The fifth chapter, and the template code it teaches out of. Events is the first
thing in the book that goes the other way — chapters 1-4 move data out of the
game and onto a page; an event changes a live world on a schedule, unattended.
**Chapter 5** covers the four declarations (budgets, option sources, leases,
actions), leads with the lease because EVENTS.md §H is right that it is the
primitive that travels and the spawn is the special case, and gives one section
each to the four things that are invisible until an outage: the envelope's
failure default, the idempotency passthrough, recording a resource before
confirming it, and under-declaring `cost`.
**Chapters 3 and 4 gain one section each** for the command plane, because
without them chapter 5 teaches a module to send an idempotency key to a sidecar
the book never told anyone to build a command path in. Both say at the top that
they are skippable until you want chapter 5.
**The template ships one of each declaration**, with `server/sidecarClient.js`
as the near end — a real timeout, a real key passthrough, a simulated transport
in one function marked for replacement. That file is named for the filename
`noGameConnection.test.js` already anticipated, so the test stays green now and
fires correctly the moment `deliver()` becomes a request.
Two things writing it found, both now in the chapter and beside the code:
* **An idempotency key belongs on a command, never on a question.** The first
draft keyed every call including the reads; an at-most-once store then
answers every future read with the first one's reply, forever. The lease
applied correctly and the module could no longer see it. Hence `ask` and
`send` as two functions.
* **A refusal's reason goes in `error`; core reads no other name.** The first
draft used `detail`, on the strength of the one place EVENTS.md §H mentions
it, and every refusal it produced was anonymous on the run console.
Proved by running the template's real declarations through core's real registry
at `edge` (all four accepted) and its real envelopes through the real
`events/dispatch.js` classifier.
**CI is RED on `checkCoreApi` and that is the mechanism working.** The template
now declares `coreApi: ^1.10.0` and `ci/core-ref.json` pins the engagement
cutover, where `main` is still 1.9.0. Equality is the check, a bump is meant to
turn this repo red until someone re-reads the chapters, and the pin move rides
in the events cutover (EVENTS_PLAN.md P16) as its own commit. Do not "fix" it.
Refs EVENTS_PLAN.md Phase 15, EVENTS.md §F, MODULE_API.md 1.10.0.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016wDDVXWMDz82WqE1i969r4
