Subtasks

Pro

All subtask endpoints are provided by FluentBoards Pro.

The Subtasks API manages subtasks inside a parent task. Subtasks are regular tasks with a parent_id and no stage_id. They are organized in subtask groups, which are task-meta rows (key: "group_name") on the parent task; each subtask points to its group through meta.subtask_group_id. Plugin source: Pro.

Board members can read; members who are not "viewer only" can write.

Endpoints

Method	Endpoint	Description
GET	`/projects/{board_id}/tasks/{task_id}/subtasks`	List subtasks grouped by subtask group
POST	`/projects/{board_id}/tasks/{task_id}/subtasks`	Create a subtask
POST	`/projects/{board_id}/tasks/{task_id}/subtasks/bulk`	Create several subtasks at once
POST	`/projects/{board_id}/tasks/{task_id}/subtask-group`	Create a subtask group
PUT	`/projects/{board_id}/tasks/{task_id}/subtask-group`	Rename a subtask group
DELETE	`/projects/{board_id}/tasks/{task_id}/subtask-group`	Delete a subtask group and its subtasks
DELETE	`/projects/{board_id}/tasks/{task_id}/delete-subtask`	Delete a subtask
POST	`/projects/{board_id}/tasks/{task_id}/move-subtask`	Move subtasks to another group
PUT	`/projects/{board_id}/tasks/update-subtask-position/{subtask_id}`	Reorder a subtask
PUT	`/projects/{board_id}/tasks/{task_id}/convert-to-subtask`	Convert a task into a subtask
PUT	`/projects/{board_id}/tasks/{task_id}/move-to-board`	Convert a subtask back into a task
POST	`/projects/{board_id}/tasks/{task_id}/clone-subtask`	Clone a subtask

Other task operations (title, status, dates, assignees, …) on a subtask use the regular Update a Task Property endpoint with the subtask ID.

Subtask Object

json

{
  "id": 123,
  "parent_id": 456,
  "board_id": 3,
  "crm_contact_id": null,
  "title": "Create wireframes",
  "slug": "create-wireframes",
  "type": "task",
  "status": "closed",
  "stage_id": null,
  "source": "web",
  "source_id": null,
  "priority": "low",
  "description": "Design wireframes for the new feature",
  "created_by": 1,
  "position": "1.00",
  "comments_count": 0,
  "reminder_type": null,
  "settings": null,
  "remind_at": null,
  "started_at": null,
  "due_at": null,
  "last_completed_at": "2024-01-15 08:01:43",
  "archived_at": null,
  "created_at": "2024-01-15T08:43:52+00:00",
  "updated_at": "2024-01-15T08:01:43+00:00",
  "meta": {
    "subtask_group_id": "127"
  },
  "repeat_task_meta": null,
  "is_pinned": false,
  "assignees": []
}

List Subtasks

Returns all subtasks of a parent task, grouped by subtask group and ordered by position. Subtasks without a group are moved into a newly created "Untitled Group" during this call.

http

GET /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/subtasks

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/456/subtasks" \
  -u "USERNAME:APPLICATION_PASSWORD"

Example Response

json

{
  "subtaskGroups": [
    {
      "id": 127,
      "task_id": 456,
      "subtasks": [
        {
          "id": 123,
          "parent_id": 456,
          "board_id": 3,
          "title": "Create wireframes",
          "status": "closed",
          "position": "1.00",
          "meta": {
            "subtask_group_id": "127"
          },
          "assignees": []
        }
      ],
      "value": "Design Phase"
    }
  ]
}

Create a Subtask

Creates a subtask in a group of the parent task. The subtask starts as open with priority low.

http

POST /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/subtasks

Parameters

Parameter	Type	Required	Description
`title`	string	Yes	Subtask title
`group_id`	integer	No	Subtask group on this parent task. If omitted, the first group is used (an "Untitled Group" is created when none exists)
`description`	string	No	Description
`due_at`	string\|null	No	Due date `Y-m-d H:i:s`
`reminder_type`	string	No	Reminder preset
`remind_at`	string	No	Reminder time
`assignees`	integer[]	No	User ID to assign. Only the first ID is used, and it must be a board member
`add_to_top`	boolean	No	Put the subtask first in the list (default `false`, appended at the end)

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/85/subtasks" \
  -X POST \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{
    "title": "The new subtask",
    "group_id": 127,
    "due_at": null,
    "add_to_top": false
  }'

Example Response

json

{
  "subtask": {
    "id": 284,
    "parent_id": 85,
    "title": "The new subtask",
    "board_id": 3,
    "status": "open",
    "priority": "low",
    "due_at": null,
    "position": 20,
    "created_by": 1,
    "type": "task",
    "slug": "the-new-subtask",
    "updated_at": "2025-08-08T04:12:47+00:00",
    "created_at": "2025-08-08T04:12:47+00:00",
    "assignees": [],
    "meta": {
      "subtask_group_id": "127"
    },
    "repeat_task_meta": null
  },
  "message": "Subtask has been added"
}

Create Subtasks in Bulk

Creates up to 15 subtasks in one transaction (used by the AI "Generate subtasks" flow). They go into the group named group_title, which is created if the parent task has no group with that name.

http

POST /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/subtasks/bulk

Parameters

Parameter	Type	Required	Description
`titles`	string[]	Yes	Subtask titles; empty values are dropped and only the first 15 are used
`group_title`	string	No	Target group name (default "Subtasks")

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/85/subtasks/bulk" \
  -X POST \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{
    "titles": ["Draft outline", "Write content", "Proofread"],
    "group_title": "Writing"
  }'

Example Response

json

{
  "group": {
    "id": 560,
    "task_id": 85,
    "key": "group_name",
    "value": "Writing"
  },
  "subtasks": [
    { "id": 301, "parent_id": 85, "title": "Draft outline", "meta": { "subtask_group_id": "560" } },
    { "id": 302, "parent_id": 85, "title": "Write content", "meta": { "subtask_group_id": "560" } },
    { "id": 303, "parent_id": 85, "title": "Proofread", "meta": { "subtask_group_id": "560" } }
  ],
  "message": "Subtasks have been added"
}

Returns 400 "No subtasks provided." when titles is empty.

Create a Subtask Group

Creates a new group on the parent task.

http

POST /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/subtask-group

Parameters

Parameter	Type	Required	Description
`title`	string	Yes	Group name

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/85/subtask-group" \
  -X POST \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{ "title": "Design Phase" }'

Example Response

json

{
  "subtaskGroup": {
    "id": 555,
    "task_id": 85,
    "key": "group_name",
    "value": "Design Phase",
    "created_at": "2025-08-08T04:12:47+00:00",
    "updated_at": "2025-08-08T04:12:47+00:00"
  },
  "message": "New Subtask group has been added"
}

Update a Subtask Group

Renames a group of this parent task.

http

PUT /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/subtask-group

Parameters

Parameter	Type	Required	Description
`group_id`	integer	Yes	Group to rename
`title`	string	Yes	New name

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/85/subtask-group" \
  -X PUT \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{
    "group_id": 555,
    "title": "Execution Phase"
  }'

Example Response

json

{
  "subtaskGroup": {
    "id": 555,
    "task_id": 85,
    "key": "group_name",
    "value": "Execution Phase",
    "created_at": "2025-08-08T04:12:47+00:00",
    "updated_at": "2025-08-08T05:10:12+00:00"
  },
  "message": "Subtask group title has been added"
}

Delete a Subtask Group

Deletes a group and every subtask in it, in one transaction.

http

DELETE /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/subtask-group

Parameters

Parameter	Type	Required	Description
`group_id`	integer	Yes	Group to delete (sent in the body or query string)

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/85/subtask-group" \
  -X DELETE \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{ "group_id": 555 }'

Example Response

json

{
  "message": "Subtask group has been deleted"
}

Delete a Subtask

Deletes a subtask. {task_id} in the path is the subtask ID. No body is needed.

http

DELETE /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/delete-subtask

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/284/delete-subtask" \
  -X DELETE \
  -u "USERNAME:APPLICATION_PASSWORD"

Example Response

json

{
  "deletedSubtask": {
    "id": 284,
    "parent_id": 85,
    "board_id": 3,
    "title": "The new subtask",
    "status": "open",
    "stage_id": null,
    "subtask_group_id": "127",
    "meta": [],
    "repeat_task_meta": null
  },
  "changedSubtasks": [],
  "message": "Task has been deleted"
}

changedSubtasks lists sibling subtasks updated in the last minute.

Move Subtasks to a Group

Moves one subtask (or several) into another group of the parent task and appends them at the end.

http

POST /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/move-subtask

Parameters

Parameter	Type	Required	Description
`group_id`	integer	Yes	Target group (must belong to `{task_id}`)
`subtask_id`	integer \| integer[]	Yes	Subtask ID, or an array of IDs

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/85/move-subtask" \
  -X POST \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{
    "group_id": 127,
    "subtask_id": 284
  }'

Example Response (201)

json

{
  "subtask": {
    "id": 284,
    "parent_id": 85,
    "position": 21,
    "assignees": []
  },
  "message": "Subtask has been moved"
}

When subtask_id is an array, subtask is an array.

Update Subtask Position

Reorders a subtask within its group or moves it to another group of the same parent.

http

PUT /wp-json/fluent-boards/v2/projects/{board_id}/tasks/update-subtask-position/{subtask_id}

Parameters

Parameter	Type	Required	Description
`newPosition`	integer	Yes	New 1-based position
`newSubtasksGroupId`	integer	Yes	Target group. The key is required; an empty value keeps the current group

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/update-subtask-position/285" \
  -X PUT \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{
    "newPosition": 1,
    "newSubtasksGroupId": 198
  }'

Example Response (201)

json

{
  "changedSubtasks": [
    {
      "id": 285,
      "parent_id": 85,
      "title": "Hello Subtask",
      "position": "1.00",
      "meta": {
        "subtask_group_id": "198"
      },
      "assignees": []
    }
  ]
}

changedSubtasks contains the parent's subtasks updated within the last minute.

Convert a Task to a Subtask

Turns {task_id} into a subtask of parent_id. Both tasks must be on the board. The task loses its stage, its notifications are removed, and it is added to a group.

http

PUT /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/convert-to-subtask

Parameters

Parameter	Type	Required	Description
`parent_id`	integer	Yes	New parent task
`subtaskGroupId`	integer	No	Group of the parent to add it to. If omitted, a new "Default Subtask Group" is created on the parent
`assigneeId`	integer	No	Replaces the task's assignees and watchers with this user

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/150/convert-to-subtask" \
  -X PUT \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{
    "parent_id": 133,
    "assigneeId": 1
  }'

Example Response

json

{
  "message": "Task has been converted to subtask",
  "parentTask": {
    "id": 133,
    "parent_id": null,
    "board_id": 3,
    "title": "Task activity check",
    "status": "open",
    "stage_id": 26,
    "meta": {
      "is_template": "no"
    },
    "repeat_task_meta": null
  }
}

Move a Subtask to the Board

Converts a subtask back into a top-level task in the given stage (placed first). {task_id} is the subtask ID.

http

PUT /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/move-to-board

Parameters

Parameter	Type	Required	Description
`stage_id`	integer	Yes	Stage on this board

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/283/move-to-board" \
  -X PUT \
  -u "USERNAME:APPLICATION_PASSWORD" \
  -H "Content-Type: application/json" \
  -d '{ "stage_id": 26 }'

Example Response (201)

json

{
  "moveSubtask": {
    "id": 283,
    "parent_id": null,
    "board_id": 3,
    "title": "Design Homepage (Cloned)",
    "status": "open",
    "stage_id": 26,
    "position": 0.25,
    "due_at": "2025-07-04 23:45:00"
  },
  "changedSubtasks": []
}

Clone a Subtask

Copies a subtask. {task_id} is the subtask ID.

http

POST /wp-json/fluent-boards/v2/projects/{board_id}/tasks/{task_id}/clone-subtask

Behavior:

The title gets the suffix (cloned).
started_at and due_at are kept.
The clone stays in the same subtask group.
Assignee and watcher relations are copied.
The clone is placed between the original and the next subtask in the group, or at the end.

Example Request

bash

curl "https://yourdomain.com/wp-json/fluent-boards/v2/projects/3/tasks/286/clone-subtask" \
  -X POST \
  -u "USERNAME:APPLICATION_PASSWORD"

Example Response

json

{
  "subtask": {
    "id": 287,
    "parent_id": 133,
    "board_id": 3,
    "title": "Lorem ipsum (cloned)",
    "status": "open",
    "stage_id": null,
    "position": 2,
    "meta": {
      "subtask_group_id": "200"
    },
    "repeat_task_meta": null,
    "assignees": []
  },
  "message": "Subtask has been cloned successfully"
}

Error Responses

See Common Error Responses for standard error formats.

Common subtask errors:

400 — task, subtask, stage or group not found on this board ("Subtask group not found", "Stage not found"), or a convert between different boards
403 — no write access to the board
404 — group or subtask not found on delete
422 — validation failed (missing title, group_id, stage_id, …)

Subtasks ​

Endpoints ​

Subtask Object ​

List Subtasks ​

Create a Subtask ​

Create Subtasks in Bulk ​

Create a Subtask Group ​

Update a Subtask Group ​

Delete a Subtask Group ​

Delete a Subtask ​

Move Subtasks to a Group ​

Update Subtask Position ​

Convert a Task to a Subtask ​

Move a Subtask to the Board ​

Clone a Subtask ​

Error Responses ​

Subtasks

Endpoints

Subtask Object

List Subtasks

Create a Subtask

Create Subtasks in Bulk

Create a Subtask Group

Update a Subtask Group

Delete a Subtask Group

Delete a Subtask

Move Subtasks to a Group

Update Subtask Position

Convert a Task to a Subtask

Move a Subtask to the Board

Clone a Subtask

Error Responses