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

# List extension namespaces for an item

> Returns every extension namespace attached to the item that the caller has permission to read. Extensions are namespaced JSON sidecars (`<app>.*`, `<publisher>.*`, `user.*`) — credentials must declare each namespace in their `extension_permissions` map; namespaces outside that map are silently filtered.

For list views, prefer `GET /items?include=extensions` to hydrate extensions inline across a page with the same permission rule applied. See [Extensions](/concepts/extensions).



## OpenAPI

````yaml /openapi.json get /items/{id}/extensions
openapi: 3.1.0
info:
  title: Marfa API
  version: 4.2.0
  description: Typed data layer for structured personal data
servers: []
security: []
paths:
  /items/{id}/extensions:
    get:
      tags:
        - Extensions
      summary: List extension namespaces for an item
      description: >-
        Returns every extension namespace attached to the item that the caller
        has permission to read. Extensions are namespaced JSON sidecars
        (`<app>.*`, `<publisher>.*`, `user.*`) — credentials must declare each
        namespace in their `extension_permissions` map; namespaces outside that
        map are silently filtered.


        For list views, prefer `GET /items?include=extensions` to hydrate
        extensions inline across a page with the same permission rule applied.
        See [Extensions](/concepts/extensions).
      parameters:
        - schema:
            type: string
          required: true
          name: id
          in: path
      responses:
        '200':
          description: Extension namespaces (filtered by permissions)
          content:
            application/json:
              schema:
                type: object
                properties:
                  extensions:
                    type: object
                    additionalProperties:
                      type: object
                      additionalProperties:
                        nullable: true
                required:
                  - extensions
        '400':
          description: Invalid item ID
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: object
                    properties:
                      code:
                        type: string
                        enum:
                          - invalid_id
                      message:
                        type: string
                      details:
                        type: object
                        additionalProperties:
                          nullable: true
                    required:
                      - code
                      - message
                required:
                  - error
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: object
                    properties:
                      code:
                        type: string
                        enum:
                          - unauthorized
                      message:
                        type: string
                      details:
                        type: object
                        additionalProperties:
                          nullable: true
                    required:
                      - code
                      - message
                required:
                  - error
        '404':
          description: Item not found
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: object
                    properties:
                      code:
                        type: string
                        enum:
                          - item_not_found
                      message:
                        type: string
                      details:
                        type: object
                        additionalProperties:
                          nullable: true
                    required:
                      - code
                      - message
                required:
                  - error
      security:
        - bearerAuth: []
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API Key or OAuth Token
      description: Pass an API key (marfa_k1_...) or OAuth access token (marfa_at_...)

````