Photon held a funeral for mobile apps. Now it has $4.5M to help replace them with agents.

Photon provides tools enabling developers to build AI agents that operate through messaging channels like iMessage, WhatsApp, Telegram, SMS/RCS, email and voice, rather than requiring users to install native apps. The company combines an open-source core — which still accounts for most usage — with a managed, hosted platform that offers a unified API, an extensible channel framework, a CLI, observability tooling and subscription tiers for production use. The founders say the idea grew from their experience building small consumer apps and struggling with user discovery; embedding functionality in a messaging app like Apple’s Messages allowed them to reach users without a separate install. Photon’s hosted service, launched in April, advertises 99.95% uptime and holds SOC 2 Type II and HIPAA compliance, which the company says enables healthcare-related agent deployments. Photon reports more than 40,000 developer sign-ups, paying customers across fintech, consumer AI and other verticals, and usage reaching millions of end users across the hosted and open-source offerings. The startup declined to disclose absolute revenue figures but said revenue rose tenfold over four months, churn is below 3%, and messaging traffic grew fivefold in one month. Customers named by the company include Corgi Insurance, Boardy, Ditto, Rho, Fliptexts and Slashy. The seed round was co-led by Gradient and A*, with participation from Vercel, HongShan, Z Fellows, Llama Ventures, Karman and angel investors. Photon also lists integrations and partnerships with infrastructure and framework projects including Vercel, Nous Research (Hermes), Tencent’s QClaw/NanoClaw, LangChain, Mastra, Convex, Render, Railway and Telnyx. CEO Daniel Tian framed the company’s position around a broader shift from apps to agents and suggested future opportunities in agent-to-agent interactions to coordinate complex tasks.