fix: align SkillTool schema error output

.gitignore

@@ -10,4 +10,3 @@ GEMINI.md
 package-lock.json
 /.claude
 coverage/
-.worktrees/

src/screens/REPL.tsx

@@ -238,7 +238,6 @@ import { usePromptsFromClaudeInChrome } from 'src/hooks/usePromptsFromClaudeInCh
 import { getTipToShowOnSpinner, recordShownTip } from 'src/services/tips/tipScheduler.js';
 import type { Theme } from 'src/utils/theme.js';
 import { isPromptTypingSuppressionActive } from './replInputSuppression.js';
-import { shouldStartStartupChecks } from './replStartupGates.js';
 import { checkAndDisableBypassPermissionsIfNeeded, checkAndDisableAutoModeIfNeeded, useKickOffCheckAndDisableBypassPermissionsIfNeeded, useKickOffCheckAndDisableAutoModeIfNeeded } from 'src/utils/permissions/bypassPermissionsKillswitch.js';
 import { SandboxManager } from 'src/utils/sandbox/sandbox-adapter.js';
 import { SANDBOX_NETWORK_ACCESS_TOOL_NAME } from 'src/cli/structuredIO.js';
@@ -785,6 +784,19 @@ export function REPL({
   });
   const tasksV2 = useTasksV2WithCollapseEffect();
 
+  // Start background plugin installations
+
+  // SECURITY: This code is guaranteed to run ONLY after the "trust this folder" dialog
+  // has been confirmed by the user. The trust dialog is shown in cli.tsx (line ~387)
+  // before the REPL component is rendered. The dialog blocks execution until the user
+  // accepts, and only then is the REPL component mounted and this effect runs.
+  // This ensures that plugin installations from repository and user settings only
+  // happen after explicit user consent to trust the current working directory.
+  useEffect(() => {
+    if (isRemoteSession) return;
+    void performStartupChecks(setAppState);
+  }, [setAppState, isRemoteSession]);
+
   // Allow Claude in Chrome MCP to send prompts through MCP notifications
   // and sync permission mode changes to the Chrome extension
   usePromptsFromClaudeInChrome(isRemoteSession ? EMPTY_MCP_CLIENTS : mcpClients, toolPermissionContext.mode);
@@ -1325,7 +1337,6 @@ export function REPL({
   const [inputValue, setInputValueRaw] = useState(() => consumeEarlyInput());
   const inputValueRef = useRef(inputValue);
   inputValueRef.current = inputValue;
-  const startupChecksStartedRef = useRef(false);
   const promptTypingSuppressionActive = isPromptTypingSuppressionActive(isPromptInputActive, inputValue);
   const insertTextRef = useRef<{
     insert: (text: string) => void;
@@ -1333,24 +1344,6 @@ export function REPL({
     cursorOffset: number;
   } | null>(null);
 
-  // Start background plugin installations after the initial input window is idle.
-  // SECURITY: This still runs only after the "trust this folder" dialog has been
-  // confirmed because the REPL is not mounted until that dialog completes.
-  useEffect(() => {
-    if (
-      !shouldStartStartupChecks({
-        isRemoteSession,
-        promptTypingSuppressionActive,
-        startupChecksStarted: startupChecksStartedRef.current,
-      })
-    ) {
-      return;
-    }
-
-    startupChecksStartedRef.current = true;
-    void performStartupChecks(setAppState);
-  }, [isRemoteSession, promptTypingSuppressionActive, setAppState]);
-
   // Wrap setInputValue to co-locate suppression state updates.
   // Both setState calls happen in the same synchronous context so React
   // batches them into a single render, eliminating the extra render that

src/screens/replStartupGates.test.ts

@@ -1,44 +0,0 @@
-import { describe, expect, test } from 'bun:test'
-import { shouldStartStartupChecks } from './replStartupGates.js'
-
-describe('shouldStartStartupChecks', () => {
-  test('returns false for remote sessions', () => {
-    expect(
-      shouldStartStartupChecks({
-        isRemoteSession: true,
-        promptTypingSuppressionActive: false,
-        startupChecksStarted: false,
-      }),
-    ).toBe(false)
-  })
-
-  test('returns false while prompt typing suppression is active', () => {
-    expect(
-      shouldStartStartupChecks({
-        isRemoteSession: false,
-        promptTypingSuppressionActive: true,
-        startupChecksStarted: false,
-      }),
-    ).toBe(false)
-  })
-
-  test('returns true once local startup is idle and checks have not started', () => {
-    expect(
-      shouldStartStartupChecks({
-        isRemoteSession: false,
-        promptTypingSuppressionActive: false,
-        startupChecksStarted: false,
-      }),
-    ).toBe(true)
-  })
-
-  test('returns false after startup checks have already started', () => {
-    expect(
-      shouldStartStartupChecks({
-        isRemoteSession: false,
-        promptTypingSuppressionActive: false,
-        startupChecksStarted: true,
-      }),
-    ).toBe(false)
-  })
-})

src/screens/replStartupGates.ts

@@ -1,11 +0,0 @@
-export function shouldStartStartupChecks(options: {
-  isRemoteSession: boolean
-  promptTypingSuppressionActive: boolean
-  startupChecksStarted: boolean
-}): boolean {
-  return (
-    !options.isRemoteSession &&
-    !options.promptTypingSuppressionActive &&
-    !options.startupChecksStarted
-  )
-}

src/services/tools/toolExecution.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, test } from 'bun:test'
+
+import { SkillTool } from '../../tools/SkillTool/SkillTool.js'
+import {
+  getSchemaValidationErrorOverride,
+  getSchemaValidationToolUseResult,
+} from './toolExecution.js'
+
+describe('getSchemaValidationErrorOverride', () => {
+  test('returns actionable missing-skill error for SkillTool', () => {
+    expect(getSchemaValidationErrorOverride(SkillTool, {})).toBe(
+      'Missing skill name. Pass the slash command name as the skill parameter (e.g., skill: "commit" for /commit, skill: "review-pr" for /review-pr).',
+    )
+  })
+
+  test('does not override unrelated tool schema failures', () => {
+    expect(getSchemaValidationErrorOverride({ name: 'Read' } as never, {})).toBe(
+      null,
+    )
+  })
+
+  test('does not override SkillTool when skill is present', () => {
+    expect(
+      getSchemaValidationErrorOverride(SkillTool, { skill: 'commit' }),
+    ).toBe(null)
+  })
+
+  test('uses the actionable override for structured toolUseResult too', () => {
+    expect(getSchemaValidationToolUseResult(SkillTool, {} as never)).toBe(
+      'InputValidationError: Missing skill name. Pass the slash command name as the skill parameter (e.g., skill: "commit" for /commit, skill: "review-pr" for /review-pr).',
+    )
+  })
+})

src/services/tools/toolExecution.ts

@@ -43,6 +43,7 @@ import { FILE_READ_TOOL_NAME } from '../../tools/FileReadTool/prompt.js'
 import { FILE_WRITE_TOOL_NAME } from '../../tools/FileWriteTool/prompt.js'
 import { NOTEBOOK_EDIT_TOOL_NAME } from '../../tools/NotebookEditTool/constants.js'
 import { POWERSHELL_TOOL_NAME } from '../../tools/PowerShellTool/toolName.js'
+import { SKILL_TOOL_NAME } from '../../tools/SkillTool/constants.js'
 import { parseGitCommitId } from '../../tools/shared/gitOperationTracking.js'
 import {
   isDeferredTool,
@@ -596,6 +597,31 @@ export function buildSchemaNotSentHint(
   )
 }
 
+export function getSchemaValidationErrorOverride(
+  tool: Tool,
+  input: unknown,
+): string | null {
+  if (tool.name !== SKILL_TOOL_NAME || !input || typeof input !== 'object') {
+    return null
+  }
+
+  const skill = (input as { skill?: unknown }).skill
+  if (skill === undefined || skill === null) {
+    return 'Missing skill name. Pass the slash command name as the skill parameter (e.g., skill: "commit" for /commit, skill: "review-pr" for /review-pr).'
+  }
+
+  return null
+}
+
+export function getSchemaValidationToolUseResult(
+  tool: Tool,
+  input: unknown,
+  fallbackMessage?: string,
+): string {
+  const override = getSchemaValidationErrorOverride(tool, input)
+  return `InputValidationError: ${override ?? fallbackMessage ?? ''}`
+}
+
 async function checkPermissionsAndCallTool(
   tool: Tool,
   toolUseID: string,
@@ -614,7 +640,9 @@ async function checkPermissionsAndCallTool(
   // Validate input types with zod (surprisingly, the model is not great at generating valid input)
   const parsedInput = tool.inputSchema.safeParse(input)
   if (!parsedInput.success) {
-    let errorContent = formatZodValidationError(tool.name, parsedInput.error)
+    const fallbackErrorContent = formatZodValidationError(tool.name, parsedInput.error)
+    let errorContent =
+      getSchemaValidationErrorOverride(tool, input) ?? fallbackErrorContent
 
     const schemaHint = buildSchemaNotSentHint(
       tool,
@@ -672,7 +700,11 @@ async function checkPermissionsAndCallTool(
               tool_use_id: toolUseID,
             },
           ],
-          toolUseResult: `InputValidationError: ${parsedInput.error.message}`,
+          toolUseResult: getSchemaValidationToolUseResult(
+            tool,
+            input,
+            parsedInput.error.message,
+          ),
           sourceToolAssistantUUID: assistantMessage.uuid,
         }),
       },

src/tools/SkillTool/SkillTool.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, test } from 'bun:test'
+
+import { SkillTool } from './SkillTool.js'
+
+describe('SkillTool missing parameter handling', () => {
+  test('missing skill stays required at the schema level', async () => {
+    const parsed = SkillTool.inputSchema.safeParse({})
+
+    expect(parsed.success).toBe(false)
+  })
+
+  test('validateInput still returns an actionable error when called with missing skill', async () => {
+    const result = await SkillTool.validateInput?.({} as never, {
+      options: { tools: [] },
+      messages: [],
+    } as never)
+
+    expect(result).toEqual({
+      result: false,
+      message:
+        'Missing skill name. Pass the slash command name as the skill parameter (e.g., skill: "commit" for /commit, skill: "review-pr" for /review-pr).',
+      errorCode: 1,
+    })
+  })
+
+  test('valid skill input still parses and validates', async () => {
+    const parsed = SkillTool.inputSchema.safeParse({ skill: 'commit' })
+
+    expect(parsed.success).toBe(true)
+  })
+})

src/tools/SkillTool/SkillTool.ts

@@ -352,6 +352,16 @@ export const SkillTool: Tool<InputSchema, Output, Progress> = buildTool({
   toAutoClassifierInput: ({ skill }) => skill ?? '',
 
   async validateInput({ skill }, context): Promise<ValidationResult> {
+    if (!skill || typeof skill !== 'string') {
+      return {
+        result: false,
+        message:
+          'Missing skill name. Pass the slash command name as the skill parameter ' +
+          '(e.g., skill: "commit" for /commit, skill: "review-pr" for /review-pr).',
+        errorCode: 1,
+      }
+    }
+
     // Skills are just skill names, no arguments
     const trimmed = skill.trim()
     if (!trimmed) {
@@ -434,7 +444,7 @@ export const SkillTool: Tool<InputSchema, Output, Progress> = buildTool({
     context,
   ): Promise<PermissionDecision> {
     // Skills are just skill names, no arguments
-    const trimmed = skill.trim()
+    const trimmed = skill ?? ''
 
     // Remove leading slash if present (for compatibility)
     const commandName = trimmed.startsWith('/') ? trimmed.substring(1) : trimmed
@@ -592,7 +602,7 @@ export const SkillTool: Tool<InputSchema, Output, Progress> = buildTool({
     // - Skill is a prompt-based skill
 
     // Skills are just names, with optional arguments
-    const trimmed = skill.trim()
+    const trimmed = skill ?? ''
 
     // Remove leading slash if present (for compatibility)
     const commandName = trimmed.startsWith('/') ? trimmed.substring(1) : trimmed

src/utils/api.test.ts

@@ -1,6 +1,7 @@
 import { expect, test } from 'bun:test'
 import { z } from 'zod/v4'
 import { getEmptyToolPermissionContext, type Tool, type Tools } from '../Tool.js'
+import { SkillTool } from '../tools/SkillTool/SkillTool.js'
 import { toolToAPISchema } from './api.js'
 
 test('toolToAPISchema preserves provider-specific schema keywords in input_schema', async () => {
@@ -64,3 +65,16 @@ test('toolToAPISchema preserves provider-specific schema keywords in input_schem
     },
   })
 })
+
+test('toolToAPISchema keeps skill required for SkillTool', async () => {
+  const schema = await toolToAPISchema(SkillTool, {
+    getToolPermissionContext: async () => getEmptyToolPermissionContext(),
+    tools: [] as unknown as Tools,
+    agents: [],
+  })
+
+  expect((schema as { input_schema: unknown }).input_schema).toMatchObject({
+    type: 'object',
+    required: ['skill'],
+  })
+})

src/utils/managedEnv.ts

@@ -8,7 +8,6 @@ import {
 } from './managedEnvConstants.js'
 import { clearMTLSCache } from './mtls.js'
 import { clearProxyCache, configureGlobalAgents } from './proxy.js'
-import { filterSettingsEnvForExplicitProvider } from './providerEnvSelection.js'
 import { applyActiveProviderProfileFromConfig } from './providerProfiles.js'
 import { isSettingSourceEnabled } from './settings/constants.js'
 import {
@@ -88,9 +87,7 @@ function filterSettingsEnv(
   env: Record<string, string> | undefined,
 ): Record<string, string> {
   return withoutCcdSpawnEnvKeys(
-    filterSettingsEnvForExplicitProvider(
+    withoutHostManagedProviderVars(withoutSSHTunnelVars(env)),
-      withoutHostManagedProviderVars(withoutSSHTunnelVars(env)),
-    ),
   )
 }
 

src/utils/providerEnvSelection.test.ts

@@ -1,116 +0,0 @@
-import { afterEach, beforeEach, describe, expect, test } from 'bun:test'
-import { filterSettingsEnvForExplicitProvider } from './providerEnvSelection.js'
-
-const originalEnv = { ...process.env }
-
-const RESET_KEYS = [
-  'CLAUDE_CODE_EXPLICIT_PROVIDER',
-  'CLAUDE_CODE_USE_OPENAI',
-  'CLAUDE_CODE_USE_GEMINI',
-  'CLAUDE_CODE_USE_GITHUB',
-  'CLAUDE_CODE_USE_BEDROCK',
-  'CLAUDE_CODE_USE_VERTEX',
-  'CLAUDE_CODE_USE_FOUNDRY',
-] as const
-
-beforeEach(() => {
-  for (const key of RESET_KEYS) {
-    delete process.env[key]
-  }
-})
-
-afterEach(() => {
-  for (const key of RESET_KEYS) {
-    if (originalEnv[key] === undefined) delete process.env[key]
-    else process.env[key] = originalEnv[key]
-  }
-})
-
-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'
-
-    expect(
-      filterSettingsEnvForExplicitProvider({
-        CLAUDE_CODE_USE_GITHUB: '1',
-        CLAUDE_CODE_USE_OPENAI: '1',
-        OTHER: 'keep-me',
-      }),
-    ).toEqual({ OTHER: 'keep-me' })
-  })
-
-  test('strips a stale GitHub model when explicit provider is not github', () => {
-    process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'openai'
-
-    expect(
-      filterSettingsEnvForExplicitProvider({
-        OPENAI_MODEL: 'github:copilot',
-        OTHER: 'keep-me',
-      }),
-    ).toEqual({ OTHER: 'keep-me' })
-  })
-
-  test('keeps a normal OpenAI model when explicit provider is openai', () => {
-    process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'openai'
-
-    expect(
-      filterSettingsEnvForExplicitProvider({
-        OPENAI_MODEL: 'gpt-4o',
-        OTHER: 'keep-me',
-      }),
-    ).toEqual({ OPENAI_MODEL: 'gpt-4o', OTHER: 'keep-me' })
-  })
-
-  test('strips a non-GitHub OpenAI model when explicit provider is github', () => {
-    process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'github'
-
-    expect(
-      filterSettingsEnvForExplicitProvider({
-        OPENAI_MODEL: 'gpt-4o',
-        OTHER: 'keep-me',
-      }),
-    ).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' })
-  })
-
-  test('preserves explicit ollama startup intent by stripping OpenAI routing settings', () => {
-    process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'ollama'
-
-    expect(
-      filterSettingsEnvForExplicitProvider({
-        OPENAI_BASE_URL: 'https://api.openai.com/v1',
-        OPENAI_MODEL: 'gpt-4o',
-        OPENAI_API_KEY: 'sk-test',
-        OTHER: 'keep-me',
-      }),
-    ).toEqual({ OTHER: 'keep-me' })
-  })
-})

src/utils/providerEnvSelection.ts

@@ -1,63 +0,0 @@
-export const EXPLICIT_PROVIDER_ENV_VAR = 'CLAUDE_CODE_EXPLICIT_PROVIDER'
-
-const PROVIDER_FLAG_KEYS = [
-  'CLAUDE_CODE_USE_OPENAI',
-  'CLAUDE_CODE_USE_GEMINI',
-  'CLAUDE_CODE_USE_GITHUB',
-  'CLAUDE_CODE_USE_BEDROCK',
-  'CLAUDE_CODE_USE_VERTEX',
-  'CLAUDE_CODE_USE_FOUNDRY',
-] as const
-
-export function clearProviderSelectionFlags(
-  env: NodeJS.ProcessEnv = process.env,
-): void {
-  for (const key of PROVIDER_FLAG_KEYS) {
-    delete env[key]
-  }
-}
-
-function getExplicitProvider(processEnv: NodeJS.ProcessEnv): string | undefined {
-  return processEnv[EXPLICIT_PROVIDER_ENV_VAR]?.trim() || undefined
-}
-
-function isGithubModel(model: string | undefined): boolean {
-  return (model ?? '').trim().toLowerCase().startsWith('github:')
-}
-
-export function filterSettingsEnvForExplicitProvider(
-  env: Record<string, string> | undefined,
-  processEnv: NodeJS.ProcessEnv = process.env,
-): Record<string, string> {
-  if (!env) return {}
-
-  const explicitProvider = getExplicitProvider(processEnv)
-  if (!explicitProvider) {
-    return env
-  }
-
-  const filtered = { ...env }
-  for (const key of PROVIDER_FLAG_KEYS) {
-    delete filtered[key]
-  }
-
-  if (explicitProvider === 'ollama') {
-    delete filtered.OPENAI_BASE_URL
-    delete filtered.OPENAI_MODEL
-    delete filtered.OPENAI_API_KEY
-    return filtered
-  }
-
-  if (explicitProvider === 'github') {
-    if (!isGithubModel(filtered.OPENAI_MODEL)) {
-      delete filtered.OPENAI_MODEL
-    }
-    return filtered
-  }
-
-  if (isGithubModel(filtered.OPENAI_MODEL)) {
-    delete filtered.OPENAI_MODEL
-  }
-
-  return filtered
-}

src/utils/providerFlag.test.ts

@@ -9,13 +9,11 @@ import {
 const originalEnv = { ...process.env }
 
 const RESET_KEYS = [
-  'CLAUDE_CODE_EXPLICIT_PROVIDER',
   'CLAUDE_CODE_USE_OPENAI',
   'CLAUDE_CODE_USE_GEMINI',
   'CLAUDE_CODE_USE_GITHUB',
   'CLAUDE_CODE_USE_BEDROCK',
   'CLAUDE_CODE_USE_VERTEX',
-  'CLAUDE_CODE_USE_FOUNDRY',
   'OPENAI_BASE_URL',
   'OPENAI_API_KEY',
   'OPENAI_MODEL',
@@ -85,16 +83,6 @@ describe('applyProviderFlag - openai', () => {
     applyProviderFlag('openai', ['--model', 'gpt-4o'])
     expect(process.env.OPENAI_MODEL).toBe('gpt-4o')
   })
-
-  test('clears a previously persisted GitHub flag', () => {
-    process.env.CLAUDE_CODE_USE_GITHUB = '1'
-
-    const result = applyProviderFlag('openai', [])
-
-    expect(result.error).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_USE_GITHUB).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_USE_OPENAI).toBe('1')
-  })
 })
 
 describe('applyProviderFlag - gemini', () => {
@@ -116,16 +104,6 @@ describe('applyProviderFlag - github', () => {
     expect(result.error).toBeUndefined()
     expect(process.env.CLAUDE_CODE_USE_GITHUB).toBe('1')
   })
-
-  test('clears a previously set OpenAI flag', () => {
-    process.env.CLAUDE_CODE_USE_OPENAI = '1'
-
-    const result = applyProviderFlag('github', [])
-
-    expect(result.error).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_USE_OPENAI).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_USE_GITHUB).toBe('1')
-  })
 })
 
 describe('applyProviderFlag - bedrock', () => {
@@ -173,19 +151,6 @@ describe('applyProviderFlag - invalid provider', () => {
   })
 })
 
-describe('applyProviderFlag - anthropic', () => {
-  test('clears third-party provider flags', () => {
-    process.env.CLAUDE_CODE_USE_GITHUB = '1'
-    process.env.CLAUDE_CODE_USE_OPENAI = '1'
-
-    const result = applyProviderFlag('anthropic', [])
-
-    expect(result.error).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_USE_GITHUB).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_USE_OPENAI).toBeUndefined()
-  })
-})
-
 describe('applyProviderFlagFromArgs', () => {
   test('applies ollama provider and model from argv in one step', () => {
     const result = applyProviderFlagFromArgs([

src/utils/providerFlag.ts

@@ -1,8 +1,3 @@
-import {
-  clearProviderSelectionFlags,
-  EXPLICIT_PROVIDER_ENV_VAR,
-} from './providerEnvSelection.js'
-
 /**
  * --provider CLI flag support.
  *
@@ -82,9 +77,6 @@ export function applyProviderFlag(
     }
   }
 
-  clearProviderSelectionFlags()
-  process.env[EXPLICIT_PROVIDER_ENV_VAR] = provider
-
   const model = parseModelFlag(args)
 
   switch (provider as ProviderFlagName) {

src/utils/providerProfile.test.ts

@@ -485,26 +485,6 @@ 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

@@ -412,10 +412,6 @@ 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 ||

src/utils/providerProfiles.test.ts

@@ -9,7 +9,6 @@ async function importFreshProvidersModule() {
 const originalEnv = { ...process.env }
 
 const RESTORED_KEYS = [
-  'CLAUDE_CODE_EXPLICIT_PROVIDER',
   'CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED',
   'CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED_ID',
   'CLAUDE_CODE_USE_OPENAI',
@@ -143,29 +142,6 @@ describe('applyProviderProfileToProcessEnv', () => {
 })
 
 describe('applyActiveProviderProfileFromConfig', () => {
-  test('does not override explicit anthropic startup selection', async () => {
-    const { applyActiveProviderProfileFromConfig } =
-      await importFreshProviderProfileModules()
-    process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'anthropic'
-
-    const applied = applyActiveProviderProfileFromConfig({
-      providerProfiles: [
-        buildProfile({
-          id: 'saved_github',
-          baseUrl: 'https://api.githubcopilot.com',
-          model: 'github:copilot',
-        }),
-      ],
-      activeProviderProfileId: 'saved_github',
-    } as any)
-
-    expect(applied).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_EXPLICIT_PROVIDER).toBe('anthropic')
-    expect(process.env.CLAUDE_CODE_USE_OPENAI).toBeUndefined()
-    expect(process.env.CLAUDE_CODE_USE_GITHUB).toBeUndefined()
-    expect(process.env.OPENAI_MODEL).toBeUndefined()
-  })
-
   test('does not override explicit startup provider selection', async () => {
     const { applyActiveProviderProfileFromConfig } =
       await importFreshProviderProfileModules()

src/utils/providerProfiles.ts

@@ -5,7 +5,6 @@ import {
   type ProviderProfile,
 } from './config.js'
 import type { ModelOption } from './model/modelOptions.js'
-import { EXPLICIT_PROVIDER_ENV_VAR } from './providerEnvSelection.js'
 
 export type ProviderPreset =
   | 'anthropic'
@@ -257,7 +256,6 @@ function hasProviderSelectionFlags(
   processEnv: NodeJS.ProcessEnv = process.env,
 ): boolean {
   return (
-    processEnv[EXPLICIT_PROVIDER_ENV_VAR] !== undefined ||
     processEnv.CLAUDE_CODE_USE_OPENAI !== undefined ||
     processEnv.CLAUDE_CODE_USE_GEMINI !== undefined ||
     processEnv.CLAUDE_CODE_USE_GITHUB !== undefined ||