Lago

Lago is an open-source billing platform for businesses that need to connect product usage and commercial terms to customer invoices. It is best suited to engineering, product, and finance teams building subscription, usage-based, prepaid, or hybrid billing. Its main appeal is the breadth of billing models and developer access; its main trade-off is that Premium pricing is custom.

Overview

Lago supports subscription charges, metered usage, prepaid credits, and hybrid pricing, with quotes, order forms, entitlements, quotas, and itemized invoices. That range makes it a fit for businesses whose billing changes with customer activity, rather than only with a fixed monthly subscription. It also supports recurring invoices, online payments, payment reminders, multi-currency invoicing, and a client portal.

For AI products, Lago can meter input, output, and cached tokens separately and attribute usage to customers. That distinction can help teams make token consumption billable without treating different token types as interchangeable. The breadth comes with operational complexity: teams must connect product activity and commercial terms to billing.

Key features

Usage and billing

Quotes and order forms can connect commercial terms to recurring or usage charges, while prepaid credits, entitlements, and quotas give teams ways to set boundaries around consumption. Itemized invoices help explain charges that combine subscription fees and usage. These are useful building blocks for flexible billing, though businesses with straightforward fixed-price subscriptions may not need all of them.

Integrations and developer access

AI integrations include OpenAI, Anthropic, AWS Bedrock, Google Gemini, Mistral, Ramp Router, Snowflake Cortex, Databricks AI Gateway, and Cloudflare AI Gateway. Payments and finance connections include Adyen, GoCardless, Stripe, NetSuite, Xero, Anrok, Avalara, HubSpot, and Salesforce. Applications can connect through a REST API, official JavaScript, Python, Ruby, and Go SDKs, and signed webhooks. This gives engineering teams several routes for connecting usage and finance workflows; the platform is less compelling for buyers looking for billing without developer involvement.

Deployment and controls

The free open-source plan is self-hosted under AGPLv3, while Premium is offered as cloud or self-hosted deployment; Lago also says it can run on-premises or in a VPC. Lago states it is SOC 2 Type II certified and undergoes regular third-party penetration tests. It describes single sign-on, role-based access controls, and audit logs. Premium includes platform support, business-hours incident management, and implementation guidance; 24x7 incident management and an assigned solution engineer are on-demand add-ons.

Pricing

Open source

The Open source plan costs nothing and is AGPLv3-licensed for self-hosted deployment. The Open-source self-hosted plan is also free, with self-hosting on your own infrastructure. These options suit teams able to manage their own deployment and operations. They do not include the Premium support package.

Lago Premium

Lago Premium has custom pricing, with quotes provided after contacting Lago, and is available as cloud or self-hosted deployment. This is the option for organizations seeking platform support, business-hours incident management, and implementation guidance, but the cost requires a sales conversation. Some features are add-ons or subject to caps, including billing entities and data pipeline volume, so buyers should confirm which limits and extras apply to their use case. The 24x7 incident-management and assigned-solution-engineer options are add-ons.

Platforms

Lago supports API, self-hosted, and web access. Self-hosting is available through the free open-source plan and Premium; Premium also offers cloud deployment.

Who it's for

Lago is aimed at engineering, product, finance, and operations teams, including fast-growing AI companies and global enterprises. It is a strong match when a business needs to meter usage, support multiple pricing models, or connect billing to finance systems. Teams that want a fixed-price subscription tool with no self-hosting or integration work may find Lago more involved than necessary.

Pros and cons

• Pros: Supports subscription, usage-based, prepaid, and hybrid billing, giving teams room to combine pricing models.
• Pros: Separately meters AI input, output, and cached tokens, useful for billing distinct kinds of model usage.
• Pros: Offers a free, self-hosted AGPLv3 plan, plus API, SDK, and webhook access for product integrations.
• Cons: Premium has custom pricing, so buyers cannot compare its cost without contacting Lago.
• Cons: Premium features can be add-ons or capped, including billing entities and data pipeline volume, which may affect the final fit and cost.
• Cons: The free plan is self-hosted, making it a weaker choice for teams that do not want to operate their own deployment.

Alternatives

For a broader comparison, see Usage-Based Billing Software, Subscription Billing Software, API Monetization Software, Dunning Management Software, and Invoicing software.

• Kill Bill is another free-plan option with a self-hosted open-source core and support for a broad range of platforms; consider it if infrastructure and data control are the priority.
• Pabbly Subscriptions has a free plan capped at 50 customers, with revenue limits and no team members or affiliate module; consider it if that capped free tier suits your needs.
• PayWhirl offers a free plan with a 3% transaction charge, before payment gateway processing fees; consider it if a no-monthly-cost option with transaction-based charges fits your billing.
• UniBee offers a free self-hosted open-source plan that requires manual setup and comes with community support; consider it if customization and self-hosting outweigh setup convenience.
• Flexprice has a free plan with 100k events per month and up to $100K in cumulative billing revenue; consider it if those caps fit your expected volume.
• Fakturia is another option to compare for billing.
• Zuora CPQ is another option to compare for billing.
• Gotransverse is another option to compare for billing.

Verdict

Choose Lago if your team needs to translate metered product activity—including distinct AI token types—into flexible invoices and has the engineering capacity to integrate or self-host a billing platform. Its free open-source plan makes self-managed evaluation possible, while Premium adds cloud deployment and support options. Look elsewhere if you need transparent Premium pricing or want a billing service without self-hosting and integration work.