Go ReAct

This is not an officially supported Google product.

Go implementation of Reason+Act based on Google's blog post.

This library provides several components to chain together to help integrate with Large Language Models (LLMs). It does so in a way that allows the using code to be type safe.

Prompters

Prompters are used to generate a prompt and LLM parameters to send to the LLM. The normal one to use is prompters.NewTextTemplate. This uses the text/template package to generate the prompt. The given TPrompt is passed to the template when it's executed. The output is then retruned. The TLLMParams are passed through so that the LLM can use them.

type Data struct {
  Product string
}
data := Data{Product: "Gophers"}
llmParams := 3

tmpl := "Come up with store names that sell {{.Product}}!"
t := prompters.NewTextTemplate[Data, int](tmpl, llmParams)

prompt, params, err := t.Hydrate(context.Background(), data)
if err != nil {
  panic(err)
}
fmt.Printf("Prompt: %s\nParams: %d\n", prompt, params)

// Output:
// Prompt: Come up with store names that sell Gophers!
// Params: 3

Parsers

Parsers are used to parse the output of an LLM. The normal one to use is predictors.NewJSONParser. This expects the output of the LLM to be JSON. It uses the given type to decode into.

type Data struct {
  Name string `json:"name"`
  Age  int    `json:"age"`
}
p := parsers.NewJSONParser[Data]()
person, err := p.Parse(`{"name": "John", "age": 30}`)
if err != nil {
  panic(err)
}
fmt.Printf("%+v\n", person)

// Output:
// {Name:John Age:30}

Predictors

Predictors are a wrapper around an LLM. It is used to predict output (TResp) based on the given TReq. It takes an llms.LLM, a prompters.Prompter and a parsers.Parser. Predictors are often chained together to add functionality.

// This example demonstrates how to chain multiple predictors together.
// The fake one will always return an error indicating that the prediction
// from the LLM failed for some reason. The JSONLogger will log the request
// while the retrier will retry the request 3 times before giving up.

var predictor predictors.Predictor[int, string] = &predictorstesting.Fake[int, string]{
	Err: fmt.Errorf("%w: some-error", predictors.ErrLLM),
}
predictor = predictors.NewJSONLogger(predictor, os.Stdout)
predictor = predictors.NewRetrier(predictor)

predictor.Predict(context.Background(), 1)

// Output:
// {"request":1}
// {"request":1}
// {"request":1}

Agents

Agents are a component that allow the configured LLM to decide which tools to use to achieve a goal. An Agent has an output type that is returned as the FinalAnswer.

Tools

A tool is invoked when its name is returned by the LLM. It should return an observation based on the output. If the input into a tool is invalid, then the tools.ErrInvalidToolInput error should wrapped and returned.

If the tool returns an error, it is changed into an observation that is given to the LLM with a ERROR: prefix.

It is a common pattern to build a tool as an Agent. This allows a hierarchy of Agents and allows more tools to be used with the LLM.

app-editor example

The app-editor example demonstrates setting up a tool set and Agent. This example allows a user to interact with the AI to build up a simple app structure.