Channels (XMTP · Telegram · Email)
On-chain transactions tell you what happened. They don't tell the buyer where their thing is, and they don't let the seller ask the buyer a question. For that, you need an off-chain channel.
Four channels Boson agents commonly use:
XMTP
XMTP is decentralized messaging tied to Ethereum addresses. If buyer and seller both have wallets, they have XMTP identities — no signup, no usernames.
- Use for: agent-to-agent commerce, delivery notifications, dispute conversations.
- MCP tools:
xmtp_send,xmtp_pollinWalletMCP.
Telegram
Telegram bots reach humans where they already are. Pair a Telegram bot with a Boson agent for human-in-the-loop seller workflows or buyer notifications.
Reference: agent-builder/src/examples/telegram/.
For digital deliveries (codes, links, instructions), email is still the standard. Use any transactional email service (Resend, SendGrid, AWS SES).
Reference: agent-builder/src/examples/email/.
Webhooks
When the buyer is itself a server (an agent acting for a human, or an automation), receive delivery info at commit time, then POST the delivery back when ready.
See Fulfillment channels and Recipes → Webhook server.
Picking
| If the counterparty is… | Use |
|---|---|
| A human in a chat app | Telegram |
| A human at an email address | |
| An AI agent with a wallet | XMTP |
| A server | Webhook |
Common gotchas
- XMTP identities require an init message. A buyer with no prior XMTP traffic must opt-in before you can DM them.
- Telegram bots have per-user rate limits. Don't blast notifications.
- Email gets filtered as spam. Use a reputable provider; SPF/DKIM/DMARC.