A Payment represents a series of logically connected financial transactions like reserving, charging, or refunding money.

A Payment holds information about the payment service provider (PSP), the payment method used, any related transactions, and the current state of the Payment. An [Order](https://docs.commercetools.com/api/projects/orders.md) or a [Cart](https://docs.commercetools.com/api/projects/carts.md) can reference a set of Payments using the [PaymentInfo](https://docs.commercetools.com/urn?urn=ctp%3Aapi%3Atype%3APaymentInfo) object.
A Payment can also reference a [Customer](https://docs.commercetools.com/api/projects/customers.md), or an [anonymous session](https://docs.commercetools.com/api/authorization.md#tokens-for-anonymous-sessions).

The actual financial process is carried out by an external PSP, which is connected to the API by [PSP-specific integrations](https://marketplace.commercetools.com/integrations/payment-service-providers).

If you are using [Checkout](https://docs.commercetools.com/checkout/overview.md) for your checkout solution, the [Checkout Payment Intents API](https://docs.commercetools.com/checkout/payment-intents-api.md) lets you request the PSP to perform actions throughout the financial process, such as payment capture, refund, and authorization cancellation.

Learn more about how to implement payment integration as part of a custom checkout flow in our self-paced Implement a custom checkout module.

# Representations

### Payment

#### PaymentResourceIdentifier

### PaymentMethodInfo

#### PaymentMethodInfoDraft 

### PaymentStatus

#### PaymentStatusDraft

### Transaction

#### TransactionState

# Get Payment

## Get Payment by Key

# Check if Payment exists

## Check if Payment exists by Query Predicate

# Update Payment

## Update Payment by Key

# Update actions

### On Payment

#### Set CustomField

### On Transaction

#### Set Transaction CustomField

# Delete Payment