ctxopt gives your AI coding agent a map of your project instead of forcing it to re-read everything each session. Free, open-source config for Claude Code, Codex, Antigravity, and Cursor — measured on a real project (64.5% less context on exploration tasks), not marketing numbers.
Hey PH 👋
I built ctxopt because I kept running out of context credits on Claude Code before finishing my workday — turns out it's not the model, it's that every task forces the agent to re-read a chunk of your project it's already seen.
Before writing a single line of marketing copy, I tested it on a real production project. The honest results: 64.5% less context on exploration tasks, but on one specific task the result came out roughly even — I left that in, because a tool that claims to "always save" isn't one I'd trust either.
It's free and open source — works with Claude Code, Codex, Antigravity, and Cursor through the AGENTS.md standard. There's also an optional paid guide pack if you want the step-by-step walkthrough instead of figuring it out yourself.
Happy to answer anything about how it works, what it doesn't do, or where it falls short — genuinely want the feedback.