---
title: "Check whether a number is on WhatsApp"
method: GET
path: "/v1/numbers/check"
tags: ["Messages"]
---

# Check whether a number is on WhatsApp

`GET /v1/numbers/check`

## Request

- Base URL: `https://www.chatrail.dev`
- URL: `https://www.chatrail.dev/v1/numbers/check`
- Auth: HTTP bearer

Answers `checked: false` when the engine cannot say. Treat that as "send anyway": refusing a message because a check failed turns a missing provider feature into a delivery failure. `chat_id` is WhatsApp's own id for the chat when it gives one. An answer from the last 24 hours is reused (`cached: true`) without asking WhatsApp again. Lookups that do reach WhatsApp go through your connected number and are limited to 10 a minute per workspace, and 30 a day on Sandbox.

## Query parameters

- `phone` string, required
- `connection` string, required

## Response `200`

The answer, or `checked: false`.

## Other responses

- `404`: No such connection.
- `429`: No lookup budget left; `Retry-After` says how long to wait.

---

[API](https://skmtc.dev/chatrail/apis/chatrail-api.md) · [All operations](https://skmtc.dev/chatrail/apis/chatrail-api/llms.txt) · [OpenAPI document](https://skmtc.dev/chatrail/apis/chatrail-api/revisions/acc5b88c6f59?raw)