MCP connection

Improve your writing in connected AI apps.

Give Hemmingway a brief to draft from, or a passage to rewrite, inside a compatible AI app. Sign in with your existing Hemmingway account; your usual writing allowance applies.

Server address

Add this address in your app’s remote MCP connection settings. You do not need an API key or client secret.

Standard Hemmingway models only. Unlocked is not available through this connection. Free account usage is limited.

Set up in Codex CLI

With a current Codex CLI installed, add the server in your terminal:
```
codex mcp add hemmingway --url https://hemmingway.io/api/mcp
```
Complete sign-in if Codex prompts you. If no sign-in flow opens, run:
```
codex mcp login hemmingway
```
Sign into Hemmingway in the browser and approve writing access.
Start a new Codex session and ask it to use Hemmingway to write from your brief or rewrite the text you supply. Review the returned text before using it.

Set up in Claude

Open Customize, then choose Connectors from the section menu.
Choose Add connector → Add custom connector.
Enter Hemmingway as the name and paste the server address above. Choose Continue.
Choose Sign in now and Use Claude’s published identity. This is the recommended option. Leave request headers and manual client credentials empty.
Choose Add, open the connector’s details and choose Connect.
If Claude opens a browser page asking you to finish connecting, choose Continue connecting. In the Hemmingway sign-in window, check the account and client, then approve writing access.
Return to Claude. Enable Hemmingway in a new conversation’s connector menu and ask it to use Hemmingway for your draft or rewrite.

Your Claude plan and organisation’s settings determine whether custom connectors are available. See Claude’s connector instructions for its current requirements.

Try a short request

Use Hemmingway to make this clearer, keeping the meaning: “Please review the revised report before our Friday meeting.”

Connect another compatible app

In the app’s MCP settings, add a remote server using the same address. The app needs Streamable HTTP and OAuth sign-in, with automatic client registration or a published client identity. Complete the Hemmingway sign-in and approve the connection.

Setup names and available interfaces vary between apps. This MCP connection returns your writing as text. Use your app’s editing and copying controls to work with the result. Follow your app’s remote MCP instructions rather than adding this address as an API key.

You control the connection

The client sends the brief, passage and writing instructions you choose to submit. Hemmingway returns the writing result to that client. The connection does not give it access to your Hemmingway conversation history, files, billing or account settings.

Manage connected clients to disconnect an individual app. Removing its Hemmingway access leaves your other connections in place.

If you need a hand

Claude says the accounts do not match.

Use the same Claude account in your browser and desktop app, then retry Connect. Complete the browser’s Continue connecting step if it appears. This check happens in Claude before Hemmingway sign-in.

I cancelled sign-in or the request expired.

Return to your app and start its connection flow again. Check the Hemmingway account shown before approving. An expired request cannot be reused.

My app asks me to reconnect.

Sign in again through the app’s connection settings. Access depends on the Hemmingway login session you approved and expires within 30 days. Signing out or revoking that session also ends its access.

I’m connected, but writing did not complete.

Check that your Hemmingway account has writing allowance available. Keep your original text and retry once when the service is available. If the connection was revoked, reconnect first. Contact support if it continues; include the app name and error message, and leave out passwords and tokens.

Do I need this for the ChatGPT plugin?

The ChatGPT plugin has its own installation and account connection. Use this MCP address when configuring a separate compatible client.