x.ai Grok CLI MCP Bridge

Use the local grok CLI as an MCP sub-agent from Claude Code or any MCP host.

This server wraps the documented x.ai headless scripting mode. The generic tools use JSON output, while grok_code_review uses plain output because it produced better review results in practice.

grok --no-auto-update --prompt-file /tmp/prompt.md --cwd /path/to/project --output-format json

Requirements

• Python 3.10+

• grok on PATH

• Auth already configured with grok login, or an environment supported by the CLI such as XAI_API_KEY

• Optional: GROK_CLI_PATH if grok is not on PATH

GROK_CLI_PATH is strict: bare commands resolve through PATH, while path values must point to an executable file. Directories and non-executable files are rejected.

Related MCP server: peer-agents-mcp

Install

cd /Users/zvisegal/devlope/XAIMsp
/opt/homebrew/bin/python3.12 -m venv .venv
. .venv/bin/activate
python -m pip install --upgrade pip
pip install -e ".[dev]"
pytest -q -p no:cacheprovider
ruff check --no-cache .

MCP Host Config

Add this server to the MCP host config. Prefer the project venv Python:

{
  "mcpServers": {
    "xai": {
      "command": "/Users/zvisegal/devlope/XAIMsp/.venv/bin/python",
      "args": ["/Users/zvisegal/devlope/XAIMsp/server.py"]
    }
  }
}

Tools

• grok_ask(prompt, workspace?, timeout_s?, model?, session_id?, max_turns?, reasoning_effort?, rules?, raw_output?)

• grok_continue(prompt, workspace?, timeout_s?, model?, resume?, max_turns?, reasoning_effort?, rules?, raw_output?)

• grok_code_review(code_or_diff, question?, primary_analysis?, workspace?, timeout_s?, model?, max_findings?, reasoning_effort?, self_check?, raw_output?)

• grok_version()

workspace defaults to the MCP server's current directory. Pass the project path explicitly when you want Grok to inspect a specific repo.

Use grok_code_review as a second-opinion reviewer after CodeHelper or manual analysis. It embeds strict offline-review rules in the prompt, disables web search, and uses --prompt-file.

Advanced parameters:

• self_check=true: Passes --check for an extra Grok verification loop. Use sparingly because it costs more time and quota.

• raw_output=true: Returns a debug payload with extracted text, stdout, stderr, return code, and parsed JSON when available.

• session_id and resume: Useful for explicit Grok session control. session_id should be a valid UUID for new sessions.

• rules: Available on generic ask/continue calls. Prefer grok_code_review for second-opinion code review because it already uses the tuned offline-review prompt.

Set XAI_MCP_DEBUG=true only when diagnosing bridge startup or CLI invocation issues.

See CLAUDE_CODE_USAGE.md for the recommended Claude Code workflow and CLAUDE_CODE_UPDATE_GROK_PATH.md for the latest path-handling update.

Security

Grok is an agentic CLI. workspace is a working directory, not a security boundary. The bridge does not expose --always-approve through MCP tools. Use grok_code_review with focused snippets or diffs, and verify findings before editing code.

Smoke Test

This makes a real Grok call and may use quota:

python test_smoke.py