Install CoS Codex Bridge in LM Studio

What you need first

• LM Studio, installed.
• Node.js, which gives the npx command the server starts with.
• Your own value for YOUR_COS_BRIDGE_CONFIG.

Steps

1. In LM Studio, open the Program tab and choose Install › Edit mcp.json.
2. Add this block. If the file already has mcpServers, add only the entry inside it.

{
  "mcpServers": {
    "cos-codex-bridge": {
      "command": "npx",
      "args": ["-y", "[email protected]", "mcp"],
      "env": { "COS_BRIDGE_CONFIG": "YOUR_COS_BRIDGE_CONFIG" }
    }
  }
}

3. Replace YOUR_COS_BRIDGE_CONFIG with your own value.
4. Save the file and restart LM Studio.

Check it worked

Ask LM Studio: List the tools of cos-codex-bridge.

If it does not start

spawn npx ENOENT

Node.js is not on the PATH that LM Studio sees. Install it, or write the full path of npx in the config.

The server starts, but its tools fail

A YOUR_… placeholder is still in the config, or its value is wrong.

Nothing changes after a restart

The file is not valid JSON any more. Look for a missing comma where the block was added.