AI startup Photon raised $4.5 million in seed funding to develop tools for agents (software that performs tasks for users) operating through messaging services rather than standalone mobile apps. The company says it has attracted more than 40,000 developers, increased revenue tenfold in four months, recorded less than 3% churn and expanded messaging volume fivefold in the past month. Photon marked its thesis with a tongue-in-cheek funeral for mobile apps at a San Francisco church on September 17, where co-founder and CEO Daniel Tian hosted a developer day featuring Vercel, Stripe and OpenAI panels and an actual coffin for app icons. Photon provides a unified API (software interface for connecting applications), channel framework, command-line interface and observability suite for agents working across iMessage, WhatsApp, Telegram, SMS or RCS, email and voice. Its hosted platform offers 99.95% uptime, SOC 2 Type II and HIPAA compliance, while the open-source version still represents 98% of usage. Investors in the seed round included Gradient, A*, Vercel, HongShan, Z Fellows, Llama Ventures, Karman and angel investors. Tian estimates the hosted and open-source products together reach millions of end users, and sees a future in which agents communicate with other agents to complete tasks for people.