enigma-relay

Offline store-and-forward relay for Enigma clients. Nodes push opaque end-to-end encrypted envelopes for recipients who may be offline; recipients pull pending envelopes later and acknowledge once processed. The relay never decrypts payloads and only sees opaque blobs plus routing metadata.

Features

• Axum HTTP server with push, pull (paged cursors), ack, and health endpoints
• Pluggable storage with in-memory and sled backends (sled enabled by default)
• Deterministic ordering by creation time + id with opaque base64 cursor tokens
• TTL and retention-based expiration with a background purger
• Canonical request/response and envelope types from enigma-node-types

Quickstart

• Run tests to see the service in action: cargo test
• Start an in-process relay from code:
  1. Create a RelayConfig (default binds to 127.0.0.1:0 and uses the sled backend when a storage path is provided)
  2. Call enigma_relay::start(config).await?
  3. Use the returned base URL for HTTP clients
• Default endpoints:
  • POST /relay/push with RelayPushRequest
  • GET /relay/pull/{user_id_hex}?cursor=&limit=
  • POST /relay/ack with RelayAckRequest
  • GET /health

Privacy and safety

• Payloads are opaque base64 blobs; the relay only enforces size and TTL policies
• Addressing is by UserId (hex) only; plaintext usernames are never accepted over HTTP
• Paging avoids loading full queues into memory and works deterministically across backends