# Lago > ## Documentation Index --- # Source: https://getlago.com/docs/faq/about-lago.md > ## Documentation Index > Fetch the complete documentation index at: https://getlago.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # About Lago ## 1. What is Lago? [Lago](https://www.getlago.com/) is the leading open-source pricing solution focused on complex billing: multi-product/geographies, transactional, usage-based, subscription hybrids, etc, chosen by unicorns like Mistral (AI, \$13.7 billion valuation), Accel-backed Swan (Embedded banking), or Groq (AI, \$6.9 billion valuation). Lago is API-first, the most loved billing solution on Github, and was voted Product of the day week, and month on Product Hunt. Lago raised a total of [\$22M of funding](https://techcrunch.com/2024/03/14/lago-a-paris-based-open-source-billing-platform-banks-22m/) from investors including Y Combinator, FirstMark Capital, SignalFire, [Meghan Gill](https://www.linkedin.com/in/meghanpgill/), who has led the monetization efforts of MongoDB for 14 years, [Romain Huet](https://www.linkedin.com/in/romainhuet/), former head of Developer Relations at Stripe - now leading OpenAI developer experience, and [Clément Delangue](https://www.linkedin.com/in/clementdelangue/), CEO of AI open platform Hugging Face.