Publishing Wasm Components to OCI Registries

Publish your WebAssembly components to OCI registries like GitHub Container Registry (GHCR) for easy distribution. Once published, load components with: wassette component load oci://ghcr.io/user/component:latest

Prerequisites

• A built .wasm component (see JavaScript, Python, Rust, or Go guides)
• Access to an OCI registry (GHCR, Docker Hub, Azure Container Registry, etc.)
• Authentication credentials for your registry

Method 1: Local Publishing with wkg CLI

Install the wkg tool:

cargo install wkg
# or faster: cargo binstall wkg -y

Authenticate to GHCR:

# Create a GitHub PAT with 'write:packages' scope at https://github.com/settings/tokens/new
echo $GITHUB_TOKEN | docker login ghcr.io -u USERNAME --password-stdin

Publish your component:

# Basic publish
wkg oci push ghcr.io/your-username/component-name:1.0.0 component.wasm

# With metadata annotations
wkg oci push ghcr.io/your-username/component-name:1.0.0 component.wasm \
  --annotation "org.opencontainers.image.description"="Component description" \
  --annotation "org.opencontainers.image.source"="https://github.com/your-username/repo" \
  --annotation "org.opencontainers.image.version"="1.0.0" \
  --annotation "org.opencontainers.image.licenses"="MIT"

Versioning Strategy

wkg oci push ghcr.io/user/component:latest component.wasm       # Latest stable
wkg oci push ghcr.io/user/component:1.0.0 component.wasm        # Semantic version
wkg oci push ghcr.io/user/component:abc1234 component.wasm      # Commit SHA
wkg oci push ghcr.io/user/component:1.0.0-beta.1 component.wasm # Pre-release

Best Practices

• Always tag with specific versions, not just latest
• Sign components with Cosign for security
• Use CI/CD for consistent builds
• Add OCI annotations for discoverability
• Follow semantic versioning (MAJOR.MINOR.PATCH)