thirds.ai Image API

openapi: 3.2.0
info:
  title: thirds.ai Image API
  version: 1.0.0
  description: Turn one design into content at scale. Create branded images and PDFs for your campaigns and clients. Automate each new version through our API or your AI tools. Render saved templates with new data, or send HTML directly. Every error uses one envelope, every response carries an x-request-id header, and every JSON request body rejects fields it does not expect.
servers:
- url: https://thirds.ai
tags:
- name: Image
paths:
  /v1/image:
    post:
      summary: Create a static image
      description: Render one PNG, JPEG, or WebP from raw HTML, an inline stateless template, or one owned saved-template version. Returns 200 for a terminal job or 202 while the accepted job remains queued or running. A terminal job can be succeeded, failed, or cancelled; check status before downloading. Send wait=false to skip the bounded wait. A successful render costs exactly one credit; a failed or cancelled render costs zero.
      operationId: createImage
      security:
      - bearerAuth: []
      parameters:
      - name: Idempotency-Key
        in: header
        required: false
        schema:
          type: string
          minLength: 1
          maxLength: 255
          pattern: ^[ -~]+$
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ImageRequest'
            examples:
              png:
                value:
                  html: <h1>Quarterly report</h1>
                  image:
                    format: png
                    width: 1280
                    height: 720
                    transparent: false
      responses:
        '200':
          description: The job is terminal. Check status for succeeded, failed, or cancelled; HTTP 200 does not mean the render succeeded.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ImageJob'
        '202':
          description: The image job is durable and remains queued or running.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
            Location:
              schema:
                type: string
            Retry-After:
              schema:
                type: string
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ImageJob'
        '400':
          $ref: '#/components/responses/Error'
        '401':
          $ref: '#/components/responses/Error'
        '402':
          $ref: '#/components/responses/Error'
        '403':
          $ref: '#/components/responses/AccountSuspended'
        '409':
          $ref: '#/components/responses/Error'
        '413':
          $ref: '#/components/responses/Error'
        '415':
          $ref: '#/components/responses/Error'
        '429':
          $ref: '#/components/responses/Error'
        '500':
          $ref: '#/components/responses/Error'
        '503':
          $ref: '#/components/responses/Error'
        '405':
          $ref: '#/components/responses/MethodNotAllowed'
        '431':
          $ref: '#/components/responses/RequestHeadersTooLarge'
      tags:
      - Image
    get:
      summary: List image history
      description: 'List the authenticated account''s image jobs, newest first. Failed or cancelled jobs removed through DELETE do not appear. Bounded by keyset: pass the previous page''s next_cursor to continue, rather than an offset, so a page already read stays stable while new jobs are created.'
      operationId: listImageHistory
      security:
      - bearerAuth: []
      parameters:
      - name: q
        in: query
        description: Case-insensitive search of references, template names, and file types.
        schema:
          type: string
          maxLength: 200
          pattern: ^[^\u0000-\u001f\u007f-\u009f]*$
      - name: limit
        in: query
        required: false
        description: 1 to 100. Defaults to 20. A value outside this range is clamped rather than refused.
        schema:
          type: integer
          default: 20
      - name: cursor
        in: query
        required: false
        description: An opaque value from an earlier page's next_cursor. A cursor that cannot be read is refused with 400.
        schema:
          type: string
          maxLength: 128
      responses:
        '405':
          $ref: '#/components/responses/MethodNotAllowed'
        '431':
          $ref: '#/components/responses/RequestHeadersTooLarge'
        '200':
          description: One page of the account's image history.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ImageHistoryPage'
        '400':
          description: The limit parameter was not a whole number, the cursor could not be read, or the query held an unknown parameter.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorEnvelope'
        '401':
          description: The request did not carry a valid, active API key.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
            WWW-Authenticate:
              description: Always "Bearer" on this response.
              schema:
                type: string
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorEnvelope'
        '500':
          description: An internal error occurred.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorEnvelope'
      tags:
      - Image
  /v1/image/{id}:
    parameters:
    - name: id
      in: path
      required: true
      schema:
        type: string
        pattern: ^image_[0-9a-f]{32}$
    get:
      summary: Get a static image's status
      operationId: getImage
      security:
      - bearerAuth: []
      responses:
        '200':
          description: The image job's current status.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ImageJob'
        '401':
          $ref: '#/components/responses/Error'
        '403':
          $ref: '#/components/responses/AccountSuspended'
        '404':
          $ref: '#/components/responses/Error'
        '500':
          $ref: '#/components/responses/Error'
        '405':
          $ref: '#/components/responses/MethodNotAllowed'
        '431':
          $ref: '#/components/responses/RequestHeadersTooLarge'
      tags:
      - Image
    delete:
      summary: Delete an image file or an unsuccessful render
      description: Remove a successful job's file, or remove a failed or cancelled job from history. Repeated requests are safe. The job stays readable by ID, and billing, abuse limits, and idempotency keys stay unchanged. Queued and running jobs return 409.
      operationId: deleteImage
      security:
      - bearerAuth: []
      responses:
        '200':
          description: The image job after file or history removal.
          headers:
            x-request-id:
              $ref: '#/components/headers/XRequestId'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ImageJob'
        '401':
          $ref: '#/components/responses/Error'
        '403':
          $ref: '#/components/responses/AccountSuspended'
        '404':
          $ref: '#/components/responses/Error'
        '409':
          $ref: '#/components/responses/Error'
        '500':
          $ref: '#/components/responses/Error'
        '405':
          $ref: '#/components/responses/MethodNotAllowed'
        '431':
          $ref: '#/components/responses/RequestHeadersTooLarge'
      tags:
      - Image
components:
  responses:
    MethodNotAllowed:
      description: The method is not allowed on this route.
      headers:
        x-request-id:
          $ref: '#/components/headers/XRequestId'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
    AccountSuspended:
      description: The authenticated account is suspended. The code is account_suspended.
      headers:
        x-request-id:
          $ref: '#/components/headers/XRequestId'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
    RequestHeadersTooLarge:
      description: The request has more than 64 headers or more than 32 KiB of header names and values.
      headers:
        x-request-id:
          $ref: '#/components/headers/XRequestId'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
    Error:
      description: The one error envelope every backend response uses.
      headers:
        x-request-id:
          $ref: '#/components/headers/XRequestId'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorEnvelope'
  schemas:
    ImageHistoryItem:
      type: object
      description: One job in a bounded account history — the subset of ImageJob a history page lists. Never carries a download link, since a history page can name many jobs at once.
      properties:
        reference:
          type: string
          minLength: 1
          maxLength: 200
          pattern: ^[^\u0000-\u001f\u007f-\u009f]+$
          description: Your reference, preserved in the job, history, and webhook. Omitted when not supplied.
        id:
          type: string
          pattern: ^image_[0-9a-f]{32}$
        status:
          type: string
          enum:
          - queued
          - running
          - succeeded
          - failed
          - cancelled
        created_at:
          type: string
          format: date-time
        finished_at:
          type:
          - string
          - 'null'
          format: date-time
        template:
          type:
          - object
          - 'null'
          description: The exact saved template version this job rendered. Null for raw HTML or an inline stateless template.
          properties:
            id:
              $ref: '#/components/schemas/TemplateId'
            version:
              type: integer
              minimum: 1
          required:
          - id
          - version
          additionalProperties: false
        credit:
          type: string
          enum:
          - reserved
          - settled
          - released
          - none
          description: 'What happened to the credit this job holds: "reserved" while it is queued or running, "settled" once it succeeded, "released" once it failed or was cancelled, and "none" when the job was never billed.'
        artifact:
          type:
          - object
          - 'null'
          properties:
            media_type:
              type: string
              enum:
              - image/png
              - image/jpeg
              - image/webp
            byte_size:
              type: integer
              minimum: 0
            sha256:
              type: string
              pattern: ^[0-9a-f]{64}$
            expires_at:
              type: string
              format: date-time
              description: When retention ends and the file stops being served.
            removed_reason:
              type:
              - string
              - 'null'
              enum:
              - expired
              - deleted
              - null
          required:
          - media_type
          - byte_size
          - sha256
          - expires_at
          - removed_reason
          additionalProperties: false
        error:
          type:
          - object
          - 'null'
          properties:
            category:
              type: string
              enum:
              - invalid_input
              - unsafe_asset
              - resource_limit
              - timeout
              - renderer_failure
              - internal_failure
            code:
              type: string
          required:
          - category
          - code
          additionalProperties: false
      required:
      - id
      - status
      - created_at
      - finished_at
      - template
      - credit
      - artifact
      - error
      additionalProperties: false
    ErrorEnvelope:
      type: object
      description: The one error shape every backend response uses.
      properties:
        error:
          type: object
          properties:
            code:
              type: string
              enum:
              - account_suspended
              - account_concurrency_limited
              - abuse_limited
              - ai_failure_limit_reached
              - ai_needs_paid_credits
              - already_subscribed
              - auth_unavailable
              - batch_row_limit
              - billing_unavailable
              - brand_asset_account_limit_reached
              - brand_asset_invalid
              - brand_asset_kind_invalid
              - brand_asset_kind_mismatch
              - brand_asset_limit_reached
              - brand_asset_too_large
              - brand_asset_type_unsupported
              - brand_data_conflict
              - brand_font_glyphs_exceeded
              - brand_font_tables_invalid
              - brand_image_animated
              - brand_image_dimensions_invalid
              - brand_image_pixels_exceeded
              - brand_kit_colours_invalid
              - brand_kit_conflict
              - brand_kit_limit
              - brand_kit_name_invalid
              - brand_kit_not_found
              - brand_kit_patch_empty
              - brand_kit_tone_invalid
              - brand_kit_unavailable
              - captcha_rejected
              - checkout_superseded
              - cross_origin_rejected
              - csrf_rejected
              - download_expired
              - email_already_set
              - gallery_template_not_found
              - generated_template_invalid
              - idempotency_conflict
              - image_asset_header_unsupported
              - image_asset_invalid
              - image_asset_limit
              - image_asset_not_found
              - image_asset_reference_invalid
              - image_asset_too_large
              - image_asset_type_unsupported
              - image_asset_unavailable
              - image_url_invalid
              - image_url_unavailable
              - insufficient_credits
              - internal_error
              - invalid_cursor
              - invalid_email
              - invalid_event
              - invalid_link
              - invalid_profile
              - invalid_request
              - invalid_upload
              - job_not_finished
              - key_concurrency_limited
              - key_limit_reached
              - method_not_allowed
              - no_billing_customer
              - not_found
              - operation_conflict
              - operation_limit_exceeded
              - operation_pending
              - overage_limit_reached
              - overage_unavailable
              - overloaded
              - playground_busy
              - playground_request_invalid
              - playground_selection_invalid
              - playground_session_limited
              - playground_unavailable
              - policy_version_stale
              - provider_unavailable
              - rate_limited
              - render_probe_busy
              - render_probe_failed
              - render_probe_not_configured
              - render_probe_required
              - render_probe_timeout
              - request_headers_too_large
              - request_too_large
              - resize_timeout
              - signed_out
              - spend_cap_reached
              - template_build_not_found
              - template_data_collection_limit
              - template_data_depth_limit
              - template_data_invalid
              - template_data_limit
              - template_depth_limit
              - template_draft_not_found
              - template_evaluation_error
              - template_invalid_filter_input
              - template_missing_data
              - template_output_limit
              - template_not_found
              - template_schema_complexity
              - template_schema_draft_unsupported
              - template_schema_invalid
              - template_schema_too_large
              - template_size_canvas_mismatch
              - template_size_data_overrides_too_large
              - template_size_duplicate_id
              - template_size_invalid_dimensions
              - template_size_invalid_id
              - template_size_invalid_name
              - template_sizes_too_large
              - template_sizes_too_many
              - template_source_limit
              - template_syntax_error
              - template_timeout
              - template_version_changed
              - template_work_limit
              - testimonial_busy
              - testimonial_invalid
              - testimonial_rate_limited
              - testimonial_unavailable
              - unauthorized
              - unsupported_media_type
              - webhook_limit_reached
              description: A fixed, machine-readable error code.
            message:
              type: string
              description: A fixed, human-readable message.
            request_id:
              type: string
              format: uuid
              description: The identifier this answer also carries in its x-request-id header.
            details:
              type: array
              description: Present on a validation failure. Schema failures return at most 16 entries with bounded data paths and fixed reasons. Values from the request are never repeated.
              items:
                $ref: '#/components/schemas/FieldDetail'
            retry:
              $ref: '#/components/schemas/RetryInfo'
            plan_limit:
              $ref: '#/components/schemas/PlanLimitInfo'
          required:
          - code
          - message
          - request_id
          additionalProperties: false
      required:
      - error
      additionalProperties: false
    TemplateId:
      type: string
      pattern: ^tpl_[0-9a-f]{32}$
    ImageRequestCommon:
      type: object
      properties:
        filename:
          type: string
          minLength: 1
          maxLength: 120
          pattern: ^(?!.* $)(?!.*\.\.)[A-Za-z0-9][A-Za-z0-9 ._-]*$
          description: Download name. Surrounding spaces are refused. The server uses the real output extension. Omit it for a safe template-name and UTC creation-date name, or html-render and date for HTML.
        reference:
          type: string
          minLength: 1
          maxLength: 200
          pattern: ^[^\u0000-\u001f\u007f-\u009f]+$
          description: Your reference, preserved in the job, history, and webhook. Omitted when not supplied.
        brand_kit_id:
          type:
          - string
          - 'null'
          pattern: ^kit_[a-f0-9]{32}$
          description: Select an owned active brand kit. This uses template evaluation and its 1 MiB source and data limits even when data is omitted. Overrides the source thirds-brand-kit meta default. Supplies reserved brand.name, brand.palette, brand.colours.primary/secondary/accent, brand.logo, brand.logos, and brand.fonts entries with family and src. data.brand is refused when a kit is selected. Only present palette roles and logos are supplied. Assets are captured before enqueue. Schemas validate customer data before brand is added.
        image:
          type: object
          properties:
            format:
              type: string
              enum:
              - png
              - jpeg
              - webp
            width:
              type: integer
              minimum: 320
              maximum: 7680
              default: 1280
            height:
              type: integer
              minimum: 200
              maximum: 4320
              default: 720
            quality:
              type: integer
              minimum: 1
              maximum: 100
            transparent:
              type: boolean
              default: false
          required:
          - format
          allOf:
          - if:
              properties:
                format:
                  const: png
            then:
              not:
                required:
                - quality
            else:
              properties:
                quality:
                  default: 80
          - if:
              properties:
                format:
                  const: jpeg
            then:
              properties:
                transparent:
                  const: false
          additionalProperties: false
        javascript:
          type: object
          properties:
            mode:
              type: string
              enum:
              - disabled
              - enabled
          additionalProperties: false
        wait:
          type: boolean
          default: true
      required:
      - image
    SavedTemplateImageRequest:
      allOf:
      - $ref: '#/components/schemas/ImageRequestCommon'
      - type: object
        properties:
          template_id:
            $ref: '#/components/schemas/TemplateId'
          version:
            type: integer
            minimum: 1
          data:
            type: object
          size_id:
            type:
            - string
            - 'null'
            pattern: ^[a-z0-9][a-z0-9-]{0,39}$
            description: Selects one saved size of the template instead of the original. The image width and height must match the size exactly.
        required:
        - template_id
        - data
      unevaluatedProperties: false
    ImageJob:
      type: object
      properties:
        reference:
          type: string
          minLength: 1
          maxLength: 200
          pattern: ^[^\u0000-\u001f\u007f-\u009f]+$
          description: Your reference, preserved in the job, history, and webhook. Omitted when not supplied.
        id:
          type: string
          pattern: ^image_[0-9a-f]{32}$
        status:
          type: string
          enum:
          - queued
          - running
          - succeeded
          - failed
          - cancelled
        created_at:
          type: string
          format: date-time
        finished_at:
          type:
          - string
          - 'null'
          format: date-time
        template:
          type:
          - object
          - 'null'
          description: The exact saved template version this job rendered. Null for raw HTML or an inline stateless template.
          properties:
            id:
              $ref: '#/components/schemas/TemplateId'
            version:
              type: integer
              minimum: 1
          required:
          - id
          - version
          additionalProperties: false
        credit:
          type: string
          enum:
          - reserved
          - settled
          - released
          - none
          description: 'What happened to the credit this job holds: "reserved" while it is queued or running, "settled" once it succeeded, "released" once it failed or was cancelled, and "none" when the job was never billed.'
        artifact:
          type:
          - object
          - 'null'
          properties:
            media_type:
              type: string
              enum:
              - image/png
              - image/jpeg
              - image/webp
            byte_size:
              type: integer
              minimum: 0
            sha256:
              type: string
              pattern: ^[0-9a-f]{64}$
            expires_at:
              type: string
              format: date-time
              description: When retention ends and the file stops being served.
            removed_reason:
              type:
              - string
              - 'null'
              enum:
              - expired
              - deleted
              - null
          required:
          - media_type
          - byte_size
          - sha256
          - expires_at
          - removed_reason
          additionalProperties: false
        error:
          type:
          - object
          - 'null'
          properties:
            category:
              type: string
              enum:
              - invalid_input
              - unsafe_asset
              - resource_limit
              - timeout
              - renderer_failure
              - internal_failure
            code:
              type: string
          required:
          - category
          - code
          additionalProperties: false
        download:
          type:
          - object
          - 'null'
          properties:
            url:
              type: string
            expires_at:
              type: string
              format: date-time
          required:
          - url
          - expires_at
          additionalProperties: false
      required:
      - id
      - status
      - created_at
      - finished_at
      - template
      - credit
      - artifact
      - error
      - download
      additionalProperties: false
    RetryInfo:
      type: object
      description: How long the caller must wait before it retries.
      properties:
        retry_after_seconds:
          type: integer
          minimum: 1
          maximum: 60
      required:
      - retry_after_seconds
      additionalProperties: false
    ImageRequest:
      oneOf:
      - $ref: '#/components/schemas/RawImageRequest'
      - $ref: '#/components/schemas/StatelessTemplateImageRequest'
      - $ref: '#/components/schemas/SavedTemplateImageRequest'
    FieldDetail:
      type: object
      description: One request field that failed, its fixed safe reason, and an optional bounded source location. Details never carry template source, customer values, rendered output, or raw evaluator prose.
      properties:
        field:
          type: string
          maxLength: 260
          description: The path to the field, such as "pdf.scale". Schema errors use data followed by a JSON Pointer, such as data/items/0/count. The pointer is cut at 256 UTF-8 bytes. Empty for a problem with the whole document.
        reason:
          type: string
          enum:
          - malformed JSON
          - missing field
          - unknown field
          - wrong type
          - invalid value
          - A required value is missing.
          - Use the expected value type.
          - Declare this variable before using it.
          - Choose an allowed value.
          - Use the required format.
          - Add a value.
          - Use a shorter value.
          - Use a number within the allowed range.
          - Check this value against its data rule.
          description: A fixed, safe reason. It never repeats the value the caller sent.
        line:
          type: integer
          minimum: 1
          maximum: 1000000
          description: The one-based template source line when the evaluator provides one within the published bound.
        column:
          type: integer
          minimum: 1
          maximum: 1000000
          description: The one-based template source column when the evaluator provides one within the published bound.
      required:
      - field
      - reason
      additionalProperties: false
    RawImageRequest:
      allOf:
      - $ref: '#/components/schemas/ImageRequestCommon'
      - type: object
        properties:
          html:
            type: string
            minLength: 1
            maxLength: 5242880
        required:
        - html
      unevaluatedProperties: false
    ImageHistoryPage:
      type: object
      description: One bounded page of an account's image history, newest first.
      properties:
        items:
          type: array
          maxItems: 100
          items:
            $ref: '#/components/schemas/ImageHistoryItem'
        next_cursor:
          type:
          - string
          - 'null'
          maxLength: 128
          description: Pass as the cursor query parameter to read the next page. Null on the last page.
      required:
      - items
      - next_cursor
      additionalProperties: false
    StatelessTemplateImageRequest:
      allOf:
      - $ref: '#/components/schemas/ImageRequestCommon'
      - type: object
        properties:
          html:
            type: string
            minLength: 1
            maxLength: 1048576
          data:
            type: object
        required:
        - html
        - data
      unevaluatedProperties: false
    PlanLimitInfo:
      type: object
      description: 'Present when the account''s plan causes the refusal: brand_kit_limit and batch_row_limit. It names the limit and the plan that sets it, so a caller can act without a second request. The message text never names the number.'
      properties:
        plan:
          type: string
          enum:
          - scale
          - growth
          - starter
          - pack
          - free
          description: The account's plan at the time of the refusal.
        limit:
          type: integer
          minimum: 1
          description: 'What that plan allows: brand kits for brand_kit_limit, rows in one run for batch_row_limit.'
      required:
      - plan
      - limit
      additionalProperties: false
  headers:
    XRequestId:
      description: The UUID that identifies this request and matches error.request_id on an error response.
      required: true
      schema:
        type: string
        format: uuid
  securitySchemes:
    sessionCookie:
      type: apiKey
      in: cookie
      name: __Host-thirds_session
      description: A browser session. Browser writes also require the matching x-csrf-token header from GET /v1/me.
    bearerAuth:
      type: http
      scheme: bearer
      description: 'An API key''s secret, sent as "Authorization: Bearer thirds_sk_v1_...".'
x-unmatched-v1-responses:
  description: A request below /v1 that matches no operation receives the shared safe envelope. OpenAPI has no standard path item for an unmatched route, so this extension records the fallback contract without claiming that a catch-all operation exists.
  '404':
    $ref: '#/components/responses/NotFound'
  '431':
    $ref: '#/components/responses/RequestHeadersTooLarge'