Process Street Attachments API

openapi: 3.2.0
info:
  title: Process Street Public Attachments API
  version: '1.1'
  description: The Process Street API is organized around REST.
servers:
- url: https://public-api.process.st/api/v1.1
tags:
- name: Attachments
  description: 'An attachment is a file uploaded to a task within a workflow run.

    Use these endpoints to list, upload, and delete task-level attachments.'
  externalDocs:
    url: https://www.process.st/help/docs/api-attachments/
    description: Process Street help article
paths:
  /attachments:
    get:
      tags:
      - Attachments
      summary: List attachments
      description: Returns task-level attachments, ordered by creation date (newest first). Supports filtering by workflow, workflow run, task, or creator.
      operationId: listAttachments
      parameters:
      - name: workflowId
        in: query
        description: Filter by workflow.
        required: false
        schema:
          type: string
      - name: workflowRunId
        in: query
        description: Filter by workflow run.
        required: false
        schema:
          type: string
      - name: taskId
        in: query
        description: Filter by task.
        required: false
        schema:
          type: string
      - name: createdById
        in: query
        description: Filter by creator.
        required: false
        schema:
          type: string
      - name: _
        in: query
        description: 'Opaque pagination cursor. Take this value from the previous response''s `links[]` entry whose `name`

          is `"next"` (typically just follow that link''s `href` instead of reading this value).

          Omit on the first page. If the previous response had no `next` link, there are no more pages.'
        required: false
        schema:
          type: string
      responses:
        '200':
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PublicApiAttachmentListResponse'
        default:
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorInfo'
      security:
      - apiKeyAuth: []
      - httpAuth: []
    post:
      tags:
      - Attachments
      summary: Upload an attachment
      description: 'Uploads a file as a task-level attachment.


        Requires `workflowRunId` and `taskId` to identify the target task.

        Accepts multipart form data (fields `workflowRunId` + `taskId` + `file`) or JSON with base64-encoded content

        (fields `workflowRunId` + `taskId` + `fileBase64`). Maximum file size: 20 MB for multipart, 10 MB for base64.

        You can also send `workflowRunId` + `taskId` + `fileUploadId` to attach a file you uploaded with

        `createFileUpload`; the `fileUploadId` is single-use.'
      operationId: uploadAttachment
      requestBody:
        content:
          multipart/form-data:
            schema:
              $ref: '#/components/schemas/UploadAttachmentRequest'
          application/json:
            schema:
              $ref: '#/components/schemas/UploadAttachmentRequest'
        required: true
      responses:
        '201':
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PublicApiAttachmentResponse'
        '400':
          description: Invalid value
          content:
            text/plain:
              schema:
                type: string
        default:
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorInfo'
      security:
      - apiKeyAuth: []
      - httpAuth: []
  /attachments/{attachmentId}:
    delete:
      tags:
      - Attachments
      summary: Delete an attachment
      description: Deletes a task-level attachment.
      operationId: deleteAttachment
      parameters:
      - name: attachmentId
        in: path
        description: The attachment ID.
        required: true
        schema:
          type: string
      responses:
        '204':
          description: ''
        default:
          description: ''
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorInfo'
      security:
      - apiKeyAuth: []
      - httpAuth: []
components:
  schemas:
    PublicApiAttachmentResponse:
      title: PublicApiAttachmentResponse
      type: object
      required:
      - data
      properties:
        data:
          title: PublicApiAttachment
          type: object
          required:
          - id
          - createdDate
          - createdBy
          - taskId
          - workflowRunId
          - workflowId
          - fileName
          - mimeType
          - size
          properties:
            id:
              title: EntityID
              description: The resource's ID.
              type: string
            createdDate:
              description: When the resource was first created. ISO-8601 UTC.
              type: string
              format: date-time
            createdBy:
              description: User who created the resource.
              examples:
              - id: iAaSNCU5lWLYGAi663hO8Q
                email: jane.doe@example.com
                username: Jane Doe
              type: object
              required:
              - id
              - email
              - username
              properties:
                id:
                  title: EntityID
                  description: The resource's ID.
                  type: string
                email:
                  description: The user's email address (also their login identifier).
                  type: string
                username:
                  description: The user's display name (e.g. `Jane Doe`).
                  type: string
            taskId:
              description: The ID of the Task
              examples:
              - mUb8c-br8usZZ0_5NQBDIQ
              type: string
            workflowRunId:
              description: The ID of the Workflow Run
              examples:
              - mUb8c-br8usZZ0_5NQBDIQ
              type: string
            workflowId:
              description: The ID of the Workflow
              examples:
              - mUb8c-br8usZZ0_5NQBDIQ
              type: string
            fileName:
              description: Original filename as uploaded.
              type: string
            mimeType:
              description: MIME type detected at upload time (e.g. `image/png`, `application/pdf`).
              type: string
            size:
              description: File size in bytes.
              type: integer
              format: int64
            links:
              description: Navigable HATEOAS links to related resources. Each entry has a `name` (RFC-5988 link relation like `self`, `edit`, `related`), an `href` URL, and a `type` (`Api` for callable endpoints, `App` for browser-facing URLs). Prefer following these `href` values over constructing URLs by hand.
              type: array
              items:
                title: Link
                description: A HATEOAS link to a related resource. Use these to navigate between resources without constructing URLs by hand.
                type: object
                required:
                - name
                - href
                - type
                properties:
                  name:
                    description: Standard link relation name (RFC 5988) indicating this link's role. Common values include `self`, `edit`, `related`, `previous`, `next`.
                    type: string
                  href:
                    title: Uri
                    description: URL of the linked resource.
                    examples:
                    - https://api.process.st/api/v1.1/resource/XXX
                    type: string
                  rel:
                    description: Optional. The kind of resource this link points to (e.g. `Workflow`, `Task`, `Comment`).
                    type: string
                    enum:
                    - Approval Task
                    - Approvals
                    - Assignees
                    - Comment
                    - Data Set Records
                    - Data Sets
                    - Form Field Values
                    - Subject Task
                    - Task
                    - Tasks
                    - Users
                    - Webhook
                    - Workflow
                    - Workflow Run
                  type:
                    description: Whether this link targets an API endpoint or a Process Street app URL. `Api` — a callable API endpoint you can fetch directly. `App` — a browser-facing URL in the Process Street UI.
                    type: string
                    enum:
                    - Api
                    - App
        links:
          description: 'Pagination links. When the result has more pages, look for an entry with `name: "next"` — its `href` is the URL to fetch the next page. Absence of `next` means there are no more pages. For single-resource responses this array is typically empty.'
          type: array
          items:
            title: Link
            description: A HATEOAS link to a related resource. Use these to navigate between resources without constructing URLs by hand.
            type: object
            required:
            - name
            - href
            - type
            properties:
              name:
                description: Standard link relation name (RFC 5988) indicating this link's role. Common values include `self`, `edit`, `related`, `previous`, `next`.
                type: string
              href:
                title: Uri
                description: URL of the linked resource.
                examples:
                - https://api.process.st/api/v1.1/resource/XXX
                type: string
              rel:
                description: Optional. The kind of resource this link points to (e.g. `Workflow`, `Task`, `Comment`).
                type: string
                enum:
                - Approval Task
                - Approvals
                - Assignees
                - Comment
                - Data Set Records
                - Data Sets
                - Form Field Values
                - Subject Task
                - Task
                - Tasks
                - Users
                - Webhook
                - Workflow
                - Workflow Run
              type:
                description: Whether this link targets an API endpoint or a Process Street app URL. `Api` — a callable API endpoint you can fetch directly. `App` — a browser-facing URL in the Process Street UI.
                type: string
                enum:
                - Api
                - App
    PublicApiAttachmentListResponse:
      title: PublicApiAttachmentListResponse
      type: object
      properties:
        data:
          description: The list of resources returned by this request.
          type: array
          items:
            title: PublicApiAttachment
            type: object
            required:
            - id
            - createdDate
            - createdBy
            - taskId
            - workflowRunId
            - workflowId
            - fileName
            - mimeType
            - size
            properties:
              id:
                title: EntityID
                description: The resource's ID.
                type: string
              createdDate:
                description: When the resource was first created. ISO-8601 UTC.
                type: string
                format: date-time
              createdBy:
                description: User who created the resource.
                examples:
                - id: iAaSNCU5lWLYGAi663hO8Q
                  email: jane.doe@example.com
                  username: Jane Doe
                type: object
                required:
                - id
                - email
                - username
                properties:
                  id:
                    title: EntityID
                    description: The resource's ID.
                    type: string
                  email:
                    description: The user's email address (also their login identifier).
                    type: string
                  username:
                    description: The user's display name (e.g. `Jane Doe`).
                    type: string
              taskId:
                description: The ID of the Task
                examples:
                - mUb8c-br8usZZ0_5NQBDIQ
                type: string
              workflowRunId:
                description: The ID of the Workflow Run
                examples:
                - mUb8c-br8usZZ0_5NQBDIQ
                type: string
              workflowId:
                description: The ID of the Workflow
                examples:
                - mUb8c-br8usZZ0_5NQBDIQ
                type: string
              fileName:
                description: Original filename as uploaded.
                type: string
              mimeType:
                description: MIME type detected at upload time (e.g. `image/png`, `application/pdf`).
                type: string
              size:
                description: File size in bytes.
                type: integer
                format: int64
              links:
                description: Navigable HATEOAS links to related resources. Each entry has a `name` (RFC-5988 link relation like `self`, `edit`, `related`), an `href` URL, and a `type` (`Api` for callable endpoints, `App` for browser-facing URLs). Prefer following these `href` values over constructing URLs by hand.
                type: array
                items:
                  title: Link
                  description: A HATEOAS link to a related resource. Use these to navigate between resources without constructing URLs by hand.
                  type: object
                  required:
                  - name
                  - href
                  - type
                  properties:
                    name:
                      description: Standard link relation name (RFC 5988) indicating this link's role. Common values include `self`, `edit`, `related`, `previous`, `next`.
                      type: string
                    href:
                      title: Uri
                      description: URL of the linked resource.
                      examples:
                      - https://api.process.st/api/v1.1/resource/XXX
                      type: string
                    rel:
                      description: Optional. The kind of resource this link points to (e.g. `Workflow`, `Task`, `Comment`).
                      type: string
                      enum:
                      - Approval Task
                      - Approvals
                      - Assignees
                      - Comment
                      - Data Set Records
                      - Data Sets
                      - Form Field Values
                      - Subject Task
                      - Task
                      - Tasks
                      - Users
                      - Webhook
                      - Workflow
                      - Workflow Run
                    type:
                      description: Whether this link targets an API endpoint or a Process Street app URL. `Api` — a callable API endpoint you can fetch directly. `App` — a browser-facing URL in the Process Street UI.
                      type: string
                      enum:
                      - Api
                      - App
        links:
          description: 'Pagination links. When the result has more pages, look for an entry with `name: "next"` — its `href` is the URL to fetch the next page. Absence of `next` means there are no more pages. For single-resource responses this array is typically empty.'
          type: array
          items:
            title: Link
            description: A HATEOAS link to a related resource. Use these to navigate between resources without constructing URLs by hand.
            type: object
            required:
            - name
            - href
            - type
            properties:
              name:
                description: Standard link relation name (RFC 5988) indicating this link's role. Common values include `self`, `edit`, `related`, `previous`, `next`.
                type: string
              href:
                title: Uri
                description: URL of the linked resource.
                examples:
                - https://api.process.st/api/v1.1/resource/XXX
                type: string
              rel:
                description: Optional. The kind of resource this link points to (e.g. `Workflow`, `Task`, `Comment`).
                type: string
                enum:
                - Approval Task
                - Approvals
                - Assignees
                - Comment
                - Data Set Records
                - Data Sets
                - Form Field Values
                - Subject Task
                - Task
                - Tasks
                - Users
                - Webhook
                - Workflow
                - Workflow Run
              type:
                description: Whether this link targets an API endpoint or a Process Street app URL. `Api` — a callable API endpoint you can fetch directly. `App` — a browser-facing URL in the Process Street UI.
                type: string
                enum:
                - Api
                - App
    UploadAttachmentRequest:
      title: UploadAttachmentRequest
      type: object
      required:
      - workflowRunId
      - taskId
      properties:
        workflowRunId:
          title: EntityID
          description: The ID of the Workflow Run.
          type: string
        taskId:
          title: EntityID
          description: The ID of the Task.
          type: string
        file:
          description: Uploaded file reference. Use the upload endpoint to attach content.
          type: string
          format: binary
        fileBase64:
          title: FileBase64
          type: object
          required:
          - content
          - filename
          properties:
            content:
              description: Rich text content. May contain merge tags.
              type: string
            filename:
              type: string
        fileUploadId:
          type: string
    ErrorInfo:
      title: ErrorInfo
      type: object
      required:
      - error
      properties:
        error:
          description: 'Human-readable error message. Suitable for logs or for surfacing to end users; do not parse it

            programmatically — use `errorCode` for that.'
          type: string
        details:
          description: 'Optional structured context. Shape depends on the error: for `Validation` errors the keys are field

            paths; for `PaymentRequired` the keys describe the limit that was hit.'
          type: object
          additionalProperties:
            type: string
        errorCode:
          title: ErrorCode
          description: 'Machine-parsable classification of the error. Always set on responses generated by the global

            exception handler. Branch your own error handling on this (not the message text).'
          type: string
          enum:
          - BadRequest
          - Unauthorized
          - PaymentRequired
          - Forbidden
          - NotFound
          - MethodNotAllowed
          - Conflict
          - PayloadTooLarge
          - Validation
          - RateLimited
          - InternalError
        requestId:
          description: Per-request correlation ID. Include this when contacting support so we can find the request in our logs.
          type: string
  securitySchemes:
    apiKeyAuth:
      type: apiKey
      name: X-API-Key
      in: header
    httpAuth:
      type: http
      description: Bearer token (beta)
      scheme: bearer
x-tagGroups:
- name: Workflows
  tags:
  - Workflows
  - Workflow Revisions
  - Form Fields
  - Workflow Logic Rules
  - Workflow Tasks
  - Workflow Task Assignment Rules
  - Workflow Widgets
  - Workflow Due Date Rules
  - Workflow Task Due Date Rules
  - Workflow Incoming Webhooks
  - Scheduled Workflows
- name: Workflow Runs
  tags:
  - Workflow Runs
  - Tasks
  - Form Field Values
  - Comments
  - Attachments
- name: Pages
  tags:
  - Pages
  - Page Revisions
  - Page Widgets
- name: Data Sets
  tags:
  - Data Sets
  - Data Set Incoming Webhooks
- name: Other
  tags:
  - Folders
  - One-Off Tasks
  - Users
  - Webhooks
  - File Uploads
  - Utilities
  - My Work
x-provenance:
  method: harvested
  publisher: Process Street
  source: https://public-api.process.st/api/v1.1/docs/openapi.json
  note: split by refine-openapis from the provider's own published document, verified by fetch (openapi/_original/*.fetch.json);
    stamped by stamp-openapi-provenance.py (roadmap#793)