Flowglad

Flowglad is an open-source payment and billing layer for web applications. It allows developers to manage subscriptions, feature gating, and usage metering without maintaining local database tables for billing states or configuring webhooks. The software is deployed as a server-side integration with a dedicated web app for configuration, enabling the creation of pricing models and the deployment of checkouts.

It provides a full-stack SDK for React and Node.js environments, including specific support for Next.js, Express, and other TypeScript-based stacks. The system is designed to handle the complexity of modern startup billing by acting as a centralized source of truth for customer billing state, which can be accessed via API calls or frontend hooks.

Key features

• Stateless billing that removes the need for local subscription tables or webhooks
• Single source of truth for customer billing state and feature access
• Integration using existing application user, organization, or team IDs
• Full-stack SDK with a server client and a React useBilling hook
• Support for multiple pricing models including hybrid usage-limit and tiered access
• Test mode for iterating on pricing models before production deployment
• Ability to rotate pricing models without redeploying the application
• Direct querying of usage meter credits and feature access via slugs

The architecture focuses on reducing the maintenance overhead of payment infrastructure. It integrates with existing authentication systems, allowing developers to query billing states using their own internal IDs rather than provider-specific customer IDs. This means the application does not need to store customer IDs from the payment provider in its own database. The system is designed for both B2C and B2B applications, supporting different identification logic for individual users or organizational teams. It includes templates for common models such as feature-gated subscriptions and tiered access with usage credits.

Flowglad is a developer-centric payments layer aimed at simplifying the integration and maintenance of complex billing systems.