# ADR-0009: Target Linux First With Tiered Platform Support

- Status: Accepted
- Date: 2026-05-27

## Context

AirCoding's first deep workflow targets C++ development and local agent execution, which depend heavily on POSIX shell/process/filesystem semantics and local toolchains.

## Decision

Use Linux x86_64 as tier-1 MVP platform, Linux arm64 and WSL2 as tier-2, macOS as experimental, and Windows native as experimental/post-MVP.

MVP shell/process/C++ workflows target POSIX-like Linux behavior.

## Consequences

- Release gates block on tier-1 Linux.
- Platform detection and path classification must be platform-aware.
- Windows native deep support and MSVC workflows are deferred.
- VibeBox ARM Linux remains compatible as a downstream branch but does not define mainline MVP release blockers.