Review / Hosted API
Chert review
Y Combinator-backed iMessage infrastructure aimed at AI agents, not at sales reps.
Chert is the most infrastructure-shaped vendor to arrive in this category. Where most of the field sells a line and an inbox, Chert sells primitives — phone number pools, reply routing, delivery and status tracking, webhook-ready event monitoring — and pitches them at teams deploying AI agents on iMessage at scale. It is Y Combinator-backed, and its investor list includes angels from OpenAI, NVIDIA and LinkedIn.
What it is good at
- **Number pools and reply routing are real infrastructure primitives**, not features bolted onto an inbox — nobody else in the category names them.
- Explicitly built for AI agents and conversational deployments rather than retrofitted for them.
- Multi-recipient threads with named senders, which most vendors either lack or do not document.
- Integrations with Salesforce, HubSpot, Slack and Attio — Attio in particular signals a startup-GTM audience.
- The strongest investor signal in the category, for whatever weight you give that on vendor durability.
Where it will bite you
- **No published pricing at all.** You cannot compare it on cost without booking a call, which rules it out for anyone evaluating quickly.
- Young, even by this category's standards — there is little independent operating history to check.
- The Y Combinator batch is not stated on the site, so 'YC-backed' is as specific as the public record gets.
- Agent-scale positioning means the smallest sensible deployment may be larger than a local business needs.
What Chert claims
Reported as the vendor's own marketing claims. We have not independently reproduced these numbers, and neither should you treat them as benchmarks.
- Real iMessage, not SMS disguised as iMessage
- Reach people at scale while keeping the native blue-bubble thread
Tracking links with Chert
UTM note
With a number pool, the sending number is not stable across a campaign. Put the campaign identifier in the UTM rather than inferring it from the line, or your analytics will fragment across the pool.
Whatever you send with, build the URL from one helper so tagging is consistent across every job and campaign. Open the UTM builder to generate one now.
Still weighing options?
The comparison table puts all five side by side.