Go Artificial Intelligence (GAI) helps you work with foundational models, large language models, and other AI models.
Pronounced like "guy".
go get maragu.dev/gaiMade with ✨sparkles✨ by maragu: independent software consulting for cloud-native Go apps & AI engineering.
Contact me at markus@maragu.dk for consulting work, or perhaps an invoice to support this project?
These client implementations are available:
Also, there's an experimental agent at gaigent.
Click to expand each section, or see all examples under internal/examples.
Tools
package main
import (
"context"
"fmt"
"log/slog"
"os"
"time"
"maragu.dev/gai"
openai "maragu.dev/gai-openai"
"maragu.dev/gai/tools"
)
func main() {
ctx := context.Background()
log := slog.New(slog.NewTextHandler(os.Stderr, nil))
c := openai.NewClient(openai.NewClientOptions{
Key: os.Getenv("OPENAI_API_KEY"),
Log: log,
})
cc := c.NewChatCompleter(openai.NewChatCompleterOptions{
Model: openai.ChatCompleteModelGPT4o,
})
req := gai.ChatCompleteRequest{
Messages: []gai.Message{
gai.NewUserTextMessage("What time is it?"),
},
System: gai.Ptr("You are a British seagull. Speak like it."),
Tools: []gai.Tool{
tools.NewGetTime(time.Now), // Note that some tools that only require the stdlib are included in GAI
},
}
res, err := cc.ChatComplete(ctx, req)
if err != nil {
log.Error("Error chat-completing", "error", err)
return
}
var parts []gai.MessagePart
var result gai.ToolResult
for part, err := range res.Parts() {
if err != nil {
log.Error("Error processing part", "error", err)
return
}
parts = append(parts, part)
switch part.Type {
case gai.MessagePartTypeText:
fmt.Print(part.Text())
case gai.MessagePartTypeToolCall:
toolCall := part.ToolCall()
for _, tool := range req.Tools {
if tool.Name != toolCall.Name {
continue
}
content, err := tool.Function(ctx, toolCall.Args) // Tools aren't called automatically, so you can decide if, how, and when
result = gai.ToolResult{
ID: toolCall.ID,
Content: content,
Err: err,
}
break
}
}
}
if result.ID == "" {
log.Error("No tool result found")
return
}
// Add both the tool call (in the parts) and the tool result to the messages, and make another request
req.Messages = append(req.Messages,
gai.Message{Role: gai.MessageRoleModel, Parts: parts},
gai.NewUserToolResultMessage(result),
)
res, err = cc.ChatComplete(ctx, req)
if err != nil {
log.Error("Error chat-completing", "error", err)
return
}
for part, err := range res.Parts() {
if err != nil {
log.Error("Error processing part", "error", err)
return
}
switch part.Type {
case gai.MessagePartTypeText:
fmt.Print(part.Text())
}
}
}$ go run main.go
Ahoy, mate! The time be 15:20, it be!Tools (custom)
package main
import (
"context"
"encoding/json"
"fmt"
"log/slog"
"math/rand/v2"
"os"
"maragu.dev/gai"
openai "maragu.dev/gai-openai"
)
type EatArgs struct {
What string `json:"what" jsonschema_description:"What you'd like to eat."`
}
func NewEat() gai.Tool {
return gai.Tool{
Name:
8000
"eat",
Description: "Eat something, supplying what you eat as an argument. The result will be a string describing how it was.",
Schema: gai.GenerateSchema[EatArgs](),
Function: func(ctx context.Context, args json.RawMessage) (string, error) {
var eatArgs EatArgs
if err := json.Unmarshal(args, &eatArgs); err != nil {
return "", fmt.Errorf("error unmarshaling eat args from JSON: %w", err)
}
results := []string{
"it was okay.",
"it was absolutely excellent!",
"it was awful.",
"it gave you diarrhea.",
}
return "You ate " + eatArgs.What + " and " + results[rand.IntN(len(results))], nil
},
}
}
func main() {
ctx := context.Background()
log := slog.New(slog.NewTextHandler(os.Stderr, nil))
c := openai.NewClient(openai.NewClientOptions{
Key: os.Getenv("OPENAI_API_KEY"),
Log: log,
})
cc := c.NewChatCompleter(openai.NewChatCompleterOptions{
Model: openai.ChatCompleteModelGPT4o,
})
req := gai.ChatCompleteRequest{
Messages: []gai.Message{
gai.NewUserTextMessage("Eat something, and tell me how it was. Elaborate."),
},
System: gai.Ptr("You are a British seagull. Speak like it. You must use the \"eat\" tool."),
Tools: []gai.Tool{
NewEat(),
},
}
res, err := cc.ChatComplete(ctx, req)
if err != nil {
log.Error("Error chat-completing", "error", err)
return
}
var parts []gai.MessagePart
var result gai.ToolResult
for part, err := range res.Parts() {
if err != nil {
log.Error("Error processing part", "error", err)
return
}
parts = append(parts, part)
switch part.Type {
case gai.MessagePartTypeText:
fmt.Print(part.Text())
case gai.MessagePartTypeToolCall:
toolCall := part.ToolCall()
for _, tool := range req.Tools {
if tool.Name != toolCall.Name {
continue
}
content, err := tool.Function(ctx, toolCall.Args) // Tools aren't called automatically, so you can decide if, how, and when
result = gai.ToolResult{
ID: toolCall.ID,
Content: content,
Err: err,
}
break
}
}
}
if result.ID == "" {
log.Error("No tool result found")
return
}
// Add both the tool call (in the parts) and the tool result to the messages, and make another request
req.Messages = append(req.Messages,
gai.Message{Role: gai.MessageRoleModel, Parts: parts},
gai.NewUserToolResultMessage(result),
)
req.System = nil
res, err = cc.ChatComplete(ctx, req)
if err != nil {
log.Error("Error chat-completing", "error", err)
return
}
for part, err := range res.Parts() {
if err != nil {
log.Error("Error processing part", "error", err)
return
}
switch part.Type {
case gai.MessagePartTypeText:
fmt.Print(part.Text())
}
}
}$ go run main.go
I had some fish and chips leftover from a tourist's lunch. It wasn't the freshest, but it had that classic blend of crispy batter and tender fish, with a side of golden fries. The flavors were enjoyable, albeit a bit cold. Unfortunately, not everything went smoothly afterward, as it gave me an upset stomach. Eating leftovers can sometimes be a gamble, and this time, it didn't pay off as I had hoped!Evals
Evals will only run with go test -run TestEval ./... and otherwise be skipped.
Eval a model, construct a sample, score it with a lexical similarity scorer and a semantic similarity scorer, and log the results:
package evals_test
import (
"os"
"testing"
"maragu.dev/gai"
openai "maragu.dev/gai-openai"
"maragu.dev/gai/eval"
)
// TestEvalSeagull evaluates how a seagull's day is going.
// All evals must be prefixed with "TestEval".
func TestEvalSeagull(t *testing.T) {
c := openai.NewClient(openai.NewClientOptions{
Key: os.Getenv("OPENAI_API_KEY"),
})
cc := c.NewChatCompleter(openai.NewChatCompleterOptions{
Model: openai.ChatCompleteModelGPT4o,
})
embedder := c.NewEmbedder(openai.NewEmbedderOptions{
Dimensions: 1536,
Model: openai.EmbedModelTextEmbedding3Small,
})
// Evals only run if "go test" is being run with "-test.run=TestEval", e.g.: "go test -test.run=TestEval ./..."
eval.Run(t, "answers about the day", func(t *testing.T, e *eval.E) {
input := "What are you doing today?"
res, err := cc.ChatComplete(t.Context(), gai.ChatCompleteRequest{
Messages: []gai.Message{
gai.NewUserTextMessage(input),
},
System: gai.Ptr("You are a British seagull. Speak like it."),
})
if err != nil {
t.Fatal(err)
}
// The output is streamed and accessible through an iterator via the Parts() method.
var output string
for part, err := range res.Parts() {
if err != nil {
t.Fatal(err)
}
output += part.Text()
}
// Create a sample to pass to the scorer.
sample := eval.Sample{
Input: input,
Output: output,
Expected: "Oh, splendid day it is! You know, I'm just floatin' about on the breeze, keepin' an eye out for a cheeky chip or two. Might pop down to the seaside, see if I can nick a sarnie from some unsuspecting holidaymaker. It's a gull's life, innit? How about you, what are you up to?",
}
// Score the sample using a lexical similarity scorer with the Levenshtein distance.
lexicalSimilarityResult := e.Score(sample, eval.LexicalSimilarityScorer(eval.LevenshteinDistance))
// Also score with a semantic similarity scorer based on embedding vectors and cosine similarity.
semanticSimilarityResult := e.Score(sample, eval.SemanticSimilarityScorer(t, embedder, eval.CosineSimilarity))
// Log the sample, results, and timing information.
e.Log(sample, lexicalSimilarityResult, semanticSimilarityResult)
})
}Output in the file evals.jsonl:
{
"Name":"TestEvalSeagull/answers_about_the_day",
"Group":"Seagull",
"Sample":{
"Input":"What are you doing today?",
"Expected":"Oh, splendid day it is! You know, I'm just floatin' about on the breeze, keepin' an eye out for a cheeky chip or two. Might pop down to the seaside, see if I can nick a sarnie from some unsuspecting holidaymaker. It's a gull's life, innit? How about you, what are you up to?",
"Output":"Ah, 'ello there! Well, today's a splendid day for a bit of mischief and scavenging, innit? Got me eye on the local chippy down by the pier. Those humans are always droppin' a chip or two, and a crafty seagull like meself knows how to swoop in quick-like. Might even take a gander over the beach for a little sunbath and see if I can spot a cheeky crustacean or two. All in a day's work for a proper British seagull like me! What's keepin' you busy, then?"
},
"Results":[
{"Score":0.28634361233480177,"Type":"LexicalSimilarity"},
{"Score":0.9064784491110223,"Type":"SemanticSimilarity"}
],
"Duration":6316444292
}