Claude Code Plugin for Any Agent

Use an already-installed and authenticated Claude Code CLI from Codex or any other MCP-compatible harness.

This is an MCP server, not a host-specific plugin: it communicates over standard input/output and starts the local claude executable. That makes its tool interface portable across MCP clients while preserving your existing CLI authentication and default model configuration.

What it provides

Tool	Purpose
claude_run	Run a task synchronously or as a managed background job.
claude_review	Run a read-only review in a working directory.
claude_status	Check local CLI availability and background-job status.
claude_result	Retrieve a completed background job's stored output.
claude_cancel	Cancel a running background job.

Every task and review accepts an optional model. If it is omitted, the server does not send --model, so the local CLI uses its normally configured default.

Prerequisites

• Node.js 18 or newer
• Claude Code already installed and authenticated
• Codex CLI, if you are using the Codex installation path below

Check the local prerequisites:

node --version
claude --version
codex --version

Install in Codex

Clone the repository, or use your existing clone:

git clone https://github.com/sarthchawla/claude-code-as-plugin.git
cd claude-code-as-plugin

Register the server. Run this from the cloned repository so the command records an absolute path:

MCP_SERVER_PATH="$(pwd)/bin/claude-code-mcp.mjs"

codex mcp add claude-code \
  --env CLAUDE_CODE_MCP_REVIEW_AFTER_RUN=false \
  -- node "$MCP_SERVER_PATH"

Verify registration:

codex mcp list

Restart Codex or start a new task. The five tools listed above should then be available.

Enable the post-task review hook

The hook is disabled by default. To enable it, replace the registration:

codex mcp remove claude-code

MCP_SERVER_PATH="$(pwd)/bin/claude-code-mcp.mjs"

codex mcp add claude-code \
  --env CLAUDE_CODE_MCP_REVIEW_AFTER_RUN=true \
  -- node "$MCP_SERVER_PATH"

The hook runs only after a successful claude_run. It uses a restricted, read-only tool set and returns its findings under review in the same tool response. It adds latency and usage, and does not attempt automatic fixes or feedback loops.

For a customized hook, add either optional environment variable during codex mcp add:

--env 'CLAUDE_CODE_MCP_REVIEW_MODEL=sonnet'
--env 'CLAUDE_CODE_MCP_REVIEW_PROMPT=Review for correctness, security, and missing tests. Do not modify files.'

Use from Codex

Ask Codex to use a tool directly. Typical calls look like these:

{
  "prompt": "Investigate the failing tests and make the smallest safe fix.",
  "cwd": "/absolute/path/to/project",
  "model": "sonnet"
}

Omit model to use the local CLI default:

{
  "prompt": "Review the current changes for regressions.",
  "cwd": "/absolute/path/to/project"
}

The default permission mode is manual. claude_run also supports permission_mode, allowed_tools, max_budget_usd, timeout_ms, and review_after_run for a single-call hook override.

Background jobs

Set background to true to receive a jobId immediately:

{
  "prompt": "Investigate the CI regression and prepare a minimal fix.",
  "cwd": "/absolute/path/to/project",
  "background": true
}

Then use:

1. claude_status with job_id while the task runs.
2. claude_result with job_id after status is completed.
3. claude_cancel with job_id to stop it.

Cancellation sends SIGTERM to the subprocess group, followed by SIGKILL after five seconds if needed. Job state and output are stored only in memory; restarting the MCP server loses prior job history.

Configure another MCP harness

Use the standard mcpServers entry in examples/mcp-server.json, replacing the placeholder path with the absolute location of bin/claude-code-mcp.mjs:

{
  "mcpServers": {
    "claude-code": {
      "command": "node",
      "args": ["/absolute/path/to/claude-code-as-plugin/bin/claude-code-mcp.mjs"],
      "env": {
        "CLAUDE_CODE_MCP_REVIEW_AFTER_RUN": "false"
      }
    }
  }
}

Troubleshooting

• The server is unavailable: run claude --version in the same terminal environment used to start Codex. The server relies on claude being on PATH.
• The model is not what you expected: omit model to use the CLI default, or supply the desired model alias/value only for that invocation.
• A background job disappeared: jobs are process-local. Re-run the task after restarting Codex or the MCP server.
• Update or remove the server: use codex mcp remove claude-code, then run the registration command again (or leave it removed).

Security

Any MCP client that can call this server can ask the local CLI to operate in its supplied cwd. Register it only with trusted harnesses and repositories. Keep the default manual permission mode unless the calling environment provides a suitable sandbox.

Development

npm test