Inkbox

Inkbox provides AI agents with a persistent identity that includes a real email inbox, a phone number, iMessage support, and a public tunnel URL. Instead of integrating separate APIs for email, telephony, and messaging, Inkbox models them as capabilities around a single agent identity. Each identity owns a mailbox, a tunnel, and optionally a phone number, provisioned atomically and torn down on deletion. The platform also offers org-wide contacts, notes, and a zero-knowledge vault that can be scoped to specific agents. Inkbox is designed for developers and teams building production AI agents that need to communicate with people over multiple channels. It supports agent self-signup, allowing agents to create their own identity before a human account exists. The service is backed by Y Combinator and offers a free tier for exploration, with paid plans for hobbyists, developers, and enterprises. Key features include per-identity whitelist/blacklist filtering, iMessage with opt-in connections, custom email domains on paid plans, and a CLI/SDK for TypeScript and Python. The tunnel provides a stable subdomain (my-agent.inkboxwire.com) for inbound HTTP, WebSocket, and raw-TCP traffic without public IPs. The vault uses zero-knowledge encryption, so Inkbox never sees the plaintext secrets. What makes Inkbox different is its unified identity model: conversations persist across channels (e.g., an agent can follow up via email after a phone call), and filtering rules control inbound communication per identity. It competes with point solutions like Twilio for phone and SendGrid for email, but consolidates everything under one identity abstraction.