APIs & protocols

Akka provides built-in support for exposing your services through multiple protocols.

HTTP

  • REST APIs — Define JSON-based HTTP endpoints with routing, request/response handling, and access control. See HTTP Endpoints.

  • OpenAPI — Schema generation is built in. See OpenAPI Endpoint schema.

  • WebSockets — Real-time bidirectional communication is built in. See WebSocket support.

  • Web application assets — Serve the files of a single-page application, or HTML generated at request time, from the same service that serves the API. See Web applications.

gRPC

High-performance APIs with protocol buffer definitions. See gRPC Endpoints.

MCP (Model Context Protocol)

  • MCP Endpoints — Expose Agent functions to remote LLMs via @FunctionTool annotations. See MCP Endpoints.

  • MCP CLI server — akka mcp serve exposes CLI operations as MCP tools for Claude Desktop, VS Code, and Cursor.

Agent protocol support

A2A and MCP clients are built into Akka’s Agent component. Agents consume tools and communicate with other agents through both protocols, with no external libraries.

  • A2A (Agent-to-Agent) — Google’s protocol for agent-to-agent communication

  • MCP (Model Context Protocol) — Anthropic’s protocol for connecting AI models to external tools

MCP

See also