Adversarial review of the relay admission surface:
- FAIL-SAFE on admission death: nostr-rs-relay fails OPEN if its gRPC admission
server is unreachable, so a dead admission = an unrestricted relay. The backend
now EXITS if the admission service stops (supervisor restarts a clean pair);
documented in RELAY.md. Pin the relay image to a digest (compose note).
- Registration-oracle protection: validate() now refuses a non-loopback
RELAY_ADMISSION_BIND unless RELAY_ADMISSION_ALLOW_PUBLIC=true (+ test).
- No N+1 on crafted events: recipient p-tags are capped (20, deduped) and resolved
in ONE batched query (db.any_registered_npub) instead of one-per-tag.
- Defence-in-depth size cap: admission denies events over max_event_bytes before
any DB work (the relay enforces its own limit too).
- Docs: RELAY.md Security section (fail-open, loopback oracle, default PoW=0 spam
footgun, client sender-verification); config.toml relay port 8088 (not 8080);
Docker Hub image; .env.example RELAY_ADMISSION_ALLOW_PUBLIC.
Note: the client-side sender-impersonation blocker is fixed separately in the
monorepo (verifying gift-wrap unwrap).
Completes the operator side of the relay integration:
- deploy/relay/: reference docker-compose + config.toml for a locked-down
nostr-rs-relay wired to the backend's gRPC admission (host networking so the
loopback admission socket stays private). Clearly marked a template to pin/
verify against the operator's nostr-rs-relay version.
- docs/operations/RELAY.md: what it is (inbox relay, not the only relay), the
admission architecture, the three write policies + NIP-13 PoW, bundled vs
external, verification, and the seam's modularity. Linked from OPERATOR_SETUP.
- .env.example: the RELAY_* block (all off/placeholder).
Backend relay integration (config → seam → policy → gRPC admission →
capabilities → NIP-05 → packaging/docs) is now complete. Client DM stack next.
jwinterm