Relay — standby access for the people who'll need it

Living-continuity for your digital life. Relay lets you build an encrypted vault of accounts, credentials, documents, and instructions, then assign scoped, reversible access to the right people under rules you set. When a trigger fires — a missed check-in, a manual emergency request, or a verified estate event — Relay runs a controlled release (notify the owner, require N-of-M trusted verifiers, observe a grace window) and only then opens a guided, prioritized access dashboard to the recipient. Emergencies are reversible: when you recover and check in, access closes automatically. Estate handoffs are permanent. The default-safe state is always ARMED.

🏆 Winner — "Most Impactful" in H0: Hack the Zero Stack with Vercel and AWS Databases (announced 2026-08-05, ~9,800 participants). Track: Monetizable B2C · AWS Database: Amazon Aurora DSQL · Devpost submission

▶ Live: https://relay-three-henna.vercel.app · 🧭 Guided demo (no account needed): https://relay-three-henna.vercel.app/demo · 🎬 Demo video: https://youtu.be/FU3azKJOesY

The live deployment runs on Aurora DSQL, multi-region active-active. The guided demo is a read-only walkthrough of the vault, the zero-knowledge envelope, the release state machine, and the hash-chained audit log — the audit chain shown there is computed and verified with the same primitives the app uses in production.

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Why it's more than a vault

• An importance engine. Import a password-manager export and dozens of accounts populate instantly; Relay ranks them by what matters in a crisis and surfaces the few that count — including the risk-graph insight that your primary email is the key that unlocks most password resets. The engine sees non-secret metadata only (zero-knowledge boundary) — the smartest part of the product never sees a secret.
• A release that's correct under pressure. The irreversible handoff is a state machine (ARMED → PENDING → GRACE → RELEASED) whose every transition is a compare-and-set validated by Aurora DSQL's optimistic concurrency — it can never double-release, even when the owner, the verifiers, and the scheduler all act at once.

The four demo moments

1. Reversible emergency — request access, verifiers confirm, recipient gets a scoped plan; owner checks in and access closes automatically.
2. Region failover — flip to the us-west-2 endpoint; access keeps working, strongly consistent, no interruption (active-active Aurora DSQL).
3. OCC correctness — two concurrent releases, exactly one advances.
4. Importance / risk graph — the importance engine ranks the vault and reveals the "gates N" dependency edges.

Stack (locked)

Next.js 14 (App Router, TypeScript) on Vercel · Amazon Aurora DSQL (two regions, active-active, IAM auth) · AWS KMS (@aws-sdk/client-kms) client-side envelope encryption · NextAuth + TOTP MFA · OpenAI (importance engine) · Resend (notifications) · node-postgres · Vitest + fast-check (property tests).

The non-obvious invariants (preserve these)

• No foreign keys (DSQL) — referential integrity is app-enforced (lib/db/integrity.ts).
• Snapshot isolation → 40001 retries — every racy write goes through withOccRetry; on exhaustion a release row ends in ARMED (safe default).
• Plaintext never leaves the browser — per-item AES-GCM-256 data key, wrapped by KMS; the server stores only ciphertext + wrapped key.
• AI sees metadata only — lib/ai/metadata-query.ts is the sole accessor for /api/ai/*; never passes secret columns to an LLM.
• Audit log is append-only + hash-chained per owner; audit writes block the triggering op if they fail.

Quickstart

npm install
npm test          # vitest --run — full suite green (405 at submission; run for the live count)
npm run build     # next build — production build
npm run dev       # http://localhost:3000  (needs DSQL + KMS env for DB-backed routes)

Tests are property-based where it matters (state machine, OCC, N-of-M, hash chain) via fast-check. Pure logic is factored into lib/ and unit-tested; route handlers are thin and build-verified. AWS provisioning + live dogfood: docs/aws-setup.md, docs/e2e-verification.md.

Status

Backend complete (28 API routes), all UI built, recipient-release notifications wired. Full suite green — run npx vitest --run for the live count; tsc --noEmit + next build clean. Deployed live and dogfooded end-to-end on Aurora DSQL + AWS KMS, submitted to H0, and awarded Most Impactful. Specs (the build contract): .kiro/specs/relay-h0-mvp/ and specs/Relay_H0_Build_Spec_v2.md; Devpost write-up: specs/Relay_Devpost_Submission.md.

License

MIT — see LICENSE.