Use MCP servers

An MCP server gives you another app’s tools. In NappAI you use it with the MCP Connection component: you pick one of the server’s tools and give it to an agent, or run it as one more step of the flow.

1. Choose the server

There are two ways:

• From the MCPs category of the palette. Press + on the canvas and open MCPs. You will find more than a hundred ready servers, sorted by topic: CRM and sales, productivity, payments, documentation, web search, databases… Each one appears with its name followed by Mcp, for example Notion Mcp or Find-A-Domain Mcp. Drag it onto the canvas: it already carries the server address and how to access it.
• With the address of any server. If the server you want is not on the list, use the MCP Connection component with an MCP Remote server credential where you write its address.

You can also find it by name in Search component.

2. Create its credential

Every server needs a credential, even an open one. In the component panel, press Add new credential or choose one you already have. Depending on the server, the credential asks you for:

Access	What you do
Open	Just give it a name and press Add.
With a key	Paste the key the app gives you.
With sign-in	Press the button to sign in to your account with the service and authorize access. NappAI keeps the permission and renews it for you.

If a server accepts several ways in, the credential lets you choose. If you create an MCP Remote server credential with the address of a server that has an integration in the palette, NappAI tells you and offers to use the integration, which is simpler.

More about credentials in Credentials.

3. Give it to an agent

1. Connect the component’s Tool output to the agent’s Tools input.
2. In Tool, choose the server tool you want. When you do, its data appears under Tool Arguments.
3. For each piece of data, press the Defined by AI button so the agent fills it in each time, or write a fixed value.
4. Explain in the agent’s instructions when it should use it.

For an agent to use several tools from the same server, add one component per tool.

Connect before choosing the tool

Connect the Tool output to the agent first and choose the tool afterwards: that way the Defined by AI buttons appear on each piece of data.

Also as a step of the flow

Without connecting it to an agent, the tool runs like any other step: you fill in its data under Tool Arguments, by hand or with values from earlier steps, and its result comes out of Data.

A Python Code component can also call an MCP tool, for example to check a whole list of items at once.

Good practices

• Try it in the playground first: under Executions you see each call to the server, with what was sent and what came back.
• If the Tool list is empty, check the credential: NappAI could not connect to the server.
• In each flow, use the credential for the right account with the service, for example the test one while you build it.