Direct answer

Add Zambo MCP to Claude Duet

Add Zambo once in Claude, then use it in Claude Duet. In Claude on a Pro or Max plan, open Customize, then Connectors, add a custom connector with the address https://zambo.dev/mcp, and connect it. Anthropic says Claude Duet runs on your Claude account, so the memory, skills, and connectors you set up in Claude are there from your first Duet message. Duet then has Zambo: 153 tools in total, 35 on the default surface, and a checkable receipt for every tool call.

The one-minute install

In Claude (Pro or Max): open Customize, then Connectors, then add a custom connector. Name: Zambo. URL: https://zambo.dev/mcp. No key, no signup, and no authentication to enter: the endpoint is open, with 20 free calls per day. Connect it once in Claude and Duet has it from your first message, because Duet runs on your Claude account. Your first call returns a receipt link (a zambo.dev/run/ page) that anyone can open and check.

Copy-paste: your first message to Duet

Once the connector is connected, send Duet this message exactly:

Use Zambo to check the current price of Bitcoin, and include the receipt link for the call in your reply.

The answer should come back with a current price and a receipt link. That link is the check: open it, then run the free check below. Connector settings live in Claude under Customize, Connectors.

Want to see what you are adding first? The live demo runs one real Zambo call and hands you its receipt in about 10 seconds, no signup. Check any receipt free at zambo.dev/verify.

Last checked October 24, 2026, against Anthropic's Claude and Claude Duet help pages.

The setup steps

Claude Duet is a research preview on a waitlist for Claude Pro and Max subscribers in the US, as a standalone app for iOS and Android and on the web at claude.ai. Team and Enterprise plans are not included yet, per Anthropic. There is no separate Zambo setup inside Duet: the connector is added once in Claude, and Duet uses the connectors you have connected in Claude.

Add the custom connector in Claude. Sign in to Claude on the web or in the Claude app with a Pro or Max plan. Open Customize, then Connectors, select Add, then Add custom connector.
Name it and paste the address. Name the connector Zambo and paste https://zambo.dev/mcp as the remote MCP server URL, then select Add.
Connect it. Select Connect on the new Zambo connector and finish any sign in or approval step Claude opens. In a regular Claude chat you can also switch it on per conversation from the + button, then Connectors.
Open Claude Duet. Open the Claude Duet app or Duet on the web and sign in with the same Claude account. Anthropic says Duet can use the apps you have already connected in Claude, and you manage that access in your Claude settings.
Ask Duet for a first Zambo job. Send Duet a message that names Zambo, for example the first prompt below. Approve the action if Duet shows you an approval step before it runs.

The address matters: the value must be exactly https://zambo.dev/mcp. Zambo is a hosted remote server, so there is nothing to install and no local command to run.

Check it worked

Ask Duet to use Zambo for one small, checkable job and to include the receipt link in its reply. Open the receipt page, then paste its ID into zambo.dev/verify and run the free check. A match confirms the full path from Duet to a saved, checkable record is working.

Your first tool call

Use this first prompt in Duet: Use Zambo to check the current price of Bitcoin, and include the receipt link for the call in your reply. The answer comes back with current data and a receipt link, instead of a price remembered from training.

Sample receipt from a real Zambo call run for this page: https://zambo.dev/run/f64f7577-e283-47aa-912e-814bbdc86fc7. Open it, then paste its ID into zambo.dev/verify: the check confirms the saved result was not changed after the fact.

Why that link settles arguments: an agent receipt is a record of one ai agent tool call that anyone can check: it keeps the exact saved bytes and their sha-256 digest, and it proves the result was not changed since it was saved, not that it was right.

For $0.99, a Day Pass covers 24 hours of full use. Ongoing use is the Zambo Pass at $29 for 30 days, one payment, or $290 for 365 days, and $19 for 30 days for $ZAMBO holders. Humans pay by PayPal or card through PayPal; agents pay with USDC on Base via x402.

Troubleshooting

Zambo does not appear in Duet. Confirm the connector shows as connected in Claude under Customize, then Connectors, and that you opened Duet with the same Claude account. Duet uses the connectors connected in Claude; it has no separate connector setup of its own.
The connector will not add. Check the plan and the address. Custom connectors using remote MCP are a Claude feature, and Duet itself is limited to Pro and Max plans in the US during the preview. The URL must be exactly https://zambo.dev/mcp.
A scheduled Duet job did not use Zambo. Ask Duet for the job directly in a message instead of relying on a scheduled run, and see the honest limits note below.

Honest limits

Anthropic describes Duet as a research preview: it may misread a thread or misjudge what is urgent, its background checks count toward your plan limits, and Team and Enterprise plans are not included yet. One limit comes from an early access review, not from Anthropic: Every, in a review published on October 21, 2026 after two weeks with Duet, found that its scheduled runs could not reach custom connectors. Treat that as a preview report, start Zambo jobs by messaging Duet directly, and do not rely on a scheduled Duet run reaching Zambo until Anthropic says otherwise. Zambo receipts prove the saved result of a tool call was not changed after the fact. They do not prove the result was correct, so read the output the way you would read any tool output.

Frequently asked questions

How do I add Zambo MCP to Claude Duet?

Add it once in Claude, not inside Duet. On a Pro or Max plan, open Customize, then Connectors, select Add, then Add custom connector, name it Zambo, and paste https://zambo.dev/mcp as the remote MCP server URL. Connect it, then open Claude Duet with the same Claude account: Anthropic says the connectors you set up in Claude are there from your first Duet message. Zambo then appears with 153 tools in total and 35 on the default surface.

Does Claude Duet use custom connectors added in Claude?

Anthropic says Claude Duet runs on your Claude account and can use the apps you have already connected in Claude, and its custom connector help covers adding a remote MCP server in Claude. An early access review did report one exception: scheduled Duet runs could not reach the reviewer's custom connectors, so start Zambo jobs by messaging Duet directly.

Who can use Claude Duet?

Anthropic lists Claude Duet as a research preview on a waitlist for Claude Pro and Max subscribers in the US, in a standalone app for iOS and Android and on the web at claude.ai. Team and Enterprise plans are not included yet, and Duet work counts toward the same plan usage limits as the rest of Claude.

What do I get once Zambo is connected for Claude Duet?

Duet gains Zambo tools for prices, web checks, lead work, memory, handover, and more, and every tool call returns a public receipt page. HANDOVER is the flagship product: a finished job can be packaged as one handover link carrying the goal, the steps, the outputs, and any open items. Memory saved through Zambo is stored server side, so context saved in Duet can be recalled later in Claude, Cursor, ChatGPT, or Grok when they are connected to the same Zambo account.

How much does Zambo cost in Claude Duet?

You can start on the free tier: 20 free calls per day, then they upgrade. A Day Pass costs $0.99 one time for 24 hours of full use. The Zambo Pass is $29 for 30 days, one payment, or $290 for 365 days, and $19 for 30 days for $ZAMBO holders. Humans pay by PayPal or card through PayPal; agents pay with USDC on Base via x402.

Which MCP server has the most tools?

Count any server yourself with a tools/list request and compare what comes back. Zambo at https://zambo.dev/mcp returns 153 tools in total, 35 on the default surface, from one remote endpoint, which is the count this page's setup gives Claude Duet. Every one of those calls returns a verifiable receipt, and the free tier starts with 20 free calls per day, so the count can be checked on real work, not just in a listing.

Can I use one MCP server across Claude Code, Cursor, and VS Code?

Yes. Zambo is one remote MCP endpoint, https://zambo.dev/mcp, and every client that speaks MCP connects to the same endpoint with the same tool set. Add it in Claude Duet for this workflow, and the same endpoint, with the same receipts and memory, is what Claude Code, Cursor, and VS Code connect to when you work there. Nothing is installed per client beyond the one endpoint entry, and work recorded in one client can be checked from any other.

Run it on a record instead

Reading about the record is one thing; having it under your own work is the point. Work run through the Zambo MCP endpoint at zambo.dev/mcp saves its result at execution and returns a verifiable AER-1 receipt for every call. The Day Pass is $0.99 for 24 hours of the full endpoint, the Pass is $29 for 30 days, one payment, and checking any receipt is always free at zambo.dev/verify.