diff --git a/packages/subagent/subagent-claude-code/tests/real-deepseek.e2e.ts b/packages/subagent/subagent-claude-code/tests/real-deepseek.e2e.ts
index 8ddba2c05f..eab7445ea5 100644
--- a/packages/subagent/subagent-claude-code/tests/real-deepseek.e2e.ts
+++ b/packages/subagent/subagent-claude-code/tests/real-deepseek.e2e.ts
@@ -20,7 +20,7 @@ import LocalSubprocessRuntime from '@deepseek-ai/dsh-subprocess-local'
 import * as claudeCode from '../src/index.ts'
 
 const execFileAsync = promisify(execFile)
-const OFFICIAL_DEEPSEEK_BASE_URL = 'https://api.deepseek.com'
+const OFFICIAL_DEEPSEEK_MESSAGES_BASE_URL = 'https://api.deepseek.com/anthropic'
 const DEEPSEEK_MODEL = 'deepseek-v4-flash'
 const sdkRoot = dirname(fileURLToPath(
   import.meta.resolve('@anthropic-ai/claude-agent-sdk'),
@@ -48,15 +48,6 @@ afterEach(async () => {
   for (const root of roots.splice(0)) rmSync(root, { recursive: true, force: true })
 })
 
-function deepSeekBaseUrl(): string {
-  const configured = (process.env.DEEPSEEK_BASE_URL ?? OFFICIAL_DEEPSEEK_BASE_URL)
-    .replace(/\/+$/, '')
-  if (configured !== OFFICIAL_DEEPSEEK_BASE_URL) {
-    throw new Error('Claude Code DeepSeek e2e requires the official DeepSeek base URL')
-  }
-  return configured
-}
-
 async function expectQuiescent(handles: readonly SubprocessHandle[]): Promise<void> {
   expect(handles.length).toBeGreaterThan(0)
   for (const handle of handles) {
@@ -90,7 +81,7 @@ describe.skipIf(!process.env.DEEPSEEK_API_KEY)(
 
       const env = {
         ANTHROPIC_AUTH_TOKEN: apiKey,
-        ANTHROPIC_BASE_URL: `${deepSeekBaseUrl()}/anthropic`,
+        ANTHROPIC_BASE_URL: OFFICIAL_DEEPSEEK_MESSAGES_BASE_URL,
         ANTHROPIC_MODEL: DEEPSEEK_MODEL,
         ANTHROPIC_DEFAULT_OPUS_MODEL: DEEPSEEK_MODEL,
         ANTHROPIC_DEFAULT_SONNET_MODEL: DEEPSEEK_MODEL,
diff --git a/packages/subagent/subagent-codex/tests/deepseek-responses-bridge.ts b/packages/subagent/subagent-codex/tests/deepseek-responses-bridge.ts
index b59738031e..2ff5c17d03 100644
--- a/packages/subagent/subagent-codex/tests/deepseek-responses-bridge.ts
+++ b/packages/subagent/subagent-codex/tests/deepseek-responses-bridge.ts
@@ -53,20 +53,11 @@ function taskText(body: Record<string, unknown>): string {
   return typeof body.instructions === 'string' ? body.instructions : ''
 }
 
-function deepSeekBaseUrl(): string {
-  const configured = (process.env.DEEPSEEK_BASE_URL ?? OFFICIAL_DEEPSEEK_BASE_URL)
-    .replace(/\/+$/, '')
-  if (configured !== OFFICIAL_DEEPSEEK_BASE_URL) {
-    throw new Error('Codex DeepSeek e2e requires the official DeepSeek base URL')
-  }
-  return configured
-}
-
 async function completeWithDeepSeek(
   authorization: string,
   task: string,
 ): Promise<string> {
-  const response = await fetch(`${deepSeekBaseUrl()}/chat/completions`, {
+  const response = await fetch(`${OFFICIAL_DEEPSEEK_BASE_URL}/chat/completions`, {
     method: 'POST',
     headers: {
       authorization,
diff --git a/scripts/ci-workflow.spec.ts b/scripts/ci-workflow.spec.ts
index 5bbe466380..54c2074e82 100644
--- a/scripts/ci-workflow.spec.ts
+++ b/scripts/ci-workflow.spec.ts
@@ -828,12 +828,14 @@ describe('Python release workflows', () => {
     expect(String(realApiPreflightPosix.if)).toContain('head.repo.fork')
     expect(String(realApiPreflightPosix.if)).toContain('dependabot[bot]')
     expect(realApiPreflightWindows).toMatchObject({ shell: 'pwsh' })
-    expect(installedRealApiPosix).toMatchObject({
-      env: {
-        DEEPSEEK_API_KEY: '${{ secrets.DEEPSEEK_API_KEY_EXTERNAL }}',
-        DEEPSEEK_BASE_URL: 'https://api.deepseek.com',
-      },
-    })
+    for (const step of [installedRealApiPosix, installedRealApiWindows]) {
+      expect(step).toMatchObject({
+        env: {
+          DEEPSEEK_API_KEY: '${{ secrets.DEEPSEEK_API_KEY_EXTERNAL }}',
+          DEEPSEEK_BASE_URL: 'https://api.deepseek.com/anthropic',
+        },
+      })
+    }
     expect(JSON.stringify(installedRealApiPosix)).toContain('--scenario sdk-live')
     expect(JSON.stringify(installedRealApiPosix)).toContain('-u DSH_RUNTIME_MODE')
     expect(installedRealApiWindows).toMatchObject({ shell: 'pwsh' })