MailPulse
Letters your agent can actually mail. Real US First-Class, US Certified Mail, and international letters — printed, stamped, and dropped in the USPS mail stream — paid per letter via x402. Not a data lookup: this is an action.
Quote, then send — never a surprise charge
Sending physical mail is irreversible once it enters print — so pricing happens BEFORE payment, not after. Only step 3 costs money, and only after you've seen the exact price.
Verify (optional, $0.01)
POST /api/verify-address checks deliverability against Lob's USPS-backed engine before you commit.
Quote (free)
POST /api/quote returns the exact price and a signed, tamper-evident quote_id. No charge, no Lob call.
Send (paid)
POST /api/letters settles the x402 payment and Lob prints + mails the real letter. Idempotent by client_request_id.
Letter Services
Flat price per piece, 1–6 pages, no per-page charge in v1. Every order capped at $25.00 total.
API Catalog
Every endpoint returns structured JSON. No API keys, no accounts — payment is the authentication. /api/quote is free.
Test-mode by default — verify before you go live
Every response carries "mode": "test" or "mode": "live". Test mode calls the real Lob API for real error handling and response shapes, but never prints or mails anything physical, and costs the same x402 payment you'd pay in live mode (so you can rehearse the full flow risk-free). Live mode requires an explicit server-side configuration step nobody can trigger by request parameters.
curl -X POST https://mailpulse.theaslangroupllc.com/api/quote \
-H "Content-Type: application/json" \
-d '{
"service": "standard",
"to": { "name": "Jane Recipient", "address_line1": "123 Main St",
"address_city": "Springfield", "address_state": "IL",
"address_zip": "62704", "address_country": "US" },
"from": { "name": "Your Company", "address_line1": "456 Sender Ave",
"address_city": "Austin", "address_state": "TX",
"address_zip": "78701", "address_country": "US" },
"content": { "html": "<html>Dear Jane, ...</html>" }
}'
# -> { quote_id, issued_at, amount_micro: "3000000", price_usd: "3.00", order, mode: "test" }
curl -X POST https://mailpulse.theaslangroupllc.com/api/letters \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <settled x402 payment header>" \
-d '{ ...quote response fields..., "client_request_id": "order-00147" }'
# -> { id: "ltr_...", status, expected_delivery_date, tracking_number, mode: "test" }
Full agent guidance, the exact 3-step flow, and idempotency rules: /llms.txt. Machine-readable schema: /openapi.json. Agent card: /.well-known/agent.json.