Stream text as it arrives

Print a model's answer while it is still being written.

package main

import (
	"context"
	"errors"
	"fmt"
	"io"
	"log"
	"os"

	"github.com/digitallysavvy/go-ai/pkg/ai"
	"github.com/digitallysavvy/go-ai/pkg/provider"
	"github.com/digitallysavvy/go-ai/pkg/providers/openai"
)

func main() {
	model, err := openai.New(openai.Config{APIKey: os.Getenv("OPENAI_API_KEY")}).
		LanguageModel(openai.ModelGPT6Astra)
	if err != nil {
		log.Fatal(err)
	}

	result, err := ai.StreamText(context.Background(), ai.StreamTextOptions{
		Model:  model,
		Prompt: "Write a haiku about concurrency.",
	})
	if err != nil {
		log.Fatal(err)
	}

	stream := result.Stream()
	for {
		chunk, err := stream.Next()
		if errors.Is(err, io.EOF) {
			break
		}
		if err != nil {
			log.Fatal(err)
		}
		if chunk.Type == provider.ChunkTypeText {
			fmt.Print(chunk.Text)
		}
	}
	if err := stream.Err(); err != nil {
		log.Fatal(err)
	}
	fmt.Println()
}

Run it:

OPENAI_API_KEY=... go run ./examples/recipes/stream-text

Notes

• ai.StreamText returns a result right away. result.Stream() yields chunks.
• Loop on stream.Next() until it returns io.EOF, then check stream.Err().
• Chunks have a Type. Text arrives as provider.ChunkTypeText with the delta in chunk.Text.
• To send the stream to a browser, use ai.PipeUIMessageStreamToResponse or PipeTextStreamToResponse.

Go deeper

• Guide: Streaming
• Reference: Stream text
• Reference: Stream transport helpers

The full program is at examples/recipes/stream-text/main.go.