Smart EHR MCP Server

# A4A Monorepo This repository contains **A4A (Agent-to-Agent) reference code** implemented in TypeScript and executed with [Bun](https://bun.sh/). It is organised as a small mono-repo with two publishable packages plus several runnable samples: • **@jmandel/a2a-bun-express-server** – the server-side framework used to build A2A agents on top of Express. • **@jmandel/a2a-client** – a lightweight, event-driven browser/Node client for talking to A2A servers. Under `samples/` you'll find a handful of **ready-to-run agents** (servers) and a `client/react-demo` single-page app that exercises the client library against those servers. --- ## Repository Layout ``` a4a/ ├── src/ → source code for the server library ├── client/ → source code for the client library │ └── react-demo/ → React demo that consumes the client lib ├── samples/ │ ├── joke-agent-v2/ → Joke agent using the new generator API │ └── prior-auth-v2/ → Prior-authorization agent (Gemini + SSE) └── … ``` Each `samples/*` folder is **stand-alone**: you can `bun install` and run it directly once the workspace links are in place (see below). --- ## Local Development with `bun link` Both libraries are unpublished drafts. To make the samples resolve the packages while you're working locally we use Bun's [link](https://bun.sh/docs/cli/link) mechanism: 1. **Create global links from the library packages** ```bash # from the repo root cd a4a bun link # creates a global link called "@jmandel/a2a-bun-express-server" cd client bun link # creates a global link called "@jmandel/a2a-client" ``` 2. **Link the server library into each sample agent** ```bash # joke-agent-v2 cd ../samples/joke-agent-v2 bun link @jmandel/a2a-bun-express-server # prior-auth-v2 cd ../prior-auth-v2 bun link @jmandel/a2a-bun-express-server ``` 3. **Link the client library into the React demo** ```bash cd ../../client/react-demo bun link @jmandel/a2a-client ``` --- ## Installing & Running After the links are established, each project follows the usual Bun flow: ```bash # inside a sample directory, e.g. a4a/samples/joke-agent-v2 bun install # installs external deps, the linked lib is already resolved bun run dev # or `bun run server.ts` for plain runs ``` For the React demo: ```bash cd a4a/client/react-demo bun install bun run dev # Vite dev-server on http://localhost:5173 by default ``` --- ## What's Inside the Server Library? `@jmandel/a2a-bun-express-server` provides: * **A2AServerCoreLite** – core finite-state machine for V2 processors (async generators). * **Express helpers** (`startA2AExpressServerV2`) – spin up an agent with a couple of lines. * **SseConnectionManager** – drop-in Server-Sent-Events broadcaster (autoprovisioned unless you explicitly disable `capabilities.streaming`). * **InMemoryTaskStore** – simple persistence implementation suitable for demos/tests. * Type definitions for tasks, messages, artifacts, etc. The V2 processor API lets you write pure async generators that `yield` status updates, artifacts or `input-required` states. See `samples/joke-agent-v2/TopicJokeProcessorV2.ts` for an annotated example. --- ## The Client Library & Demo `@jmandel/a2a-client` is a minimal wrapper around the JSON-RPC / SSE protocol. The React demo (`client/react-demo`) shows: * a "session" layer that wires the client to components (`PaSession`) * an `ehr.html` viewer that renders mock EHR snippets * a `tester.html` helper for ad-hoc requests Open the demo in your browser after running `bun run dev` and point it at a running agent (e.g. `http://localhost:3006/a2a` for the joke agent). --- ## Publishing (optional) When ready, publish from each library folder: ```bash # inside a4a (server lib) npm publish --access public # inside a4a/client (client lib) npm publish --access public ``` Make sure to bump the version numbers first. The samples will then be able to depend on the real npm packages instead of Bun links. --- Happy hacking! 🎉