fix: preserve explicit provider startup intent

src/utils/providerEnvSelection.test.ts

@@ -27,6 +27,22 @@ afterEach(() => {
 })
 
 describe('filterSettingsEnvForExplicitProvider', () => {
+  test('does not treat plain provider flags as an explicit CLI override', () => {
+    process.env.CLAUDE_CODE_USE_GITHUB = '1'
+
+    expect(
+      filterSettingsEnvForExplicitProvider({
+        CLAUDE_CODE_USE_OPENAI: '1',
+        OPENAI_MODEL: 'gpt-4o',
+        OTHER: 'keep-me',
+      }),
+    ).toEqual({
+      CLAUDE_CODE_USE_OPENAI: '1',
+      OPENAI_MODEL: 'gpt-4o',
+      OTHER: 'keep-me',
+    })
+  })
+
   test('strips settings-sourced provider flags when CLI provider is explicit', () => {
     process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'openai'
 
@@ -71,4 +87,17 @@ describe('filterSettingsEnvForExplicitProvider', () => {
       }),
     ).toEqual({ OTHER: 'keep-me' })
   })
+
+  test('preserves anthropic startup intent by stripping stale GitHub/OpenAI settings', () => {
+    process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'anthropic'
+
+    expect(
+      filterSettingsEnvForExplicitProvider({
+        CLAUDE_CODE_USE_GITHUB: '1',
+        CLAUDE_CODE_USE_OPENAI: '1',
+        OPENAI_MODEL: 'github:copilot',
+        OTHER: 'keep-me',
+      }),
+    ).toEqual({ OTHER: 'keep-me' })
+  })
 })

src/utils/providerEnvSelection.ts

@@ -1,5 +1,3 @@
-import { isEnvTruthy } from './envUtils.js'
-
 export const EXPLICIT_PROVIDER_ENV_VAR = 'CLAUDE_CODE_EXPLICIT_PROVIDER'
 
 const PROVIDER_FLAG_KEYS = [
@@ -20,17 +18,7 @@ export function clearProviderSelectionFlags(
 }
 
 function getExplicitProvider(processEnv: NodeJS.ProcessEnv): string | undefined {
-  const explicitProvider = processEnv[EXPLICIT_PROVIDER_ENV_VAR]?.trim()
-  if (explicitProvider) return explicitProvider
-
-  if (isEnvTruthy(processEnv.CLAUDE_CODE_USE_GEMINI)) return 'gemini'
-  if (isEnvTruthy(processEnv.CLAUDE_CODE_USE_GITHUB)) return 'github'
-  if (isEnvTruthy(processEnv.CLAUDE_CODE_USE_OPENAI)) return 'openai'
-  if (isEnvTruthy(processEnv.CLAUDE_CODE_USE_BEDROCK)) return 'bedrock'
-  if (isEnvTruthy(processEnv.CLAUDE_CODE_USE_VERTEX)) return 'vertex'
-  if (isEnvTruthy(processEnv.CLAUDE_CODE_USE_FOUNDRY)) return 'foundry'
-
-  return undefined
+  return processEnv[EXPLICIT_PROVIDER_ENV_VAR]?.trim() || undefined
 }
 
 function isGithubModel(model: string | undefined): boolean {

src/utils/providerProfile.test.ts

@@ -485,6 +485,26 @@ test('buildStartupEnvFromProfile leaves explicit provider selections untouched',
   assert.equal(env.OPENAI_API_KEY, undefined)
 })
 
+test('buildStartupEnvFromProfile preserves explicit anthropic startup selection', async () => {
+  const processEnv = {
+    CLAUDE_CODE_EXPLICIT_PROVIDER: 'anthropic',
+  }
+
+  const env = await buildStartupEnvFromProfile({
+    persisted: profile('openai', {
+      CLAUDE_CODE_USE_GITHUB: '1',
+      OPENAI_MODEL: 'github:copilot',
+    }),
+    processEnv,
+  })
+
+  assert.equal(env, processEnv)
+  assert.equal(env.CLAUDE_CODE_EXPLICIT_PROVIDER, 'anthropic')
+  assert.equal(env.CLAUDE_CODE_USE_OPENAI, undefined)
+  assert.equal(env.CLAUDE_CODE_USE_GITHUB, undefined)
+  assert.equal(env.OPENAI_MODEL, undefined)
+})
+
 test('buildStartupEnvFromProfile leaves profile-managed env untouched', async () => {
   const processEnv = {
     CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED: '1',

src/utils/providerProfile.ts

@@ -412,6 +412,10 @@ export function hasExplicitProviderSelection(
     return true
   }
 
+  if (processEnv.CLAUDE_CODE_EXPLICIT_PROVIDER?.trim()) {
+    return true
+  }
+
   return (
     processEnv.CLAUDE_CODE_USE_OPENAI !== undefined ||
     processEnv.CLAUDE_CODE_USE_GITHUB !== undefined ||