> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.hollr.ai/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.hollr.ai/_mcp/server.

# Make a call

The Calls API is the main reason to integrate with HollrAI programmatically.

Build and deploy your agent in [app.hollr.ai](https://app.hollr.ai), then use your backend to trigger a call whenever something happens in your product: a new lead arrives, an order needs confirmation, a candidate needs screening, a customer needs a follow-up, or any other workflow that benefits from a single phone conversation.

Use `/v1/call/make-call` to trigger one outbound call.

```bash
curl -X POST https://api.hollr.ai/v1/call/make-call \
  -H "hollr-api-key: $HOLLR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "campaign_id": "CAMPAIGN_ID",
    "to": "+15551234567",
    "metadata": {
      "orderId": "ORD-4821",
      "customerId": "CUST-1042"
    }
  }'
```

`campaign_id` and `to` are required. `metadata` is optional and accepts arbitrary JSON values you want associated with the call request.

## When to use this vs. a batch

* **Single event-driven call:** use `make-call`.
* **Multiple contacts, one request, optionally scheduled for later:** use [batches](/calls/batches).
* **Repeated or recurring workflows:** keep the business logic in your application and trigger the appropriate endpoint when the call should happen.

HollrAI handles the voice conversation itself. Your application decides **when** to call and **who** to call.

## Response

`make-call` currently passes through the response returned by HollrAI's underlying call server, so the API reference intentionally exposes the response as an open object rather than pretending it has a fixed schema.

## Limits

`make-call` is subject to the standard 60 requests/minute limit per API key, plus a 5 concurrent-call limit per API key.

See [errors and rate limits](/errors-and-rate-limits) for the full details.

## After triggering a call

A completed call can be read through the [Conversations API](/conversations). Use the conversation record when your application needs the transcript, summary, sentiment, recording information, call identifiers, or other call data.