Photon Announces $4.5M Seed Round to Help Developers Build AI Agents for iMessage and WhatsApp

AI startup Photon has secured $4.5 million in seed funding co-led by Gradient and A*, with participation from Vercel, HSG, Z Fellows, Llama Ventures, Karman and angel investors. The company says it has attracted more than 40,000 developer sign-ups and grown revenue tenfold in four months, with churn below 3% and messaging volume up fivefold in the past month.

Photon offers a unified API, channel framework, CLI and observability suite that let developers build agents working over iMessage, WhatsApp, Telegram, SMS, email, voice and more. Co-founder and CEO Daniel Tian said the shift from apps to agents will take time but is inevitable, a belief the company marked with a tongue-in-cheek app funeral in San Francisco in September.

Tian and CTO Ryan Zhu developed the idea after struggling to get users to discover their student-built apps. Their open source iMessage bot drew thousands of developers and still accounts for 98% of usage, while a hosted platform introduced in April offers 99.95% uptime with SOC 2 Type II and HIPAA compliance.

Customers include Corgi Insurance, Boardy, Ditto and Rho, and Photon powers Nous Research’s Hermes agent. Tian sees future growth in agent-to-agent communication.

Featured image: Credit: Photon