HeyForm Images API

openapi: 3.0.3
info:
  title: HeyForm Auth Images API
  description: HeyForm is an open-source conversational form builder providing REST and GraphQL endpoints for managing forms, submissions, workspaces, integrations, and webhooks. The primary data API uses GraphQL; this document covers the publicly accessible REST endpoints discovered in the open-source codebase.
  version: 1.0.0
  contact:
    name: HeyForm Support
    url: https://docs.heyform.net
  license:
    name: AGPL-3.0
    url: https://github.com/heyform/heyform/blob/main/LICENSE
servers:
- url: https://api.heyform.net
  description: HeyForm Cloud API
- url: http://localhost:8000
  description: Self-hosted HeyForm instance (default port)
tags:
- name: Images
  description: Image proxy and resizing
paths:
  /api/image:
    get:
      operationId: proxyImage
      summary: Proxy and resize an image
      description: Fetches a remote image from an allowed host, optionally resizes it, and returns the result with long-lived cache headers. Useful for embedding external images in forms without leaking user IP addresses.
      tags:
      - Images
      parameters:
      - name: url
        in: query
        required: true
        description: The URL of the remote image to proxy.
        schema:
          type: string
          format: uri
        example: https://images.unsplash.com/photo-abc123
      - name: w
        in: query
        required: false
        description: Target width in pixels.
        schema:
          type: integer
          minimum: 1
        example: 800
      - name: h
        in: query
        required: false
        description: Target height in pixels.
        schema:
          type: integer
          minimum: 1
        example: 600
      responses:
        '200':
          description: Image content
          content:
            image/*:
              schema:
                type: string
                format: binary
          headers:
            Cache-Control:
              schema:
                type: string
              example: public, max-age=315360000, must-revalidate
        '204':
          description: Empty response when the image cannot be fetched or is invalid.
        '400':
          $ref: '#/components/responses/BadRequest'
components:
  responses:
    BadRequest:
      description: Bad request — invalid input or business logic violation
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            statusCode: 400
            message: The form does not exist
            error: Bad Request
  schemas:
    Error:
      type: object
      properties:
        statusCode:
          type: integer
        message:
          type: string
        error:
          type: string
  securitySchemes:
    cookieAuth:
      type: apiKey
      in: cookie
      name: heyform_sid
      description: Session cookie set by the login mutation or OAuth callback. All authenticated GraphQL mutations and the CSV export endpoint require this cookie.
externalDocs:
  description: HeyForm Documentation
  url: https://docs.heyform.net