Live Data (MCP)

Live data lets your agent look something up while it's on a call: open appointment times in your calendar, a row in a spreadsheet, or the status of an order. You connect an MCP server, tick the tools the agent may use, and publish. When a caller asks something the agent needs to check, it calls one of those tools and answers from the result.

MCP (Model Context Protocol) is the standard way AI assistants use outside tools. There are two ways to get one:

• The easiest: Zapier. It connects Google Calendar, Google Sheets, Google Drive and thousands of other apps in a few minutes, with no code.
• Your own MCP server. If you already have one, or a developer who can build one, connect it directly. n8n and many software vendors offer MCP servers too.

Live data is set up on the Connections tab, in the Live data (MCP) card.

Before you connect

Your agent answers anyone who calls your number, and it can't check who they are. Anything a tool can return, any caller can ask for. Before you tick a tool, make sure you'd be happy for a stranger to hear everything it returns.

• Return only what callers may hear. For appointments, a tool that returns open times is safe; one that returns your bookings with patient names is not. A Google Drive search will read out the names of any matching files, private ones included.
• Ask for something only the caller knows. For order status, a tool that needs an order number and the email or ZIP code on the order is far safer than one that takes an order number alone. Your server must check that second detail; the agent can't.
• Look things up; don't change them. Use tools that read (search, find, look up). Tools that create, update or delete things can be triggered by any caller.
• Keep it fast. The caller waits while the tool runs. Aim for an answer within about 3 seconds; the agent tells the caller it's checking, but long silences feel broken.

The agent is told to share only what the caller needs and never to read out other people's details, but that's a backstop, not a guarantee. The tool you connect is what protects your data.

Add a connection

1. Open your agent and go to the Connections tab.
2. In Live data (MCP), click Add a connection.
3. Fill in:
   • Name: anything that helps you recognise it, up to 60 characters (for example Bookings).
   • Server URL: the server's address. It must start with https://.
   • Access token (optional): the server's token or API key, if it has one. It's sent to the server as Authorization: Bearer <token>.
4. Click Connect. FlyNumber checks the server and lists its tools. If it can't reach the server, check the URL and token and try again.

The URL and token are stored encrypted and are never shown again. Connections belong to your account, so all your agents can use them. An account can have up to 5 connections.

Choose what the agent can use

1. Under Live data for this agent, pick the connection. (Each agent uses one connection, or Don't use live data.)

2. Under Tools the agent can use, tick the tools this agent may call. Nothing is ticked to start with, and an agent can use up to 10 tools. Each tool is labelled:

   • Read-only: the server says the tool only looks things up.
   • May change data: the server doesn't say it's read-only. It might create, change or delete things, so tick it only if you're sure what it does.

   Select read-only tools ticks every read-only tool at once (up to 10).

3. Save, then publish. Callers get live data once the new version is live.

It helps to add a rule that says when to look things up, for example "When a caller asks for an appointment, check the open times before offering one."

Connect with Zapier (easiest)

Zapier MCP turns Zapier actions into tools. It's the quickest way to connect apps such as Google Calendar, Google Sheets, Calendly or Shopify.

1. Create an MCP server at mcp.zapier.com.
2. Switch the server to managed mode, where you pick its tools yourself. In Zapier's default mode the AI can find and turn on more actions by itself, which you don't want for a phone line anyone can call. (Zapier's guide to tool modes)
3. Add only lookup actions. For a dentist's calendar, Google Calendar's Find Busy Periods in Calendar returns busy times without the names of the people booked. For a list of open slots, use a Google Sheets row lookup on a sheet that holds only the slots.
4. Generate a connection token. Zapier shows it once, so copy it straight away. (Zapier's guide to connections)
5. In FlyNumber, add a connection with Server URL https://mcp.zapier.com/api/v1/connect and the token as the Access token.

Each tool call counts toward your Zapier plan's task allowance.

Connect with n8n

In n8n, build a workflow that starts with the MCP Server Trigger node and add the tools it should offer. (n8n's MCP Server Trigger docs)

1. In the trigger, set Authentication to Bearer Auth and create a token.
2. Publish (activate) the workflow, then copy the trigger's Production URL. The test URL only works while you're testing in the editor.
3. In FlyNumber, add a connection with that URL and the token.

Use your own server

Any MCP server reachable over the internet works if it:

• speaks MCP over Streamable HTTP (MCP spec version 2026-07-28 or 2025-11-25),
• uses https:// with a valid certificate,
• accepts Authorization: Bearer <token> if it needs authentication, and
• answers within a few seconds.

Give each tool a clear name and description. The agent decides when to use a tool from those alone. Mark lookup tools with the readOnlyHint annotation so they show as Read-only.

Change or remove a connection

• Tools changed on the server? Click Refresh tools on the connection, then review the agent's ticks, save and publish. A tool the server no longer offers is flagged so you can untick it.
• New URL or token? Add a new connection, switch the agent to it, save and publish, then remove the old one.
• Remove a connection with the bin icon. You can't remove a connection while an agent's current, latest or pending version still uses it: choose Don't use live data for that agent, save and publish first.

Troubleshooting

What you see	What to check
"We couldn't reach that server or it refused the token."	The URL is the server's full https:// address (for n8n, the Production URL of a published workflow); the token is current (regenerating it in Zapier invalidates the old one).
"That server doesn't offer any tools yet."	Add tools on the server (in Zapier, add actions), then try again.
"Some selected lookups are no longer offered by that connection."	Click Refresh tools, untick anything flagged, then save.
The agent says it can't check right now	The server was slow, offline or returned an error. Test the tool in Zapier, n8n or your own system. If the server fails during a call, the agent stops using live data for the rest of that call and still answers from what it knows.
The agent answers without looking anything up	Add a rule that says when to check, and make sure the tool's description says what it's for.

Privacy

To use a tool, the agent sends the details it needs (for example a date or an order number) to your MCP server through our AI provider. Your server, and the service behind it (Zapier, n8n, your own system), handles that data under its own terms. FlyNumber stores which tools were used on each call (shown as Tools used in the call details), but not what was sent or returned. Anything the agent says aloud is part of the call's transcript.