---
page_title: Introduction
product: Consumer Specs
page_source: https://juspay.io/pe/docs/upi-consumer-stack-pe/docs/overview/introduction
llms_txt: https://juspay.io/pe/docs/llms.txt
product_llms_txt: https://juspay.io/pe/docs/upi-consumer-stack-pe/llms.txt
---


# Introduction   



Welcome to the UPI PSP Backend API Reference Document. This doc consists of the comprehensive information about our Server-to-Server APIs. We use **application/json**  content type for our request and response.

This documentation is designed to guide you through each API in detail. From API descriptions to the step-by-step flow, everything you need is outlined in the sections below. Each section includes crucial information about the API's structure, including the Request and Response body specifications.

Before you dive into the APIs, we recommend familiarizing yourself with the [Request](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/overview/api-guide-issuance#Request-Structure) and [Response](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/overview/api-guide-issuance#Response-Structure) structure. This will provide you with essential insights into prerequisites and overall formatting, ensuring a smooth integration process.


## **Customer Onboarding** 



The UPI [Registration Flow](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/customer-onboarding/registration-flow)  is the process of linking a bank account to a UPI-enabled mobile app by selecting the bank, creating a unique Virtual Payment Address (VPA), and setting up a secure PIN to facilitate instant money transfers and transactions via smartphones.

**[Account management](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/customer-onboarding/account-management-flow)**  in UPI involves overseeing linked bank accounts within the UPI-enabled app, allowing users to handle multiple accounts, change or reset their UPI PIN, view transaction histories, and maintain security measures to ensure safe and convenient money transfers.


## **Customer Transactions** 



There are two primary methods for UPI transactions: [Intent-based payments](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/customer-transactions/intent-flow) and [Collect](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/customer-transactions/collect-flow)[Requests](https://docs.juspay.in/upi-consumer-stack/docs/customer-transactions/collect-flow).

1. [Intent Payments](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/customer-transactions/intent-flow) refer to initiating transactions where the user directly authorises and initiates a payment from their UPI app to another party by entering the recipient's Virtual Payment Address (VPA) or scanning a QR code. This method allows users to send money by actively initiating the transaction through their UPI app.
2. [Collect Requests](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/customer-transactions/collect-flow) involve requesting funds from another UPI user. The recipient generates a collect request by entering the payer's VPA or scanning their QR code. The payer then receives a notification to approve or decline the request, giving them control over the payment.


## **New Features** 



1. **[UPI Mapper](https://docs.juspay.io/pe/docs/upi-consumer-stack-pe/docs/advance-features/upi-mapper)** **:** UPI Mapper is a component or system within the UPI infrastructure responsible for mapping and associating various identifiers (such as mobile numbers, bank account numbers, virtual payment addresses, etc.) with UPI handles or unique identifiers. It helps route transactions accurately to the intended recipient by resolving different identifiers to their corresponding UPI addresses or accounts.

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## See Also

- [Onboarding Guide (Issuance)](https://juspay.io/pe/docs/upi-consumer-stack-pe/docs/overview/onboarding-guide-issuance)