Sharing Tags

A Tag holds a value Tasks read.

The first instinct is one Tag per Task — it feels safe. Repeat that across the codebase, and you end up with many Tags meaning almost the same thing.

A simpler rule: one Tag for the same meaning; a new Tag for a different one.

A Tag with only one reader is fine; the rule is about meaning, not Task count.

✅ Correct

import { auth } from "./auth"

const userId = tag<string>("userId")

const dashboard = createTask({
  name: "dashboard",
  run: {
    context: userId.value,
    fn: (id) => console.log(`dashboard for ${id}`),
  },
})

const profile = createTask({
  name: "profile",
  run: {
    context: userId.value,
    fn: (id) => console.log(`profile for ${id}`),
  },
})

compose()
  .step(auth)
  .step(createWire({ from: auth.result.id, to: userId }))
  .step([dashboard, profile])
  .run()

❌ Wrong

import { auth } from "./auth"

const dashboardUserId = tag<string>("dashboardUserId")

const dashboard = createTask({
  name: "dashboard",
  run: {
    context: dashboardUserId.value,
    fn: (id) => console.log(`dashboard for ${id}`),
  },
})

// ❌ anti-pattern: same meaning, new Tag with no semantic reason
const profileUserId = tag<string>("profileUserId")

const profile = createTask({
  name: "profile",
  run: {
    context: profileUserId.value,
    fn: (id) => console.log(`profile for ${id}`),
  },
})

compose()
  .step(auth)
  .step([
    createWire({ from: auth.result.id, to: dashboardUserId }),
    createWire({ from: auth.result.id, to: profileUserId }),
  ])
  .step([dashboard, profile])
  .run()