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

# Read segmentation artifact file

> Read one org-scoped mask OME-Zarr, cell morphology, marker-expression, or provenance file.

Use paths from the layer manifest. `mask/...` addresses the uint32 OME-Zarr store, `features/instances.parquet` contains cell IDs, mask labels, geometry, and morphology, and `features/markers/{marker}.parquet` contains per-cell mean/median expression joined by `instance_id`.


## OpenAPI

````yaml GET /samples/{id}/segmentation/{layerId}/files/{path}
openapi: 3.1.0
info:
  title: Strand AI Platform API
  version: v1
  description: >-
    REST surface for uploading WSIs, submitting Lattice inference jobs, and
    streaming results. All endpoints require an API key or Strand AI OAuth
    access token in the `Authorization: Bearer` header.
servers:
  - url: https://app.strandai.com/api/v1
    description: Production
security:
  - ApiKey: []
  - OAuth2: []
paths:
  /samples/{id}/segmentation/{layerId}/files/{path}:
    get:
      summary: Read one segmentation artifact file
      description: >-
        Bearer-authenticated, org-scoped byte proxy for the paths declared by
        the segmentation manifest.
      parameters:
        - name: id
          in: path
          required: true
          schema:
            type: string
            format: uuid
        - name: layerId
          in: path
          required: true
          schema:
            type: string
            format: uuid
        - name: path
          in: path
          required: true
          schema:
            type: string
      responses:
        '200':
          description: Artifact bytes
          content:
            application/octet-stream:
              schema:
                type: string
                format: binary
        '400':
          description: Invalid artifact path
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Authentication required
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '403':
          description: OAuth token lacks a required scope
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '404':
          description: Artifact not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '500':
          description: Storage proxy failure
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
      security:
        - ApiKey: []
        - OAuth2:
            - samples:read
            - results:read
components:
  schemas:
    Error:
      type: object
      required:
        - error
        - message
      properties:
        error:
          type: string
        message:
          type: string
        required:
          type: integer
          nullable: true
        retryAfterSeconds:
          type: integer
          nullable: true
  securitySchemes:
    ApiKey:
      type: http
      scheme: bearer
      bearerFormat: sk-strand-XXXXXXXXXXXXXXXXXXXXXXXX
    OAuth2:
      type: oauth2
      description: >-
        Strand AI authorization-code flow with S256 PKCE, explicit organization
        consent, and RFC 8707 resource binding.
      flows:
        authorizationCode:
          authorizationUrl: https://auth.strandai.com/oauth2/auth
          tokenUrl: https://auth.strandai.com/oauth2/token
          scopes:
            samples:read: Read slide metadata and estimates
            samples:write: Upload and change slides
            jobs:read: Read run status
            jobs:write: Start, export, or cancel runs
            results:read: Read and download results
            credits:spend: Reserve and spend organization credits

````