Agent skill · vercel
migrating-world-v4-to-v5
Upgrades a custom Workflow SDK World implementation from the v4 spec to v5. Use when a package implements the `World` interface from `@workflow/world` and is moving to 5.x — event IDs that are ULIDs rather than slot positions, `Event id is not slot-numbered` at replay time, a `specVersion` the runtime refuses, `writeToStream` / `closeStream` / `readFromStream` as top-level World methods, `steps.get` or `events.listByCorrelationId` without a `runId`, a `'step'` queue kind or `__wkf_step_*` topics, a `preconditionGuard` capability, or a `createLocalWorld` / `createVercelWorld` factory.
What it needs
About 11k tokens when loaded.
What this skill does
Migrating a World from the v4 spec to v5 This skill is for a package that implements World from @workflow/world: a storage, queue and stream backend the Workflow runtime talks to. It is not for application code. If the task is bumping an app's workflow dependency, use the migrating-workflow-v4-to-v5 skill instead; if the app both uses Workflow and ships its own World, run that skill first and this one second. An app on the Vercel, Local or Postgres World needs nothing from this skill. Those ship with the SDK and are already on the v5 spec. One change dominates the work. Event ID allocation is required, is not visible from the type signatures, and a World that skips it type-checks, starts runs, and fails on the first replay. Do that part first, then the mechanical rewrites. Do not begin with the type errors: they are the small half, and finishing them produces a World that looks migrated and is not. Intake Before editing, establish and report each of these: 1. Where the World is. Grep for implements World, : World, World> and from '@workflow/world'. Read the factory it exports. 2. How event IDs are minted today. Grep for eventId, ulid, uuid, nanoid, nextval, AUTOINCREMENT, IDENTITY. Find the exact line that produces the ID written to storage. 3. What settles a write race. Read the events.create implementation. Note whether the ID or ordering is decided in process (read-then-write, an in-memory counter, a Math.max over loaded events) or in the store (unique constraint, conditional write, INSERT ... ON CONFLICT, a transaction). 4. Which specVersion it declares. Grep for specVersion. Note whether it is a literal or an imported constant. 5. Which optional members exist. Grep for capabilities, analytics, getRuntimeDeadline, getEnvironment, createRunId, describeRun, getEncryptionKeyForRun, resolveLatestDeploymentId, cancelMany, experimentalSetAttributes. 6. Whether it provisions step topics. Grep for 'step', wkfstep, stepQueue. 7. Whether it rejects stale writes. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills vercel/migrating-world-v4-to-v5