# Process a merchant.

## Overview

[Overview - R2 API Docs](https://r2-api-docs.readme.io/docs/overview): This section provides a general overview of the R2 API, detailing its purpose, capabilities, and how it can be utilized to manage merchants and transactions effectively.

## Merchant Management

[merchants](https://r2-api-docs.readme.io/reference/patch_webhooks-merchants-external-id): This page outlines the functionalities available for managing merchants within the R2 API, including creating, updating, and retrieving merchant information.

## Transaction Management

[transactions](https://r2-api-docs.readme.io/reference/post_transactions): This section covers the various operations related to transactions, including how to create, retrieve, and manage transaction data.

[Create transactions asynchronously.post](https://r2-api-docs.readme.io/reference/post_transactions-async): This endpoint allows users to create transactions in an asynchronous manner, enabling better performance and user experience.

[Show a transaction by its id.get](https://r2-api-docs.readme.io/reference/get_transactions-id): This endpoint retrieves detailed information about a specific transaction using its unique identifier.

## Financing Management

[financings](https://r2-api-docs.readme.io/reference/get_financings): This page describes the financing options available for merchants, including how to manage and retrieve financing information.

[Show a financing by its id.get](https://r2-api-docs.readme.io/reference/get_financings-id): This endpoint allows users to view details of a specific financing option by its unique identifier.

## Collection Management

[collections](https://r2-api-docs.readme.io/reference/get_collections): This section provides information on managing collections, including how to add and retrieve collection data.

[Add one or more collections.post](https://r2-api-docs.readme.io/reference/post_collections): This endpoint enables users to add multiple collections at once, streamlining the process of managing collections.

[Show a collection by its id as filtering key.get](https://r2-api-docs.readme.io/reference/get_collections-id): This endpoint retrieves a specific collection's details using its unique identifier.

[Revert one collection.post](https://r2-api-docs.readme.io/reference/post_api-payments-payin-revert-id): This endpoint allows users to revert a collection, effectively undoing the last operation performed on it.

## Payment Management

[payments](https://r2-api-docs.readme.io/reference/post_api-payments-payin-refund-id): This page outlines the payment functionalities available within the R2 API, detailing how to manage and process payments.

## Callback Management

[callbacks](https://r2-api-docs.readme.io/reference/get_callbacks): This section describes how to manage callbacks, which are essential for handling asynchronous events in the API.

[Add a new callback.post](https://r2-api-docs.readme.io/reference/post_callbacks): This endpoint allows users to add a new callback, facilitating the integration of external systems with the R2 API.

[Show a callback by its id as filtering key.get](https://r2-api-docs.readme.io/reference/get_callbacks-id): This endpoint retrieves details of a specific callback using its unique identifier.

[Update a callback.put](https://r2-api-docs.readme.io/reference/put_callbacks-id): This endpoint enables users to update an existing callback, ensuring that the integration remains current and functional.

## Additional Resources

[Guides](https://r2-api-docs.readme.io/docs): This section provides various guides to help users understand and utilize the R2 API effectively.

[API Reference](https://r2-api-docs.readme.io/reference): This page serves as a comprehensive reference for all API endpoints, detailing their usage, parameters, and expected responses.

[Changelog](https://r2-api-docs.readme.io/changelog): This section lists all changes made to the API, including new features, bug fixes, and updates.

[Discussions](https://r2-api-docs.readme.io/discuss): This page provides a platform for users to discuss issues, share insights, and collaborate on using the R2 API.

[Log In](https://r2-api-docs.readme.io/login?redirect_uri=/reference/patch_webhooks-merchants-external-id): This link directs users to the login page for accessing the R2 API services.

[v1.2.0 - R2 API Docs](https://r2-api-docs.readme.io/changelog/v120): This page details the specific version of the R2 API, including any version-specific features or changes.

[Content Security Policy (CSP) - R2 API Docs](https://r2-api-docs.readme.io/docs/content-security-policy-csp): This section outlines the Content Security Policy for the R2 API, detailing security measures and best practices for developers.