Agentic Resource Discovery (ARD) Search API

openapi: 3.2.0
info:
  title: Agentic Resource Discovery Registry Search API
  version: 0.5.0
  description: 'Universal federated discovery API specification for AI agents, tools, and capabilities.

    Allows LLM orchestrators to semantically search and discover registries for relevant capabilities

    and enables registry-to-registry federated query routing.

    '
tags:
- name: Search
paths:
  /search:
    post:
      summary: Semantic Search Registry
      description: 'Query a registry with natural language to find matching capabilities.

        Accepts a shared semantic and structural query object. Supports multi-hop federation.

        '
      operationId: searchAgents
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SearchRequest'
      responses:
        '200':
          description: Successful search operation.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SearchResponse'
        '400':
          $ref: '#/components/responses/400BadRequest'
        '401':
          $ref: '#/components/responses/401Unauthorized'
        '429':
          $ref: '#/components/responses/429TooManyRequests'
        '500':
          $ref: '#/components/responses/500InternalError'
      tags:
      - Search
components:
  schemas:
    RegistryReferral:
      type: object
      required:
      - identifier
      - displayName
      - type
      - url
      properties:
        identifier:
          type: string
          description: Logical identifier of the referred registry.
          example: urn:air:nlweb.ai:registry:public
        displayName:
          type: string
          description: Name of the referred registry.
          example: Public Agent Finder
        type:
          type: string
          enum:
          - application/ai-registry
          - application/ai-registry+json
          description: Registry media type identifier.
        url:
          type: string
          format: uri
          description: Endpoint URL for the referred registry's search route.
          example: https://finder.nlweb.ai/search
    SearchQueryModel:
      allOf:
      - $ref: '#/components/schemas/QueryModel'
      - type: object
        required:
        - text
    SearchRequest:
      type: object
      required:
      - query
      properties:
        query:
          $ref: '#/components/schemas/SearchQueryModel'
        federation:
          type: string
          enum:
          - auto
          - referrals
          - none
          default: auto
        pageSize:
          type: integer
          default: 10
          description: Maximum number of search results to return.
        pageToken:
          type: string
          description: Pagination token.
      additionalProperties: false
    SearchResultItem:
      allOf:
      - $ref: ./ai-catalog.schema.json#/$defs/catalogEntry
      type: object
      required:
      - score
      - source
      properties:
        score:
          type: integer
          minimum: 0
          maximum: 100
          description: 'Semantic relevance rating (0 to 100) computed by the registry. Note: This is not a security or trust score.'
          example: 95
        source:
          type: string
          format: uri
          description: The URL endpoint of the registry where this entry was indexed.
          example: https://registry.acme.com/api/v1/
    QueryModel:
      type: object
      properties:
        text:
          type: string
          description: Natural language description narrows the set by semantic relevance.
          example: find me a weather lookup tool
        filter:
          type: object
          description: "Structured constraints. Keys are field paths (can be dot-separated for nested fields). \nValues are arrays or scalar values.\n"
          additionalProperties:
            oneOf:
            - type: string
            - type: array
              items:
                type: string
          example:
            type:
            - application/mcp-server-card+json
            trustManifest.attestations.type:
            - SOC2-Type2
      additionalProperties: false
    SearchResponse:
      type: object
      required:
      - results
      properties:
        results:
          type: array
          items:
            $ref: '#/components/schemas/SearchResultItem'
        referrals:
          type: array
          description: List of upstream registries recommended to the client. Only returned in 'referrals' federation mode.
          items:
            $ref: '#/components/schemas/RegistryReferral'
        pageToken:
          type: string
          description: Token for paging subsequent results.
      additionalProperties: false
    Error:
      type: object
      required:
      - errorCode
      - message
      properties:
        errorCode:
          type: string
          description: Standard uppercase error classification code.
          example: INVALID_ARGUMENT
        message:
          type: string
          description: Human-readable description explaining the error.
          example: The filter expression syntax 'type = MCP' is invalid. Did you mean 'type = application/mcp-server-card+json'?
  responses:
    500InternalError:
      description: Internal server error.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    429TooManyRequests:
      description: Rate limit exceeded.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    401Unauthorized:
      description: Credentials missing or rejected.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    400BadRequest:
      description: Malformed request payload or invalid syntax.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'