Architecture Decision Records

An ADR captures one significant architectural decision: the context that forced a choice, the option taken, and the consequences that followed. Format is Michael Nygard's classic: Title, Status, Context, Decision, Consequences.

These records are immutable. A decision that changes is not edited in place, a new ADR supersedes it and both link, so the reasoning trail stays honest. This is the difference from the lessons log: lessons are debugging war-stories, pruned as they are absorbed; ADRs are decisions, kept as an append-only record. The forward-looking counterpart, what we set out to build, is the plan archive.

Agents do not read this directory automatically, only when a decision's rationale is in question (the same rule as history/ and backlog/).

Index

#	Decision	Status
0001	Persist POD module state with memcpy, not JSON	Accepted
0002	Adaptive allocation with a degradation cascade	Accepted
0003	The layer buffer persists frame-to-frame	Accepted
0004	Build the map physical→logical so modifiers compose	Accepted
0005	A generic set-control primitive on the Scheduler	Accepted
0006	UDP presence for discovery, mDNS advertise-only	Accepted
0007	MoonLive is expressions + host-bound functions	Accepted
0008	Board injection: SET_BOARD name-only, controls over HTTP	Accepted
0009	Two doc surfaces: generated technical + hand-written summary	Accepted
0010	Integration identity is a stable hardware id	Accepted
0011	Inter-module data/events: pull + prepare-pass, not pub/sub	Accepted
0012	HA discovery: WLED by default, MQTT discovery opt-in	Accepted
0013	No migration code — robust persistence + documented breaks	Accepted
0014	Our own i80 DMA driver, one level below esp_lcd	Accepted
0015	The source tree splits by domain/type; library origin is a tag, not a folder	Accepted