$ ctxfs product
How it works
A copy-on-write filesystem for running lots of agents on one repository. What ctxfs does, what it’s built with, and how far along it is.
The premise
On Windows, running ten coding agents against one repository usually means ten full copies of it. ctxfs gives each agent its own writable view of the same repository. Reads come from a shared, read-only snapshot, and each agent’s writes land in its own layer on top.
Each of those views is a normal git repository, so you bring work back together with ordinary git merges. The shared snapshot is pinned to one commit and never changes.
What’s included
A shared read-only snapshot, with a copy-on-write layer for each agent
Every view is a normal git repository, so merging work back is just a merge
Passthrough, overlay, git lifecycle and hardening milestones are done
Verified with a live Claude Code session running on a mounted view (ctxfs run demo -- claude)
How it’s built
ctxfs is built on Go, WinFsp, SQLite and git.
It carries 66 commits since Jul 2026, most recently changed in Jul 2026.
How the work is done
Every project here starts as a written spec, and the spec stays the source of truth once there’s code. The repository keeps a build plan with current status, an append-only decision log of where the code departed from the plan, and a handoff document that describes where things stand, including the unfinished parts.
That’s how one person keeps this many projects moving, and it’s what this page is written from.
Current state
In development. Being worked on now.
The source is private, so the way to check what this page says is to use the product.
Next
Put ctxfs in your pipeline
Ask about hooking it up to the repositories and agents you already run.