openapi: 3.1.0
info:
title: Process Street Public Attachments One-Off Tasks 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: One-Off Tasks
description: 'A one-off task is a standalone task that can optionally be linked to a
workflow run. Use these endpoints to create, view, and manage one-off tasks.'
externalDocs:
url: https://www.process.st/help/docs/one-off-tasks/
description: Process Street help article
paths:
/work/tasks:
post:
tags:
- One-Off Tasks
summary: Create a one-off task
description: Creates a new one-off task, optionally linked to a workflow run.
operationId: createOneOffTask
requestBody:
content:
application/json:
schema:
$ref: '#/components/schemas/CreateOneOffTaskRequest'
examples:
Create a one-off task:
summary: Creates a task with two subtasks assigned to a user
value:
name: Review contract
description: Check the terms and conditions
dueDate: '2026-04-01T09:00:00.000Z'
required: false
assigneeEmails:
- jane@example.com
subtasks:
- name: Check terms
- name: Verify dates
required: true
responses:
'201':
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/PublicApiOneOffTaskResponse'
'400':
description: 'Invalid value for: body'
content:
text/plain:
schema:
type: string
default:
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorInfo'
security:
- apiKeyAuth: []
- httpAuth: []
/work/tasks/{taskId}:
get:
tags:
- One-Off Tasks
summary: Get a one-off task
description: Returns a one-off task by its ID, including assignments and subtasks.
operationId: getOneOffTask
parameters:
- name: taskId
in: path
description: The ID of the One-Off Task
required: true
schema:
type: string
responses:
'200':
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/PublicApiOneOffTaskResponse'
default:
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorInfo'
security:
- apiKeyAuth: []
- httpAuth: []
put:
tags:
- One-Off Tasks
summary: Update a one-off task
description: 'Updates a one-off task. PUT semantics: all fields must be provided. Returns the updated task.'
operationId: updateOneOffTask
parameters:
- name: taskId
in: path
description: The ID of the One-Off Task
required: true
schema:
type: string
requestBody:
content:
application/json:
schema:
$ref: '#/components/schemas/UpdateOneOffTaskRequest'
examples:
Update a one-off task:
summary: Update task details, reassign, and modify subtasks
value:
name: Review contract
description: Check the terms and conditions
dueDate: '2026-04-02T09:00:00.000Z'
required: true
assigneeEmails:
- jane@example.com
- john@example.com
subtasks:
- id: kPcr3wSdMURUe6zuyZxOlA
name: Check terms
status: Completed
- name: Contact lawyer
status: NotCompleted
required: true
responses:
'200':
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/PublicApiOneOffTaskResponse'
'400':
description: 'Invalid value for: body'
content:
text/plain:
schema:
type: string
default:
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorInfo'
security:
- apiKeyAuth: []
- httpAuth: []
delete:
tags:
- One-Off Tasks
summary: Delete a one-off task
description: Deletes a one-off task permanently.
operationId: deleteOneOffTask
parameters:
- name: taskId
in: path
description: The ID of the One-Off Task
required: true
schema:
type: string
responses:
'204':
description: ''
default:
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorInfo'
security:
- apiKeyAuth: []
- httpAuth: []
/work/tasks/{taskId}/complete:
post:
tags:
- One-Off Tasks
summary: Complete a one-off task
description: Sets the task status to Completed. No-op if already completed. Returns the updated task.
operationId: completeOneOffTask
parameters:
- name: taskId
in: path
description: The ID of the One-Off Task
required: true
schema:
type: string
responses:
'200':
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/PublicApiOneOffTaskResponse'
default:
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorInfo'
security:
- apiKeyAuth: []
- httpAuth: []
/work/tasks/{taskId}/uncomplete:
post:
tags:
- One-Off Tasks
summary: Uncomplete a one-off task
description: Sets the task status to NotCompleted. No-op if already not completed. Returns the updated task.
operationId: uncompleteOneOffTask
parameters:
- name: taskId
in: path
description: The ID of the One-Off Task
required: true
schema:
type: string
responses:
'200':
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/PublicApiOneOffTaskResponse'
default:
description: ''
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorInfo'
security:
- apiKeyAuth: []
- httpAuth: []
components:
schemas:
UpdateOneOffTaskRequest:
title: UpdateOneOffTaskRequest
type: object
required:
- name
- required
properties:
name:
description: Display name.
type: string
minLength: 1
description:
description: Optional long-form description.
type: string
dueDate:
description: Due date. ISO-8601 UTC.
type: string
format: date-time
required:
description: When `true`, the form field must have a value before its task can be completed.
type: boolean
linkedWorkflowRunId:
title: EntityID
type: string
assigneeEmails:
type: array
minItems: 1
items:
type: string
subtasks:
type: array
items:
title: UpdateSubtaskRequest
type: object
required:
- name
- status
properties:
id:
title: EntityID
description: The resource's ID.
type: string
name:
description: Display name.
type: string
minLength: 1
status:
title: Status
description: 'Whether this subtask has been checked off.
- `Completed` — the subtask is checked.
- `NotCompleted` — the subtask is unchecked.
'
type: string
enum:
- Completed
- NotCompleted
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
PublicApiOneOffTaskResponse:
title: PublicApiOneOffTaskResponse
type: object
required:
- data
properties:
data:
title: PublicApiOneOffTask
description: The resource returned by this request.
type: object
required:
- id
- createdDate
- createdBy
- updatedDate
- updatedBy
- organizationId
- name
- status
- required
- visibility
properties:
id:
description: The ID of the One-Off Task
examples:
- quuif1gveYFEcueHcehDig
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
updatedDate:
description: When the resource was last modified. ISO-8601 UTC.
type: string
format: date-time
updatedBy:
description: User who last modified 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
organizationId:
title: EntityID
description: The ID of the organization this resource belongs to.
type: string
name:
description: Display name of the one-off task.
type: string
description:
description: Optional long-form description of the one-off task.
type: string
status:
title: Status
type: string
enum:
- NotCompleted
- Completed
dueDate:
description: Optional due date. ISO-8601 UTC.
type: string
format: date-time
required:
description: When `true`, the task must be completed before the linked workflow run can be completed.
type: boolean
visibility:
title: Visibility
description: Who can see this one-off task. `Private` — only the creator and assignees. `Public` — visible to anyone in the organization.
type: string
enum:
- Private
- Public
assignments:
type: array
items:
title: PublicApiOneOffTaskAssignment
type: object
required:
- id
- user
properties:
id:
title: EntityID
description: The resource's ID.
type: string
user:
description: User this entry refers to.
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
linkedWorkflowRun:
title: PublicApiLinkedWorkflowRun
type: object
required:
- id
- name
- templateId
- templateName
properties:
id:
description: The ID of the Workflow Run
examples:
- oQsycxGFswNfZYdiCp5F9g
type: string
name:
description: Display name.
type: string
templateId:
description: The ID of the Workflow
examples:
- oQsycxGFswNfZYdiCp5F9g
type: string
templateName:
type: string
subtasks:
type: array
items:
title: PublicApiSubtask
type: object
required:
- id
- name
- status
properties:
id:
title: EntityID
description: The resource's ID.
type: string
name:
description: Display name.
type: string
status:
description: Whether this subtask is complete. `Completed` — the subtask has been checked off. `NotCompleted` — the subtask has not yet been checked off.
type: string
enum:
- Completed
- NotCompleted
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
CreateOneOffTaskRequest:
title: CreateOneOffTaskRequest
type: object
required:
- name
- required
properties:
name:
description: Display name.
type: string
minLength: 1
description:
description: Optional long-form description.
type: string
dueDate:
description: Due date. ISO-8601 UTC.
type: string
format: date-time
required:
description: When `true`, the form field must have a value before its task can be completed.
type: boolean
linkedWorkflowRunId:
title: EntityID
type: string
assigneeEmails:
type: array
minItems: 1
items:
type: string
subtasks:
type: array
items:
title: CreateSubtaskRequest
type: object
required:
- name
properties:
name:
description: Display name.
type: string
minLength: 1
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