OpenClaw

openclaw gateway stopopenclaw mcp add nextmail --url https://api.nextmail.sh/mcp --transport streamable-http --auth oauthopenclaw mcp login nextmailopenclaw gateway start

Run these where OpenClaw is installed. Adding a server and signing in from the terminal need the Gateway stopped, and --transport streamable-http matters: without it OpenClaw connects over SSE.

login prints a link and waits for your browser. Sign in, pick the workspace, the access, the addresses OpenClaw may reach and how long the approval lasts, and approve. When the browser runs on another machine and cannot reach the callback, copy the code from the address it was sent to and pass it with openclaw mcp login nextmail --code <code>. The Control UI can do the same under Settings → MCP, where Sign in starts the approval for a server that uses OAuth.

The server registers up to 600 tools, and OpenClaw sees the ones both your role and the approval allow. With the Gateway stopped, openclaw mcp tools keeps it to the ones you name, and openclaw mcp doctor nextmail --probe connects and reports what the server offers.

openclaw mcp tools nextmail --include 'whoAmI,listThreads,getThread,createDraft,replyToEmail,sendEmail'

• —OpenClaw is listed in Account → Connected apps, where you can narrow what it reaches or remove it.
• —The MCP server never asks before a tool acts, so a tool that sends or deletes does it at once.
• —A tool that needs a verification code is refused, because OpenClaw cannot ask you for one. Choose Allow changes for 60 minutes on OpenClaw in Account → Connected apps when it has to make such a change.

OpenClaw can start the local bridge instead of signing in itself. Sign in once with npx @nextmail/cli login on the same machine, then, with the Gateway stopped, add the server as a command. Remove that sign-in with npx @nextmail/cli logout.

openclaw mcp add nextmail --command npx --arg -y --arg @nextmail/cli --arg mcp --arg serve