SDK execution error in Agent SDK 0.2.27+ causes crash before API calls

[wesleysmyth]

Description

After the Agent SDK was bumped to 0.2.27 (commit 0ed5eea on Jan 30, 2025), the claude-code-action crashes with an SDK execution error before any API calls are made.

Environment

• Action version: @v1 (currently points to Agent SDK 0.2.27+)
• Last working version: SHA 01e756b (Agent SDK 0.2.25)
• Runner: ubuntu-latest
• Workflow trigger: pull_request

Error Output

{
  "type": "result",
  "subtype": "success",
  "is_error": true,
  "duration_ms": 372,
  "num_turns": 1,
  "total_cost_usd": 0,
  "permission_denials": []
}
SDK execution error: 14 |     depsCount: ${Q},
15 |     deps: ${$}}`};var Pj={keyword:"dependencies",type:"object",schemaType:"object",error:EB.error,code(X){...
...
error: Claude Code process exited with code 1
      at $ (/home/runner/work/_actions/anthropics/claude-code-action/v1/base-action/node_modules/@anthropic-ai/claude-agent-sdk/sdk.mjs:19:7668)
      at emit (node:events:98:22)
      at #handleOnExit (node:child_process:520:14)

Key Observations

1. total_cost_usd: 0 - No API calls are made before the crash
2. is_error: true with subtype: "success" - Contradictory status
3. Error appears to be in JSON schema validation (ajv library) based on the minified code referencing dependencies, schemaType, etc.
4. Crash happens during SDK initialization, not during API communication

Reproduction

The issue occurs with a minimal workflow configuration:

- name: Run Claude Code Review
  uses: anthropics/claude-code-action@v1
  with:
    anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
    github_token: ${{ secrets.GITHUB_TOKEN }}
    model: claude-opus-4-5-20251101
    prompt: "Review this PR"

We also tested:

• ❌ Removing allowed_tools - still crashes
• ❌ Using model input instead of claude_args - still crashes
• ✅ Pinning to SHA 01e756b (SDK 0.2.25) - works correctly

Workaround

Pin to the last working SHA:

uses: anthropics/claude-code-action@01e756b34ef7a1447e9508f674143b07d20c2631

Timeline

Commit	Date	SDK Version	Status
01e756b	Jan 29	0.2.25	✅ Working
0ed5eea	Jan 30	0.2.27	❌ Broken
70e16de	Jan 31	0.2.29	❌ Broken
4ce5f17	Feb 1	Latest	❌ Broken

Expected Behavior

The action should successfully initialize and make API calls to perform code review.

Actual Behavior

The action crashes with an SDK execution error during initialization, before any API calls are made.

[wesleysmyth]

Update: Bug affects ALL SDK versions tested, not just 0.2.27+

After extensive testing, we found the same crash occurs across multiple SDK versions:

• SDK 0.2.22 (SHA 2817c54) - CRASH
• SDK 0.2.25 (SHA 01e756b) - CRASH
• SDK 0.2.29 (SHA 4ce5f17) - CRASH

We also tested with a minimal configuration (just API key, GitHub token, and prompt - no model, no allowed_tools, no claude_args) and the crash still occurs.

This suggests the bug may be:

1. Related to how the SDK processes repository configuration files (like .mcp.json)
2. A general issue with ajv schema validation in the bundled SDK

The repository has a .mcp.json with multiple MCP server definitions (MongoDB, LaunchDarkly, Salesforce, etc.), which may be triggering the validation crash when enableAllProjectMcpServers: true is set.

Error trace is always the same:

SDK execution error: 14 |     depsCount: ${Q},
15 |     deps: ${$}}`};var Pj={keyword:"dependencies"...

Key observation: total_cost_usd: 0 in all cases confirms no API calls are made - the crash happens during SDK initialization/configuration validation.

[lawwu]

I'm running into a similar error. Not sure if it's related to the SDK version Claude Code Action that ran on this ticket to triage issues worked, it's using @anthropic-ai/claude-agent-sdk@0.2.29: https://github.com/anthropics/claude-code-action/actions/runs/21598394777/job/62237199463#step:3:50

[dreddak47]

I think it is working, but with minimal configuration.

      - name: Run Claude
        uses: anthropics/claude-code-action@v1
        with:
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
          prompt: ${{ steps.args.outputs.prompt }}
          track_progress: true
          additional_permissions: |
            actions: read

If it helps, this worked as soon as i removed claude_args.

[firstloop-jake]

Running into the same issue. Apologies for the clutter (and adding more with this comment). My Claude referenced this issue while adjusting the workflow

[natelegion]

Also experiencing this issue.
Environment:

Action version: @v1 and tried pinning to @01e756b34ef7a1447e9508f674143b07d20c2631
Runner: ubuntu-latest
Trigger: issue_comment with @claude mention

Workflow:

yamlname: Claude Code

on:
  issue_comment:
    types: [created]
  pull_request_review_comment:
    types: [created]
  issues:
    types: [opened, assigned]
  pull_request_review:
    types: [submitted]

jobs:
  claude:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
      issues: write
      id-token: write
      actions: read
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 1

      - uses: anthropics/claude-code-action@01e756b34ef7a1447e9508f674143b07d20c2631
        with:
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}

Observations:

Pinning to 01e756b (SDK 0.2.25) still crashes with the same AJV error
All setup steps succeed (OIDC, permissions, checkout, git config)
Crashes immediately during SDK initialization with total_cost_usd: 0

This is blocking our PR review workflows. Any ETA on a fix?