Retool

Retool helps engineering and business teams build and operate internal software connected to their databases, APIs, and business systems. Its AI app builder generates applications from prompts, with editable React frontends and TypeScript backends. Teams can also import existing React apps or build through coding agents using Retool’s MCP server. A shared runtime supplies authentication, permissions, auditability, and release management, with deployment on Retool Cloud, in a customer’s VPC, or on premises.

Founded in 2017 by current CEO David Hsu, Retool grew from the repetitive internal tooling work behind his earlier payments startup, Cashew. Its original approach combined reusable visual components with custom business logic. The rebuilt platform introduced in 2026 separates standard application code from centralized governance, allowing externally built apps to inherit the same controls. Retool RPC extends this approach to private backend functions: an SDK inside the customer’s infrastructure polls for calls through outbound connections, without requiring a separate REST layer or inbound internet exposure.

As of August 2026, Retool reported over 10,000 organizations, including Amazon, Stripe, and Brex, operate production software on their business data using the platform. In 2022, it raised $45 million in Series C2 financing at a $3.2 billion valuation, with participation from existing investors including Sequoia.