Compatibility and supported platforms

This page defines the compatibility contract for August 1.x. August 1.0.0 is the first stable release. Its tagged qualification records the source, artifacts and checks for each supported host.

The ownership and task conformance page records checked behavior for moves, aliasing, cleanup, cancellation, and delayed errors.

What stays stable in 1.x

Area	1.x contract
August source	Accepted syntax, import visibility, labeled calls, types, ownership, effects, checked errors, tasks, and same-file tests keep their documented meaning through 1.x. Minor releases can add syntax or APIs.
CLI and project files	Documented aug commands, main.yaml keys, aug-package.json, and aug.lock.json retain compatible reading within 1.x. New fields have defaults; removing or changing a field requires a major release.
First-party packages	CLI, standard, web, and crypto packages use one exact version. A release tests installed tarballs together; mixing versions is unsupported. August 1.0 accepts author-declared bounded compiler ranges; exports still come from export.aug. See package compatibility.
Generated specifications	aug spec remains deterministic for a given compiler and project. Text and layout can improve between versions; tools should link to source and declarations rather than parse Markdown prose.
Native boundary	aug-native-abi-1 uses fixed-width scalars, copied buffers and opaque resources over the target C ABI. Package descriptors preserve ownership, release, errors and platform requirements. The runtime's AugValue layout and pointer-call services remain compiler-private. The ABI reference fixes the existing public contract.

A change that makes valid 1.x source fail to compile, changes its observable behavior, or removes a documented public name is breaking. A safety or correctness repair may require a narrow exception, but its release must explain the affected code, provide a diagnostic, and provide aug migrate support when mechanical migration is possible. Security fixes can be released promptly; they still get a compatibility note.

Migration between versions

Each release documents source, configuration, package, and native changes in the changelog. When spelling can be changed safely, aug migrate PROJECT performs or suggests the edit. For changes requiring a choice, the diagnostic explains the alternatives without rewriting behavior silently. Install a compatible compiler and extension. aug install checks package requirements while retaining locked repository commits. Use aug install --update only when you intend to change those revisions too. Then run:

aug check PROJECT
aug test PROJECT
aug spec PROJECT --check

Rebuild native executables and private dependencies for the target platform after a compiler upgrade. aug.lock.json and the pinned native dependency manifest provide the input versions; a compiled executable is not promised to work with a different runtime image or native dependency set.

Platform evidence

Target	Qualification	Support
macOS 14+ ARM64	Installed CLI and real public native libraries pass on macOS 14 with Xcode and Command Line Tools removed.	Supported; every release repeats language, debugger, sanitizer, performance and consumer gates.
GNU/Linux ARM64, glibc 2.36+	Debian 12 CI runs LLVM language/runtime regressions and public imports in a consumer image without compilers, Git or headers. An earlier physical DGX Spark run records additional parity, safety and library evidence with its own source and measurements.	Supported; qualify each compiler candidate and deployment bundle.
GNU/Linux x86-64, glibc 2.36+	The same Debian 12 CI and clean-consumer profile passes on native x86-64 runners.	Supported; qualify each compiler candidate and deployment bundle.
Windows and other targets	No full native verification.	Outside the 1.0 support matrix.

The consumer workflow requires Node.js 24+ and a supported host. August downloads its pinned compiler/runtime and package artifacts; consumers do not install Clang, LLVM or an SDK. Explicit C reference builds and binding authoring require their maintainer tools. Musl, Windows and cross compilation are outside this profile. Cooperative tasks share their current thread and heap. Worker tasks run on OS threads with isolated heaps and copied inputs and results. HTTP and OIDC library conformance is tracked separately in the web and crypto gap ledger; that library work is tracked separately from the core language's 1.0 requirements.

The 1.0 tagged build passed qualification on all three supported hosts. Each release repeats CI, installed-package and native integration gates; dependency and archive review and the documented update path remain required. See production readiness for present limits.