Launch HN: Simantic (YC F26) – Firmware Simulation for AI Agents

Simantic is building a simulation and testing layer for firmware, aimed at both engineers and AI coding agents. Its founders, former firmware engineers at Neuralink and Tesla, argue that AI can now write firmware quickly but cannot test it as easily as ordinary software: traditional validation requires flashing physical boards and running manual tests with costly, aging tools. Simantic offers virtual development boards runnable through an API, a firmware code-review bot that uses simulation evidence, and CI/CD checks that test firmware on every commit. Customers use it for bare-metal and RTOS projects including flight controllers, electric vehicles, robots, and satellites. One satellite startup tested firmware before obtaining hardware, which Simantic says reduced the cost and time to roughly one hundredth of what hardware-based testing would require.

The company began with a wrapper around Renode, an open-source emulator, but says its pace of development, performance, excess features, and insufficient timing accuracy constrained the product. It built a new simulation engine in Rust, prioritizing accuracy for selected hardware models over broad coverage. To compare simulations against real devices, Simantic runs hardware rigs continuously, using logic-analysis and debugging equipment to find discrepancies. The cloud simulator is available now, with a local binary for developer-plan customers. Current support includes some STM32F0, F4, and H7 chips, ESP32-S3 and C3, and RP2040, with additional models in development. The founders see accurate simulation as especially important in safety-critical fields, where firmware defects can endanger people or compromise expensive systems.