Lago

Lago is an open-source billing platform that turns product usage and commercial terms into customer invoices. It supports usage-based, subscription, prepaid, and hybrid pricing, along with quotes, order forms, credits, entitlements, quotas, and itemized invoices. For AI services, it can meter input, output, and cached tokens separately and assign that usage to customers for billing. Applications can connect through a REST API, official JavaScript, Python, Ruby, and Go SDKs, or signed webhooks. Listed AI integrations include OpenAI, Anthropic, AWS Bedrock, Google Gemini, Mistral, and others; payment and finance connections include Adyen, Stripe, NetSuite, and Xero. The Open source plan is free under AGPLv3 and is self-hosted. Lago Premium is available as cloud or self-hosted deployment, including on-premises or in a VPC, but its price is provided after contacting Lago. Lago states that it is SOC 2 Type II certified and supports single sign-on, role-based access controls, and audit logs.

Lago covers several billing models and provides tools for metering product usage, including separate AI token categories. The open-source option is self-hosted; Premium offers cloud or self-hosting, with pricing available by contacting Lago.

Lago is intended for engineering, product, finance, and operations teams handling usage-based or subscription billing. Its AI token metering may fit AI companies, while cloud and self-hosting options also address global enterprises.

Lago is a billing platform for teams whose invoices need to reflect both customer activity and commercial terms. It is a strong fit for engineering-led products with usage, subscription, prepaid, or hybrid charges, especially AI services that bill different token types separately. Fixed-subscription businesses may find its range of billing controls more than they need.

Overview

Lago combines recurring and usage charges with prepaid credits, quotes, order forms, entitlements, quotas, and itemized invoices. This breadth suits products where customer bills change with consumption or combine several kinds of charges; itemization can make those bills easier to understand. The trade-off is that teams need to connect product activity and commercial terms to the billing workflow.

It also supports online payments, payment reminders, multi-currency invoicing, and a client portal, covering several parts of the customer billing experience alongside invoice generation.

Key features

Usage metering and developer access

Lago can measure AI input, output, and cached tokens separately and attribute each category to customers for billing. That separation is useful when an AI product needs to account for different kinds of token consumption rather than roll them into one usage figure. Integrations include OpenAI, Anthropic, AWS Bedrock, Google Gemini, Mistral, Ramp Router, Snowflake Cortex, Databricks AI Gateway, and Cloudflare AI Gateway.

Applications can connect through a REST API, official JavaScript, Python, Ruby, and Go SDKs, and signed webhooks. This gives development teams several supported ways to connect product events and billing operations; teams seeking a billing tool without integration work are less likely to benefit from that flexibility.

Payments, finance, and controls

Payment integrations include Adyen, GoCardless, and Stripe; finance and business integrations include NetSuite, Xero, Anrok, Avalara, HubSpot, and Salesforce. Lago states that it is SOC 2 Type II certified and undergoes regular third-party penetration tests. Single sign-on, role-based access controls, and audit logs are also supported, which are relevant controls for organizations managing billing access across teams.

Pricing

Open source

Open source costs nothing and is licensed under AGPLv3 for self-hosted deployment. It is the no-cost option for teams able to run the software on their own infrastructure. Its self-hosted model puts deployment on the team, rather than providing Lago Premium's cloud option and included support.

Lago Premium

Lago Premium has custom pricing, provided after contacting Lago, and is available as cloud or self-hosted deployment. Lago says it can also be run on-premises or in a VPC. Premium includes platform support, business-hours incident management, and implementation guidance; 24x7 incident management and an assigned solution engineer are on-demand add-ons. Some features are add-ons or subject to caps, including billing entities and data pipeline volume, so teams should clarify the scope and limits that apply to their deployment. Premium suits organizations that need a managed option or implementation support and can evaluate a custom quote.

Platforms

Lago supports API and web access, while its open-source deployment is self-hosted. Premium can be deployed in the cloud or self-hosted, giving teams a choice of operating model.

Who it's for

Lago is aimed at engineering, product, finance, and operations teams, including fast-growing AI companies and global enterprises. It is most compelling when a company needs to connect metered activity, commercial terms, and customer invoices, or needs controls such as multi-currency billing and access roles. A business with simple fixed subscriptions and little need for usage controls may prefer a narrower billing setup.

Pros and cons

• Pros: Supports subscription, usage, prepaid, and hybrid charges, letting teams combine billing models within one platform.
• Pros: Separate metering for AI input, output, and cached tokens supports customer-level billing by token category.
• Pros: The open-source self-hosted option costs nothing, and Premium offers cloud or self-hosted deployment.
• Cons: Premium uses custom pricing, so teams must contact Lago to assess cost.
• Cons: Some Premium capabilities have add-ons or caps, including billing entities and data pipeline volume.
• Cons: Open source requires self-hosting, which is a poor fit for teams seeking a cloud deployment without Premium.

Alternatives

Aforo is worth considering for teams that want a free API-and-web option with a published Starter plan: free for 50K events per month, one storefront, six pricing models, basic revenue intelligence, Stripe integration, and community support.

Credyt may fit teams building and testing wallet-based billing: its free plan covers the first 10 active wallets each month, with full feature access in test mode, no credit card, and no time limit.

Flexprice is an alternative for developers who want a published free allowance: its Developer plan includes up to 100,000 events per month, one pricing plan, a REST API and one SDK, basic invoice generation, email support, and 14-day data retention.

Solvimon may suit qualifying teams focused on AI usage metering and credits, with an AI Essentials offer that is free for the first $3M and then 0.4% of volume; qualification criteria apply.

Zuora CPQ is another option for teams seeking quote-to-order software with pricing tailored to products, scope, transaction volume, business model, regions, and implementation needs.

Aria Billing is another paid API-and-web billing option.

Cheddar may suit teams looking for a published paid plan: Builder costs $99 a month and 30¢ per transaction, with email support, documentation, and multiple payment gateways.

Continuous Command is another paid API-and-web option with custom pricing scoped to transaction volume and configuration complexity.

Browse Usage-Based Billing Software, Subscription Billing Software, Dunning Management Software, API Monetization Software, and Invoicing software for more options by category.

Verdict

Choose Lago if your product needs flexible usage, subscription, prepaid, or hybrid billing and your team can connect product events to invoices; AI companies can benefit particularly from separate token-category metering. The open-source plan gives self-hosting teams a no-cost route, while Premium adds cloud deployment and support. Look elsewhere if you need transparent Premium pricing upfront or only require straightforward fixed subscriptions.