AI model marketplace OpenRouter raises $40 million in funding, led by a16z and Menlo Ventures

ChainCatcher news, AI model marketplace OpenRouter announced the completion of a $40 million seed and Series A funding round, with the company valued at approximately $500 million.

This round of financing was led by Andreessen Horowitz and Menlo Ventures, with participation from Sequoia and several well-known industry investors. The funds will be used for product development, introducing new model types, and expanding enterprise support.

OpenRouter was founded in 2023 by OpenSea co-founder and CTO Alex Atallah and Louis Vichy, providing a unified interface to connect over 400 large language models (LLMs), helping developers and enterprises simplify multi-model integration. Since its launch, the company has attracted over 1 million developers to use its API, with annual inference spending growing from $10 million in October 2024 to over $100 million by May 2025. Customers range from startups to multinational corporations, supporting routing for mission-critical traffic.