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

# Midcall AI Tool

> Build tools your assistant can trigger during live calls to fetch, create, or update data via API integrations.

With a **midcall tool**, your assistant can trigger automations **during an active call** - for example checking customer records, matching phone numbers, or retrieving appointment availability.

<div style={{ position: "relative", paddingBottom: "56.25%", height: 0 }}>
  <iframe style={{ position: "absolute", top: 0, left: 0, width: "100%", height: "100%", border: 0 }} src="https://www.tella.tv/video/vid_cmn385rzm00p807mg1ict5c8p/embed?b=0&title=0&a=1&loop=0&t=0&muted=0&wt=0&o=1" allowFullScreen allowTransparency />
</div>

## 1. Where to find midcall tools

Use the dedicated **Tools during the call** section (below knowledge bases). There you can create your first tool, e.g. "Check appointment availability".

## 2. Description quality drives trigger quality

The **tool description** acts like a mini-prompt for the model and strongly affects **when** the tool is called.

* State the trigger condition clearly.
* Explain expected behavior and output.
* Practical tip: many teams write descriptions in **English** for more consistent model behavior.

## 3. Choose the right HTTP method

* **GET**: fetch data (e.g. available slots)
* **POST**: create data (e.g. new customer)
* **PUT**: replace/update a full record
* **PATCH**: update specific fields only
* **DELETE**: remove data

## 4. Headers and parameters

Most integrations use JSON, so `Content-Type: application/json` is commonly correct.

For **tool parameters**:

* use parameter names exactly as required by your target API
* choose the correct type (`text`, `number`, `true/false`)
* add precise descriptions so the assistant fills values reliably during calls

## 5. Endpoint via webhook + `/sync`

If your direct API requires additional auth handling (for example Bearer token flows), it is often better to route through an **automation webhook**.

Important: append **`/sync`** to the webhook endpoint used by the midcall tool.

Example:

`https://automation.famulor.com/webhook/abc123/sync`

Without `sync`, requests may be sent but the assistant may not reliably receive a synchronous response payload.

## 6. Assign the tool to your assistant

In **Prompt & Tools**, scroll to **Tools during the call** and select your created tool.

Optional best practice: add a short system-prompt rule that explicitly states when the assistant should use the tool.

<Tip>
  Test each midcall tool with realistic call scenarios. If triggering is inconsistent, refine the tool description first.

  Deep dives: [Custom mid-call tools](/en/ai-assistants/custom-mid-call-tools), [Webhook API](/en/automation/webhook-api), and [API integration examples](/en/developers/api-integration-examples).
</Tip>

<Tip>
  Need a whole toolset instead of building HTTP actions one by one? Connect an external **MCP server** — tools are discovered automatically. See [MCP Servers](/en/platform/mcp-servers).
</Tip>