> ## Documentation Index
> Fetch the complete documentation index at: https://docs.assist.fm/llms.txt
> Use this file to discover all available pages before exploring further.

# Connections overview

> Give your agent the ability to use external tools and APIs during calls.

## What are connections?

Connections (also called tools) are external services your agent can invoke during a phone call. When a caller asks a question that requires live data — like looking up an address, checking availability, or creating a booking — the agent calls the connected tool and uses the result in its response.

## How tools work

1. You configure a tool with its API endpoint and parameters.
2. You link the tool to your agent.
3. During a call, the AI model decides when to invoke the tool based on the conversation context.
4. The tool is called, and the result is fed back into the conversation.

```mermaid theme={null}
sequenceDiagram
    Caller->>Agent: "What's the address of your Amsterdam office?"
    Agent->>Google Maps: lookup("Amsterdam office")
    Google Maps-->>Agent: "Keizersgracht 123, Amsterdam"
    Agent->>Caller: "Our Amsterdam office is at Keizersgracht 123."
```

## Available tools

> [card] [Google Maps](https://docs.assist.fm/connections/google-maps)
>
> Look up addresses, get directions, and find nearby locations.

> [card] [Custom API tools](https://docs.assist.fm/connections/custom-tools)
>
> Connect any REST API endpoint as a tool your agent can use.

## Linking tools to an agent

1. Go to your agent's settings.
2. Open the **Tools** tab.
3. Browse available tools or create a custom tool.
4. Click **Add** to link a tool to the agent.
5. Configure any required settings (API keys, endpoints).

> [!NOTE]
>
> Tools are invoked automatically by the AI model when relevant. You can control this behavior with the **tool choice** setting — see [AI models](https://docs.assist.fm/agents/models).

## Tool execution

When a tool is invoked during a call:

* The agent pauses briefly while the tool executes.
* The tool's response is returned to the agent as context.
* The agent incorporates the result into its spoken response.
* Tool calls are logged in the call transcript.

> [!WARNING]
>
> Tools that take longer than 10 seconds to respond may cause noticeable pauses in the conversation. Keep your API endpoints fast.


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