Connecting in Claude

Connecting is a few clicks and a browser sign-in. The one thing you paste is the MCP server URL below.

The URL is not access

Mailhub registers each client in advance — an MCP client cannot register itself, and knowing the address changes none of that. Confirm that your assistant and environment can be used through the support arrangement already in place for your account; Developer Support explains what to include.

Do Before You Connect first. The usual first-run failure is not a failed connection — it is a connection that succeeds and then refuses every tool, because Agent Access or the user's permissions were not ready.

Which server to use

Mailhub runs one MCP server per environment, and this portal publishes the one that belongs to its own environment — the Production portal gives you the Production server, a testing portal the testing one. Read this page on the portal for the environment you mean to work in.

MCP server URL — paste this into Claude	https://mcp.mailhub.com
OAuth client id	mailhub-claude-mcp

You sign in on the ordinary Mailhub web app

Pressing Connect sends Claude to the Mailhub authorization host for that environment, which redirects your browser straight to the Mailhub web app you already use — the familiar login screen, then the consent screen. You never type either host; they matter only if a firewall or proxy has to allow them, and Mailhub gives you both if it does.

There is no client secret. The connection uses OAuth 2.1 with PKCE, which is what Claude expects from a public client — Authentication has the full contract.

Environments do not share anything: accounts, carriers, and wallet funds are separate, and mailhub_buy_label spends real money only in Production.

The steps

1. Open your connector settings in Claude and add a custom connector.
2. Give it a name and the MCP server URL. The name is yours to choose.
3. Connect. Claude opens your normal Mailhub sign-in in the browser — the same one you use for the application, with your 2FA if you have it. There is no MCP password and no API key to enter.
4. Approve the consent screen. It names the client and the access it asks for. Denying it grants nothing and changes nothing.
5. Check that the tools are there. Claude should now list the eight Mailhub tools. Ask it to list your Orders — a read is the cheapest proof that both gates are open.

Other Claude surfaces use the same URL and the same browser sign-in; only where you paste it differs.

If it connected but nothing works

That is the expected shape of a missing gate, not a broken connection:

• Every tool is refused → Agent Access is probably off for the account. It is an account-level switch, and enabling it needs permission to manage the account's integrations. See Authentication.
• Only some calls are refused → check the connecting user's Orders permissions. Getting Rates needs update access, not view.
• You keep being asked to sign in again → that symptom has three different causes; Errors & Troubleshooting separates them.

Next

Read Authentication to understand what you approved and how long it lasts, then Confirmations & Spend Safety before you let an assistant change anything.