> ## Documentation Index
> Fetch the complete documentation index at: https://yuno-3979e326-docs-agent-readable-descriptions.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Understanding Flows

> Compare payment and enrollment flows in Yuno SDKs with diagrams and step sequences.

In Yuno SDKs, **payment flows** and **enrollment flows** are separate. Payment is the process of completing a transaction; enrollment is the process of saving a payment method (e.g. a card) to a customer account for future use. This page explains both flows at a high level with diagrams and step sequences. Use the Quickstart guide and platform flow pages for implementation details.

## Payment flow

The SDK provides a unified payment experience: customers complete transactions using multiple payment methods within a single integration. The diagram below illustrates the main payment workflow.

![Full (Web) payment flow](https://files.readme.io/0b97d1a-Diagrama_-_Full_SDK.png)

### Payment flow steps

1. Merchant Server: `Create Customer` → Yuno Server: `Creates Customer`
2. Merchant Client: `Initiate Checkout` → Merchant Server: `Create Checkout session`
3. Merchant Server: `Create Checkout session` → Yuno Server: `Creates Checkout session`
4. Merchant Client: `Initiate Checkout` → `Initiate SDK` to continue payment flow
5. Merchant Client: `Initiate SDK` to continue payment flow → Yuno SDK: `Receive checkout session`
6. Yuno SDK: `Receive checkout session` → `List payment methods`
7. Yuno SDK: `List payment methods` → User selects payment methods
8. Yuno SDK: User selects payment methods → Callback with the `one-time token`
9. Yuno SDK: Callback with the `one-time token` → Merchant Client: Receive `one-time token` (single use)
10. Merchant Client: Receive `one-time token` (single use) → `Initiate payment`
11. Merchant Client: `Initiate payment` → `Initiate SDK` to continue payment flow
12. Merchant Client: `Initiate SDK` to continue payment flow → Yuno SDK: `Continue with the payment flow`
13. Yuno SDK: `Continue with the payment flow` → Show screen for the user to complete payment
14. Yuno SDK: Show screen for the user to complete payment → Display `payment result` (optional)
15. Merchant Client: `Initiate payment` → Merchant Server: `Create payment`
16. Merchant Server: `Create payment` → Yuno Server: `Creates payment` in the payment provider

### Payment flow using a vaulted token

If a customer has an enrolled payment method, they can use a **vaulted token** to pay without entering payment details again.

![Vaulted token payment flow](https://files.readme.io/e257d04-Diagrama_-_Vaulted_token_Full.png)

#### Vaulted token flow steps

1. Merchant Client: `Initiate checkout` → Merchant Server: `Create Customer`
2. Merchant Server: `Create Customer` → Yuno Server: `Create Customer`
3. Merchant Client: `Initiate SDK` with the `checkout session` → Yuno SDK: `Receive checkout session`
4. Yuno SDK: `Receive checkout session` → `List payment methods`
5. Yuno SDK: `List payment methods` → User selects payment methods
6. Yuno SDK: User selects payment method → Callback with the `one-time token`
7. Yuno SDK: Callback with the `one-time token` → Merchant Client: `Initiate payment`
8. Merchant Client: `Initiate payment` → Merchant Server: `Create payment`
9. Merchant Server: `Create payment` → Yuno Server: `Creates payment` in the payment provider
10. Merchant Client: Show `payment result` → Merchant Server: `Receive payment result`
11. Merchant Server: `Receive payment result` → Yuno Server: Provides `payment result`

## Enrollment flow

**Enrollment** is the process of saving a payment method (e.g. a card) to a customer’s account so it can be used later (e.g. with a vaulted token). full-checkout supports enrollment; the diagram below describes the enrollment workflow.

![Enrollment flow](https://files.readme.io/deacb45-Diagrama_-_SDK_Lite_enrollment.png)

### Enrollment flow steps

1. Merchant Server: `Create Customer` → Yuno Server: `Creates Customer`
2. Merchant Client: `Add payment method` → Merchant Server: `Create customer session`
3. Merchant Server: `Create customer session` → Yuno Server: `Creates customer session`
4. Merchant Client: `Display payment methods to enroll` → Merchant Server: `Request available payment methods to enroll`
5. Merchant Server: `Request available payment methods to enroll` → Yuno Server: `Returns available payment method`
6. Merchant Client: `Display payment methods to enroll` → Merchant Client: User selects payment method to enroll
7. Merchant Client: User selects payment method to enroll → Merchant Client: `Initiate enrollment`
8. Merchant Client: `Initiate enrollment` → Merchant Client: `Initiate SDK` to continue enrollment
9. Merchant Client: `Initiate SDK` to continue enrollment → Yuno SDK: `Continue enrollment flow`
10. Yuno SDK: `Continue enrollment flow` → Yuno SDK: Shows screens for the user to complete enrollment
11. Merchant Server: Receive `enrollment result` via webhook → Yuno Server: Receive `enrollment results` from payment provider
12. Yuno Server: Receive `enrollment results` from payment provider → Yuno SDK: Display `enrollment result` (optional)