1package main
 2
 3// This is a basic example illustrting how to create an agent with a custom
 4// tool call.
 5
 6import (
 7	"context"
 8	"fmt"
 9	"os"
10
11	"charm.land/fantasy"
12	"charm.land/fantasy/providers/openrouter"
13)
14
15func main() {
16	// Choose your fave provider.
17	provider, err := openrouter.New(openrouter.WithAPIKey(os.Getenv("OPENROUTER_API_KEY")))
18	if err != nil {
19		fmt.Fprintln(os.Stderr, "Whoops:", err)
20		os.Exit(1)
21	}
22
23	ctx := context.Background()
24
25	// Pick your fave model.
26	model, err := provider.LanguageModel(ctx, "moonshotai/kimi-k2")
27	if err != nil {
28		fmt.Fprintln(os.Stderr, "Dang:", err)
29		os.Exit(1)
30	}
31
32	// Let's make a tool that fetches info about cute dogs. Here's a schema
33	// for the tool's input.
34	type cuteDogQuery struct {
35		Location string `json:"location" description:"The location to search for cute dogs."`
36	}
37
38	// And here's the implementation of that tool.
39	fetchCuteDogInfo := func(ctx context.Context, input cuteDogQuery, _ fantasy.ToolCall) (fantasy.ToolResponse, error) {
40		if input.Location == "Silver Lake, Los Angeles" {
41			return fantasy.NewTextResponse("Cute dogs are everywhere!"), nil
42		}
43		return fantasy.NewTextResponse("No cute dogs found."), nil
44	}
45
46	// Add the tool.
47	cuteDogTool := fantasy.NewAgentTool("cute_dog_tool", "Provide up-to-date info on cute dogs.", fetchCuteDogInfo)
48
49	// Equip your agent.
50	agent := fantasy.NewAgent(model, fantasy.WithTools(cuteDogTool))
51
52	// Put that agent to work!
53	const prompt = "Find all the cute dogs in Silver Lake, Los Angeles."
54	result, err := agent.Generate(ctx, fantasy.AgentCall{Prompt: prompt})
55	if err != nil {
56		fmt.Fprintln(os.Stderr, "Oof:", err)
57		os.Exit(1)
58	}
59	fmt.Println(result.Response.Content.Text())
60}