Resolver library

The resolver library provides tools for resolving identities to EVM addresses and keeping track of them in a cache

Quick start

import { getUserInfo } from "xmtp";
 
// Because user identifiers come in all shapes and sizes!
const identifier = "vitalik.eth"; // Could also be "0x123...", "@fabri", or even a website
const userInfo = await getUserInfo(identifier);
 
console.log(userInfo);
/*
{
  ensDomain: 'vitalik.eth',
  address: '0x1234...',
  preferredName: 'vitalik.eth',
  converseUsername: '',
  avatar: 'https://...',
  converseEndpoint: ''
}
*/

Supported identifiers

Ethereum Addresses : Example: 0x1234...
ENS Domains : Example: vitalik.eth
Converse Usernames : Example: @fabri
Inbox ID : Example: 0x1234... (Converse inbox ID)
Website Header Tag : Example: https://example.com containing xmtp=0x1234...
Website TXT Record : Example: meta="xmtp" content="0x1234..."

Returned UserInfo

The resolver always returns a UserInfo object with these fields:

Field	Description
ensDomain	The user’s ENS domain (if any)
address	The Ethereum address
preferredName	Best name to display
converseUsername	The user’s Converse username (if any)
avatar	URL of the user’s profile picture (if any)
converseEndpoint	Endpoint for the user’s Converse profile

Sending Messages

Here’s a quick snippet showing how you can utilize the resolver for your messaging:

// Example user message object
let textMessage: userMessage = {
  message: "Hello, world!",
  receivers: [
    "0x123...", // Ethereum address
    "vitalik.eth", // ENS
    "@fabri", // Converse username
    "https://example.com", // Website header tag or TXT record
  ],
  originalMessage: message, // optional original reference
};
 
await xmtp.send(textMessage);

Cache

Skip the repeated lookups—use the built-in cache to store user data. Clear it whenever you need a fresh slate:

import { userInfoCache } from "xmtp";
 
// Clear the entire cache:
userInfoCache.clear();
 
// Clear a specific address from the cache:
userInfoCache.clear("0x1234...");

This makes repeated lookups lightning-fast, so you can focus on building cool stuff instead of waiting on network calls.