AgentStamp

Instructions

Implementation Reference

• src/mcp-server.js:611-669 (handler)

  The `dns_discovery` tool handler is defined and implemented directly in `src/mcp-server.js`. It performs DNS TXT record lookups for agent discovery and validates against the local database.

  server.tool(
    'dns_discovery',
    'Check if a domain has an AgentStamp DNS TXT record for agent discovery. Verifies _agentstamp.domain.com TXT record and cross-checks with the registry. Free.',
    {
      domain: z.string().describe('Domain to check (e.g., shippingrates.org)'),
    },
    async ({ domain }) => {
      try {
        const dns = require('dns');
        const cleanDomain = domain.toLowerCase().replace(/[^a-z0-9.\-]/g, '');
        if (!cleanDomain || cleanDomain.length > 253) {
          return { content: [{ type: 'text', text: JSON.stringify({ success: false, error: 'Invalid domain' }, null, 2) }] };
        }
        const txtHost = `_agentstamp.${cleanDomain}`;
  
        const records = await new Promise((resolve, reject) => {
          dns.resolveTxt(txtHost, (err, recs) => {
            if (err) reject(err);
            else resolve(recs);
          });
        }).catch(() => null);
  
        if (!records) {
          return { content: [{ type: 'text', text: JSON.stringify({
            found: false, domain: cleanDomain, txt_host: txtHost,
            message: 'No _agentstamp TXT record found',
            setup: `Add TXT record: ${txtHost} "v=as1; wallet=YOUR_WALLET; stamp=TIER"`,
          }, null, 2) }] };
        }
  
        const flat = records.map(r => r.join('')).filter(r => r.startsWith('v=as1'));
        if (flat.length === 0) {
          return { content: [{ type: 'text', text: JSON.stringify({ found: true, valid: false, message: 'TXT exists but not AgentStamp format' }, null, 2) }] };
        }
  
        const fields = Object.fromEntries(
          flat[0].split(';').map(s => s.trim().split('=', 2)).filter(([k]) => k)
        );
  
        const { getDb } = require('./database');
        const db = getDb();
        // Validate wallet from untrusted DNS source
        const { validateWalletAddress } = require('./utils/validators');
        const walletCheck = validateWalletAddress(fields.wallet || '');
        if (!walletCheck.valid) {
          return { content: [{ type: 'text', text: JSON.stringify({ found: true, valid: false, error: 'TXT record contains invalid wallet address' }, null, 2) }] };
        }
  
        const agent = db.prepare("SELECT id, name FROM agents WHERE wallet_address = ? AND status = 'active' LIMIT 1").get(fields.wallet);
  
        return { content: [{ type: 'text', text: JSON.stringify({
          found: true, valid: !!agent, domain: cleanDomain,
          wallet: fields.wallet, claimed_stamp: fields.stamp,
          agent: agent ? { id: agent.id, name: agent.name } : null,
          trust_check_url: `https://agentstamp.org/api/v1/trust/check/${fields.wallet}`,
        }, null, 2) }] };
      } catch (err) {
        return { content: [{ type: 'text', text: JSON.stringify({ success: false, error: 'DNS lookup failed' }, null, 2) }] };
      }