Architecture Decision Records

Every significant architectural choice in this project is recorded here as a numbered ADR. Newer decisions supersede older ones when a header row says so; the superseded file is kept for history.

#	Decision	Status	Summary
001	Use OBO flows for device-local agent identity	Superseded by 002	Original approach — agents authenticate via human device-code → OBO exchange
002	Agent User over OBO	Accepted	Agents authenticate autonomously via three-hop Agent User flow — no human in the loop
003	Certificate auth over client secrets	Accepted	Blueprint signs a JWT assertion with a private key stored in the OS keystore; no secrets on disk (ADR-003)
005	Cloud-hosted memory via Azure Blob Storage	Accepted — Phases 1, 2, 5, 6a shipped	Operational memory (interaction log, daily summaries, watched chats, email cursor) routes through a MemoryBackend protocol with LocalBackend and BlobBackend implementations. Blob is opt-in via setup.sh --use-cloud-memory. Remaining phases: 3 (interaction-log migration to ETag-concurrent writes), 4 (email cursor + watched chats migration), 6b (end-to-end persona continuity test), 7 (governance + retention) — see 005-cloud-hosted-memory.md for the full phase plan.

Note on numbering. ADR 004 was reserved during planning but never landed as a separate decision — its scope was folded into ADR 005 Phase 5. The number is kept out of circulation to avoid confusion.