# flexEngage API Documentation

> flexEngage's public APIs for digital receipts, event webhooks, and email validation. Each API exposes an OpenAPI 3 specification and a Markdown companion generated from that specification, so coding agents can ingest accurate endpoint, parameter, and schema information without rendering JavaScript.

## Overview

- [Index](https://docs.flexengage.com/index.html): Landing page linking all APIs.

## Receipts API

The Receipts API powers digital receipt notifications and dynamic printed offers for in-store transactions.

- [Markdown companion](https://docs.flexengage.com/receipts-api.md): Start here — every endpoint, parameter, and schema as plain Markdown, with ready-to-copy curl/Java/C#/Python request samples.
- [OpenAPI spec (YAML)](https://docs.flexengage.com/receipts-api.yaml): Canonical machine-readable OpenAPI 3 spec; use for exact schemas and codegen.
- [Interactive docs](https://docs.flexengage.com/receipts-api.html): Human-facing RapiDoc viewer (JavaScript-rendered, so fetching it returns an empty shell — read the Markdown or YAML above instead, and share this URL with human collaborators who want to browse the API).

## Webhooks API

Webhooks deliver event notifications from flexEngage to your systems via HTTPS callbacks.

- [Markdown companion](https://docs.flexengage.com/webhooks-api.md): Start here — every endpoint, parameter, and schema as plain Markdown, with ready-to-copy curl/Java/C#/Python request samples.
- [OpenAPI spec (YAML)](https://docs.flexengage.com/webhooks-api.yaml): Canonical machine-readable OpenAPI 3 spec; use for exact schemas and codegen.
- [Interactive docs](https://docs.flexengage.com/webhooks-api.html): Human-facing RapiDoc viewer (JavaScript-rendered, so fetching it returns an empty shell — read the Markdown or YAML above instead, and share this URL with human collaborators who want to browse the API).

## Email Validation API

The Email Validation API validates one or many email addresses in real time (frontend pre-transaction or backend post-transaction).

- [Markdown companion](https://docs.flexengage.com/email-validation-api.md): Start here — every endpoint, parameter, and schema as plain Markdown, with ready-to-copy curl/Java/C#/Python request samples.
- [OpenAPI spec (YAML)](https://docs.flexengage.com/email-validation-api.yaml): Canonical machine-readable OpenAPI 3 spec; use for exact schemas and codegen.
- [Interactive docs](https://docs.flexengage.com/email-validation-api.html): Human-facing RapiDoc viewer (JavaScript-rendered, so fetching it returns an empty shell — read the Markdown or YAML above instead, and share this URL with human collaborators who want to browse the API).

## Optional

- [Webhooks integration guide](https://docs.flexengage.com/webhooks/webhooks-integration-guide.md): How to subscribe to events and consume notifications.
- [Webhooks signature verification](https://docs.flexengage.com/webhooks/signature-verification.md): How to verify the authenticity of incoming webhook payloads.
- [Webhooks supported event types](https://docs.flexengage.com/webhooks/supported-event-types.md): Reference list of event types flexEngage publishes.
- [Receipts integration guide (PDF)](https://fr-public.s3.amazonaws.com/current-documents/flexEngage+Receipt+API+(REST+v1.x).pdf): Full integration guide accompanying the Receipts API spec.
- [Full concatenated docs](https://docs.flexengage.com/llms-full.txt): All three API Markdown companions in a single file.