Milestones overview

Milestones mark dated checkpoints in a project.

The milestone object

Attributes

• archived_at string (date-time)

  When the record was archived, or null if it is active.

• created_at string (date-time)

  When the record was created.

• created_by_id string (uuid)

  The user who created the record.

• external_id string

  Your system's identifier for this record, for sync and import correlation.

• external_source string

  The system external_id came from, for example github or jira.

• id string (uuid)

  Unique identifier.

• target_date string (date)

  Planned due date, as YYYY-MM-DD.

• title string

  Title.

Response200

{
  "archived_at": null,
  "created_at": "2026-01-14T09:22:41.478363Z",
  "created_by_id": "16c61a3a-512a-48ac-b0be-b6b46fe6f430",
  "external_id": null,
  "external_source": null,
  "id": "b7e42a19-3c5d-4f80-9a26-8d1c0f4e7b53",
  "target_date": "2026-01-20",
  "title": "Example title"
}

Endpoints

Method	Path	Description
GET	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/	List milestones
GET	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/{pk}/	Get a milestone
POST	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/	Create a milestone
PATCH	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/{pk}/	Update a milestone
DELETE	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/{pk}/	Delete a milestone
POST	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/upsert/	Upsert a milestone
POST	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/bulk-create/	Bulk create milestones
POST	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/bulk-update/	Bulk update milestones
POST	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/bulk-delete/	Bulk delete milestones
POST	/api/v2/workspaces/{slug}/projects/{project_id}/milestones/{pk}/work-items/	Add or remove milestone work items

Response shaping

Every milestone read accepts ?fields= for sparse responses — see Sparse fields. Errors follow the shared problem+json contract.