openapi: 3.0.1
info:
  title: HTML/CSS to Image Image Generation Signed URLs API
  description: REST API for rendering HTML, CSS, and JavaScript (or a URL) into high quality images (PNG, JPG, WebP, PDF). Supports single and batch image creation, image retrieval with resize/crop options, reusable templates with variable substitution, and HMAC-signed URLs for GET-based templated image generation. Authentication is HTTP Basic using your User ID as the username and your API Key as the password.
  termsOfService: https://htmlcsstoimage.com/terms
  contact:
    name: HTML/CSS to Image Support
    email: support@htmlcsstoimage.com
    url: https://htmlcsstoimage.com
  version: '1.0'
servers:
- url: https://hcti.io/v1
security:
- basicAuth: []
tags:
- name: Signed URLs
paths:
  /image/{template_id}/{signed_token}{format}:
    get:
      operationId: getSignedTemplatedImage
      tags:
      - Signed URLs
      summary: Generate a templated image from an HMAC-signed URL.
      description: Render an image from a template using a signed token that encodes the template_values. The token is HMAC-signed with the API key so values cannot be modified by anyone without the key, allowing image generation from a simple GET request with no POST or stored URL.
      security: []
      parameters:
      - name: template_id
        in: path
        required: true
        schema:
          type: string
      - name: signed_token
        in: path
        required: true
        schema:
          type: string
        description: HMAC-signed token encoding the template_values.
      - name: format
        in: path
        required: true
        schema:
          type: string
          enum:
          - .png
          - .jpg
          - .webp
          - .pdf
        description: Output format extension.
      responses:
        '200':
          description: The rendered image binary.
          content:
            image/png:
              schema:
                type: string
                format: binary
            image/jpeg:
              schema:
                type: string
                format: binary
            image/webp:
              schema:
                type: string
                format: binary
            application/pdf:
              schema:
                type: string
                format: binary
        '403':
          description: Invalid signature.
components:
  securitySchemes:
    basicAuth:
      type: http
      scheme: basic
      description: HTTP Basic authentication using your User ID as the username and your API Key as the password, both from the HTML/CSS to Image dashboard.