👉 Try the demo: https://github.com/LM-Kit/lm-kit-net-samples/tree/main/console_net/agents/tool_calling_assistant

Tool Calling Assistant for C# .NET Applications

Purpose of the Sample

Tool Calling Assistant demonstrates how to use LM-Kit.NET to build AI assistants that can invoke custom tools during conversations using the native tool-calling system.

The sample shows how to:

Implement the ITool interface.
Define JSON schemas for tool parameters.
Register tools with ToolRegistry.
Use MultiTurnConversation with tools.
Handle tool invocation events for logging and debugging.

Why Tool Calling with LM-Kit.NET?

Real capabilities: tools perform actions LLMs cannot (API calls, calculations, data access).
Native format: uses the model's built-in tool-calling format for reliability.
Type safety: JSON schemas validate tool parameters.
Extensibility: easily add new tools for new capabilities.
Local-first: all tool invocations run on your hardware.

Sample Application Description

Console app that:

Creates three practical tools: Weather, Currency Conversion, Unit Conversion.
Registers tools with the conversation system.
Allows natural language queries that trigger tool use.
Displays tool invocation details in real-time.
Demonstrates multi-tool conversations.

Key Features

WeatherTool: real-time weather via Open-Meteo API (free, no key).
CurrencyTool: currency conversion via ECB rates (free, no key).
UnitConversionTool: offline unit conversions (length, mass, temp, etc.).
Native Tool Calling: uses model's built-in JSON tool format.

Tool Implementation Pattern

using LMKit.Agents.Tools;

public class WeatherTool : ITool
{
    public string Name => "get_weather";

    public string Description => "Get current weather for a location";

    public string InputSchema => @"{
        ""type"": ""object"",
        ""properties"": {
            ""location"": {
                ""type"": ""string"",
                ""description"": ""City name or coordinates""
            }
        },
        ""required"": [""location""]
    }";

    public async Task<string> InvokeAsync(string arguments, CancellationToken ct)
    {
        // Parse arguments, call API, return JSON result
    }
}

Available Tools

Tool	API	Description
`get_weather`	Open-Meteo (free)	Current weather + forecast
`convert_currency`	ECB Frankfurter (free)	Real-time exchange rates
`convert_units`	Offline	Length, mass, temperature, etc.

Example Queries

"What's the weather in Paris?"
"Convert 100 USD to EUR"
"How many kilometers is 5 miles?"
"What's 72 Fahrenheit in Celsius?"

Getting Started

Prerequisites

.NET 8.0 or later
VRAM for selected model (4-11 GB)
Internet connection (for weather/currency)

Run

cd demos/console_net/agents/tool_calling_assistant
dotnet build
dotnet run

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