> For the complete documentation index, see [llms.txt](https://docs.idlayr.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.idlayr.com/products/number-verification/reverse-sms/endpoints.md).

# Endpoints

{% hint style="info" %}
**Backend API** · Early Access
{% endhint %}

Summary of the Reverse SMS endpoints. Full request and response schemas live in the API Reference.

| Method | Path                                                    | Purpose                                          |
| ------ | ------------------------------------------------------- | ------------------------------------------------ |
| `POST` | `/v1/number-verification/reverse-sms-checks`            | Create a check                                   |
| `GET`  | `/v1/number-verification/reverse-sms-checks/{check_id}` | Get a check (used for polling)                   |
| `GET`  | `/v1/number-verification/reverse-sms-checks`            | List checks (paginated; supports RSQL filtering) |

Unlike Secure SNA, **there is no PATCH endpoint** — the device sending the SMS is itself the completion trigger. The check resolves on the IDlayr side when the carrier delivers the verification SMS, and the result reaches your backend via callback or polling.

## Common requirements

All endpoints require:

* HTTPS.
* An OAuth2 Bearer token with the `reverse_sms` scope on the `Authorization` header.
* The `{data_residency}` host prefix matching your workspace region (`eu.api.idlayr.com` or `us.api.idlayr.com`). See [Data residency](/get-started/concepts/data-residency.md).

## Common response headers

* `X-RateLimit-Limit`, `X-RateLimit-Remaining`, `X-RateLimit-Reset` — see Rate limits in the API Reference.
* On `429`, a `Retry-After` header indicates seconds before retrying.

## Common error responses

`400` invalid phone number, `400` country not supported, `401` unauthorized, `404` check not found, `429` rate limit reached. See [Error codes](/products/number-verification/reverse-sms/error-codes.md) for the full taxonomy.

## See also

* The [Integration page](/products/number-verification/reverse-sms/integration.md) walks through creating a check with cURL.
* The full API Reference will carry the complete request/response schemas for each endpoint (linked from here once published).


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.idlayr.com/products/number-verification/reverse-sms/endpoints.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.