AI Package

AI package API reference (Go)

The ai package provides core AI functionality including generation, models, tools, and prompts.

Generate Options

WithModelName()

Specifies the model by name.

ai.WithModelName("googleai/gemini-2.0-flash")

WithModel()

Specifies the model instance.

model := genkit.LookupModel(g, "googleai/gemini-2.0-flash")
ai.WithModel(model)

WithPrompt()

Sets the user prompt.

ai.WithPrompt("Tell me a joke about programming.")

WithSystem()

Sets system instructions.

ai.WithSystem("You are a helpful coding assistant.")

WithMessages()

Provides conversation history.

ai.WithMessages([]*ai.Message{
    {Role: ai.RoleUser, Content: []*ai.Part{ai.NewTextPart("Hello")}},
    {Role: ai.RoleModel, Content: []*ai.Part{ai.NewTextPart("Hi!")}},
})

WithTools()

Enables tools for the model.

ai.WithTools(weatherTool, calculatorTool)

WithToolChoice()

Controls tool usage.

ai.WithToolChoice(ai.ToolChoiceRequired) // Force tool use
ai.WithToolChoice(ai.ToolChoiceNone)     // Disable tools
ai.WithToolChoice(ai.ToolChoiceAuto)     // Let model decide

WithConfig()

Sets generation parameters.

ai.WithConfig(&ai.GenerationCommonConfig{
    Temperature: 0.7,
    MaxOutputTokens: 1000,
    TopP: 0.9,
})

WithOutputType()

Sets structured output schema from type.

type Person struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
}

ai.WithOutputType(Person{})

WithOutputSchema()

Sets output JSON schema.

ai.WithOutputSchema(map[string]any{
    "type": "object",
    "properties": map[string]any{
        "name": map[string]any{"type": "string"},
    },
})

WithDocs()

Provides context documents.

ai.WithDocs([]*ai.Document{
    ai.Document.FromText("Context document 1"),
    ai.Document.FromText("Context document 2"),
})

WithStreaming()

Enables streaming with callback.

ai.WithStreaming(func(ctx context.Context, chunk *ai.ModelResponseChunk) error {
    fmt.Print(chunk.Text())
    return nil
})

Types

Message

type Message struct {
    Role     Role
    Content  []*Part
    Metadata map[string]any
}

Roles:

• ai.RoleUser
• ai.RoleModel
• ai.RoleSystem
• ai.RoleTool

Part

// Create parts
ai.NewTextPart("Hello")
ai.NewMediaPart("image/png", imageData)
ai.NewToolRequestPart(name, input)
ai.NewToolResponsePart(name, output)

ModelResponse

type ModelResponse struct {
    Message      *Message
    FinishReason FinishReason
    Usage        *GenerationUsage
    Request      *ModelRequest
    Custom       map[string]any
}

// Methods
resp.Text() string
resp.Output(v any) error

ModelRequest

type ModelRequest struct {
    Messages []*Message
    Tools    []*ToolDefinition
    Config   any
    Output   *OutputConfig
}

GenerationCommonConfig

type GenerationCommonConfig struct {
    Temperature     float64
    MaxOutputTokens int
    TopK            int
    TopP            float64
    StopSequences   []string
}