Caliber
A context layer that keeps CLAUDE.md, Cursor rules, AGENTS.md, and Copilot instructions synchronized to a codebase, writing them from a pre-commit hook and mirroring shared skills, rules, and MCP servers across agents.
Caliber is an open-source context layer for coding agents that bootstraps and continuously syncs the setup files each one reads: CLAUDE.md, Cursor rules, AGENTS.md, and Copilot instructions. A pre-commit hook reads the current diff and refreshes those context files, and a no-LLM scoring command checks them against the repository for drift, such as file paths that no longer exist or commands that are no longer real.
Writing a skill, rule, plugin, or MCP server for one agent and running a sync command mirrors it into every other configured agent deterministically, degrading gracefully where a target agent lacks a feature, such as turning a skill into a Copilot instruction file, and never overwriting a file a person edited by hand. A separate Jev-based compaction feature scores each tool call in a session transcript, drops stale ones, and keeps the rest byte-for-byte, as a plugin replacing Claude Code's built-in /compact or as an equivalent CLI command for other agents.
It runs on Node 20 or later and can bootstrap and sync using a Claude Code or Cursor seat or the user's own Anthropic, OpenAI, MiniMax, or Vertex key.