Free placement test API

The Inbox Check API is public, RESTful, and doesn't require a signup for basic use. You can script a placement test in 10 lines and ship it to production.

Core endpoints

• POST /api/tests — start a placement test.
• GET /api/tests/:token — fetch results, live-updating.
• GET /api/providers — enumerate providers + seed availability.
• POST /presend — analyze a draft before send.
• POST /api/monitor/domain — add a domain to daily monitoring.

Anonymous example

curl -X POST https://check.live-direct-marketing.online/api/tests \
  -H "Content-Type: application/json" \
  -d '{
    "from": "you@yourdomain.com",
    "subject": "Quick question about {{company}}",
    "body": "Hi {{first_name}}...",
    "providers": ["gmail", "outlook", "yahoo", "mail-ru", "yandex"]
  }'
# -> { "token": "abc123...", "pollUrl": "/api/tests/abc123" }

OAuth for higher limits

Standard OAuth 2.0: /oauth/authorize, /oauth/token, /oauth/me. Native Zapier/Make/n8n connectors use this flow.

# Bearer token on any request
curl -H "Authorization: Bearer $TOKEN" https://check.live-direct-marketing.online/api/tests

Pre-built integrations

• Zapier: “Inbox Check” app on the Zapier directory.
• Make: native module with OAuth connection.
• n8n: community node + OAuth2 credential.
• MCP server: agent-native tool use (see our MCP article).
• A2A endpoint: for orchestrator->specialist delegation.

Rate limits

• 3 tests per sending address per 24h rolling window (anonymous).
• 10 tests per IP per 24h rolling window (anonymous).
• 200 inbound per seed mailbox per 24h rolling window.
• OAuth-authenticated use: 5–20x higher, depending on tier.

FAQ