# Tool / custom-API invocations across many calls

> GET /functions. HeyRik API parameters and documented request and response examples.

Source: https://www.heyrik.com/docs/api-reference/analytics/get-functions-tool-custom-api-invocations-across-many-calls

GET https://server.heyrik.com/api/v1/functions

## Headers

Authorization: Bearer $HEYRIK_API_KEY (required). Keep your key on your server.

## Parameters

- agency_id (string, required): …or call_id. One of the two is required.
- call_id (string): Narrow to a single call.
- tool_name (string): Only this tool.
- limit (number): Default 200.

## Notes

Without agency_id or call_id this returns 400 — an unfiltered dump across every call would be unbounded.

## Request example

```sh
curl "https://server.heyrik.com/api/v1/functions?agency_id=agc_9f2a1c30&tool_name=check_order_status" \
  -H "Authorization: Bearer $HEYRIK_API_KEY"
```