Sinew

Sinew is an open-source integrated development environment designed for deep customization and control over your development process. Key features include: • Editable tools, prompts, and modes • Three autonomy levels: Act, Plan, and Goal • Compatible with major language model providers (Claude, ChatGPT, Gemini, Kimi, OpenRouter) • Cross-platform availability (macOS, Windows, Linux) • Open-source (MIT licensed) and built in Rust This IDE allows developers to entirely reshape how their coding assistant operates. Users can activate or deactivate any tool, modify the descriptions models read for each tool, and rewrite the system prompts for different operational modes. This level of configurability means the harness is truly shaped by the user, without requiring any app modification. Sinew offers distinct modes for various development needs: 'Act' for turn-by-turn execution with diff previews, 'Plan' for read-only codebase exploration and question-asking, and 'Goal' for autonomous, long-running tasks. Each mode can be configured with a different underlying model and system prompt, allowing for optimized performance based on the task at hand. Context auto-compaction in 'Goal' mode ensures that even lengthy processes maintain focus. Built for developers who value flexibility and control, Sinew integrates with your existing language model subscriptions. It's ideal for individual developers and teams looking to fine-tune their development environment for specific coding challenges and workflows.