> ## 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.

# Post a research study answer

> Post one answer for an active research study. Same payload as the MCP `post_research_answer` tool, except the study is identified by UUID in the path (MCP uses a 0-based `study_index` in the `studies` array returned by `get_active_studies`). One answer per user per study.



## OpenAPI

````yaml /api-reference/openapi.json post /v1/project/{project_id}/research/studies/{study_id}/answers/
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/{study_id}/answers/:
    post:
      tags:
        - Research
      summary: Post a research study answer
      description: >-
        Post one answer for an active research study. Same payload as the MCP
        `post_research_answer` tool, except the study is identified by UUID in
        the path (MCP uses a 0-based `study_index` in the `studies` array
        returned by `get_active_studies`). One answer per user per study.
      operationId: createResearchStudyAnswer
      parameters:
        - name: project_id
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: Project UUID
        - name: study_id
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: >-
            Research study UUID (from the Correl8 app when the study was
            created)
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ResearchAnswerCreate'
            example:
              user_id: user-42
              interaction_id: conv_9f3a2b1c
              answer: >-
                The user said they could not find the invite button and expected
                it on the team settings page.
      responses:
        '201':
          description: Answer created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ResearchAnswer'
        '400':
          description: >-
            Validation error (missing fields, inactive study, user not in
            sample, etc.)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Missing or invalid API key
        '404':
          description: Project or study not found, or key not authorized for this project
        '409':
          description: User already answered this study
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    ResearchAnswerCreate:
      type: object
      required:
        - user_id
        - interaction_id
        - answer
      properties:
        user_id:
          type: string
          maxLength: 512
          description: Your identifier for the end user
        interaction_id:
          type: string
          maxLength: 512
          description: Your identifier for the conversation thread
        answer:
          type: string
          description: >-
            Informative summary of what you learned (plain prose; include quotes
            and context when helpful)
    ResearchAnswer:
      type: object
      properties:
        id:
          type: string
          format: uuid
          description: Created answer UUID
        posted_at:
          type: string
          format: date-time
    Error:
      type: object
      properties:
        detail: {}
  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`.

````