# Process.Run

Last updated: 2026-09-09

Run an explicitly selected Windows program in an owned job and wait for its exit.

Built into Yeho; no import is needed. These additions have Windows CPU-oracle developer-host evidence. Kyber rejects these operations; this does not qualify Starfish or other targets.

`Process.Run(text executable, list of text arguments, text workingDirectory, int timeoutMilliseconds) -> int64`

Returns a nonnegative Windows DWORD exit code, or -1 invalid arguments, -2 setup failure, -3 timeout, -4 supervision failure, -5 unsupported host. Job cleanup terminates remaining descendants. This is lifecycle containment, not a security sandbox. No output capture. The illustrative executable is not supplied or run during type checking.

Contract and host execution evidence: yeho/docs/runtime/hardware-host-tools.md. This small example was type checked, not executed.

## Parameters

- executable (text): Absolute Windows executable path; no shell or PATH search.
- arguments (list of text): Individually quoted arguments; at most 256.
- workingDirectory (text): Child directory; empty text inherits the caller directory.
- timeoutMilliseconds (int): 1 through 3,600,000 ms, or explicit 0 for an unbounded wait.

## Type-checked example

```yeho
int64 result = Process.Run("C:/example/tool.exe", [], "", 1000)
```

project.mech:

```toml
manifestVersion = "2"
package = "api.example.runtime__process_run"
version = "0.1.0"
languageEdition = "yeho-core-2026.1"

[app]
kind = "headless"
```

Source: yeho/src/compiler/common/intrinsic_registry.cpp:808