> ## Documentation Index
> Fetch the complete documentation index at: https://developers.vizito.eu/llms.txt
> Use this file to discover all available pages before exploring further.

# Fetching a registered visitor

> One registered visitor in full, including any photo and signature stored
for prefilling their sign-in.

A record that does not exist answers `200` with
`{ "message": "No Known Visitor found!" }`, not a `404`.




## OpenAPI

````yaml https://vizito.eu/openapi.yaml get /knownvisitors/{knownvisitor_id}
openapi: 3.1.0
info:
  title: Vizito API
  version: 1.0.0
  description: |
    Read and write your Vizito visitor data over HTTPS.

    Every endpoint takes and returns JSON, and is authenticated with an API key
    created by a global admin on the Integrations page of the Backoffice.

    Almost every endpoint names a **location** — `company_id` in the API. Your
    key is pinned to a set of locations; naming one outside that set is refused
    with `403`. Start at `GET /companiesList`, the one endpoint that needs no
    location id.
  contact:
    name: Vizito support
    email: support@vizito.eu
    url: https://vizito.eu
  termsOfService: https://vizito.eu/terms
servers:
  - url: https://api.vizito.eu/api
    description: Production
security:
  - apiKey: []
tags:
  - name: Locations
    description: The locations your credential covers, and their configuration.
  - name: Visitors
    description: The visits themselves — one visitor is one visit, not a person.
  - name: Registered visitors
    description: Expected visitors — pre-register, invite, and sign in on arrival.
  - name: Hosts
    description: The people who can be visited.
  - name: Visit types
    description: The sign-in flows, and the questions they ask.
  - name: Entry points
    description: The doors and desks within a location.
  - name: Agreements
    description: The documents visitors sign, and the signed PDFs that come out.
  - name: Devices
    description: The kiosks at a location.
  - name: Reporting
    description: Counters, graphs and exports.
  - name: Webhooks
    description: The endpoint Vizito calls when something happens.
paths:
  /knownvisitors/{knownvisitor_id}:
    parameters:
      - name: knownvisitor_id
        in: path
        required: true
        description: The registered visitor id.
        schema:
          $ref: '#/components/schemas/ObjectId'
    get:
      tags:
        - Registered visitors
      summary: Fetching a registered visitor
      description: |
        One registered visitor in full, including any photo and signature stored
        for prefilling their sign-in.

        A record that does not exist answers `200` with
        `{ "message": "No Known Visitor found!" }`, not a `404`.
      operationId: getRegisteredVisitor
      responses:
        '200':
          description: The registered visitor, or a message when there is none.
          content:
            application/json:
              schema:
                oneOf:
                  - $ref: '#/components/schemas/RegisteredVisitor'
                  - $ref: '#/components/schemas/Message'
        '400':
          $ref: '#/components/responses/BadRequest'
        '403':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    ObjectId:
      type: string
      pattern: ^[0-9a-fA-F]{24}$
      description: A 24-character hexadecimal id.
      example: 5f2a1b9c4d3e2f0011223344
    RegisteredVisitor:
      type: object
      description: |
        An expected visitor. Custom fields defined by the visit type are stored
        here too, under their own `field_name`, and carried onto the visit.
      additionalProperties: true
      properties:
        _id:
          $ref: '#/components/schemas/ObjectId'
        company_id:
          type: array
          items:
            $ref: '#/components/schemas/ObjectId'
        first_name:
          type: string
        last_name:
          type: string
        company:
          type: string
        email:
          type: string
          format: email
        phone:
          type: string
        recipient:
          type: string
        visit_type:
          $ref: '#/components/schemas/ObjectId'
        visiting_on:
          $ref: '#/components/schemas/VisitingOn'
        persistent:
          type: boolean
          description: Kept after the visit; never removed by data retention.
        language:
          type: string
          description: Language of the invitation email.
        pre_registration_by_visitor:
          type: boolean
          description: The visitor filled in their own details through the invitation.
        create_date:
          type: string
          format: date-time
        mod_date:
          type: string
          format: date-time
    Message:
      type: object
      properties:
        message:
          type: string
    VisitingOn:
      type: object
      description: When a visit is expected. Absent means "any day".
      properties:
        startDate:
          type: string
          format: date-time
        endDate:
          type: string
          format: date-time
  responses:
    BadRequest:
      description: The request was understood but could not be carried out.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Message'
    Unauthorized:
      description: |
        The credential was refused, or the endpoint is off limits to API keys.
        Every refusal answers identically — see the Authentication page.
      content:
        application/json:
          schema:
            type: object
            properties:
              error:
                type: string
                example: Invalid API key
  securitySchemes:
    apiKey:
      type: http
      scheme: bearer
      description: >
        An API key issued in the Backoffice, sent as `Authorization: Bearer
        vzk_<key id>_<secret>`.

        A Microsoft Entra ID access token obtained with the client credentials

        grant is accepted on the same header. The same value is also accepted in

        an `X-API-Key` header.

````

## Related topics

- [Fetching a visitor](/api-reference/visitors/fetching-a-visitor.md)
- [Listing registered visitors](/api-reference/registered-visitors/listing-registered-visitors.md)
- [Signing in registered visitors](/api-reference/registered-visitors/signing-in-registered-visitors.md)
- [Creating a registered visitor](/api-reference/registered-visitors/creating-a-registered-visitor.md)
- [Deleting a registered visitor](/api-reference/registered-visitors/deleting-a-registered-visitor.md)