Humanize AI text inside Codex

OpenAI's Codex CLI can call SupWriter's tools over MCP. Add the server to your Codex config and humanize, paraphrase, grammar-check, or detect AI text straight from the terminal.

https://supwriter.com/api/mcpDirect API key · uses your plan credits

How to connect

Codex connects with a Direct API key. Calls use your existing plan credits.

Recommended

Connect with a Direct API key

For clients that take an Authorization header (and headless agents). Requires a Pro or Ultra plan.

1
Create an API key
In SupWriter, open Settings → API & MCP and create a key (Pro or Ultra plan).
2
Export the key as an env var
Codex sends the value of an environment variable as the bearer token, so export it where you launch Codex: export SUPWRITER_TOKEN=sw_live_your_key.
3
Add the server
Run: codex mcp add supwriter --url https://supwriter.com/api/mcp --bearer-token-env-var SUPWRITER_TOKEN — or add an [mcp_servers.supwriter] block to ~/.codex/config.toml with url = "https://supwriter.com/api/mcp" and bearer_token_env_var = "SUPWRITER_TOKEN".
4
Use it
Restart Codex and ask: "Humanize the draft above." (On older Codex builds, add experimental_use_rmcp_client = true to enable remote MCP servers.)

Example client config

# Cursor / Claude Code — JSON, "mcpServers" key (~/.cursor/mcp.json)
{
  "mcpServers": {
    "supwriter": {
      "url": "https://supwriter.com/api/mcp",
      "headers": { "Authorization": "Bearer sw_live_your_key" }
    }
  }
}

# VS Code — JSON, "servers" key, type "http" (.vscode/mcp.json)
{
  "servers": {
    "supwriter": {
      "type": "http",
      "url": "https://supwriter.com/api/mcp",
      "headers": { "Authorization": "Bearer sw_live_your_key" }
    }
  }
}

# Codex — TOML (~/.codex/config.toml). Codex sends the env var's VALUE as the
# bearer token, so export SUPWRITER_TOKEN=sw_live_your_key first.
[mcp_servers.supwriter]
url = "https://supwriter.com/api/mcp"
bearer_token_env_var = "SUPWRITER_TOKEN"

# Claude Code — one command
claude mcp add --transport http supwriter https://supwriter.com/api/mcp \
  --header "Authorization: Bearer sw_live_your_key"

Create an API key

Test it

Once connected, ask Codex to use a tool. A few prompts that work well:

“Humanize this so it reads naturally: <your text>”
“Paraphrase this in a casual tone: <your text>”
“Grammar-check and fix this paragraph: <your text>”
“Run an AI-detection check on the text above and tell me which sentences look AI-written.”

FAQ

Does connecting cost anything extra?

No separate MCP fee — calls draw on the word credits already in your SupWriter plan (one credit per word). AI detection is metered over MCP too (one credit per word analyzed), the same as the REST API; it's free only inside the web app.

Is my account safe?

Yes. You authorize either through SupWriter's own OAuth sign-in — approving a consent screen that lists exactly what the client can do — or with a scoped API key. OAuth tokens are short-lived, and keys can be rotated or revoked any time from Settings → API & MCP.

Which tools become available?

Four: humanize, paraphrase, grammar-check, and AI detection — the same engines that power the SupWriter editor.

Want the full walkthrough with screenshots?

Read the Codex setup guide