Relay Information

Reference for NIP-11 relay information documents and relay discovery.

NIP-11 Information Document

Relays serve metadata via HTTP at their root URL.

Request

curl -H "Accept: application/nostr+json" https://relay.example.com/

Response Format

{
  "name": "Example Relay",
  "description": "A Nostr relay for everyone",
  "pubkey": "32-byte-hex-pubkey",
  "contact": "admin@example.com",
  "supported_nips": [1, 2, 9, 11, 12, 15, 16, 20, 22, 33, 40],
  "software": "https://github.com/Cameri/nostream",
  "version": "1.22.6",
  "limitation": {
    "max_message_length": 65535,
    "max_subscriptions": 20,
    "max_filters": 10,
    "max_subid_length": 100,
    "max_event_tags": 100,
    "max_content_length": 65535,
    "min_pow_difficulty": 0,
    "auth_required": false,
    "payment_required": false,
    "created_at_lower_limit": 31536000,
    "created_at_upper_limit": 60
  },
  "relay_countries": ["US", "EU"],
  "language_tags": ["en"],
  "tags": ["community", "public"],
  "posting_policy": "https://relay.example.com/policy",
  "payments_url": "https://relay.example.com/pay",
  "fees": {
    "admission": [{"amount": 1000000, "unit": "msats"}],
    "subscription": [{"amount": 5000000, "unit": "msats", "period": 2592000}],
    "publication": [{"kinds": [4], "amount": 100, "unit": "msats"}]
  },
  "icon": "https://relay.example.com/icon.png"
}

Field Reference

Basic Info

Field	Type	Description
name	string	Relay name
description	string	Relay description
pubkey	string	Admin's public key
contact	string	Contact email/URL
software	string	Software URL
version	string	Software version
icon	string	Relay icon URL

Supported NIPs

{
  "supported_nips": [1, 2, 9, 11, 12, 15, 16, 20, 22, 33, 40]
}

Check before using features:

async function checkNipSupport(relayUrl, nip) {
  const info = await getRelayInfo(relayUrl);
  return info.supported_nips?.includes(nip) ?? false;
}

Limitations

Field	Description
max_message_length	Maximum WebSocket message size
max_subscriptions	Max concurrent subscriptions
max_filters	Max filters per subscription
max_subid_length	Max subscription ID length
max_event_tags	Max tags per event
max_content_length	Max event content length
min_pow_difficulty	Required proof-of-work
auth_required	NIP-42 auth required
payment_required	Payment required to use
created_at_lower_limit	Max age of events (seconds)
created_at_upper_limit	Max future date (seconds)

Fees

{
  "fees": {
    "admission": [{"amount": 1000000, "unit": "msats"}],
    "subscription": [
      {"amount": 5000000, "unit": "msats", "period": 2592000}
    ],
    "publication": [
      {"kinds": [4], "amount": 100, "unit": "msats"}
    ]
  }
}

Fetching Relay Info

JavaScript

async function getRelayInfo(relayUrl) {
  const httpUrl = relayUrl
    .replace('wss://', 'https://')
    .replace('ws://', 'http://');

  const response = await fetch(httpUrl, {
    headers: { Accept: 'application/nostr+json' }
  });

  if (!response.ok) {
    throw new Error(`Failed to fetch relay info: ${response.status}`);
  }

  return response.json();
}

// Usage
const info = await getRelayInfo('wss://relay.damus.io');
console.log(info.name);
console.log(info.supported_nips);

With Timeout

async function getRelayInfoWithTimeout(relayUrl, timeout = 5000) {
  const controller = new AbortController();
  const timeoutId = setTimeout(() => controller.abort(), timeout);

  try {
    const httpUrl = relayUrl
      .replace('wss://', 'https://')
      .replace('ws://', 'http://');

    const response = await fetch(httpUrl, {
      headers: { Accept: 'application/nostr+json' },
      signal: controller.signal
    });

    return response.json();
  } finally {
    clearTimeout(timeoutId);
  }
}

Relay Discovery

From User's Relay List (NIP-65)

async function getUserRelays(pubkey) {
  const events = await pool.querySync(defaultRelays, {
    kinds: [10002],
    authors: [pubkey],
    limit: 1
  });

  if (events.length === 0) return [];

  return events[0].tags
    .filter(t => t[0] === 'r')
    .map(t => ({
      url: t[1],
      read: !t[2] || t[2] === 'read',
      write: !t[2] || t[2] === 'write'
    }));
}

From NIP-05 Verification

async function getRelaysFromNip05(identifier) {
  const [name, domain] = identifier.split('@');
  const url = `https://${domain}/.well-known/nostr.json?name=${name}`;

  const response = await fetch(url);
  const data = await response.json();

  const pubkey = data.names?.[name];
  if (!pubkey) return [];

  return data.relays?.[pubkey] || [];
}

Public Relay Lists

Monitoring Services

Service	URL	Description
nostr.watch	nostr.watch	Relay monitoring
nostr.info	nostr.info/relays	Relay directory

Default Relays

Common default relay lists:

const DEFAULT_RELAYS = [
  'wss://relay.damus.io',
  'wss://nos.lol',
  'wss://relay.nostr.band',
  'wss://relay.snort.social',
  'wss://nostr.wine',
  'wss://relay.primal.net',
  'wss://purplepag.es'
];

Relay Categories

By Purpose

Type	Description	Example
General	Accept most events	relay.damus.io
Paid	Require payment	nostr.wine
Private	Auth required	Personal relays
Specialized	Specific content	Long-form only

By Region

Consider geographic distribution for:

• Lower latency
• Legal compliance
• Resilience

Best Practices

1. Check NIP support before using features
2. Respect limitations to avoid disconnection
3. Use multiple relays for reliability
4. Cache relay info to reduce requests
5. Handle missing fields gracefully

function getMaxContent(relayInfo) {
  return relayInfo?.limitation?.max_content_length ?? 65535;
}

function isAuthRequired(relayInfo) {
  return relayInfo?.limitation?.auth_required ?? false;
}

See Also

• Relay Implementations
• Running a Relay
• NIP-11 Specification