What vx is, and what it refuses to be

vx runs and caches your task graph, correctly, and stops there. Here is what that means in practice.

A run is a pipeline

flowchart LR
  L[read the lock] --> G[build the graph]
  G --> K[derive keys]
  K --> S[schedule]
  S --> X[executor: where it runs]
  S --> C[cache: where artifacts live]
  S --> T[telemetry: who watches]
  style K stroke:#c6f84e,stroke-width:2px

1. Lock. vx lock runs each vx.config.ts once and saves the result. A run reads only that.
2. Graph. One task graph for the whole repo.
3. Key. Each task gets a hash of its inputs, its config and the keys of everything before it.
4. Schedule. Restore hits. Run misses. Save.

In plugin terms the stages are named, in order:

• config → discover → project → graph → key → fingerprint → measures → schedule → admit
• then executor, cache, telemetry, output, setup, teardown and commands

A plugin can fill any of them.

Core turns on no plugin by default. With none, vx still runs and caches on your machine.

A task is one command

build: {
  exec: { command: 'tsc -b' },
  inputs: { files: ['src/**', 'tsconfig.json'] },
  outputs: { files: ['dist/**', '*.tsbuildinfo'] },
  cache: true,
}

• Caching is opt-in. No cache: true, no cache. vx never guesses what a task reads.
• One command per task. A plugin may change where it runs, never what it is.
• A project reads only its own folder. What it needs from another project comes through the graph.

What is not inside

Never in vx	Why
A cloud, account or dashboard	vx does not need to know your company exists.
A daemon	A second copy of the truth can go stale. Git is read fresh per run.
Inferred or traced inputs	A trace says what a task read once. A key is needed before it runs.
JavaScript-function tasks	The shell is the API. Your tools stay yours.
Named, global inputs or env	Configs are TypeScript. A shared preset is an import.

Remote caches, remote execution, telemetry and CI summaries are plugins in their own packages. @vzn/vx-reapi (Bazel’s Remote Execution API) shows the plugin points are wide enough.

With no cloud to sell, vx has one job: be correct and fast on the machine in front of you.

Next: Why vx is fast. Reference: Architecture. More at vznjs.github.io/vx.