`; overrides saved credentials. |
 | `MINIMAX_REGION` | `global` or `cn`. |
 | `MINIMAX_BASE_URL` | Override the API base URL. |
 | `MINIMAX_OUTPUT` | `text` or `json`. |
diff --git a/README_CN.md b/README_CN.md
index db48fb4..49ab43e 100644
--- a/README_CN.md
+++ b/README_CN.md
@@ -149,6 +149,8 @@ mmx auth logout
 都保存在 `~/.mmx/config.json` 里，**两者互斥** —— 用一种登录会清掉另一种。
 也可以每次通过 `--api-key` 直接传入。使用 API Key 登录时，会自动同时探测
 Global 与中国两个 region，选用能通过的那个。
+凭据优先级：`--api-key` 参数 > `MINIMAX_API_KEY` 环境变量 >
+OAuth（配置文件）> `api_key`（配置文件）。
 
 ### `mmx config` · `mmx quota`
 
diff --git a/src/auth/resolver.ts b/src/auth/resolver.ts
index 8046aaf..b505776 100644
--- a/src/auth/resolver.ts
+++ b/src/auth/resolver.ts
@@ -7,9 +7,13 @@ import { ExitCode } from '../errors/codes';
 import { buildNoCredentialsHint } from './hints';
 
 export async function resolveCredential(config: Config): Promise<ResolvedCredential> {
-  // 1. --api-key flag
+  // 1. Explicit API key (--api-key takes precedence over MINIMAX_API_KEY)
   if (config.apiKey) {
-    return { token: config.apiKey, method: 'api-key', source: 'flag' };
+    return {
+      token: config.apiKey,
+      method: 'api-key',
+      source: config.apiKeySource ?? 'flag',
+    };
   }
 
   // 2. OAuth credentials in config file
diff --git a/src/auth/setup.ts b/src/auth/setup.ts
index 0b404b7..bda5c4f 100644
--- a/src/auth/setup.ts
+++ b/src/auth/setup.ts
@@ -26,10 +26,13 @@ function stripScheme(url: string): string {
 }
 
 export async function ensureAuth(config: Config): Promise<void> {
-  if (config.apiKey || config.fileApiKey) return;
+  if (config.apiKey && config.apiKeySource !== 'env') return;
+  if (config.fileApiKey) return;
   if (await loadCredentials()) return;
 
-  const envKey = process.env.MINIMAX_API_KEY;
+  const envKey = config.apiKeySource === 'env'
+    ? config.apiKey
+    : process.env.MINIMAX_API_KEY;
   if (envKey) {
     if (!isInteractive({ nonInteractive: config.nonInteractive })) {
       return; // env key is enough; no prompt
diff --git a/src/config/loader.ts b/src/config/loader.ts
index 7768044..fec543b 100644
--- a/src/config/loader.ts
+++ b/src/config/loader.ts
@@ -64,7 +64,10 @@ export async function writeConfigFile(
 export function loadConfig(flags: GlobalFlags): Config {
   const file = readConfigFile();
 
-  const apiKey = flags.apiKey || undefined;
+  const flagApiKey = flags.apiKey || undefined;
+  const envApiKey = process.env.MINIMAX_API_KEY || undefined;
+  const apiKey = flagApiKey || envApiKey;
+  const apiKeySource = flagApiKey ? 'flag' : envApiKey ? 'env' : undefined;
   const fileApiKey = file.api_key;
 
   const explicitRegion = (flags.region as string) || process.env.MINIMAX_REGION || undefined;
@@ -100,6 +103,7 @@ export function loadConfig(flags: GlobalFlags): Config {
 
   return {
     apiKey,
+    apiKeySource,
     fileApiKey,
     fileRegion: file.region,
     configPath: getConfigPath(),
diff --git a/src/config/schema.ts b/src/config/schema.ts
index 5eaaea4..4486b2b 100644
--- a/src/config/schema.ts
+++ b/src/config/schema.ts
@@ -83,6 +83,7 @@ export function parseConfigFile(raw: unknown): ConfigFile {
 
 export interface Config {
   apiKey?: string;
+  apiKeySource?: 'flag' | 'env';
   fileApiKey?: string;
   fileRegion?: Region;
   configPath?: string;
diff --git a/src/output/status-bar.ts b/src/output/status-bar.ts
index f02f8f2..79fd70c 100644
--- a/src/output/status-bar.ts
+++ b/src/output/status-bar.ts
@@ -30,7 +30,11 @@ export function maybeShowStatusBar(config: Config, token: string, model?: string
 
   const filePath   = config.configPath ? tildePath(config.configPath) : '~/.mmx/config.json';
   const baseUrlStr = stripScheme(config.baseUrl);
-  const keySrc     = config.apiKey ? '(flag)' : '(file)';
+  const keySrc     = config.apiKeySource === 'env'
+    ? '(env)'
+    : config.apiKey
+      ? '(flag)'
+      : '(file)';
   const maskedKey  = maskToken(token);
   const modelStr   = model ? ` ${dim}|${reset} ${dim}Model:${reset} ${mmPurple}${model}${reset}` : '';
 
diff --git a/test/auth/resolver.test.ts b/test/auth/resolver.test.ts
index 25b8cb0..7b06d2b 100644
--- a/test/auth/resolver.test.ts
+++ b/test/auth/resolver.test.ts
@@ -53,6 +53,17 @@ describe('resolveCredential', () => {
     expect(cred.method).toBe('api-key');
   });
 
+  it('preserves the environment credential source', async () => {
+    const config = makeConfig({
+      apiKey: 'sk-from-env',
+      apiKeySource: 'env',
+    });
+    const cred = await resolveCredential(config);
+    expect(cred.token).toBe('sk-from-env');
+    expect(cred.method).toBe('api-key');
+    expect(cred.source).toBe('env');
+  });
+
   it('resolves from config file api key', async () => {
     const config = makeConfig({ fileApiKey: 'sk-from-file' });
     const cred = await resolveCredential(config);
diff --git a/test/config/loader.test.ts b/test/config/loader.test.ts
index 1fcd815..3be6946 100644
--- a/test/config/loader.test.ts
+++ b/test/config/loader.test.ts
@@ -21,17 +21,21 @@ describe('loadConfig', () => {
   const testDir = join(tmpdir(), `mmx-config-test-${Date.now()}`);
   const originalHome = process.env.HOME;
   const originalRegion = process.env.MINIMAX_REGION;
+  const originalApiKey = process.env.MINIMAX_API_KEY;
 
   beforeEach(() => {
     mkdirSync(join(testDir, '.mmx'), { recursive: true });
     process.env.HOME = testDir;
     delete process.env.MINIMAX_REGION;
+    delete process.env.MINIMAX_API_KEY;
   });
 
   afterEach(() => {
     process.env.HOME = originalHome;
     if (originalRegion === undefined) delete process.env.MINIMAX_REGION;
     else process.env.MINIMAX_REGION = originalRegion;
+    if (originalApiKey === undefined) delete process.env.MINIMAX_API_KEY;
+    else process.env.MINIMAX_API_KEY = originalApiKey;
     rmSync(testDir, { recursive: true, force: true });
   });
 
@@ -56,6 +60,25 @@ describe('loadConfig', () => {
     expect(config.region).toBe('cn');
     expect(config.baseUrl).toBe('https://api.minimaxi.com');
   });
+
+  it('loads MINIMAX_API_KEY as an environment credential', () => {
+    process.env.MINIMAX_API_KEY = 'sk-from-env';
+
+    const config = loadConfig(baseFlags);
+
+    expect(config.apiKey).toBe('sk-from-env');
+    expect(config.apiKeySource).toBe('env');
+    expect(config.needsRegionDetection).toBe(true);
+  });
+
+  it('prefers --api-key over MINIMAX_API_KEY', () => {
+    process.env.MINIMAX_API_KEY = 'sk-from-env';
+
+    const config = loadConfig({ ...baseFlags, apiKey: 'sk-from-flag' });
+
+    expect(config.apiKey).toBe('sk-from-flag');
+    expect(config.apiKeySource).toBe('flag');
+  });
 });
 
 describe('writeConfigFile', () => {