go

Kimi Agent SDK for Go

Go SDK for programmatically controlling Kimi Agent sessions via the kimi-cli.

Installation

go get github.com/MoonshotAI/kimi-agent-sdk/go

Prerequisites

• kimi CLI installed and available in PATH
• KIMI_BASE_URL, KIMI_API_KEY, KIMI_MODEL_NAME environment variables set, or use kimi.Option instead

Usage

package main

import (
    "context"
    "fmt"

    kimi "github.com/MoonshotAI/kimi-agent-sdk/go"
    "github.com/MoonshotAI/kimi-agent-sdk/go/wire"
)

func main() {
    session, err := kimi.NewSession(
        kimi.WithBaseURL("https://api.moonshot.ai/v1"),
        kimi.WithAPIKey("your-api-key"),
        kimi.WithModel("kimi-k2-thinking-turbo"),
    )
    if err != nil {
        panic(err)
    }
    defer session.Close()

    turn, err := session.Prompt(context.Background(), wire.NewStringContent("Hello!"))
    if err != nil {
        panic(err)
    }

    for step := range turn.Steps {
        for msg := range step.Messages {
            if cp, ok := msg.(wire.ContentPart); ok && cp.Type == wire.ContentPartTypeText {
                fmt.Print(cp.Text.Value)
            }
        }
    }

    // Check for errors that occurred during streaming
    if err := turn.Err(); err != nil {
        panic(err)
    }
}

Turn Methods

After consuming all messages from a turn, you can inspect the turn's final state:

• turn.Err() - Returns any error that occurred during streaming
• turn.Result() - Returns the wire.PromptResult containing the final status
• turn.Usage() - Returns token usage information (Context and Tokens)

Responding to Requests

For wire.Request messages (e.g., ApprovalRequest), you must call Respond(). Failing to do so will block the session indefinitely.

for step := range turn.Steps {
    for msg := range step.Messages {
        if req, ok := msg.(wire.ApprovalRequest); ok {
            // Approve the request
            req.Respond(wire.ApprovalRequestResponseApprove)
            // Or reject: req.Respond(wire.ApprovalRequestResponseReject)
        }
    }
}

External Tools

You can register external tools that the model can call during a session. Use kimi.CreateTool to create a tool from a Go function, and kimi.WithTools to register them.

Note: External tools require wire_protocol_version >= 2. The SDK automatically detects the protocol version from the CLI. If your CLI version doesn't support protocol v2, external tools will be silently ignored.

Defining a Tool

// Define argument struct - JSON schema is generated automatically
type WeatherArgs struct {
    Location string `json:"location" description:"City name"`
    Unit     string `json:"unit,omitempty" description:"Temperature unit (celsius or fahrenheit)"`
}

// Define result type - can be string, fmt.Stringer, or any JSON-serializable type
type WeatherResult struct {
    Temperature float64 `json:"temperature"`
    Condition   string  `json:"condition"`
}

// Create the tool function
func getWeather(args WeatherArgs) (WeatherResult, error) {
    // Your implementation here
    return WeatherResult{Temperature: 22.0, Condition: "Sunny"}, nil
}

Registering Tools

tool, err := kimi.CreateTool(getWeather,
    kimi.WithName("get_weather"),
    kimi.WithDescription("Get current weather for a location"),
)
if err != nil {
    panic(err)
}

session, err := kimi.NewSession(
    kimi.WithTools(tool),
    // ... other options
)

Tool Options

• kimi.WithName(name) - Set tool name (defaults to function name)
• kimi.WithDescription(desc) - Set tool description
• kimi.WithFieldDescription(field, desc) - Set description for a struct field (alternative to description tag)
• kimi.WithSchema(schema) - Set JSON schema directly, bypassing automatic generation

JSON Schema Generation

The SDK automatically generates JSON schema from the argument struct:

• Struct fields become object properties
• Fields with omitempty or omitzero tag are optional
• Pointer fields are always optional
• Use description tag or kimi.WithFieldDescription to document fields

How It Works

When the model calls your tool, the SDK automatically:

1. Receives ToolCall request from the CLI
2. Parses arguments and calls your function
3. Converts the result to string:
   • string → returned directly
   • fmt.Stringer → calls .String()
   • Other types → JSON serialized
4. Sends the result back via ToolResult

You don't need to handle external tool calls manually - just consume messages as usual.

Important Notes

1. Sequential Prompts: Call Prompt sequentially. Wait for the previous turn to complete before starting a new one.

2. Resource Cleanup: Always use defer session.Close() to ensure proper cleanup.

3. Consume All Messages: You must consume all messages from step.Messages and all steps from turn.Steps before starting a new Prompt.

4. Cancellation: You can cancel a turn either by canceling the context or by calling turn.Cancel() explicitly.