Claude Agent SDK for Go

A Go SDK for the Claude Agent, enabling programmatic interaction with Claude Code.

Installation

go get github.com/python3isfun/claude-agent-sdk-go

Prerequisites

• Go 1.21 or later
• Claude Code CLI installed and accessible in PATH

Quick Start

Simple Query

package main

import (
    "context"
    "fmt"
    "log"

    claude "github.com/python3isfun/claude-agent-sdk-go"
    "github.com/python3isfun/claude-agent-sdk-go/message"
)

func main() {
    ctx := context.Background()

    msgChan, errChan := claude.Query(ctx, "Hello Claude!",
        claude.WithSystemPrompt("You are helpful"),
    )

    for msg := range msgChan {
        if assistant, ok := msg.(*message.AssistantMessage); ok {
            fmt.Print(assistant.TextContent())
        }
    }

    if err := <-errChan; err != nil {
        log.Fatal(err)
    }
}

Interactive Session

client, err := claude.NewClient(
    claude.WithSystemPrompt("You are a coding assistant"),
    claude.WithWorkingDir("/path/to/project"),
)
if err != nil {
    log.Fatal(err)
}
defer client.Close()

client.Start(ctx)
client.SendMessage(ctx, "What files are here?")

for msg := range client.Receive() {
    // process messages
}

Custom MCP Tools

server := mcp.NewBuilder("math-tools", "1.0.0").
    ToolFunc("add", "Add two numbers", func(ctx context.Context, input map[string]interface{}) (mcp.ToolResult, error) {
        a := input["a"].(float64)
        b := input["b"].(float64)
        return mcp.TextResult(fmt.Sprintf("%.2f", a+b)), nil
    }).
    Build()

claude.Query(ctx, "What is 2+2?", claude.WithMCPServer("math", server))

Hooks for Permission Control

bashGuard := func(ctx context.Context, input hooks.Input, hctx hooks.Context) (hooks.Result, error) {
    cmd := input.ToolInput["command"].(string)
    if strings.Contains(cmd, "rm -rf") {
        return hooks.Deny("Dangerous command blocked"), nil
    }
    return hooks.Allow(), nil
}

claude.Query(ctx, prompt, claude.WithPreToolUseHook("Bash", bashGuard))

Features

• Streaming responses via Go channels
• Interactive sessions with multi-turn conversations
• Custom MCP tools with in-process servers
• Hooks system for intercepting tool use
• Permission control with multiple modes
• Context-based cancellation and timeouts

Package Structure

github.com/python3isfun/claude-agent-sdk-go/
├── agent.go              # Query() entry point
├── client.go             # Interactive client
├── options.go            # Configuration options
├── errors.go             # Error types
├── message/              # Message types
├── transport/            # CLI communication
├── mcp/                  # MCP server integration
├── hooks/                # Hook system
└── permission/           # Permission management

Options

Option	Description
WithSystemPrompt(s)	Set system prompt
WithMaxTurns(n)	Limit conversation turns
WithAllowedTools(...)	Allowlist tools
WithPermissionMode(m)	Set permission mode
WithWorkingDir(d)	Set working directory
WithMCPServer(n, s)	Add MCP server
WithPreToolUseHook(p, h)	Add pre-tool hook
WithTimeout(d)	Set request timeout
WithModel(m)	Set Claude model

Permission Modes

• ModeDefault - Requires approval for sensitive operations
• ModeAcceptEdits - Auto-approves file edits
• ModePlan - Requires explicit approval for all changes
• ModeBypassPermissions - Skips all permission checks
• ModeDontAsk - Suppresses prompts, uses defaults

License

This SDK is governed by Anthropic's Commercial Terms of Service.

Contributing

Contributions are welcome! Please open an issue or submit a pull request.