Claude Code Action crashes with exit code 1 on PR reviews

[AXD-dev01]

Claude Code Action Crash Report

Issue Summary

The anthropics/claude-code-action@v1 is consistently crashing with exit code 1 approximately 2 seconds after starting, preventing PR security reviews from completing.

Environment

• Action Version: anthropics/claude-code-action@v1 (SHA: 7145c3e0510bcdbdd29f67cc4a8c1958f1acfa2f)
• Runner: ubuntu-latest (Ubuntu 24.04.3 LTS)
• Event: pull_request (opened, synchronize, reopened)
• Repository: AXD-enterprise/axd-hub (private)
• Date: December 30, 2025

Configuration

- name: Claude Code Security Review
  uses: anthropics/claude-code-action@v1
  with:
    prompt: |
      Review this PR for security issues and code quality...
    anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
    claude_args: |
      --system-prompt "..."
      --max-turns 10
      --model claude-sonnet-4-5
      --mcp-config .claude/mcp-config.json

Observed Behavior

1. ✅ Authentication succeeds (OIDC token exchange works)
2. ✅ Claude Code SDK initializes
3. ✅ Settings file created at /home/runner/.claude/settings.json
4. ✅ Prompt file created at /home/runner/work/_temp/claude-prompts/claude-prompt.txt
5. ❌ Claude Code process exits with code 1 after ~2 seconds
6. ❌ No PR comments posted
7. ❌ No detailed error message in logs

Error Output

SDK execution error: 13243 |       throw error;
13244 |     }
13245 |   }
13246 |   getProcessExitError(code, signal) {
13247 |     if (code !== 0 && code !== null) {
13248 |       return new Error(`Claude Code process exited with code ${code}`);
                     ^
error: Claude Code process exited with code 1
      at getProcessExitError (/home/runner/work/_actions/anthropics/claude-code-action/v1/base-action/node_modules/@anthropic-ai/claude-agent-sdk/sdk.mjs:13248:14)
      at exitHandler (/home/runner/work/_actions/anthropics/claude-code-action/v1/base-action/node_modules/@anthropic-ai/claude-agent-sdk/sdk.mjs:13373:28)
      at emit (node:events:92:22)
      at #handleOnExit (node:child_process:511:14)

SDK Options Used

{
  "systemPrompt": {
    "type": "preset",
    "preset": "claude_code"
  },
  "pathToClaudeCodeExecutable": "",
  "extraArgs": {
    "system-prompt": "...",
    "max-turns": "10",
    "model": "claude-sonnet-4-5",
    "mcp-config": ".claude/mcp-config.json"
  },
  "settingSources": ["user", "project", "local"]
}

Troubleshooting Steps Taken

1. ✅ Verified ANTHROPIC_API_KEY secret exists and is valid
2. ✅ Corrected model name from invalid claude-sonnet-4-5-20250929 to valid claude-sonnet-4-5
3. ✅ Ensured workflow file matches between PR and main branch
4. ✅ Verified MCP config file exists at .claude/mcp-config.json
5. ✅ Enabled show_full_output: true (still no additional error details)
6. ✅ Confirmed authentication works (OIDC token exchange successful)

Expected Behavior

Claude Code should:

1. Analyze the PR changes
2. Post review comments on specific lines
3. Complete with exit code 0 (or appropriate non-zero if issues found but commented)

Actual Behavior

Claude Code crashes immediately without:

• Posting any comments
• Providing detailed error messages
• Indicating what caused the failure

Impact

• Unable to use automated Claude security reviews
• PRs blocked by failed required check
• Manual security review required as workaround

Workaround Applied

Merged PR manually after verifying security issues were addressed through other means.

Related Workflow Runs

• Run ID: 20601268576 (initial failure)
• Run ID: 20602080944 (after model name fix)
• Run ID: 20602966122 (after auth fix)
• Run ID: 20603048271 (with full output enabled)
• Run ID: 20603165965 (after workflow file sync)

All runs show identical crash pattern.

Request

Please investigate why the Claude Code process is exiting with code 1 immediately after initialization without providing actionable error messages.

Additional Context

• Using @anthropic-ai/[email protected]
• The action worked correctly in generating PR comments on other repositories
• This appears to be a recent regression or environment-specific issue

[vibe-kanban-cloud[bot]]

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