OpenRouter, an AI platform founded by former co-founder of OpenSea, has raised $40 million in Series A funding, led by a16z and other investors

OpenRouter, an AI model marketplace platform, announced the completion of a $40 million seed and Series A funding round, with a company valuation of approximately $500 million. This round of financing is 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, introduction of new model types, and expansion of enterprise support. OpenRouter was founded by Alex Atallah, co-founder and CTO of OpenSea, and Louis Vichy in 2023. It provides 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, and annual inference spending has increased from $10 million in October 2024 to over $100 million in May 2025. Our clients range from startups to multinational corporations, supporting the routing of critical task traffic.