openapi: 3.0.3
info:
  title: Castor EDC / CDMS Audit Trail Data Export 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: Data Export
  description: Bulk export of study data, structure, and option groups.
paths:
  /study/{study_id}/export/data:
    get:
      operationId: exportStudyData
      tags:
      - Data Export
      summary: Export study data
      description: Exports the collected data of a study (CSV).
      x-endpoint-status: confirmed
      parameters:
      - $ref: '#/components/parameters/StudyId'
      responses:
        '200':
          description: The exported study data.
          content:
            text/csv:
              schema:
                type: string
  /study/{study_id}/export/structure:
    get:
      operationId: exportStudyStructure
      tags:
      - Data Export
      summary: Export study structure
      description: Exports the structure (forms, fields, phases) of a study.
      x-endpoint-status: confirmed
      parameters:
      - $ref: '#/components/parameters/StudyId'
      responses:
        '200':
          description: The exported study structure.
          content:
            text/csv:
              schema:
                type: string
  /study/{study_id}/export/optiongroups:
    get:
      operationId: exportOptionGroups
      tags:
      - Data Export
      summary: Export option groups
      description: Exports the option groups (answer choices) of a study.
      x-endpoint-status: confirmed
      parameters:
      - $ref: '#/components/parameters/StudyId'
      responses:
        '200':
          description: The exported option groups.
          content:
            text/csv:
              schema:
                type: string
components:
  parameters:
    StudyId:
      name: study_id
      in: path
      required: true
      description: The study GUID (uppercase, 8-4-4-4-12 format).
      schema:
        type: string
  securitySchemes:
    oauth2ClientCredentials:
      type: oauth2
      flows:
        clientCredentials:
          tokenUrl: https://data.castoredc.com/api/oauth/token
          scopes: {}