Config in TypeScript, and why there are no named inputs

A vx.config.ts is TypeScript. Share settings with an import, not a
special config key. Here is what bunx @vzn/vx-migrate writes from two
package.json scripts:

$ cat packages/ui/package.json
{"name":"ui","scripts":{"build":"tsc -b","test":"vitest run"}}

$ bunx @vzn/vx-migrate
  from      package.json scripts
  tasks     1 clean · 1 todo
  files     packages/ui/vx.config.ts
…
$ cat packages/ui/vx.config.ts
import type { ProjectConfig } from '@vzn/vx/config'

export default {
  tasks: {
    // TODO(vx-migrate): cache: add `inputs: { files: ['src/**'] }, cache: { outputs: { files: ['dist/**'] } }` with this package's real inputs and outputs — …
    build: {
      // inputs: { files: ['src/**'] }, cache: { outputs: { files: ['dist/**'] } },
      exec: {
        command: 'tsc -b',
      },
      dependsOn: ['^build'],
    },
    test: {
      exec: {
        command: 'vitest run',
      },
      dependsOn: ['build'],
    },
  },
} satisfies ProjectConfig

Each script became a task with the same command. The tool suggests
inputs and outputs in a comment, and doesn't guess them.

vx-migrate 69617eb · 2026-10-23

satisfies ProjectConfig gives autocomplete and type checks with no
runtime import. defineProject works too.

Composition is an import

A shared preset is a file:

// vx-preset.ts (workspace root)
export const lib = (entry: string) => ({
  build: {
    exec: { command: `tsup ${entry}` },
    inputs: { files: ['src/**', 'tsup.config.ts'] }, cache: { outputs: { files: ['dist/**'] } },
  },
})

// packages/ui/vx.config.ts
import type { ProjectConfig } from '@vzn/vx/config'
import { lib } from '../../vx-preset.ts'
export default { tasks: { ...lib('src/index.ts') } } satisfies ProjectConfig

The key hashes the config after it runs.
Edit vx-preset.ts, run vx lock, and every task that uses it gets a
new key.

No list of global dependencies to keep up to date: the import is the
dependency.

JSON configs need	In a TypeScript module
globalDependencies	the import
namedInputs	a constant
targetDefaults	a function returning a task
extends	...spread

Your compiler checks it, your editor refactors it.

What a config may not do

A config can't read another project. Globs stay inside the project
folder, and ../shared/** is an error. inputs.workspaceFiles is the
one exception, for files at the workspace root.

A config may read process.env, the clock or the network, but only
once, when vx lock runs it. No run runs the
config again.

bunx @vzn/vx-migrate also reads turbo.json or an Nx graph. A
globalDependencies list becomes a preset file and its import. Schema:
Configuration schema.

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.}