A2A Server Rust Agent

This project is a minimal A2A (Agent-to-Agent) server agent implementation in Rust.

Project Overview

a2a-server-rust is a sample application that demonstrates how to implement an A2A agent using the a2a-rs crate (v0.2.0). It is designed to be deployed as a containerized application on Google Cloud Run and supports the A2A protocol for agentic communication.

Key Technologies

• Language: Rust (Edition 2024)
• A2A Framework: a2a-rs (v0.2.0)
• Async Runtime: Tokio
• Containerization: Docker
• Deployment: Google Cloud Run
• CI/CD: Google Cloud Build

Features

• Standard A2A Endpoints: Implements /agentcard, /tasks, and /notifications.
• Echo Skill: A built-in skill that echoes back user messages.
• Task Management: In-memory task storage and state management.
• Streaming Support: Supports Server-Sent Events (SSE) for task status and artifact updates.
• Observability: Integrated tracing and logging via a2a-rs::observability.

Getting Started

This project uses a Makefile to simplify common development tasks.

Prerequisites

• Rust Toolchain
• Docker
• Google Cloud SDK

Initial Setup

1. Install Dependencies:

   cargo build
   

2. Run the application locally:

   make start
   

   The server will start on port 8080.

Development Workflow

The Makefile provides targets for common development tasks. Run make help to see all available targets.

Building and Running

• Development Build: make build
• Release Build: make release
• Run Locally: make start (starts on port 8080)
• Check Agent Card: make card (requires local server running)
• Update Dependencies: make update

Code Quality

• Formatting: make format
• Linting: make lint (runs clippy and format check)
• Testing: make test

Deployment

Deployment is handled by Google Cloud Build and defined in cloudbuild.yaml.

To deploy to Cloud Run:

make deploy

This command:

1. Submits the build to Google Cloud Build.
2. Builds the Docker image using the multi-stage Dockerfile.
3. Pushes the image to Artifact Registry/GCR.
4. Deploys the image to Google Cloud Run.

Remote Validation

After deployment, you can verify the remote service:

• Check Status: make status
• Get Endpoint: make endpoint
• Get Remote Agent Card: make card-remote
• Run Remote Tests: make test-remote
• Run Remote Echo Test: make a2a-remote