A production key will not work against the sandbox URL, and the other way around.
Create an agent key
To create an agent key, follow these steps:- Go to the API keys page.
- Under Agent keys, click Create agent key.
- Enter a Name — for example
ClaudeorChatGPT. This is how the agent appears in events and Approvals. - Optionally enter a Note for where the key is used.
- Click Create.
- Copy the key and store it somewhere safe. You cannot view it again.
Claude
Add Yorlet as a custom connector. Claude talks to Yorlet over the internet, so the same connector works in claude.ai, Claude Desktop, Cowork, and the Claude mobile app. To add Yorlet in Claude, follow these steps:- Create an agent key.
- In Claude, go to Customize → Connectors. On a Team or Enterprise plan, an owner must add the connector first under Organization settings → Connectors.
- Click Add custom connector. If Claude asks for a type, choose Web.
- Name it Yorlet.
- Paste the MCP URL from the table above.
- Open Request headers. Add a header named Authorization. For the value, enter
Bearerfollowed by your agent key, including the space afterBearer. Mark it as Required. - Click Add, then Connect.
- In a chat, click + → Connectors and turn Yorlet on for that conversation.
Request headers is how Claude sends an agent key. If that section is missing, Claude will try to sign in with OAuth instead, which Yorlet does not use. Wait until Request headers appears on your account, or ask Anthropic for access.
ChatGPT
Yorlet is a remote MCP server. In ChatGPT you add it as a custom app (web) or as an MCP server (desktop). You need ChatGPT Plus, Pro, Business, Enterprise, or Edu — custom connectors are not on the free plan.ChatGPT on the web
To add Yorlet in ChatGPT on the web, follow these steps:- Create an agent key.
- In ChatGPT, open Settings → Security and login (on some accounts, Settings → Apps → Advanced settings) and turn on Developer mode.
- Open Settings → Apps. Click the plus button and create a custom app for a remote MCP server.
- Name it Yorlet.
- Paste the MCP URL from the table above.
- For authentication, choose Token (sometimes labelled API key). Paste the agent key. If the field wants a full header value, enter
Bearerfollowed by the key, including the space. - Save the app.
- Start a chat, open the tools menu, choose Developer mode, and enable Yorlet.
ChatGPT desktop
The ChatGPT desktop app can send a bearer token directly. To add Yorlet there, follow these steps:- Create an agent key.
- Open Settings → MCP servers.
- Click Add server.
- Name it Yorlet, choose Streamable HTTP, and paste the MCP URL from the table above.
- Enter the agent key as the bearer token.
- Save, then Restart.
- In the composer, type
/mcpto confirm Yorlet is connected.
What they can do
Once connected, Claude or ChatGPT can propose:
A proposed write is not finished until policy says so. If policy is Require approval, open Approvals in Yorlet and approve it there. Do not tell a customer that an email has gone out until the approval status is Executed.
Troubleshooting
- Claude asks you to sign in with OAuth. Request headers is missing, or the Authorization header was not marked required. Add
Authorizationwith valueBearerplus the key. - 401, or ChatGPT starts an OAuth flow. The key is missing, has extra spaces, or belongs to the other environment. Fix the token rather than completing a login prompt.
- The connector adds but no tools appear. Turn the connector on in that chat (+ → Connectors in Claude, Developer mode in ChatGPT).
- A send or enrolment did not happen. Open Approvals. Those actions wait for a person by default.
- Send email fails. Provision an address and set it as the agent address. See Agents and Inbox.
Agent keys are not a substitute for secret or restricted API keys. Use a secret or restricted key when your own systems call the Yorlet API as an integration, not as an agent in Claude or ChatGPT.