Photon raises $4.5M to build agents that replace mobile apps

Photon is so confident that agents will eventually replace mobile apps that it held a literal funeral for them — in a church, with speeches and a coffin for app icons. The AI startup, which helps developers build agents that work over iMessage and WhatsApp, has raised $4.5 million in seed funding to develop its products. The round comes after Photon signed up more than 40,000 developers and grew its revenue 10x in four months, the company says.

Co-founder and CEO Daniel Tian said the “app funeral,” held in San Francisco on September 17, doubled as a developer day featuring panels from Vercel, Stripe, and OpenAI. The stunt was tongue-in-cheek, but Tian believes the app era is ending. “Honestly, it’s going to take a while, but I think, directionally, it’s inevitable,” he said of the shift from apps to agents.

The startup’s thesis is that users no longer want to install new apps and instead want agents that work through messaging apps they already use. Meta’s Muse, which has climbed to No. 1 on app stores, is testing that theory. But even if Muse comes to dominate consumer AI, Tian sees a market serving developers who want their applications to work over messaging — which is why Photon offers a unified API, a channel framework, a command-line interface, and an observability suite that together let developers build and run an agent experience across iMessage, WhatsApp, Telegram, SMS, RCS, email, voice, and other channels.

Photon grew out of Tian and co-founder Ryan Zhu’s attempts to build consumer apps as students; every app they finished hit the same bottleneck of getting people to discover it. Building an agent that worked within iMessage let them reach people through an app people already use daily. When they open-sourced the technology, thousands of developers adopted it, and the open-source version still accounts for 98% of Photon’s use today. This April, the founders launched a managed, subscription-based hosted platform offering 99.95% uptime and SOC 2 Type II and HIPAA compliance, opening the door to healthcare use cases. The platform has attracted more than 40,000 developer sign-ups and now includes paying clients; usage beyond 10 users requires a paid tier. The company says it is seeing less than 3% churn and messaging volume growing 5x in the past month alone.

Customers include Corgi Insurance, social-introductions app Boardy, dating platform Ditto, business banking platform Rho, finance assistant Fliptexts, and email client Slashy. Technology partners include Vercel, with Nous Research’s Hermes agent and Tencent’s QClaw and NanoClaw also built on Photon’s layer. The seed round was co-led by Gradient and A*, with participation from Vercel, HongShan, Z Fellows, Llama Ventures, Karman, and other angel investors.

Why it matters

Photon’s bet is that the near-term opportunity in agentic AI isn’t a single winning consumer app but the infrastructure layer that lets many developers’ agents reach users through the messaging apps people already have open.