wisp - a lightweight nostr relay

A fast, lightweight nostr relay written in Zig.

Why Wisp?

• Fast: ~9x higher throughput than strfry, sub-millisecond p99 latency
• Small: Single binary, ~11MB RAM at idle
• Simple: One command to run your personal relay with your feed
• Spider Mode: Automatically syncs events from people you follow

Quickstart

Docker

docker run -d -p 7777:7777 -v wisp-data:/data ghcr.io/privkeyio/wisp --spider-admin npub1yourkey...

Build from source

Download the latest release or build from source:

# 1. Install dependencies (requires Zig 0.16.0)
sudo apt install -y liblmdb-dev libsecp256k1-dev libssl-dev

# 2. Build
git clone https://github.com/privkeyio/wisp && cd wisp
zig build -Doptimize=ReleaseFast

# 3. Run (replace with your npub)
./zig-out/bin/wisp --spider-admin npub1yourkey...

That's it. Wisp will fetch your follow list, sync notes from popular relays, and serve them at ws://localhost:7777. Add this relay URL to your Nostr client.

For more options, see wisp.toml.example.

Features

• NIPs: 1, 2, 9, 11, 13, 16, 33, 40, 42, 45, 50, 65, 70, 77, 86
• LMDB storage (no external database)
• Spider mode for syncing events from external relays
• Import/export to JSONL
• Prometheus metrics at GET /metrics

Monitoring

Operational metrics are exposed in Prometheus format at GET /metrics on the relay's port (connections, events stored/rejected/broadcast, REQ count, rate limiting). The endpoint honors the relay's IP allowlist/blocklist, so restrict it there or at your reverse proxy/firewall if you don't want it public.

Import/Export

./zig-out/bin/wisp export > backup.jsonl
./zig-out/bin/wisp import < backup.jsonl

Configuration

Copy wisp.toml.example to wisp.toml and customize, or use environment variables with the WISP_ prefix:

WISP_PORT=8080 ./zig-out/bin/wisp

Environment variables override the config file. See the Configuration reference for every setting, its environment variable, default, and meaning.

Deploy (wss://)

To make your relay publicly accessible with TLS, run wisp with Caddy:

# Run wisp
docker run -d --restart always -p 7777:7777 -v wisp-data:/data \
  ghcr.io/privkeyio/wisp --spider-admin npub1yourkey...

# Install Caddy for automatic TLS
sudo apt install -y caddy

Create /etc/caddy/Caddyfile:

relay.yourdomain.com {
    reverse_proxy localhost:7777
}

sudo systemctl restart caddy

Your relay is now live at wss://relay.yourdomain.com.

Benchmarks

Peak write throughput, all relays at 100% delivery:

Relay	Events/sec	p99 Latency	Memory (RSS)
Wisp	25,600	0.28 ms	11 MB
nostr-rs-relay	5,400	5.9 ms	20 MB
strfry	2,800	2.9 ms	3 MB

nostr-bench, 5,000 events x 4 workers at peak rate (--rate 0), native release builds on a 16-core Linux host, with the event-rate limit raised. RssAnon sampled during the run. These are peak figures with Wisp in sync = none (non-durable); Wisp's default is sync = meta (durable, never corrupts), which trades raw throughput for crash safety. strfry and nostr-rs-relay write durably by default, so a fair durable comparison runs Wisp in meta/full (see benchmarks). Wisp leads on throughput (~9x strfry, ~5x nostr-rs-relay) and p99 latency; strfry stays smallest in memory.

Contributing

See CONTRIBUTING.md for guidelines on reporting issues and submitting pull requests.

Changelog

See CHANGELOG.md for a history of changes to this project.

License

MIT