Chert

What is Chert

Chert is an iMessage infrastructure and API designed for scalable, personalized AI messaging. It enables businesses to build and deploy AI on iMessage, reaching people at scale while maintaining quality, trust, and personalized interaction. It is backed by Y Combinator.

How to use Chert

Chert exposes a REST API and webhooks for every inbound and outbound event, allowing integration with CRMs, sales tools, voice agents, or internal data stores. Native synchronization for common cases like lead creation, meeting booking, and opt-outs is also provided. Integrations can be handled during onboarding if manual building is not preferred.

Features of Chert

• Real iMessage: Utilizes Apple's iMessage protocol for a blue-bubble user experience.
• SMS Fallback: Automatically reroutes to SMS when a recipient is not on iMessage, with API distinction.
• Peer-to-Peer Experience: Delivers a conversation thread that appears in the same inbox as personal messages, supporting read receipts and tapbacks.
• Deliverability: Avoids carrier-side filtering common with A2P SMS by rotating sending identities, warming them gradually, and capping volume.
• Typing Indicators & Tapbacks: Captures live typing indicators and reactions natively.
• Group Chats: Supports multi-recipient threads with named senders.
• Attachments: Allows sending photos, PDFs, and links natively within the thread.
• Live Delivery State: Provides sub-second deliverability telemetry per message.
• API & Webhooks: Offers a REST API and webhooks for seamless integration with existing tools.

Use Cases of Chert

• Onboarding: Welcoming new users immediately after sign-up.
• Customer Support: Resolving customer issues directly within iMessage without requiring a portal or ticket queue.
• B2C Agents: Automating tasks like booking, rescheduling, and answering queries, mimicking human interaction.
• Cold Outbound: Engaging potential customers with a higher reply rate than cold email, avoiding spam flags.

FAQ

• Is this real iMessage, or just SMS branded as iMessage? Real iMessage. Outbound and inbound flow over Apple’s iMessage protocol with the blue-bubble UX your customers already trust. We fall back to SMS only if a recipient isn’t on iMessage, and we surface that distinction in the API so you always know which channel a message landed on.
• How is this different from sending SMS through Twilio? Twilio is an A2P SMS pipe: carrier-filtered, 10DLC-registered, and visibly automated. Chert delivers a peer-to-peer iMessage thread that opens with the blue bubble, supports read receipts and tapbacks, and lives in the same inbox as a recipient’s family and friends. Open and reply rates are categorically different because the channel is.
• What about deliverability and spam flags? Because iMessage is end-to-end and tied to Apple ID, it doesn’t inherit the carrier-side filtering that hammers A2P SMS. We rotate sending identities, warm them gradually, and cap volume per identity per day to stay well below the heuristics Apple uses to throttle abusive senders. Anyone promising "unlimited blast" volume is one ban away from disappearing.
• How do I connect Chert to the tools my team already uses? We expose a REST API and webhooks for every inbound and outbound event, so you can wire conversations into your CRM, sales tools, voice agents, or internal data store with a few hours of work. We also ship native sync for the common cases (lead created, meeting booked, opt-out received). If you’d rather not build, we’ll handle the integration during onboarding.