Codex CLI

Learn how to set up the Mixedbread MCP server with the Codex CLI.

Prerequisites

Before we configure Codex, make sure you have the following:

• Codex CLI installed
• Node.js 22+ installed
• A Mixedbread API key from our platform

Configuration

Codex configures MCP servers via a configuration file named config.toml.

1. Locate the configuration file

   Global scope: ~/.codex/config.toml

   If this file doesn't exist yet, you can create it manually.

2. Add a Mixedbread server entry

   Add the following to your config.toml:

[mcp_servers.mixedbread]
command = "npx"
args = [
  "-y",
  "mcp-remote@latest",
  "https://www.mcp.mixedbread.com/api/mcp",
  "--header",
  "Authorization:${MXBAI_AUTH_HEADER}"
]
env = { MXBAI_AUTH_HEADER = "Bearer YOUR_MIXEDBREAD_API_KEY" }

• command tells Codex to run mcp-remote via npx.
• args specify the remote MCP endpoint and the header used for authentication.
• env sets an environment variable that contains your API key.

Replace YOUR_MIXEDBREAD_API_KEY with your actual API key from the Mixedbread platform.

Verification

Now let's confirm the integration is working.

1. Open the Codex CLI.

2. Run a status check to list MCP servers:

   Copy to clipboard

   codex servers list

   You should see Mixedbread in the output.

3. Test the connection with a simple command in chat:

   Copy to clipboard

   Create a new store called "my-knowledge-base"

Now you can manage your Stores and perform Search directly from the Codex CLI.

References

• Codex docs: Model Context Protocol