Open-source usage-based billing with event ingestion, prepaid wallets, progressive billing, and accounting sync.
Lago is an open-source billing engine built for usage-based and hybrid pricing: it ingests usage events through an API, aggregates them into billable metrics, rates them against plans, and generates invoices — with prepaid credit wallets, threshold-triggered progressive billing, and a customer portal on top. Engineering-led teams at API, AI, and infrastructure companies are the typical adopters, choosing between the self-hosted open-source core and the hosted cloud version. In the revenue stack it replaces the metering-to-invoice pipeline teams otherwise build in house, and hands finished invoices to payment providers and the GL.
Which of the capability map's modules Lago covers — each links to the module's own page, with every tool that supports it.
| Module | Phase | Depth | Note |
|---|---|---|---|
| Fulfill & Bill | |||
| Usage Event Ingestion (API) | Consume & Meter | Core | API-first event ingestion feeding billable metrics. |
| Aggregation & Rollups | Consume & Meter | Core | Aggregates raw events into billable metrics per period and customer. |
| Rating Engine | Rate & Bill | Core | Rates usage against plans spanning subscription, usage, and hybrid models. |
| Invoice Generation | Rate & Bill | Core | |
| Wallet / Credit Drawdown | Consume & Meter | Core | Prepaid credit wallets drawn down by usage — the AI-pricing staple. |
| Auto Top-Up / Replenishment | Consume & Meter | Supported | Wallets can replenish automatically when balances run low. |
| Threshold Invoicing | Rate & Bill | Supported | Progressive billing invoices mid-period when usage crosses thresholds. |
| Self-Service Billing Portal | Rate & Bill | Supported | |
| GL Posting / Accounting Sync | Rate & Bill | Supported | Integrations push billing data to accounting systems. |
Scored against UsagePricing's Usage-based billing & metering rubric v1.0 (0 weak · 1 adequate · 2 strong), assessed July 2026. Requirements we couldn't verify from public material stay unscored — never guessed. Read the method.
| Requirement | Score | Why |
|---|---|---|
| Real-time balances & drawdown Can a customer (and your product) see an accurate credit or spend balance mid-period? | 1 · Adequate | Wallets and prepaid credits exist; real-time enforcement at request time is left to the host application. |
| Correction & re-rating When a meter was wrong, can you fix history without hand-editing invoices? | 1 · Adequate | Corrections flow through adjustments and credit notes rather than full event replay. |
| Commits, credits & custom rate cards Can it express how enterprise AI deals are actually signed? | 1 · Adequate | Minimum commitments and volume discounts cover common cases; complex ramp and drawdown contracts need modeling work. |
| Billable-metric flexibility Can finance define a new meter without re-instrumenting the product? | 1 · Adequate | Configurable aggregations with filters and expressions over events; not free-form SQL. |
| Invoice & proration correctness Do mid-cycle changes, consolidation, and multi-currency come out right? | 1 · Adequate | Proration and standard invoicing are covered; consolidation and multi-entity depth trail the incumbents. |
| Rev-rec & ERP handoff Can the numbers survive an audit once they leave the billing system? | 1 · Adequate | Accounting integrations and exports; the ERP owns rev-rec. |
| Ingestion scale & integrity Does the meter stay correct at production event volumes? | 2 · Strong | High-volume event pipeline with idempotency, built on an OLAP store and run self-hosted at scale. |
| Price-change velocity How fast can you ship a pricing change safely? | 1 · Adequate | Plans are editable with versioning; dry-run simulation against live data is limited. |
Open source is the wedge: the billing logic is inspectable, self-hostable, and extensible, which lands with engineers who distrust black-box billing and with companies whose data cannot leave their infrastructure. It pairs that with genuinely modern usage mechanics — prepaid wallets with auto top-up and billing thresholds — that many closed subscription platforms bolted on late.
Open-source core plus quoted cloud/enterprise. Self-hosting is free; the managed cloud and premium features are sales-quoted.
1 of the companies the Blueprint tracks — from public job posts, engineering blogs, and filings. Every claim links to its evidence on the company page.
Control and auditability. You can read the rating logic, self-host where compliance demands it, and extend edge cases instead of waiting on a vendor roadmap. The trade-off is operational ownership if you self-host — which is why Lago also runs a hosted cloud offering.
No — deliberately. Lago meters, rates, and invoices, then integrates with payment providers for collection and tax engines for calculation. It competes with the billing pipeline you would build in house, not with your payment processor.
By overlap on the capability map — computed, not curated.