add readme

tools/perplexity/README.md

@@ -0,0 +1,62 @@
+
+# Perplexity Tool Integration for Agents
+
+Use perplexity in your AI Agent to enrich it with data from the web.
+
+Full code example:
+
+```go
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/tmc/langchaingo/agents"
+	"github.com/tmc/langchaingo/callbacks"
+	"github.com/tmc/langchaingo/chains"
+	"github.com/tmc/langchaingo/llms/openai"
+	"github.com/tmc/langchaingo/tools"
+	"github.com/tmc/langchaingo/tools/perplexity"
+)
+
+func main() {
+	if err := run(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	llm, err := openai.New(
+		openai.WithModel("gpt-4o-mini"),
+		openai.WithCallback(callbacks.LogHandler{}),
+	)
+	if err != nil {
+		return err
+	}
+
+	perpl, err := perplexity.NewPerplexity(perplexity.ModelLlamaSonarSmall)
+	if err != nil {
+		return err
+	}
+
+	agentTools := []tools.Tool{
+		perpl,
+	}
+
+	agent := agents.NewOneShotAgent(llm,
+		agentTools,
+		agents.WithMaxIterations(2),
+	)
+	executor := agents.NewExecutor(agent)
+
+	question := "what's the latest and best LLM on the market at the moment?"
+	answer, err := chains.Run(context.Background(), executor, question)
+
+	fmt.Println(answer)
+
+	return err
+}
+```