---
title: "API Call in a SIM test"
sidebarTitle: "API Call"
description: Send an HTTP request over the cellular connection and verify the response.
lastUpdated: "2026-09-23"
---

> **For AI agents:** the complete documentation index is at [llms.txt](/llms.txt). Append `.md` to any page URL for its markdown version.

Send a full HTTP request (method, headers, body) over the SIM's data connection and verify the response: status code, body content, headers, and the complete timing breakdown. Test your APIs exactly as a mobile client reaches them.

## Parameters

| Parameter | Required | Description |
| ----------- | ---------- | ------------- |
| HTTP Method | Yes | `GET` (default), `POST`, `PUT`, `PATCH`, `DELETE`, `OPTIONS`, `HEAD`. |
| URL | Yes | The endpoint to call. Supports variables. |
| Headers | No | Key/value list (Authorization, Content-Type...). |
| Body | No | Request body, for methods that send one. |
| Follow redirect | No | Follow 3xx responses. Default: on. |
| Ignore SSL certificate | No | Skip certificate verification. Default: off. |
| Enable cookies | No | Keep cookies across redirects. Default: off. |
| Web access should fail | No | Invert the verdict. |

Plus the shared [connection settings](/tests/actions/cellular/overview#connection-settings) and DNS override. The action ships with a default assertion: `status_code == 200`.

## Results and metrics

In the action report (`result`):

| Field | Description |
|-------|-------------|
| `status_code` | HTTP status of the response. |
| `body` | Response body. Assert on it or extract values into variables. |
| `header` | Response headers. |
| `dnslookup_duration`, `tcpconnection_duration`, `appconnect_duration`, `starttransfer_duration`, `contenttransfer_duration`, `total_duration` | The timing waterfall: DNS, TCP, TLS, time to first byte, transfer, total. |
| `duration` | Total execution time in seconds. |

In Analytics, each run feeds the HTTP API measurement with the full waterfall durations and `duration_seconds`, tagged by status, URL, HTTP method, status code, APN, antenna, and access technology.

## What's next?

<Columns cols={2}>
  <Card title="HTTP Ping" icon="globe" href="/tests/actions/cellular/http-ping">

    Just the latency, repeated N times

</Card>
  <Card title="Check SSL/TLS Certificate" icon="id-card" href="/tests/actions/cellular/check-certificate">

    Verify the endpoint's certificate separately

</Card>
</Columns>