# How to Connect Codex to MewCP

Add MewCP to Codex once, and Codex can use every app you have connected in MewCP: Gmail, Calendar, Slack, GitHub and the rest. Codex connects to MewCP directly over HTTP, so there is nothing to install.

The Codex CLI, the Codex IDE extension and the ChatGPT desktop app share one config file, so setting it up once covers all three.

---

## Before you start

- **Codex** installed. For the CLI, check with `codex --version`, or see the [Codex docs](https://developers.openai.com/codex)
- **A API Key** from **Dashboard → API Keys**, see [API Key](/mewcp/authentication/mewcp-key)
- **At least one app connected** in the dashboard under **Servers**

---

## Set up MewCP

Codex reads MCP servers from `~/.codex/config.toml`. The file is TOML, not JSON or YAML, and each server is a `[mcp_servers.<name>]` table. Create the file if it does not exist.

Choose how Codex gets your key:

### Key in an environment variable (recommended)

Add this to `~/.codex/config.toml`:

```toml
[mcp_servers.mewcp]
url = "https://gateway.mewcp.com/personal/mcp"
bearer_token_env_var = "MEWCP_API_KEY"
```

Then set the variable in your shell profile (`~/.zshrc` or `~/.bashrc`) and open a new terminal:

```bash
export MEWCP_API_KEY="API_KEY"
```

Codex sends `Authorization: Bearer <your key>` for you, so set the variable to the key alone.

### Key in the file

If you start Codex from somewhere that does not load your shell profile, such as the ChatGPT desktop app, put the header in the file instead:

```toml
[mcp_servers.mewcp]
url = "https://gateway.mewcp.com/personal/mcp"
http_headers = { "Authorization" = "Bearer API_KEY" }
```

This is the entire configuration either way. One entry reaches every app you have connected, and connecting another app later needs no change here.

MewCP loads the next time you start Codex. In the IDE extension, choose **Restart extension**. In the ChatGPT desktop app, choose **Restart** under **Settings → MCP servers**.

### Only in one project

To use MewCP in a single project, put the same table in `.codex/config.toml` inside that project. Codex reads project config only for projects you have marked as trusted.

---

## Check it works

Run:

```bash
codex mcp list
```

`mewcp` should be listed. Inside the `codex` terminal UI, type `/mcp` to see your active servers.

You will see four tools, not the tools of every app: `search`, `get_schema`, `list_accounts` and `call_tool`. That is expected. Codex uses them to find and run the right tool for whatever you ask. See [How MewCP works](/mewcp/getting-started#how-mewcp-works).

Then ask for something from an app you have connected:

```bash
codex "What is on my calendar tomorrow?"
```

---

## Troubleshooting

### Codex ignores the MewCP entry

- Check the file is `~/.codex/config.toml` and the entry is a TOML table named `[mcp_servers.mewcp]`. Codex does not read `mcpServers` blocks in JSON or YAML, which older guides show.
- For `.codex/config.toml` inside a project, check you have trusted that project.

### MewCP returns `401`

Codex connects without a key when it cannot find one, so a missing key shows up as a `401` from MewCP.

- With `bearer_token_env_var`, check `MEWCP_API_KEY` is set where you start Codex: `echo $MEWCP_API_KEY`. The variable holds the key alone, without `Bearer`.
- With `http_headers`, check the value reads `Bearer ` followed by the whole key, which starts with `mcp_live_`.

A `403` that says the billing period is not active means your MewCP plan needs renewing in the dashboard.

### MewCP times out at startup or during a tool call

Codex waits 10 seconds for a server to start and 60 seconds for a tool to finish. On a slow network, raise the limits:

```toml
[mcp_servers.mewcp]
url = "https://gateway.mewcp.com/personal/mcp"
bearer_token_env_var = "MEWCP_API_KEY"
startup_timeout_sec = 30
tool_timeout_sec = 120
```

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_Last checked against Codex's documentation on 13 October 2026._