> ## Documentation Index > Fetch the complete documentation index at: https://docs.periskope.app/llms.txt > Use this file to discover all available pages before exploring further. # Check Contact Exists > Checks whether each given number is registered on WhatsApp, live through the phone in the x-phone header (must be connected). ## OpenAPI ````yaml api-reference/openapi-generated.json POST /v1/contacts/check openapi: 3.0.3 info: title: Periskope API version: 1.0.0 description: >- Periskope external API. Responses use a flat, unwrapped shape: most endpoints return the resource at the top level, and list endpoints return a wrapper object with pagination inline (e.g. `{ from, to, count, chats: [...] }`). The documented response schemas describe these shapes directly. servers: - url: https://api.periskope.app security: - bearerAuth: [] paths: /v1/contacts/check: post: tags: - Contacts summary: Check if contacts exist on WhatsApp description: >- Checks whether each given number is registered on WhatsApp, live through the phone in the x-phone header (must be connected). operationId: checkContacts parameters: - schema: type: string example: '919876543210' description: >- Optional. Phone to act with: country code + number without symbols or spaces (e.g. 911111111111), or a phone_id (phone-xxxxxxxxxxxx). Omit to let the API select an eligible phone automatically — within the token's phone scopes and connected; chat actions use a phone that has the chat (a group admin where required), message actions use the phone the message belongs to. required: false description: >- Optional. Phone to act with: country code + number without symbols or spaces (e.g. 911111111111), or a phone_id (phone-xxxxxxxxxxxx). Omit to let the API select an eligible phone automatically — within the token's phone scopes and connected; chat actions use a phone that has the chat (a group admin where required), message actions use the phone the message belongs to. name: x-phone in: header requestBody: content: application/json: schema: type: object properties: contact_ids: type: array items: type: string minLength: 1 minItems: 1 description: >- Phone numbers to check: country code + number without symbols or spaces (e.g. 911111111111). The @c.us suffix is accepted and ignored for matching. example: - '911111111111' - '911111111111' required: - contact_ids responses: '200': description: Existence result for each requested contact_id content: application/json: schema: type: array items: $ref: '#/components/schemas/ContactCheckResult' description: >- One entry per requested contact_id, in the same order as the request examples: default: summary: Response body value: - contact_id: '911111111111' exists: true '400': description: The phone server is disconnected or not reachable content: application/json: examples: error: summary: The phone server is disconnected or not reachable value: code: ERROR message: The phone server is disconnected or not reachable status: 400 schema: type: object properties: code: type: string example: ERROR message: type: string example: The phone server is disconnected or not reachable status: type: integer example: 400 example: code: ERROR message: The phone server is disconnected or not reachable status: 400 '401': description: Invalid, expired or missing API token content: application/json: examples: error: summary: Invalid, expired or missing API token value: code: UNAUTHORIZED_ERROR message: Invalid bearer auth token status: 401 schema: type: object properties: code: type: string example: UNAUTHORIZED_ERROR message: type: string example: Invalid bearer auth token status: type: integer example: 401 example: code: UNAUTHORIZED_ERROR message: Invalid bearer auth token status: 401 '422': description: Request validation failed content: application/json: examples: error: summary: Request validation failed value: code: VALIDATION_ERROR message: Request validation failed status: 422 fields: body.chat_id: message: chat_id is required schema: type: object properties: code: type: string example: VALIDATION_ERROR message: type: string example: Request validation failed status: type: integer example: 422 fields: type: object additionalProperties: type: object properties: message: type: string value: {} example: body.chat_id: message: chat_id is required example: code: VALIDATION_ERROR message: Request validation failed status: 422 fields: body.chat_id: message: chat_id is required '429': description: Rate limit exceeded content: application/json: examples: error: summary: Rate limit exceeded value: code: RATE_LIMIT_ERROR message: You can only make 100 requests per second status: 429 schema: type: object properties: code: type: string example: RATE_LIMIT_ERROR message: type: string example: You can only make 100 requests per second status: type: integer example: 429 example: code: RATE_LIMIT_ERROR message: You can only make 100 requests per second status: 429 '500': description: Internal server error content: application/json: examples: error: summary: Internal server error value: code: UNKNOWN_ERROR message: Internal server error status: 500 schema: type: object properties: code: type: string example: UNKNOWN_ERROR message: type: string example: Internal server error status: type: integer example: 500 example: code: UNKNOWN_ERROR message: Internal server error status: 500 security: - bearerAuth: [] x-codeSamples: - lang: typescript label: TypeScript source: |- import { PeriskopeApi } from '@periskope/periskope-client'; const client = new PeriskopeApi({ authToken: 'YOUR_API_KEY', phone: '919876543210', // the phone to act with (x-phone) }); async function main() { const response = await client.contacts.checkContacts({ contact_ids: [ '911111111111', '911111111111', ], }); console.log(response); } main(); - lang: bash label: cURL source: |- curl -X POST 'https://api.periskope.app/v1/contacts/check' \ -H 'Authorization: Bearer YOUR_API_KEY' \ -H 'x-phone: 919876543210' \ -H 'Content-Type: application/json' \ -d '{ "contact_ids": [ "911111111111", "911111111111" ] }' components: schemas: ContactCheckResult: type: object properties: contact_id: type: string description: The contact_id exactly as sent in the request example: '911111111111' exists: type: boolean description: Whether the number is registered on WhatsApp example: true description: >- Existence check outcome for one contact_id from a POST /contacts/check request securitySchemes: bearerAuth: type: http scheme: bearer description: >- Your Periskope API token, sent as `Authorization: Bearer `. Generate one from the Periskope dashboard under **Settings → API & Webhooks**. API access requires an active Pro or Enterprise plan. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.