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

# Get detailed metadata for a single SAE feature

> Return all available metadata for one SAE feature: longform description, top activating UniRef90 and SwissProt proteins, decoder nearest neighbors, and activation statistics.



## OpenAPI

````yaml openapi/metagenomic-atlas-openapi.json GET /esm/protein/api/v1alpha1/features/{feature_index}
openapi: 3.1.0
info:
  title: ESM Atlas API Reference
  description: Interfaces may change without notice.
  version: 0.1.0
servers:
  - url: https://biohub.ai
security: []
paths:
  /esm/protein/api/v1alpha1/features/{feature_index}:
    get:
      tags:
        - Features
      summary: Get detailed metadata for a single SAE feature
      description: >-
        Return all available metadata for one SAE feature: longform description,
        top activating UniRef90 and SwissProt proteins, decoder nearest
        neighbors, and activation statistics.
      operationId: get_feature_detail_esm_protein_api_v1alpha1_features__feature_index__get
      parameters:
        - name: feature_index
          in: path
          required: true
          schema:
            type: integer
            minimum: 0
            exclusiveMaximum: 16384
            title: Feature Index
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SAEFeatureDetail'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    SAEFeatureDetail:
      properties:
        feature_index:
          type: integer
          title: Feature Index
        label:
          type: string
          title: Label
        summary:
          type: string
          title: Summary
        description:
          type: string
          title: Description
        activation_pattern:
          anyOf:
            - type: string
            - type: 'null'
          title: Activation Pattern
        category:
          anyOf:
            - type: string
            - type: 'null'
          title: Category
        exemplar_protein_families:
          anyOf:
            - type: string
            - type: 'null'
          title: Exemplar Protein Families
        uniref90_frequency:
          type: integer
          title: Uniref90 Frequency
        uniref90_idf:
          type: number
          title: Uniref90 Idf
        uniref90_max_activation:
          type: number
          title: Uniref90 Max Activation
        top_100_uniref_ids:
          items:
            $ref: '#/components/schemas/TopUnirefEntry'
          type: array
          title: Top 100 Uniref Ids
          default: []
        top_swissprot_activations:
          items:
            $ref: '#/components/schemas/TopSwissprotEntry'
          type: array
          title: Top Swissprot Activations
          default: []
        decoder_nearest_neighbors:
          items:
            type: integer
          type: array
          title: Decoder Nearest Neighbors
          default: []
        threshold:
          type: number
          title: Threshold
      type: object
      required:
        - feature_index
        - label
        - summary
        - description
        - uniref90_frequency
        - uniref90_idf
        - uniref90_max_activation
        - threshold
      title: SAEFeatureDetail
      description: >-
        Detailed SAE feature metadata — loaded on demand from parquet.


        Field names match the parquet columns (with ``feature_id`` →
        ``feature_index``).

        ``summary`` is the short blurb; ``description`` is the longform
        write-up.

        Note: the list endpoint's ``description`` field currently returns the

        parquet's ``summary`` column for backward compatibility — do not
        conflate.
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    TopUnirefEntry:
      properties:
        uniref_id:
          type: string
          title: Uniref Id
        activation:
          type: number
          title: Activation
      type: object
      required:
        - uniref_id
        - activation
      title: TopUnirefEntry
      description: One entry in the top-100 UniRef90 activation list.
    TopSwissprotEntry:
      properties:
        uniprot_id:
          type: string
          title: Uniprot Id
        activation:
          type: number
          title: Activation
      type: object
      required:
        - uniprot_id
        - activation
      title: TopSwissprotEntry
      description: One entry in the top-20 SwissProt activation list.
    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

````