> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gumnut.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Manually stack assets

> Groups two or more existing assets into a new user-owned stack (`origin = user`) for collapsed display. A user-owned stack is never re-segmented by burst re-detection.

An asset already in another stack is repointed into the new one, folding that stack in whole if it was its pinned cover; a stack left with fewer than 2 members dissolves. The photos themselves are untouched.

If a concurrent stack change invalidates the request mid-flight, it returns 409 and nothing is created; retry the request unchanged.



## OpenAPI

````yaml https://api.gumnut.ai/openapi.json post /api/stacks
openapi: 3.1.0
info:
  title: Gumnut API
  description: API for using Gumnut to manage photos and videos
  version: 0.1.0
servers: []
security: []
paths:
  /api/stacks:
    post:
      tags:
        - stacks
      summary: Manually stack assets
      description: >-
        Groups two or more existing assets into a new user-owned stack (`origin
        = user`) for collapsed display. A user-owned stack is never re-segmented
        by burst re-detection.


        An asset already in another stack is repointed into the new one, folding
        that stack in whole if it was its pinned cover; a stack left with fewer
        than 2 members dissolves. The photos themselves are untouched.


        If a concurrent stack change invalidates the request mid-flight, it
        returns 409 and nothing is created; retry the request unchanged.
      operationId: create_stack
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/StackCreate'
      responses:
        '201':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/StackResponse'
        '404':
          description: Not found
        '409':
          description: A concurrent stack change invalidated the request
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    StackCreate:
      properties:
        asset_ids:
          items:
            type: string
          type: array
          maxItems: 200
          minItems: 2
          title: Asset Ids
          description: >-
            Asset IDs (with `asset_` prefix) to group into the new stack — at
            least 2 distinct ids, all in the target library.
        primary_asset_id:
          anyOf:
            - type: string
            - type: 'null'
          title: Primary Asset Id
          description: >-
            Asset ID (with `asset_` prefix) to pin as the stack's cover; must be
            one of `asset_ids`. Omit to leave the cover unpinned — there is no
            automatic pick, and clients choose their own display cover for an
            unpinned stack.
        library_id:
          anyOf:
            - type: string
            - type: 'null'
          title: Library Id
          description: >-
            Library to create the stack in. Optional if the user has a single
            library; required when they have multiple.
      type: object
      required:
        - asset_ids
      title: StackCreate
    StackResponse:
      properties:
        id:
          type: string
          title: Id
          description: Unique stack identifier with 'asset_stack_' prefix
        primary_asset_id:
          anyOf:
            - type: string
            - type: 'null'
          title: Primary Asset Id
          description: >-
            ID of the asset the user pinned as the stack's cover, or null if
            none is pinned. Null for an auto-detected burst unless a user has
            since pinned a cover — there is no server-selected default, so a
            client showing a stack with no pinned cover picks its own. A pinned
            cover that has been trashed keeps its ID here; it is cleared only
            once the asset is permanently deleted.
        asset_count:
          type: integer
          title: Asset Count
          description: >-
            Number of live assets in this stack. Excludes trashed members, so it
            can drop below the number of frames originally grouped.
        origin:
          $ref: '#/components/schemas/StackOrigin'
        created_at:
          type: string
          format: date-time
          title: Created At
          description: When this stack was created
        updated_at:
          type: string
          format: date-time
          title: Updated At
          description: When this stack was last updated
      type: object
      required:
        - id
        - asset_count
        - origin
        - created_at
        - updated_at
      title: StackResponse
      description: Represents a group of assets displayed as a single tile.
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    StackOrigin:
      type: string
      enum:
        - auto_burst
        - user
      title: StackOrigin
      description: >-
        How a stack came to exist.


        `auto_burst` marks a stack the burst detector created from the time +

        EXIF-camera signal; `user` marks a stack a user created or edited
        (manual

        create, set-cover, add/remove, unstack). The distinction is what keeps

        re-detection from stomping a user's correction — the detection pass
        skips

        `user` stacks.
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError

````