Tools

Blades provides convenient support for custom tools, allowing you to create your own functional tools.

Functional Tools

Defining Tools

tools.NewFunc(...) is the core method for creating a function-based tool, which includes the following parameters:

name: The name of the tool, used to identify the tool.

description: The description of the tool, used to inform the user about the tool’s functionality.

handler: The handler function of the tool, used to process the tool’s request and return the result. When defining the handler, a wrapper is required to convert an ordinary Go function into a tool handler function that blades can recognize.

// WeatherReq represents a request for weather information.
type WeatherReq struct {
    Location string `json:"location" jsonschema:"Get the current weather for a given city"`
}

// WeatherRes represents a response containing weather information.
type WeatherRes struct {
    Forecast string `json:"forecast" jsonschema:"The weather forecast"`
}
weatherTool, err := tools.NewFunc(
    "get_weather",
    "Get the current weather for a given city",
    weatherHandle,
)

Creating an Agent and Importing Tools

// Configure OpenAI API key and base URL using environment variables:
model := openai.NewModel("gpt-5", openai.Config{
    APIKey: os.Getenv("OPENAI_API_KEY"),
})
agent, err := blades.NewAgent(
    "Weather Agent",
    blades.WithModel(model),
    blades.WithInstruction("You are a helpful assistant that provides weather information."),
    blades.WithTools(weatherTool),
)
if err != nil {
    log.Fatal(err)
}

Running

input := blades.UserMessage("What is the weather in New York City?")
    session := blades.NewSession()
    runner := blades.NewRunner(agent, blades.WithSession(session))
    ctx := context.Background()
    output, err := runner.Run(ctx, input)
    if err != nil {
        log.Fatal(err)
    }
    log.Println("state:", session.State())
    log.Println("output:", output.Text())

After successfully running the code, you will see output similar to the following:

2025/11/14 11:01:18 stream status: completed output: The weather in San Francisco is currently sunny with a temperature of 25°C.