mocrelay

A middleware-composable Nostr relay implementation in Go.

Features

• Middleware Architecture: Compose handlers and middlewares to build your relay
• NIP-11 Driven: Middlewares map directly to NIP-11 limitation fields
• Pure Go: No cgo dependencies, easy deployment
• Persistent Storage: Pebble-based storage with MVCC support
• Full-text Search: Bleve-based search with CJK support (NIP-50)

Requirements

• Go 1.25+
• GOEXPERIMENT=jsonv2 (for encoding/json/v2 features)

export GOEXPERIMENT=jsonv2

Installation

go get github.com/high-moctane/mocrelay

Quick Start

package main

import (
    "log"
    "net/http"

    "github.com/high-moctane/mocrelay"
)

func main() {
    // Create storage
    storage, _ := mocrelay.NewPebbleStorage("/var/lib/mocrelay/data", nil)
    defer storage.Close()

    // Build handler with middlewares
    handler := mocrelay.NewMergeHandler(
        mocrelay.NewStorageHandler(storage),
        mocrelay.NewRouterHandler(mocrelay.NewRouter()),
    )

    // Apply middlewares
    handler = mocrelay.NewMaxSubscriptionsMiddleware(10)(handler)
    handler = mocrelay.NewMaxContentLengthMiddleware(8192)(handler)
    handler = mocrelay.NewCreatedAtLimitsMiddleware(60*60*24*30, 60*60)(handler) // 30 days old to 1 hour future

    // Create relay
    relay := mocrelay.NewRelay(handler, nil)

    log.Fatal(http.ListenAndServe(":8080", relay))
}

Available Middlewares

Middleware	NIP-11 Field	Description
NewMaxSubscriptionsMiddleware	max_subscriptions	Limit subscriptions per connection
NewMaxSubidLengthMiddleware	max_subid_length	Limit subscription ID length
NewMaxLimitMiddleware	max_limit	Clamp filter limit values
NewMaxEventTagsMiddleware	max_event_tags	Limit tags per event
NewMaxContentLengthMiddleware	max_content_length	Limit content length
NewCreatedAtLimitsMiddleware	created_at_*_limit	Restrict event timestamps
NewKindBlacklistMiddleware	retention	Block specific event kinds
NewRestrictedWritesMiddleware	restricted_writes	Pubkey whitelist/blacklist
NewMinPowDifficultyMiddleware	min_pow_difficulty	Require proof-of-work (NIP-13)
NewAuthMiddleware	auth_required	Require authentication (NIP-42)
NewExpirationMiddleware	-	Handle event expiration (NIP-40)
NewProtectedEventsMiddleware	-	Protect events from republishing (NIP-70)

NIP Support

NIP	Status	Description
01	✅	Basic Protocol
09	✅	Event Deletion
11	✅	Relay Information
13	✅	Proof of Work
40	✅	Expiration Timestamp
42	✅	Authentication
45	✅	Event Counts
50	✅	Search Capability
70	✅	Protected Events

License

MIT License