# topi

> topi is a European hardware-as-a-service (HaaS) fintech that lets B2B sellers offer tech devices and equipment as monthly rental subscriptions instead of outright purchases, across eCommerce, telesales, and point-of-sale channels. Merchants integrate via the topi Seller API and the topi Elements web components. Backed by Creandum.

## API
- [topi Seller API reference](https://developer.topi.eu/api): 31 operations across catalog, offers, orders, shipments, and shipping methods.
- [OpenAPI 3.0.3 spec](https://developer.topi.eu/redocusaurus/plugin-redoc-0.yaml): machine-readable definition of the Seller API.

## Authentication
- OAuth2 client_credentials grant. Token endpoint: https://identity.topi.eu/oauth2/token (sandbox: https://identity.topi-sandbox.eu/oauth2/token).
- Header: `Authorization: Bearer $ACCESS_TOKEN`. 13 seller-* scopes (catalog, offer, order, shipment, shipping-method, branding, metrics, scenario-simulations, user-info).

## Docs
- [Getting started](https://developer.topi.eu/docs/get-started/introduction)
- [Integration guide](https://developer.topi.eu/docs/integration-guide/syncing-your-catalog)
- [Sandbox / testing](https://developer.topi.eu/docs/sandbox/introduction)
- [topi Elements (web components)](https://developer.topi.eu/docs/topi-elements/what-is-topi-elements)

## Conventions
- Base URLs: production https://seller-api.topi.eu ; sandbox https://seller-api-sandbox.topi-sandbox.eu
- Versioning: URI-path, current v1.
- Pagination: offset (page/limit) and cursor styles; prefer the *_paginated endpoints.
- Errors: Goa media type `application/vnd.goa.error` (Error envelope: name, id, message, temporary, timeout, fault).
- Localization: `Accept-Language` header (RFC-2616).
- Webhooks: Offer Updates (accepted/declined/voided/pending_review/expired) and Order Events.
- No idempotency-key contract is documented.

## Company
- [Website](https://www.topi.eu/en/)
- [For merchants](https://www.topi.eu/en/merchant)
- [Privacy policy](https://www.topi.eu/en/privacy-policy)
- [Imprint](https://www.topi.eu/en/imprint)