Status:
accepted · ADR-21 · Filed 2026-04-19Decision
Supersedes ADR-19. Same architectural decision, one naming correction: PRISM_MODE values are nowlocal, lan, cloud (previously personal, lan, cloud). All other content stands: two-bucket env split (HOST_ENV discovered, PRISM_ENV chosen), 4-tier resolution (system -> env -> config -> MODE_PROFILES), startup provenance logs, one-codebase mode-awareness concentrated in MODE_PROFILES. Contract in SPEC-019 v1.1.
Rationale
local / lan / cloud mirrors standard dev conventions (.env.local, .env.lan, .env.cloud; next-style NEXT_ENV=local; Rails RAILS_ENV=local) — a developer reading PRISM_MODE=local immediately knows the shape. personal was a Prism-internal coinage that required explanation and would confuse external collaborators reading SPEC-019 or the PDF Lola is compiling. Renaming now (before any implementation code is written against SPEC-019) is free; renaming after implementation would cost a cascade. Existing artifacts that carry the old name (docker-compose.personal.yml, container names prism-personal-*, neo4j/prism_personal auth, BackendMode literal in install/backend.py) are renamed as part of SPEC-019’s migration path — they’re implementation-side, not decision-side, so the rename follows the new decision mechanically.
Alternatives Considered
(a) Edit ADR-19 in place: violates PRISM.md §A3 ADR immutability. (b) Keeppersonal: loses dev-convention recognizability, forces explanation in every external-facing doc including Lola’s PDF. (c) Use self-hosted instead of local: more descriptive but longer, and local already denotes the common case (my machine, no remote).