Reconsidered pure Go (would mean reimplementing and re-verifying the
already-tested AI pipeline) and pure Python (leaves perceived
performance/concurrency headroom on the table for a preemptive
scale bet). Landed on: Go handles auth/messaging/DB, Python keeps
owning generate_draft/escalation_filter/retrieve_style behind an
internal API. backend/ (Python) is now labeled a verified prototype
for the Go rewrite to match, not the final service.
FastAPI app with invite-code signup, message send/relay over
WebSocket, and the DB schema from roadmap.md Phase 1 §2.1 (users,
contacts, conversations, messages, twin_settings, whitelist_rules,
escalation_logs). Defaults to SQLite for local dev, PostgreSQL in
prod per tech-design.md §8.
Verified end-to-end with TestClient: signup, duplicate-invite-code
rejection (409), message persistence, 404 on an unknown conversation,
and WebSocket broadcast delivery all behave as expected.
Push notifications and the AI pipeline integration (item 3) are not
in this commit -- see backend/README.md and roadmap.md's checklist.
Claude