# OneTrial

> One API call that answers "should this signup get a free trial?" -> allow / challenge / deny. Trial-abuse prevention for SaaS.

- Full reference (token-efficient): https://onetrial.dev/llms-full.txt
- OpenAPI 3.1: https://onetrial.dev/openapi.json
- Dashboard: https://onetrial.dev/dashboard
- Snippet: <script src="https://onetrial.dev/v1.js" data-key="YOUR_PUBLIC_KEY" async></script>
- Decide: POST https://onetrial.dev/api/v1/decisions  (Authorization: Bearer ot_test_...)  body { visitorToken, email, ip, cardFingerprint?, userId?, event?: "signup" | "promo", promoCode? }
- Coupon abuse: send event:"promo" with promoCode at redemption. Promo events never count as consumed trials.
- Verify integration: GET https://onetrial.dev/api/v1/integration/status
- Errors always: { error: { code, message, fix } }
- MCP server: npx @onetrial/mcp (tools: create_test_api_key, get_integration_guide, verify_integration, query_decisions, update_thresholds)
- One-command install: npx onetrial init