Your customer service bot can parse sentiment, route tickets, and draft responses in seconds. But try having it send a proper iMessage—blue bubbles, read receipts, the works—and you hit a wall.
That's the gap a small San Francisco startup thinks it can fill. Inkbox, a Y Combinator company, is building what its founders describe as the "identity and communication layer" for AI agents. The proposition sounds almost quaint in its simplicity: if software is going to pose as something close to human in our inboxes and text threads, it should probably have the basic communication tools that humans take for granted.
Ray Liao, the company's CEO and an MIT-trained computer scientist, puts it plainly. "We are building the communication layer for AI agents," reads the team's pitch. What that means in practice is less philosophical: every agent gets a real email address, an optional phone number that handles calls and texts, and—perhaps most notably—access to Apple's fiercely guarded iMessage platform through a shared router system.
It's a narrow problem to solve. But for companies spinning up agents meant to interact with customers or colleagues over days and weeks, the question of persistent identity isn't trivial.
More Than Just an API Key
When a developer provisions an identity through Inkbox, they're handed a bundle: a mailbox (defaulting to an inkboxmail.com domain), a stable public tunnel at a permanent hostname, and optionally a real phone number pulled from the public switched telephone network. The phone line handles inbound calls with automatic transcription, SMS, and MMS. Agents can work with the pre-processed text or, if they're built for it, handle raw audio streams directly.
Email access comes through a REST API—search, send, forward, flag, manage attachments, the usual. The tunnel routes HTTP, WebSocket, or raw TCP traffic over a single persistent connection, with optional passthrough TLS for developers who want to manage their own certificates.
The crucial bit: everything ties back to the same identity. A support bot keeps its email and number across weeks of back-and-forth. A scheduling assistant texts you from the same contact every time, not a rotating pool of generic numbers.
The iMessage Puzzle
Then there's iMessage, which is where things get technically interesting—and legally murky.
Apple doesn't offer a public API for its messaging platform. The company has spent years swatting down third-party bridges and locking down who gets to play in that blue-bubble ecosystem. Yet Inkbox is offering agents a way in.
The design is clever, if constrained. Rather than giving each agent its own iMessage-capable number (expensive, and likely to draw Apple's ire), Inkbox runs a shared router model. The company manages a pool of iMessage lines; when a person wants to reach an agent, they send a connect command to the router, which then bridges that conversation to the agent's identity. The agent can't cold-message someone—the human has to initiate—but once the connection is live, it's full iMessage: typing indicators, tapbacks, read receipts, even send effects like confetti or invisible ink.
There are limits. One-to-one conversations only, no group threads. Each identity can send up to 100 iMessages in a rolling 24-hour window, with automatic fallback to SMS or RCS when that cap is hit.
It's a workaround that threads a needle. Apple did approve an AI agent called Poke for Messages for Business—a shopping assistant—so there's an official path into the platform. But that route appears selective and may carry per-user fees payable to Apple. Inkbox's router abstraction offers an alternative: no per-agent iMessage number, but the native messaging experience intact.
Whether Apple will tolerate this setup long-term is an open question. The company declined to comment for this story.
A Team With Adjacent Bets
Liao previously cofounded Empallo, an AI-driven virtual clinic, and holds a PhD in computer science from MIT. Alex Wilcox, Inkbox's CTO, comes from ML engineering and networking research at Northeastern. Dima Vremenko, the third cofounder, worked on clinical machine learning at Harvard Medical School before joining the team.
Backing comes from NFX and Night Capital, though the company hasn't disclosed funding amounts. The team of three is based in San Francisco and founded the company in 2025.
Building the Stack
Inkbox rolled out its first SDK updates in late June, releasing Python and TypeScript libraries. There's a self-signup flow that lets AI agents register themselves, issuing provisional identities and API keys pending human approval. (Yes, agents signing up agents—a recursive wrinkle the team seems to find amusing.)
Early partner integrations are starting to surface. Maritime, a platform for deploying AI agents, now lets users spin up an OpenClaw agent "with identity" through Inkbox, handing each one a phone number and email on the spot. Documentation shows example setups with frameworks like Hermes Agent and Kernel, stitching together email, phone, and tunnels in unified workflows.
Crowded Territory, Different Angle
Inkbox isn't alone in the broader agent infrastructure land grab. Retell and Vapi offer voice-first platforms, charging per-minute rates that blend telephony and model costs. OpenAI's Realtime API gives developers low-latency voice with SIP support baked in. Bandwidth, the telecom provider, just launched a product called "Build" in late June that lets agents autonomously provision communication services.
Where Inkbox diverges is the emphasis on bundled, persistent identity. It's not just voice or just email, but the full communication surface—phone, text, iMessage, email, tunnel—all under one stable identity with shared context across channels. There's also zero-knowledge encrypted storage for credentials and an org-wide contacts system, features that hint at the company's eye toward enterprises with compliance concerns.
Pricing follows a tiered model with monthly quotas for calls, texts, and iMessages. Enterprise plans promise dedicated iMessage infrastructure and higher limits. The company's terms of service read like they were drafted by lawyers who've seen telemarketing lawsuits: explicit references to call-recording consent, TCPA requirements, 10DLC rules for messaging, and a data protection addendum updated in late June covering CCPA and similar privacy laws.
For teams building agents that need to feel less like bots and more like persistent contacts—assistants that stick around, support systems that remember your history—Inkbox is wagering that identity infrastructure will prove more valuable than the sum of its communication APIs.
Whether that bet holds depends partly on how long companies can keep routing around the walled gardens that messaging platforms have spent decades building. And perhaps on whether Apple decides a shared router model is creative engineering or something closer to trespassing.
