After a cache hit, dist holds only what was cached

After a cache hit, your output folder holds exactly what was cached. A
deleted file never lingers in dist/ and gets shipped.

$ echo "stale" > packages/a/dist/old.js
$ ls packages/a/dist
index.js  old.js

$ vx run packages/a#build
└─ packages/a#build ── (20ms) restored-local

$ ls packages/a/dist
index.js

Demo workspace · vx 69617eb · 2026-10-23

A task owns its output globs

Before a miss runs, vx deletes what the output globs match. So an old
dist/old.js cannot be saved as new output. A hit moves each file into
place, so a reader never sees one missing.

Two tasks cannot own one file

$ vx lock
✗ vx lock  lock not written

  packages/a#notes and packages/a#slow both write out/** / out/copy.ts
  vx clears a task's outputs before it runs, so one deletes the other's

  fix  give each task its own output path

Overlaps vx can prove are refused. Set rules.exclusiveOutputs: false
to let a later task add to an earlier one's folder. It works, but its
own output path is faster.

It is also the fast path

vx records each output file (size, mode, mtime-ms, inode, ctime).

On the next hit, if the set and every file match, the restore is a few
stats and no writes, and it is the no-op row in the
benchmarks.

Their restore row deletes the outputs first, so every artifact is
extracted, and it costs more.

What the wipe never touches

• Files outside the declared globs.
• Another project's directory.
• The project root's .git, .vx and vx.lock.json.
• A file git tracks. It is still saved and restored.
• node_modules, unless a glob names it. node_modules/** is a legitimate output of an install task.

You get a clean git status

A task with no cache block owns nothing, and vx leaves its files
alone. More at vznjs.github.io/vx.

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Originally published on the vx blog. vx is open-source (MIT) task orchestration with a build cache: vznjs.github.io/vx · GitHub.

_{Written with AI assistance.}