> ## Documentation Index > Fetch the complete documentation index at: https://docs.fingerprint.com/llms.txt > Use this file to discover all available pages before exploring further. # Get related visitors > > 🚧 Deprecation Notice > > This version of the API will **soon be deprecated** under our [API Deprecation Policy](https://dev.fingerprint.com/reference/api-deprecation-policy). The deprecation period will begin once all proxy and library integrations (both backend and frontend) are released. We will continue to provide full support for 12 months from that effective date. This notice will be updated with the **official deprecation date once it is set**. The API will be fully removed after the deprecation period ends. Related visitors API lets you link web visits and in-app browser visits that originated from the same mobile device. It searches the past 6 months of identification events to find the visitor IDs that belong to the same mobile device as the given visitor ID. ⚠️ Please note that this API is not enabled by default and is billable separately. ⚠️ If you would like to use Related visitors API, please contact our [support team](https://fingerprint.com/support). To learn more, see [Related visitors API reference](https://dev.fingerprint.com/reference/related-visitors-api). ## OpenAPI ````yaml reference/fingerprint-pro-server-api.json GET /related-visitors openapi: 3.0.3 info: title: Server API v3 (deprecated) description: > > 🚧 Deprecation Notice > > This version of the API will **soon be deprecated** under our [API Deprecation Policy](https://dev.fingerprint.com/reference/api-deprecation-policy). The deprecation period will begin once all proxy and library integrations (both backend and frontend) are released. We will continue to provide full support for 12 months from that effective date. This notice will be updated with the **official deprecation date once it is set**. If you don’t use libraries or proxy integrations, you can use this [migration guide](https://dev.fingerprint.com/reference/migrating-from-server-api-v3-to-v4) to **start the transition to the new API today**. Fingerprint Server API allows you to search, update, and delete identification events in a server environment. It can be used for data exports, decision-making, and data analysis scenarios. Server API is intended for server-side usage, it's not intended to be used from the client side, whether it's a browser or a mobile device. version: '3' contact: name: Fingerprint Support email: support@fingerprint.com license: name: MIT url: >- https://github.com/fingerprintjs/fingerprint-pro-server-api-openapi/blob/main/LICENSE servers: - url: https://api.fpjs.io description: Global - url: https://eu.api.fpjs.io description: EU - url: https://ap.api.fpjs.io description: Asia (Mumbai) security: - ApiKeyHeader: [] - ApiKeyQuery: [] tags: - name: Events description: > Retrieve or update information about individual events using the event's request ID. - name: Event Search description: | Search for events matching one or more filters. - name: Visitors description: | Retrieve all events of an individual visitor using their visitor ID. - name: Related Visitors description: > Find visitor IDs that originated from a different browser on the same mobile device. paths: /related-visitors: get: tags: - Related Visitors summary: Get Related Visitors description: > > 🚧 Deprecation Notice > > This version of the API will **soon be deprecated** under our [API Deprecation Policy](https://dev.fingerprint.com/reference/api-deprecation-policy). The deprecation period will begin once all proxy and library integrations (both backend and frontend) are released. We will continue to provide full support for 12 months from that effective date. This notice will be updated with the **official deprecation date once it is set**. The API will be fully removed after the deprecation period ends. Related visitors API lets you link web visits and in-app browser visits that originated from the same mobile device. It searches the past 6 months of identification events to find the visitor IDs that belong to the same mobile device as the given visitor ID. ⚠️ Please note that this API is not enabled by default and is billable separately. ⚠️ If you would like to use Related visitors API, please contact our [support team](https://fingerprint.com/support). To learn more, see [Related visitors API reference](https://dev.fingerprint.com/reference/related-visitors-api). operationId: getRelatedVisitors parameters: - name: visitor_id in: query required: true schema: type: string description: >- The [visitor ID](https://dev.fingerprint.com/reference/get-function#visitorid) for which you want to find the other visitor IDs that originated from the same mobile device. responses: '200': description: OK. content: application/json: schema: $ref: '#/components/schemas/RelatedVisitorsResponse' examples: 200-success-empty-response: summary: Success, empty response value: relatedVisitors: [] 200-success-response: summary: Success response value: relatedVisitors: - visitorId: NtCUJGceWX9RpvSbhvOm - visitorId: 25ee02iZwGxeyT0jMNkZ '400': description: >- Bad request. The visitor ID parameter is missing or in the wrong format. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: 400-visitor-id-required: summary: >- Error response when the request does not include a visitor ID. value: error: code: RequestCannotBeParsed message: visitor id is required 400-visitor-id-invalid: summary: Error response when the visitor ID is incorrectly formatted. value: error: code: RequestCannotBeParsed message: invalid visitor id '403': description: Forbidden. Access to this API is denied. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: 403-token-required: summary: Error response when the secret API key was not provided. value: error: code: TokenRequired message: secret key is required 403-token-not-found: summary: >- Error response when the provided secret API key does not exist. value: error: code: TokenNotFound message: secret key is not found 403-wrong-region: summary: >- Error response when the API region is different from the region, the calling application is configured with. value: error: code: WrongRegion message: wrong region 403-subscription-not-active: summary: Error response when the subscription is not active. value: error: code: SubscriptionNotActive message: forbidden 403-feature-not-enabled: summary: >- Error response when this feature is not enabled for a subscription. value: error: code: FeatureNotEnabled message: feature not enabled '404': description: >- Not found. The visitor ID cannot be found in this application's data. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: 404-visitor-not-found: summary: >- Error response when the visitor ID cannot be found in this application's data. value: error: code: VisitorNotFound message: visitor not found '429': description: Too Many Requests. The request is throttled. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: 429-too-many-requests: summary: >- Error response when the limit on the provided secret API key requests per second has been exceeded. value: error: code: TooManyRequests message: too many requests components: schemas: RelatedVisitorsResponse: type: object additionalProperties: false required: - relatedVisitors properties: relatedVisitors: type: array items: $ref: '#/components/schemas/RelatedVisitor' ErrorResponse: type: object additionalProperties: false required: - error properties: error: $ref: '#/components/schemas/Error' RelatedVisitor: type: object additionalProperties: false required: - visitorId properties: visitorId: type: string description: >- Visitor ID of a browser that originates from the same mobile device as the input visitor ID. Error: type: object additionalProperties: false required: - code - message properties: code: $ref: '#/components/schemas/ErrorCode' message: type: string ErrorCode: type: string enum: - RequestCannotBeParsed - TokenRequired - TokenNotFound - SubscriptionNotActive - WrongRegion - FeatureNotEnabled - WorkspaceScopedSecretKeyRequired - RequestNotFound - VisitorNotFound - TooManyRequests - 429 Too Many Requests - StateNotReady - Failed description: | Error code: * `RequestCannotBeParsed` - the query parameters or JSON payload contains some errors that prevented us from parsing it (wrong type/surpassed limits). * `TokenRequired` - `Auth-API-Key` header is missing or empty. * `TokenNotFound` - no Fingerprint application found for specified secret key. * `SubscriptionNotActive` - Fingerprint application is not active. * `WrongRegion` - server and application region differ. * `FeatureNotEnabled` - this feature (for example, Delete API) is not enabled for your application. * `WorkspaceScopedSecretKeyRequired` - The provided secret API key is scoped to an environment, but this operation requires a workspace-scoped secret API key. * `RequestNotFound` - the specified request ID was not found. It never existed, expired, or it has been deleted. * `VisitorNotFound` - The specified visitor ID was not found. It never existed or it may have already been deleted. * `TooManyRequests` - the limit on secret API key requests per second has been exceeded. * `429 Too Many Requests` - the limit on secret API key requests per second has been exceeded. * `StateNotReady` - The event specified with request id is not ready for updates yet. Try again. This error happens in rare cases when update API is called immediately after receiving the request id on the client. In case you need to send information right away, we recommend using the JS agent API instead. * `Failed` - internal server error. securitySchemes: ApiKeyHeader: type: apiKey in: header name: Auth-API-Key ApiKeyQuery: type: apiKey in: query name: api_key ````