Stack AI

Stack AI is a no-code platform for building, deploying and managing enterprise AI agents and LLM workflows. It connects data sources, models and tools on a visual canvas to automate document processing, question answering and data tasks, with a strong focus on enterprise security and governance.

Stack AI is a no-code builder for AI agents and LLM-powered workflows. Using a visual interface, teams connect data sources, LLMs, tools and logic to automate tasks such as document processing, question answering over knowledge bases, data extraction and internal assistants. It is designed so business users can assemble agents without heavy engineering, while still offering the security and governance features enterprises expect. After graduating from Y Combinator's W23 batch, Stack AI deliberately pivoted toward the enterprise, reportedly moving away from smaller SMB customers to focus on large, F500-scale buyers. Its customer roster includes named enterprise logos, and its feature set leans into compliance, security and scaled deployment. The company has raised roughly $19.6 million across two rounds, including a $16 million Series A in May 2025 led by Lobby Capital, with earlier backing from Gradient Ventures and Y Combinator. Pricing has moved upmarket, with builder and team tiers plus enterprise plans; smaller teams may find it less accessible than lighter chatbot builders, but enterprises get a governed, no-code agent platform.