openapi: 3.0.3
info:
  title: Castor EDC / CDMS Audit Trail Participants API
  description: 'The Castor EDC / CDMS API is a RESTful interface to Castor''s cloud electronic data capture (EDC) and clinical data management platform. It exposes study configuration and collected data - studies, participants (records), institutes (sites), users, fields and field metadata, study data points, repeating data (reports), surveys and survey packages, the audit trail, and batch data export. Authentication is OAuth2 with the Client Credentials flow: request an access token from POST /oauth/token using an API Client ID and Client Secret generated in Castor User Settings, then send it as a Bearer token. Access tokens are valid for 5 hours. Most identifiers (study, field, report / repeating-data instance, survey package instance) are uppercase GUIDs in 8-4-4-4-12 format; the participant ID is the exception.


    Endpoint status: paths that this document marks with `x-endpoint-status: confirmed` were observed directly in Castor''s published API reference and helpdesk documentation. Paths marked `x-endpoint-status: modeled` reflect the documented resource model and the coverage of the official R and Python wrapper packages, but the exact path or shape was inferred and should be verified against https://data.castoredc.com/api during reconciliation.'
  version: '1.0'
  contact:
    name: Castor
    url: https://www.castoredc.com
  license:
    name: Proprietary
    url: https://www.castoredc.com/legal/
servers:
- url: https://data.castoredc.com/api
  description: Castor EU (default)
- url: https://us.castoredc.com/api
  description: Castor US region
security:
- oauth2ClientCredentials: []
tags:
- name: Participants
  description: Participants (records / subjects) enrolled in a study.
paths:
  /study/{study_id}/participant:
    get:
      operationId: listParticipants
      tags:
      - Participants
      summary: List participants
      description: Lists the participants (records) enrolled in a study.
      x-endpoint-status: confirmed
      parameters:
      - $ref: '#/components/parameters/StudyId'
      - $ref: '#/components/parameters/Page'
      responses:
        '200':
          description: A paginated list of participants.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ParticipantCollection'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      operationId: createParticipant
      tags:
      - Participants
      summary: Create a participant
      description: Creates a new participant (record) in a study.
      x-endpoint-status: confirmed
      parameters:
      - $ref: '#/components/parameters/StudyId'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ParticipantInput'
      responses:
        '201':
          description: The created participant.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Participant'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /study/{study_id}/participant/{participant_id}:
    get:
      operationId: getParticipant
      tags:
      - Participants
      summary: Retrieve a participant
      description: Retrieves a single participant by ID.
      x-endpoint-status: confirmed
      parameters:
      - $ref: '#/components/parameters/StudyId'
      - $ref: '#/components/parameters/ParticipantId'
      responses:
        '200':
          description: A participant.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Participant'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  schemas:
    ParticipantInput:
      type: object
      properties:
        participant_id:
          type: string
        institute_id:
          type: string
          format: uuid
        email_address:
          type: string
    Participant:
      allOf:
      - $ref: '#/components/schemas/ParticipantInput'
      - type: object
        properties:
          status:
            type: string
          randomized_id:
            type: string
          progress:
            type: integer
          created_on:
            type: string
            format: date-time
    ParticipantCollection:
      type: object
      properties:
        _embedded:
          type: object
          properties:
            participants:
              type: array
              items:
                $ref: '#/components/schemas/Participant'
        page_count:
          type: integer
        total_items:
          type: integer
  parameters:
    Page:
      name: page
      in: query
      required: false
      description: Page number for paginated (HAL) collections.
      schema:
        type: integer
        minimum: 1
    ParticipantId:
      name: participant_id
      in: path
      required: true
      description: The participant (record) ID.
      schema:
        type: string
    StudyId:
      name: study_id
      in: path
      required: true
      description: The study GUID (uppercase, 8-4-4-4-12 format).
      schema:
        type: string
  responses:
    NotFound:
      description: The requested resource was not found.
    Unauthorized:
      description: Missing or invalid access token.
  securitySchemes:
    oauth2ClientCredentials:
      type: oauth2
      flows:
        clientCredentials:
          tokenUrl: https://data.castoredc.com/api/oauth/token
          scopes: {}