AI Tools

The AI conversation service supports Microsoft.Extensions.AI tools (AITool) that are automatically included in every chat request. This lets the AI call functions on the user’s behalf.

How Tools Are Registered

Any AITool registered in DI is automatically injected into the service and included in chat requests. This means that any library that registers AITool instances in your service collection will have those tools available to the AI — no extra wiring needed.

For example, if you add Shiny.DI’s generated AI tools, Shiny.DocumentDb’s AI tools, or Shiny.Mediator’s AI tools to your DI container, they are automatically picked up by the conversation service and made available to the AI model during chat.

// These tools are all automatically discovered and included in AI chat requests

// Shiny.DI source-generated tools
builder.Services.AddGeneratedAITools();

// Shiny.DocumentDb tools
builder.Services.AddDocumentStoreAITools(tools => { /* ... */ });

// Your own custom tools
builder.Services.AddSingleton<AITool>(sp =>
{
    return AIFunctionFactory.Create((string city) =>
    {
        return $"The weather in {city} is sunny, 72°F.";
    }, "GetWeather", "Gets the current weather for a city");
});

Built-in: Chat History Lookup

When you register an IMessageStore with addAiLookupTool: true (the default), a ChatLookupAITool is automatically registered:

opts.SetMessageStore<MyMessageStore>(addAiLookupTool: true);

This gives the AI the ability to search past conversations. Users can ask questions like:

• “What did we discuss yesterday?”
• “Find the conversation where we talked about deployment”
• “What was the recipe you gave me last week?”

The tool exposes these search parameters to the AI:

Parameter	Type	Description
messageContains	string?	Text to search for in messages
fromDate	DateTimeOffset?	Start of date range
toDate	DateTimeOffset?	End of date range
limit	int?	Maximum results to return

Custom Tools

You can register any number of custom tools. They’re standard Microsoft.Extensions.AI tools:

// Function-based tool
builder.Services.AddSingleton<AITool>(sp =>
    AIFunctionFactory.Create(
        async (string query, CancellationToken ct) =>
        {
            var db = sp.GetRequiredService<IDatabase>();
            var results = await db.Search(query, ct);
            return string.Join("\n", results);
        },
        "SearchDatabase",
        "Searches the application database"
    )
);

Note

Tools are only included in the chat request if at least one tool is registered. The service checks the tool collection and only sets ChatOptions.Tools when it’s non-empty.