Weld

Weld logo

Weld is a graph-native publication system for Elixir monorepos.

It keeps the source repo as a normal multi-project workspace, builds a workspace graph, resolves one artifact boundary from a repo-local manifest, projects a standalone Mix package, verifies that generated package with normal Mix tooling, and prepares an archiveable release bundle for publication.

What It Does

discovers workspace projects from manifest globs, blitz_workspace, or filesystem fallback
classifies projects as runtime, tooling, proof, or ignored
separates publication role from project classification
classifies internal edges by execution meaning
exposes inspect, graph, query, affected, project, verify, and release tasks
emits a deterministic projection.lock.json
generates a standalone Mix package under dist/hex/<package>/
canonicalizes external workspace path or git deps into manifest-owned Hex deps
synthesizes a merged application module when selected projects publish OTP children
prepares a deterministic release bundle under dist/release_bundles/<package>/...
archives released bundles without turning generated output into a long-lived source tree

Installation

Add weld to the root project that owns the repo's packaging and release flow.

def deps do
  [
    {:weld, "~> 0.1.0", runtime: false}
  ]
end

Release Lifecycle

The intended lifecycle is:

run the normal source-repo checks
run mix weld.release.prepare ...
run mix hex.publish from the prepared bundle
run mix weld.release.archive ...

weld owns create, welded-package verification, and archive preparation. Hex publish remains external.

Example Manifest

[
  workspace: [
    root: "../..",
    project_globs: ["core/*", "runtime/*"]
  ],
  dependencies: [
    external_lib: [
      requirement: "~> 1.2",
      opts: []
    ]
  ],
  artifacts: [
    my_bundle: [
      roots: ["runtime/local"],
      package: [
        name: "my_bundle",
        otp_app: :my_bundle,
        version: "0.1.0",
        description: "My welded package"
      ],
      output: [
        docs: ["README.md", "guides/architecture.md"]
      ],
      verify: [
        artifact_tests: ["packaging/weld/my_bundle/test"],
        smoke: [
          enabled: true,
          entry_file: "packaging/weld/my_bundle/smoke.ex"
        ]
      ]
    ]
  ]
]

Core Commands

mix weld.inspect packaging/weld/my_bundle.exs
mix weld.graph packaging/weld/my_bundle.exs --format dot
mix weld.query deps packaging/weld/my_bundle.exs runtime/local
mix weld.project packaging/weld/my_bundle.exs
mix weld.verify packaging/weld/my_bundle.exs
mix weld.release.prepare packaging/weld/my_bundle.exs
mix weld.release.archive packaging/weld/my_bundle.exs
mix weld.affected packaging/weld/my_bundle.exs --task verify.all --base main --head HEAD

Generated Output

Weld projects a standalone package under dist/hex/<package>/ using a component-preserving layout:

dist/
  hex/
    my_bundle/
      mix.exs
      projection.lock.json
      lib/
        my_bundle/
          application.ex
      components/
        core/contracts/
        runtime/local/
      test/

When selected projects expose OTP applications, weld synthesizes a merged lib/<otp_app>/application.ex that starts those children inside the welded package.

The welded artifact is a normal Mix project. weld.verify runs:

mix compile --warnings-as-errors
mix test
mix docs --warnings-as-errors
mix hex.build
mix hex.publish --dry-run --yes
optional smoke-app compilation