Rewrite SDK to Claude Code SDK for Go with Anthropic Focus

[ryanhill4L]

Summary

• Complete rewrite of the SDK aligning with the official Python Claude Code SDK architecture
• Focus exclusively on Anthropic Claude API, removing multi-provider support
• Introduces dual interface pattern: simple stateless queries and interactive client for conversations
• Replaces agents and runners with a unified client interface
• Implements new permission system replacing guardrails
• Adds hooks system replacing tracing for event-driven extensibility
• Adds native streaming support and built-in session management
• Simplifies package structure and improves type safety
• Removes agent handoffs in favor of tool-based delegation

Changes

Core SDK

• New claudecode package as main entry point
• Added NewClient and Query functions for interactive and simple query usage
• Removed old agents, providers, and runner packages
• Introduced client package managing conversation state, tools, hooks, permissions, and transport
• Integrated official anthropic-sdk-go for API communication
• Added comprehensive error handling in errors package

Package Structure

• Simplified imports to claudecode and pkg/types, pkg/tools, etc.
• Removed multi-provider support; only Anthropic transport remains

Features

• Dual interface: Query for simple one-off queries, Client for stateful conversations
• Tools system enhanced with type safety and permission controls
• Permissions replace guardrails with callback-based access control
• Hooks replace tracing with event hooks for pre/post message and tool use
• Session management built-in with SQLite backend
• Streaming support for real-time response chunks

Examples

• Removed old multi-provider and multi-agent examples
• Added new examples demonstrating simple queries, interactive client, tools, permissions, hooks, and streaming

Documentation

• Updated README to reflect new architecture, usage patterns, and migration guide
• Added MIGRATION.md detailing step-by-step migration from v1 to v2

Migration Notes

• No more multi-provider or agent handoffs; use tools and single Anthropic client
• Replace old agent/runner code with claudecode.NewClient and client.SendMessage
• Update imports to new package structure
• Implement permission callbacks instead of guardrails
• Use hooks for event handling instead of tracing

Test Plan

• Verified all new examples run successfully
• Manual testing of simple queries and interactive client
• Permission and hook callbacks tested with example scenarios
• Streaming tested with real-time output

This rewrite modernizes the SDK, focusing on Anthropic Claude with a clean, idiomatic Go interface and improved developer experience.

🌿 Generated by Terry

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📎 Task: https://www.terragonlabs.com/task/cb2fc764-f070-499f-a35c-c65607bbe0d0