A C# implementation of the A2A (Agent-to-Agent) protocol using the official A2A .NET SDK v0.3.3-preview with JSON-RPC and REST transport support.

• Two Transport Modes: JSON-RPC and REST (HTTP+JSON)
• Official A2A SDK: Uses A2A + A2A.AspNetCore 0.3.3-preview NuGet packages
• ASP.NET Core: Minimal API
• LLM Integration: Uses Ollama with qwen2.5 model via Semantic Kernel
• Tool Support: Roll dice and check prime numbers
• Streaming: SSE streaming support for both transports

Note: gRPC is not supported in the C# A2A SDK v0.3.3-preview.

• .NET 9.0 SDK
• Ollama running locally (http://localhost:11434) with the qwen2.5 model

cd aloha-csharp
dotnet restore
dotnet build

Or use the build script:

# Bash
cd aloha-csharp && ./scripts/build

# PowerShell
cd aloha-csharp && ./scripts/build.bat

Convenience scripts are provided for running servers and clients:

Both transports start simultaneously when running either script.

# Bash - Start JSON-RPC server
./Server/scripts/jsonrpc_server

# PowerShell - Start REST server
./Server/scripts/rest_server.bat

# Bash - Test with JSON-RPC client
./Client/scripts/jsonrpc_client

# PowerShell - Test with REST client
./Client/scripts/rest_client.bat

Note: gRPC is not supported in the C# A2A SDK v0.3.3-preview.

cd aloha-csharp/Server
dotnet run

Both transports start simultaneously:

• JSON-RPC: http://localhost:15001
• REST: http://localhost:15002
• Agent Card: http://localhost:15001/.well-known/agent-card.json

The client uses the A2A SDK with JSON-RPC transport.

cd aloha-csharp/Client
dotnet run -- --message "Roll a 20-sided dice"

cd aloha-csharp/Server
dotnet run

Both transports start simultaneously:

• JSON-RPC: http://localhost:15001
• REST (HTTP+JSON): http://localhost:15002
• Agent Card: http://localhost:15001/.well-known/agent-card.json

The client uses the A2A SDK with JSON-RPC transport.

cd aloha-csharp/Client
dotnet run -- --message "Roll a 20-sided dice"

# Non-streaming (default)
dotnet run -- --message "Roll a 20-sided dice"

# With streaming
dotnet run -- --stream --message "Check if 17 is prime"

# With custom port
dotnet run -- --port 15001 --message "Roll a 6-sided dice"

All settings are in Server/appsettings.json. Override with environment variables.

Environment variables (OLLAMA_BASE_URL, OLLAMA_MODEL) take precedence over config file.

1. roll_dice(N): Rolls an N-sided dice

   • Example: "Roll a 20-sided dice"
   • Example (Chinese): "投掷一个6面骰子"

2. check_prime(nums): Checks if numbers are prime

   • Example: "Check if 2, 4, 7, 9, 11 are prime"
   • Example (Chinese): "检查17是否为质数"

• A2A Protocol Specification
• A2A .NET SDK v0.3.3-preview
• Semantic Kernel Documentation