Multi-Turn Conversations

GoAI supports multi-turn conversations through WithMessages. After each generation call, ResponseMessages provides the full assistant and tool message history, ready to append to your conversation.

The Problem

When using tools with WithMaxSteps, GoAI runs an automatic tool loop: generate, execute tools, re-generate. The result contains the final text, but your conversation history needs the intermediate tool call and tool result messages too. Without them, the model may re-execute tools on the next turn.

ResponseMessages

ResponseMessages on TextResult (and ObjectResult) contains all assistant and tool messages produced during a generation call. Append it directly to your message history:

var messages []provider.Message

// Turn 1
messages = append(messages, goai.UserMessage("What's the weather in Tokyo?"))
result, err := goai.GenerateText(ctx, model,
    goai.WithMessages(messages...),
    goai.WithTools(weatherTool),
    goai.WithMaxSteps(5),
)
if err != nil {
    log.Fatal(err)
}

// Append the full response history (assistant + tool messages).
messages = append(messages, result.ResponseMessages...)

// Turn 2 - model sees the tool was already called, won't repeat it.
messages = append(messages, goai.UserMessage("Is that warm enough for a picnic?"))
result, err = goai.GenerateText(ctx, model,
    goai.WithMessages(messages...),
    goai.WithTools(weatherTool),
    goai.WithMaxSteps(5),
)

What ResponseMessages Contains

The contents depend on what happened during generation:

Scenario	ResponseMessages
Simple text (no tools)	1 assistant message with text
Tool loop (2 steps)	assistant (tool calls) + tool (results) + assistant (final text)
Parallel tool calls	Tool results merged into a single message per round-trip
MaxSteps exhausted	All completed round-trips (no duplicate final message)
Streaming with reasoning	Reasoning boundaries preserved as one or more PartReasoning values with metadata

Streaming

ResponseMessages works the same way with StreamText. Call Result() after consuming the stream:

stream, err := goai.StreamText(ctx, model,
    goai.WithMessages(messages...),
    goai.WithTools(weatherTool),
    goai.WithMaxSteps(5),
)
if err != nil {
    log.Fatal(err)
}
// Consume the stream.
for chunk := range stream.Stream() {
    fmt.Print(chunk.Text)
}
// Check for errors before using ResponseMessages.
if err := stream.Err(); err != nil {
    log.Fatal(err)
}
// Append to history.
messages = append(messages, stream.Result().ResponseMessages...)

On stream errors, ResponseMessages may be partial. Always check Err() first.

Structured Output

GenerateObject and StreamObject also populate ResponseMessages:

result, err := goai.GenerateObject[MyStruct](ctx, model,
    goai.WithMessages(messages...),
    goai.WithTools(helperTool),
    goai.WithMaxSteps(5),
)
messages = append(messages, result.ResponseMessages...)

Without ResponseMessages

If you prefer manual control, you can build messages from result.Steps. Completed tool outputs are available in StepResult.ToolResults; WithOnToolCall is only needed for real-time observation. ResponseMessages handles reconstruction automatically.

TIP

See examples/multi-turn/ for a runnable example.