> ## Documentation Index > Fetch the complete documentation index at: https://developer.watson-orchestrate.ibm.com/llms.txt > Use this file to discover all available pages before exploring further. # Get supported A2A protocol versions > Returns the list of supported A2A protocol versions for a specific role (client or server). - **role**: Specify 'client' or 'server' to get versions for that role - Returns version information including feature support matrix - Client role is currently implemented - Server role is not yet implemented ## OpenAPI ````yaml get /v1/a2a/versions openapi: 3.1.0 info: title: WxO Server API summary: API for the next gen watsonx Orchestrate stack description: >+ The watsonx Orchestrate Server provides a set of APIs to power the watsonx Orchestrate AI assistant. This includes the following core services: * Orchestrate Assistant - a built-in AI assistant that powers the Orchestrate end-user experience. * Custom Assistants - a service layer for interacting with existing AI assistatns (such as those in watsonx Assistant). * Message Threads - a chat history and async message tracking store. * Document Store - manage collections of documents in nearly any format including text, pdf, html and many more. * Information Extraction - automatically extract clean text and images from any document in the Document Store. Also extract other useful metadata like questions answered, keywords, and named entities. * Embedding - generate vector embeddings for text and images in the Document Store. * Vector Index and Retrieval - automatically index documents with rich metadata for vector search or hybrid search. * Search Engine - create a Gen AI powered search engine that works like Bing or Google. * Query Engine - configure your own RAG (Retrieval Augmented Generation) engine supporting advanced retrieval patterns and automated data management. * Model Proxy - create your own LLM model endpoints for chat completions and embeddings. Supports IBM watsonx.ai, IBM BAM, OpenAI, MistralAI, or Ollama for local models. WxO API Server utilizes the following open source projects: * [PostgreSQL](https://www.postgresql.org/) * [PGVector](https://github.com/pgvector/pgvector) * [LlamaIndex](https://docs.llamaindex.ai/en/stable/) * [LangChain](https://python.langchain.com/docs/get_started/introduction) * [FastAPI](https://fastapi.tiangolo.com/) * [Unstructured](https://unstructured.io/) * [Celery](https://docs.celeryproject.org/en/stable/) version: 0.1.0 servers: - url: https://{api_endpoint} description: version security: [] paths: /v1/a2a/versions: get: tags: - A2A Protocol summary: Get supported A2A protocol versions description: >- Returns the list of supported A2A protocol versions for a specific role (client or server). - **role**: Specify 'client' or 'server' to get versions for that role - Returns version information including feature support matrix - Client role is currently implemented - Server role is not yet implemented operationId: get_supported_versions_v1_a2a_versions_get parameters: - name: role in: query required: false schema: enum: - client - server type: string description: >- Role type: 'client' for A2A client versions, 'server' for A2A server versions default: client title: Role description: >- Role type: 'client' for A2A client versions, 'server' for A2A server versions responses: '200': description: Successfully retrieved A2A supported versions content: application/json: schema: $ref: '#/components/schemas/A2ASupportedVersionsResponse' '400': description: Invalid role parameter '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' '501': description: A2A server role not yet implemented components: schemas: A2ASupportedVersionsResponse: properties: protocol: type: string title: Protocol description: Protocol name default: A2A role: type: string enum: - client - server title: Role description: Role type (client or server) versions: items: $ref: '#/components/schemas/A2AVersionInfo' type: array title: Versions description: List of supported versions with their features current_version: anyOf: - type: string - type: 'null' title: Current Version description: Current/recommended version for this role is_implemented: type: boolean title: Is Implemented description: Whether this role is currently implemented type: object required: - role - versions - current_version - is_implemented title: A2ASupportedVersionsResponse description: Response model for A2A supported versions endpoint. HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError A2AVersionInfo: properties: version: type: string title: Version description: Version string (e.g., '0.3.0') status: type: string enum: - current - supported - deprecated - unsupported title: Status description: Version status indicator features: $ref: '#/components/schemas/VersionFeatures' description: Feature support matrix for this version type: object required: - version - status - features title: A2AVersionInfo description: Information about a specific A2A protocol version. ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type type: object required: - loc - msg - type title: ValidationError VersionFeatures: properties: push_notifications: type: boolean title: Push Notifications description: Support for push notifications from agent to server streaming: type: boolean title: Streaming description: Support for streaming responses send_history: type: boolean title: Send History description: Support for sending conversation history type: object required: - push_notifications - streaming - send_history title: VersionFeatures description: Feature flags supported by a specific A2A version. ````