Create custom email domains for AI agents via the AgentMail API, paid per-call over MPP.
What it does
This endpoint registers a new custom email domain within the AgentMail platform. AgentMail provides programmatic email inboxes designed for AI agents — letting them send, receive, and manage email just like humans use Gmail. The Create Domain endpoint (POST /v0/domains) accepts a JSON body specifying the domain name and whether bounce/complaint feedback notifications are enabled. On success it returns a Domain object containing the domain_id, verification status, required DNS records (TXT, CNAME, MX), and timestamps.
The endpoint is part of a comprehensive MPP-gated API that also covers inboxes, messages, threads, drafts, webhooks, pods, and allow/block lists. Payment is settled via the Tempo method on chain 4217. Creating a domain costs a fixed price of 10 (units as advertised in the OpenAPI x-payment-info field; the exact currency token is identified by address 0x20C0…8b50 on chain 4217 — likely pathUSD with 6 decimals, which would make the price $10.00 per domain creation). Most read operations (GET, LIST) are priced at 0, while write operations like creating inboxes ($2.00), sending messages ($0.01), and creating drafts ($0.01) carry small fixed fees.
The API uses Bearer token authentication. After creating a domain, you must configure the returned DNS records and call the Verify Domain endpoint to complete setup. The full OpenAPI 3.1 spec is served from the gateway and covers all resource types including pods (multi-tenant grouping), inbox-level allow/block lists, message metrics, and webhook event subscriptions.
Capabilities
Use cases
- —Provisioning a branded custom domain so AI agents send email from your-company.com
- —Setting up dedicated email infrastructure for multi-agent workflows
- —Automating customer outreach where each agent has its own inbox on a verified domain
- —Building SaaS products that give end-users agent-managed email addresses on custom domains
- —Creating isolated email environments (pods) with per-domain DNS verification
Fit
Best for
- —AI agent developers needing programmatic email send/receive on custom domains
- —Multi-agent orchestration platforms requiring per-agent inboxes
- —Startups building email-first AI products that need branded domains
Not for
- —Bulk marketing email campaigns (no mention of high-volume sending optimizations)
- —Human-facing email clients or webmail UIs
- —Free-tier experimentation without crypto wallet (MPP requires Tempo settlement)
Quick start
curl -X POST https://mpp.api.agentmail.to/v0/domains \
-H "Authorization: Bearer <MPP_TOKEN>" \
-H "Content-Type: application/json" \
-d '{"domain": "example.com", "feedback_enabled": true}'Example
Request
{
"domain": "example.com",
"feedback_enabled": true
}Response
{
"status": "NOT_STARTED",
"records": [
{
"name": "_agentmail.example.com",
"type": "TXT",
"value": "v=agentmail1 ...",
"status": "MISSING"
},
{
"name": "example.com",
"type": "MX",
"value": "inbound.agentmail.to",
"status": "MISSING",
"priority": 10
}
],
"domain_id": "example.com",
"created_at": "2025-01-15T12:00:00Z",
"updated_at": "2025-01-15T12:00:00Z",
"feedback_enabled": true
}Endpoint
Quality
Full OpenAPI 3.1 spec with detailed schemas and x-payment-info on every operation. Live MPP 402 challenge confirmed. Minor gaps: no standalone docs page served from the MPP gateway, response examples are inferred from schema rather than captured, and the exact stablecoin behind the currency address is not 100% confirmed.
Warnings
- —Currency token at address 0x20C0…8b50 on chain 4217 is assumed to be pathUSD (6 decimals); if different, the $10.00 price interpretation may be wrong.
- —MPP requires a Tempo-compatible crypto wallet for payment settlement — no fiat/card option available on this gateway.
- —The /docs, /api, /pricing paths on the MPP gateway return 'Endpoint not found'; external docs are at docs.agentmail.to.
Citations
- —AgentMail provides email inboxes for AI agents and raised $6M in seed funding.https://mpp.api.agentmail.to
- —Create Domain endpoint is POST /v0/domains with fixed price 10.000000 via MPP.https://mpp.api.agentmail.to
- —MPP challenge uses method=tempo, intent=charge, chainId=4217.https://mpp.api.agentmail.to
- —CreateDomainRequest requires domain (string) and feedback_enabled (boolean) fields.https://mpp.api.agentmail.to
- —Domain response includes domain_id, status (verification), records array, and timestamps.https://mpp.api.agentmail.to
- —Create Inbox costs 2.000000, Send Message costs 0.01, Create Draft costs 0.01.https://mpp.api.agentmail.to