> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prescaler.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Host test runner

> Run host-executable C tests and inspect results.

Run host-executable C tests and inspect results.

## Before you start

A native host compiler and tests compatible with the host runner.

## Workflow

Add test\_\*.c or \*\_test.c files, rescan in Test Runner and run tests. Review per-case failures and available coverage. Keep hardware-dependent tests separate unless a documented harness supplies the device behavior.

## Interpret the result

Host execution does not validate MCU timing, peripheral behavior or board wiring. A successful host test is one layer of validation.

For an unexplained result, preserve the source/configuration and observation together. Use [Diagnose a failure](/workflows/diagnose) to turn it into a reproducible investigation. Check [support boundaries](/reference/limitations) before assuming a vendor-specific operation is implemented.