> ## Documentation Index
> Fetch the complete documentation index at: https://docs.correl8.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Get active studies

> Same JSON as the MCP tool `get_active_studies`. Returns active research studies sampled in for a user (sampling, duration, and answer caps checked server-side), each with its question, eligibility criteria, and any answer already logged for that user. Eligibility criteria are not checked server-side — the caller must evaluate them.



## OpenAPI

````yaml /api-reference/openapi.json get /v1/project/{project_id}/research/studies/
openapi: 3.1.0
info:
  title: Correl8 API
  description: >-
    Public REST API for Correl8 custom integrations — observations, guidelines,
    and research answers. MCP integration is documented separately.
  version: 1.0.0
servers:
  - url: https://api.correl8.ai
    description: Production
security:
  - ApiKeyAuth: []
paths:
  /v1/project/{project_id}/research/studies/:
    get:
      tags:
        - Research
      summary: Get active studies
      description: >-
        Same JSON as the MCP tool `get_active_studies`. Returns active research
        studies sampled in for a user (sampling, duration, and answer caps
        checked server-side), each with its question, eligibility criteria, and
        any answer already logged for that user. Eligibility criteria are not
        checked server-side — the caller must evaluate them.
      operationId: getActiveStudies
      parameters:
        - name: project_id
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: Project UUID
        - name: user_id
          in: query
          required: true
          schema:
            type: string
          description: End-user identifier
      responses:
        '200':
          description: Active studies payload
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ResearchStudiesPayload'
              example:
                user_id: user-42
                studies:
                  - question: What do users struggle with?
                    eligibility_criteria: All users
                    answer: null
        '400':
          description: Missing user_id query parameter
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Missing or invalid API key
        '404':
          description: Project not found or key not authorized for this project
components:
  schemas:
    ResearchStudiesPayload:
      type: object
      required:
        - user_id
        - studies
      properties:
        user_id:
          type: string
          description: Same value as the `user_id` query parameter
        studies:
          type: array
          description: >-
            Active studies sampled in for this user (empty when none).
            Eligibility is not checked server-side.
          items:
            $ref: '#/components/schemas/ResearchStudyEntry'
    Error:
      type: object
      properties:
        detail: {}
    ResearchStudyEntry:
      type: object
      required:
        - question
        - eligibility_criteria
        - answer
      properties:
        question:
          type: string
          description: What the study wants to learn
        eligibility_criteria:
          type: string
          description: >-
            When the agent should pursue this study. Not checked server-side —
            the caller must evaluate it.
        answer:
          type: string
          nullable: true
          description: The answer already logged for this user, or null if none yet
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: Authorization
      description: >-
        Project API key prefixed with `ApiKey`, e.g. `Authorization: ApiKey
        c8.xxx`. Alternatively use header `X-Api-Key: c8.xxx`.

````