Host Environment
Validator runtime bridge. For now it exposes a single ability: run a Smart Action and hand the VM its attested result.
Smart Action Host Call
The VM describes which Smart Action to run (uses: string), its inputs, and the current workflow context.
The runtime looks up the Smart Action manifest entry, executes the code in the appropriate trust domain (onchain call, TEE, external service), and returns a receipt containing the step id and outputs. The VM then pushes that receipt onto its stack so later steps and the final workflow result can reference it.