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Open architecture
The Flexprice core (metering, credits, pricing, billing) has an open and composable design.
Your application, whether it's running backend APIs, AI agents, or custom workflows, can send usage data to Flexprice. You can directly stream data from data warehouses or analytics pipelines as well.
At the core, Flexprice processes this data in real time. We handle everything that usually ends up as custom logic built by developers. Our platform calculates pricing based on the customer’s plan, applies any prepaid or promotional credits, enforces feature limits, and generates accurate invoices automatically. Whether you're using seat-based subscriptions, usage-based pricing, or prepaid credit bundles, you can set up and iterate on your pricing model without writing billing infrastructure from scratch.
After billing is computed, our platform connects to your existing tools for payments, CPQ, CRM, and accounting, ensuring billing information flows into the systems your business already uses. It can sync invoices to your payment processor, update customer data in your CRM, and push revenue numbers to your accounting tools.
With this architecture, you get full control over how billing works inside your product, while saving your team from the complexity of maintaining it all.
Why billing is a developer problem?
TL;DR
When existing billing tools don’t flex to your product’s needs, developers shoulder the burden eating up valuable development time and causing ongoing maintenance headaches.
Modern app developers often find themselves wrestling with billing systems. Here are some of the biggest pain points that turn billing into a “developer problem”:
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Rigid billing tools (lack of flexibility): Traditional billing services handle simple subscriptions or payments, but anything beyond that – usage metering, credit systems, feature gating, custom invoice logic – usually isn’t supported out of the box. Developers end up writing countless workarounds or custom code to accommodate these needs. In other words, if your pricing model doesn’t fit the tool, you’re stuck bending your product or building logic from scratch.
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Complex usage metering at scale: Implementing accurate usage tracking is hard. It involves capturing high-volume events, aggregating them in real time, handling edge cases (prorations, time zones, etc.), and ensuring it all works reliably at scale. Few teams anticipate how many moving parts this requires until they’re deep in the weeds of building it.
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Vendor lock-in and black boxes: Relying on third-party billing platforms can mean surrendering flexibility. Many SaaS billing providers are closed systems or charge a percentage fee on revenue, which frustrates engineers who want full control over their pricing logic and data. Changing providers later can be a massive undertaking, so teams feel “stuck” with a less-than-ideal solution.
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Delayed monetization & opportunity cost: Every week spent building or patching a billing system is a week not spent on core product features. If it takes months to implement a new pricing model or usage-based feature, that’s delayed revenue and lost agility for the business. What might be scoped as a “quick two-month project” can quickly spiral into a multi-year maintenance headache, tying up engineering resources and slowing time-to-market for new offerings.
How Flexprice solves this
Flexprice’s approach is to abstract away the hard parts of billing while preserving maximum flexibility and transparency for developers. It addresses the above pain points in several key ways:
- Developer-first design: Flexprice is built API-first with easy integrations. You can instrument your app by simply sending usage events via SDKs, and Flexprice handles the aggregation, metering, and billing logic in real time. This means minimal code to write on your end and no need to reinvent metering or invoice calculations.
- Open-source and self-hostable: Flexprice is open-source, so you can run it on your own infrastructure for full transparency and control. There’s no black-box dependency or surprise fees and you’re free from vendor lock-in. You can inspect the code, extend functionality, and trust that your billing logic is fully in your hands.
- Composable with your stack: Rather than replacing your existing billing or payment provider, Flexprice augments it. You can build it from scratch or build on top of your existing billing providers like Stripe or Chargebee to manage usage data, pricing rules, credits, and entitlements. You can easily integrate with your existing payment gateways, CRM, CPQ, etc. This layered approach preserves your current workflows and customer touchpoints.
- Flexible pricing models out-of-the-box: Whether you need pure usage-based billing, tiered plans, seat-based subscriptions, prepaid credits, free tiers with overage, or any hybrid model, Flexprice’s data model and rules engine can support it. Flexprice is designed to accommodate changing pricing strategies in minutues that would normally require schema updates and migration scripts.
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