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Custom Toolcalls let the AI agent on a phone number act in your own systems while it is on the call: look up where an order is, place a purchase, change a delivery address, update an account, or kick off a Zapier automation. Each toolcall is added to the agent’s instructions and tool list as soon as you save it. Find it at Configure → Answer, open a phone number, then the Custom Toolcalls tab.

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Add a toolcall

Click Add toolcall and start from a template or from scratch: Then fill in three parts:
1

What it does

A name and a description of what it does and when to use it, for example “Look up the status of an order. Use when the caller asks where their order is.” The agent decides when to call it from this description. Tick Confirm with the caller before running for anything that changes data or spends money.
2

Your backend

Pick REST API, Webhook or GraphQL and enter the endpoint. Reference inputs in the URL, headers or body as {{order_number}}. Put credentials in a header, never in the URL. Webhooks are signed with a secret you can rotate, sent as X-LumisReach-Signature-256, so your server can verify the request came from LumisReach.
3

Inputs the agent collects

The details the agent asks the caller for, each with a type, a description and, if you like, a list of allowed values (for example small, medium, large).
A connection test must pass before the toolcall can be saved.

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Call details you can use

These are filled in automatically at call time and never asked of the caller: Requests also carry an X-LumisReach-Call-Id header, and X-LumisReach-Test: true when they come from a test.

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Limits

  • Up to 20 toolcalls per phone number, and up to 20 inputs per toolcall.
  • Your endpoint has up to 20 seconds to respond.
  • Toolcalls work on both voice stacks.

Custom prompts

Tell the agent how to use the results.

Test your agent

Run a test call before you go live.