openapi: 3.1.0
info:
title: Process Street Public Attachments API
version: '1.1'
description: "The Process Street API is organized around REST. Our API has predictable resource-oriented URLs,\naccepts JSON-encoded request bodies, returns JSON-encoded responses, and uses standard HTTP response\ncodes, authentication, and verbs.\n\nAn [MCP server](https://www.process.st/help/docs/mcp-server/) is also available for integrating with AI agents and tools.\n\n## Core concepts\n\n**Workflow vs Workflow Run.** A **Workflow** (sometimes called a \"playbook\" or template) is the reusable\ndefinition — tasks, form fields, logic, automations. A **Workflow Run** (sometimes called a \"checklist\")\nis one *instance* of running a Workflow. You list available templates via `listWorkflows`; you start one\nvia `createWorkflowRun` (or by scheduling); and you read or update the live state of an in-progress run\nvia the Workflow Runs / Tasks / Form Field Values endpoints. The two are easy to confuse — when in doubt,\n\"Workflow\" is the *blueprint*, \"Workflow Run\" is *one execution*.\n\n**Pages** are similar but standalone: a Page is a content document (no tasks/form fields). A\n**Page Revision** is a versioned snapshot of its content.\n\n## IDs\n\nAll resource IDs are opaque 22-character URL-safe strings (Muids — a base64-encoded UUID). Treat them\nas opaque tokens. Do not parse them, attempt to sort by them, or assume any internal structure. You can\ncompare two IDs for equality with a plain string comparison.\n\n## Dates and times\n\nAll timestamps in requests and responses are ISO-8601, UTC, with millisecond precision\n(e.g. `2024-09-15T14:32:00.000Z`). For date-only fields (typically due dates), use a calendar date\n(`2024-09-15`).\n\n## Pagination\n\nList endpoints page through results using an opaque cursor named `_` (yes, just an underscore).\nThe flow:\n\n1. Call the list endpoint without `_` to get the first page.\n2. Each response includes a `links[]` array. If there are more pages, you'll find an entry with\n `name: \"next\"` whose `href` is a fully-formed URL you can `GET` directly.\n3. Keep following `next.href` until the `next` link is absent — that's the end.\n\nYou can also reuse the `_` value from one response by passing it as the `_` query parameter on the\nnext request, but **following the `href` is simpler and forward-compatible**.\n\n## Authentication\n\nEvery request must include an API key as `X-API-KEY: <your-key>`. Generate keys from your\norganization settings in the Process Street app. Each key carries the permissions of the user that\ncreated it.\n\n## Idempotency and retries\n\n- `GET` requests are safe to retry on any error.\n- `PUT` requests are idempotent — calling them twice with the same body is equivalent to calling once.\n Safe to retry on `5xx`.\n- `DELETE` is idempotent (deleting an already-deleted resource returns `404`, which is fine to ignore).\n- `POST` is generally **not** safe to blindly retry. For workflow runs, attach a `referenceId`\n on create — calling `createWorkflowRun` twice with the same `referenceId` will return the existing\n run instead of creating a duplicate.\n\n## Errors\n\nErrors are returned as a JSON object with this shape:\n\n```json\n{\n \"error\": \"human-readable message\",\n \"errorCode\": \"NotFound\",\n \"requestId\": \"abc123…\",\n \"details\": { \"fieldPath\": \"what went wrong\" }\n}\n```\n\n**When present**, branch on `errorCode` rather than regex'ing `error` (we may rewrite the wording). Include\n`requestId` if you contact support so we can find the request in our logs.\n\n`errorCode` and `requestId` are populated on responses generated by the public API exception handler, which\ncovers the great majority of errors. A few low-level failures (e.g. JSON parse failures caught before the\nhandler runs, framework-level routing errors) may return an `ErrorInfo` without these fields. In that case,\nfall back to the HTTP status code (`400`/`401`/`403`/`404`/`409`/`422`/`429`/`5xx`) — its semantics match\nthe corresponding `errorCode` value.\n\n## Rate limits\n\nAll requests are subject to rate limits. If you receive a `429` response, wait for the duration\nspecified in the `Retry-After` header before retrying.\n"
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:
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
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
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