Create a server-side key
Open Developer → API keys, name the key after its environment and copy it once. Never expose it in browser code.
Developer platform
Email infrastructure your product can explain.
Send transactional email, render saved templates and run verification flows through one authenticated API. The documentation shows the request, response, cost and failure behaviour for every supported endpoint.
first-send
curl -X POST https://mail.hihemax.com/api/v1/send \
-H "X-API-Key: hm_your_key" \
-H "Content-Type: application/json" \
-d '{
"to": "ada@example.com",
"subject": "Your account is ready",
"text": "Sign in to finish setting up your workspace."
}'202
accepted
1
credit / recipient
hm_
key prefix
First production integration
The sequence is short. Each step has an observable result and a specific failure path.
Send one message
Call POST /api/v1/send with direct content or the ID of an active template. A valid request returns HTTP 202.
Read the result
Store the returned message ID, watch creditsRemaining and inspect the usage feed when diagnosing a send.
Handle limits safely
Treat 400, 401 and 402 as non-retryable until corrected. Honour Retry-After for 429 responses.
Transactional sending
Send onboarding, receipts, password resets and operational alerts from a backend.
Reusable templates
Publish branded templates once, then provide validated variables from your application.
OTP and magic links
Start and check verification flows without building email delivery infrastructure yourself.
Usage you can inspect
Read balance, request counts and recent usage through the API or authenticated dashboard.
API reference
Every endpoint, field, response, error and retry rule.
Product documentation
Domains, mailboxes, webmail, contacts, campaigns and billing.
Developer dashboard
Create keys, inspect credits and review recorded usage.
Ready for one real request