Unitpost is a communication platform for sending email and SMS messages. It supports transactional messages, including receipts, password resets, and sign in codes, as well as marketing campaigns such as newsletters. The platform is designed for integration with applications and AI agents, providing access through an API, software development kits (SDKs), and the Model Context Protocol (MCP). Pricing is based on the volume of messages sent rather than the number of contacts stored. The platform offers tools for email, SMS, and automations. Transactional messages include features like idempotent sending and per message tracking. Marketing campaigns are priced per send and include an automatic unsubscribe footer. Unitpost unifies transactional and marketing communications under a single domain to support deliverability. Typical use cases include sending order confirmations, shipping updates, one time sign in codes, and automated flows triggered by user actions, such as cart abandonment. Workflows can be configured to wait for a specific duration before executing a sequence of actions. The same set of actions can be initiated by an AI agent or through direct API calls, allowing for flexible integration into existing systems.