---
name: resolving-domains-17a714ff1bea
description: ENS and Web3 identity resolution for XMTP agents. Use when resolving domain names, extracting mentions, or fetching Farcaster profiles. Triggers on ENS resolution, Farcaster lookup, or mention extraction.
license: MIT
metadata:
  author: xmtp
  version: "1.0.0"
---

# XMTP domain resolver

Resolve Web3 identities including ENS, Farcaster, Basenames, and Lens Protocol.

## When to apply

Reference these guidelines when:
- Resolving ENS names to addresses
- Extracting @mentions from messages
- Fetching Farcaster profiles
- Working with shortened addresses in groups

## Rule categories by priority

| Priority | Category | Impact | Prefix |
|----------|----------|--------|--------|
| 1 | Resolve | HIGH | `resolve-` |
| 2 | Extract | HIGH | `extract-` |
| 3 | Profiles | MEDIUM | `profiles-` |

## Quick reference

### Resolve (HIGH)
- `resolve-address` - Resolve domain names to addresses
- `resolve-mentions` - Resolve all mentions in a message

### Extract (HIGH)
- `extract-mentions` - Extract @mentions from text

### Profiles (MEDIUM)
- `profiles-farcaster` - Fetch Farcaster profile data

## Supported platforms

- **ENS** - `vitalik.eth`
- **Farcaster** - `dwr.eth`, `username.farcaster.eth`
- **Basenames** - `tony.base.eth`
- **Lens Protocol** - `stani.lens`

## Quick start

```typescript
import { createNameResolver } from "@xmtp/agent-sdk/user";

// Resolve a single name using the SDK resolver
const resolver = createNameResolver(process.env.WEB3_BIO_API_KEY || "");
const address = await resolver("vitalik.eth");

// Resolve all mentions in a message
const resolved = await resolveMentionsInMessage(
  ctx.message.content,
  await ctx.conversation.members()
);
// Returns: { "bankr.eth": "0x...", "@fabri": "0x..." }

// Get Farcaster profile via web3.bio API
const profile = await fetchFarcasterProfile("dwr.eth");
console.log(profile.username, profile.fid);
```

## Implementation snippets

**Extract mentions from text:**

```typescript
const extractMentions = (message: string): string[] => {
  const mentions: string[] = [];
  
  // Full addresses
  const addresses = message.match(/(0x[a-fA-F0-9]{40})\b/g);
  if (addresses) mentions.push(...addresses);
  
  // @mentions and domains
  const atMentions = message.match(/@(?!0x)([\w.-]+\.eth|[\w.-]+)/g);
  if (atMentions) mentions.push(...atMentions.map(m => m.slice(1)));
  
  // Standalone domains
  const domains = message.match(/\b([\w-]+(?:\.[\w-]+)*\.eth)\b/g);
  if (domains) mentions.push(...domains);
  
  return [...new Set(mentions)];
};
```

**Resolve mentions in message:**

```typescript
import { createNameResolver } from "@xmtp/agent-sdk/user";

const resolveMentionsInMessage = async (
  message: string, members?: GroupMember[]
): Promise<Record<string, string | null>> => {
  const resolver = createNameResolver(process.env.WEB3_BIO_API_KEY || "");
  const mentions = extractMentions(message);
  const results: Record<string, string | null> = {};
  
  await Promise.all(mentions.map(async (mention) => {
    if (mention.match(/^0x[a-fA-F0-9]{40}$/)) {
      results[mention] = mention;
    } else {
      const name = mention.includes(".") ? mention : `${mention}.farcaster.eth`;
      results[mention] = await resolver(name).catch(() => null);
    }
  }));
  return results;
};
```

**Fetch Farcaster profile:**

```typescript
const fetchFarcasterProfile = async (name: string) => {
  const response = await fetch(`https://api.web3.bio/profile/${encodeURIComponent(name)}`);
  if (!response.ok) return { address: null, username: null, fid: null };
  const data = await response.json();
  const profile = data?.find((p: any) => p.platform === "farcaster");
  return {
    address: profile?.address,
    username: profile?.displayName,
    fid: profile?.social?.uid?.toString(),
  };
};
```

## How to use

Read individual rule files for detailed explanations:

```
rules/resolve-address.md
rules/extract-mentions.md
rules/profiles-farcaster.md
```



---
Source attribution: kbarbel640-del
Original project: https://github.com/kbarbel640-del/skills/blob/e7e336ac628c3e3bd771aff1aaa469c93778f94a/skills/humanagent/xmtp-agent/resolving-domains/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 clawdbot

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: kbarbel640-del
Original project: https://github.com/kbarbel640-del/skills/blob/e7e336ac628c3e3bd771aff1aaa469c93778f94a/skills/humanagent/xmtp-agent/resolving-domains/SKILL.md
Attribution basis: Source repository record

Fields of work: Marketing
Roles: Growth Marketer, Product Marketer, Social Media Manager
Specialties: API
Tools: Web3.Bio
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 09fd0cf89b5fe8604771d10b9b2342ae54c05b80638d6860762d6afb9b4d1160