# Codex

Add the Sai MCP server to OpenAI Codex.

Codex reads MCP servers from `~/.codex/config.toml`. The same `npx` command that Claude Code uses works here.

## Install

```bash
codex mcp add sai --env SAI_API_KEY=sapi_... -- npx -y @simular-ai/sai-mcp
```

Or edit the config by hand:

```toml
[mcp_servers.sai]
command = "npx"
args = ["-y", "@simular-ai/sai-mcp"]
# sai_task_wait holds for up to 110 s; Codex's default tool timeout is 60 s.
tool_timeout_sec = 120

[mcp_servers.sai.env]
SAI_API_KEY = "sapi_..."
```

Restart Codex after editing the file.

## Verify

```bash
codex mcp list
```

Then ask:

```
Use Sai to open the Downloads folder on my computer and list the five newest files.
```

## Tools and loop

The tool set and the start, wait, approve loop are the same as in [Claude Code](/documentation/coding-agents/claude-code#tools). Codex calls `sai_task_wait` repeatedly until `status` is `idle`.

## Gotchas

- Codex has no equivalent of Claude Code channels, so there is no push mode. Polling through `sai_task_wait` is the only path.
- Keep the key out of the repository. `~/.codex/config.toml` is per user; a project-level `.codex/config.toml` is committed by default in many repositories.
- Codex applies its own timeout to tool calls, 60 seconds by default. `sai_task_wait` can hold for up to 110 seconds, so set `tool_timeout_sec = 120` as above. A wait that returns early can be called again with the returned `cursor`.
- The Codex app shows the task view in the conversation but keeps it offline, so the screen can't stream there. Open the `watch_url` link instead; see [Watch Sai work](/documentation/coding-agents/live-view).
- `sai_task_wait` retries a gateway `502`, `503` or `504` on its own before reporting an error.