API & Integrations
Send via REST or SMTP — your choice
A modern REST API for greenfield projects and a drop-in SMTP relay for existing stacks. Webhooks and SDKs included — integrate in minutes, not weeks.
REST API with JSON responses
Send messages with a single POST request. Structured JSON responses with message IDs, queuing status, and validation feedback — no XML, no guesswork.
Drop-in SMTP relay
Point your existing SMTP config to FlashPost and everything just works. No code changes needed — migrate in under five minutes.
Real-time webhooks
Get instant HTTP callbacks for delivered, opened, clicked, bounced, and complained events. Retry logic and signature verification included.
Official SDKs
Type-safe client libraries for Node.js, Python, Go, and Ruby. Auto-generated from our OpenAPI spec, so they're always up to date.
Ship faster with a first-class API.
From first request to production in under ten minutes. FlashPost APIs are built for developers who value their time.