YC-Backed Chert Builds iMessage API for Business Messaging, Betting on Blue Bubbles Over SMS

A startup out of Y Combinator's P26 batch is trying to do for iMessage what Twilio did for SMS: turn it into a programmable communications layer that businesses can plug into their products. The company is called Chert, and its founders Gary and Ian are pitching an API that lets businesses send, receive, and automate iMessage conversations at scale — something Apple does not officially support through any public developer interface.

The pitch is specific. iMessage carries features SMS does not: read receipts, typing indicators, reactions, and high-resolution media, all rendered inside Apple's native messaging app. For companies running AI-driven or agent-based customer interactions, those signals carry real operational value. A typing indicator tells the other party something is happening. A reaction can serve as a lightweight confirmation. The "blue bubble" experience, as Chert's founders frame it, changes how the conversation feels to an end user in ways that plain SMS cannot replicate. For more on the topic discussed above, see US Business Chronicle.

The Regulatory and Technical Overhang

The central question for any operator evaluating Chert is one that the company cannot fully answer on its own: how durable is access to iMessage outside Apple's sanctioned developer ecosystem? Apple has not published an iMessage API for third-party business use. Solutions that exist today tend to rely on Apple hardware running macOS or iOS, essentially automating the native Messages application rather than connecting through a formal protocol. That approach carries platform risk. Apple has historically moved to close workarounds that it views as violating its terms of service, and the company's messaging infrastructure is not subject to the same interoperability obligations that apply to SMS carriers under U.S. telecommunications rules — though the European Union's Digital Markets Act, which took effect in March 2024, has required Apple to open iMessage to third-party interoperability in the EU.

Chert is entering a market where the underlying access method is ambiguous and where a single policy decision by Apple could reshape the product entirely. That is not an argument against the company, but it is the variable that any potential customer or investor needs to price in.

What Operators Should Actually Evaluate

For startups and growth-stage companies considering a channel like this, the practical checklist is short but important. First, confirm in writing what happens to queued messages and conversation history if the underlying access method is interrupted. Second, understand whether Chert's architecture depends on specific Apple hardware that could be deprecated or restricted. Third, look at whether the use case actually requires iMessage specifically — for transactional notifications, SMS or email may carry fewer platform dependencies at comparable cost.

The Twilio comparison Chert is drawing is a useful frame, but Twilio built on top of carrier agreements and public telephony standards. iMessage is a proprietary protocol owned by one of the most valuable companies in the world. The opportunity is real if the access holds. The business model makes sense if the channel stays open. Those are meaningful conditions, and operators should treat them as such before committing to any integration.