Cline has made a significant leap in the AI agent ecosystem by open-sourcing its internal runtime as the @cline/sdk. This release provides developers with a highly versatile and powerful toolkit to build custom AI agents using Cline's proven architecture. The SDK features a modular four-layer stack, meticulously designed to support advanced features such as native plugins, subagents, and CRON scheduling.
The performance metrics of the new SDK are particularly impressive. In the Terminal Benchmark 2.0, Cline's runtime outperformed Anthropic’s own Claude Code, demonstrating superior efficiency and accuracy in executing terminal-based tasks. This benchmark success validates the SDK’s capability to handle complex, real-world development workflows better than leading proprietary alternatives.
Currently, the @cline/sdk is already powering Cline’s CLI and Kanban tools, with IDE extensions being migrated to the new runtime. For developers looking to integrate this technology, the runtime is available via npm and requires Node.js 22 or higher. The inclusion of Model Context Protocol (MCP) connectors ensures that agents built with this SDK can seamlessly interface with a wide range of external tools and data environments.
