Connect Claude Code to Postal

Check these points before opening the Claude Code setup. They prevent most connection failures.

• A team with the "MCP server" plan feature (mcp_access); without it the server responds 403 plan_limit_reached.
• To send emails, the team needs at least one verified domain.
• If you will use an API key: create the key in the dashboard, under API keys. It starts with ps_; a send-only key is enough if you will only send.
• Each connection acts on a single team. To use another team, connect again and pick the other one.
• Connections are listed under Settings › AI connections in the dashboard, where they can be revoked at any time.

Follow the steps in order. The server address is always https://api.postal.so/mcp. Recommended path: sign in with your account (OAuth). The API key is the alternative. Wherever ps_... appears, use your own API key: the value shown is only an example.

1. 1

   Run the command below (--scope user applies to all projects; without the option, it applies only to the current project).

2. 2

   Inside Claude Code, type /mcp, choose "postal" and follow the login in the browser. In a terminal without a browser, use: claude mcp login postal.

3. 3

   On the Postal screen, choose the team and click Allow. Claude Code stores and renews the tokens.

4. 4

   For an API key, use the second command (the key stays in your local configuration file; do not put it in a versioned .mcp.json, use ${POSTAL_API_KEY}).

5. 5

   To limit access to read and send, pin the scopes in .mcp.json (third snippet).

claude mcp add --transport http --scope user postal https://api.postal.so/mcp

claude mcp add --transport http --scope user postal https://api.postal.so/mcp --header "Authorization: Bearer ps_..."

{
  "mcpServers": {
    "postal": {
      "type": "http",
      "url": "https://api.postal.so/mcp",
      "oauth": {
        "scopes": "mcp:read mcp:send"
      }
    }
  }
}

Postal splits access into three levels, explained in the scopes table. For Claude Code:

The simplest proof is to ask for something read-only inside Claude Code itself. The connection also shows up under Settings › AI connections in the Postal dashboard, with the app, the team and the last use.

For those who want the technical proof

npx @modelcontextprotocol/inspector --cli https://api.postal.so/mcp \
  --transport http \
  --header "Authorization: Bearer ps_..." \
  --method tools/list

The Inspector proves that the Postal server responds. It does not test Claude Code itself. The full walkthrough is in Validate the connection.

Go through the list in order. Then read what we know (and what we don't know) about Claude Code.

What was tested and what was not