Chert launches Twilio-for-iMessage API and GTM service
YC-backed Chert is pitching a single API for blue-bubble threads with SMS/RCS fallback and CRM integrations, and says it will run outbound as a service for teams.
By Ryan Merket ยท Published
Why it matters
If Chert can make blue-bubble outreach programmable and compliant, founders get a new high-intent channel for onboarding, support, and AI agents. If it cannot, it is just another SMS workflow with extra steps. The upside is higher response and trust; the risk is policy, deliverability, and scale limits on iMessage.
Chert, a YC-backed company, is launching an iMessage-first messaging platform and API that it says lets teams "build and deploy AI on iMessage to reach people at scale," per its homepage. The site frames the product as Twilio-for-iMessage with a services layer that books meetings and runs conversations, not just a dashboard.
The team behind Chert argues that traditional outbound is broken: inboxes are saturated and LinkedIn is noisy. Their bet is that the next wave of outreach and customer engagement will be conversational, personal, and delivered in blue bubbles people already trust. They also pitch that AI agents need an emotional layer of trust to be effective in sales, so they are offering full-stack execution rather than self-serve tooling.
What ships, according to Chert
Chert presents a "One API, many features" surface that exposes iMessage-native behaviors programmatically, plus SMS/RCS fallback when the recipient is off-platform. From the homepage:
- Blue-bubble threads with verified senders and end-to-end encryption
- Typing indicators and tapbacks captured natively
- Group chats with named senders
- SMS/RCS fallback auto-routing, noted inline when used
- Attachments (photos, PDFs, links)
- Delivery telemetry with per-message states
- Webhooks, message receipts, verified numbers, and compliance audits
Chert positions itself between a team's systems and a customer's phone. The homepage highlights integrations and workflows with Salesforce, HubSpot, Slack, Attio, GoHighLevel, Close, and Vapi, with the promise of "one thread, everywhere your team works." Chert points to four primary use cases: lifecycle onboarding, support without a ticket portal, B2C conversational agents that can book or reschedule, and cold outbound that aims to outperform email.
Logos shown under "Trusted by growing teams" include Tour, Symbal, DCNHC, Vela, Whop, Rubbrband, Blue Navy, Chasi, Fintech, and Autosana. The site invites prospective customers to book a call to get started and links to an agent page.
Outcomes, not just APIs
Beyond the API, Chert is pitching a services-style engagement for go-to-market teams. According to the company narrative on its site, Chert will handle ICP definition, lead sourcing, the conversations themselves, and meeting booking. The promise is less tooling overhead and more pipeline, with iMessage-native UX preserved for recipients.
The marketing copy leans into reply performance claims versus cold email in mock conversations, though the site does not publish aggregate metrics, pricing, or customer counts. It also highlights deliverability practices like rotating and warming sending identities to avoid throttling, but leaves the underlying iMessage access path and policy compliance details unspecified.
What we do not know yet
Chert lists Y Combinator as a backer on its site. Chert's site does not identify founders, headcount, pricing, or revenue, and it does not explain how the platform interfaces with Apple iMessage under Apple's policies. For buyers evaluating risk, those implementation details, rate limits, and compliance posture will matter as much as the API surface.
Still, if Chert can reliably deliver verified blue-bubble conversations at scale and wire them into the tools sales and support teams already use, it opens a new channel for both human reps and AI agents that want to live where customers actually respond.