| tags | Newline-delimited list of image:tag | no | — |
| image | Base image repo(s), newline-delimited (e.g., ghcr.io/org/app). Must NOT include :tag or @digest. | no | — |
| base_tag | Primary tag value (e.g., v1.2.3 or branch-date) | no | — |
| tag_latest_on_default_branch | Add :latest tag when building from default branch (main/master) | no | true |
| tag_sha | Also tag :sha-<short> for traceability | no | true |
| include_ref_tags | Also generate branch/PR ref tags via metadata-action | no | false |
| include_semver_tags | If building a SemVer tag, also add major/minor tags via metadata-action | no | true |
| context | Build context | no | . |
| dockerfile | Path to Dockerfile (relative to context or absolute) | no | Dockerfile |
| platforms | Comma-separated platforms | no | linux/amd64 |
| build_args | Multiline KEY=VALUE build args | no | — |
| cache_from | Build cache sources | no | type=gha |
| cache_to | Build cache exports | no | type=gha,mode=max |
| push | Push images to registry | no | true |
| load | Load into local Docker (mutually exclusive with push) | no | false |
| no_cache | Disable cache | no | false |
| pull | Always pull newer base images | no | false |
| target | Target stage | no | — |
| secrets | Build secrets (multiline) | no | — |
| ssh | SSH agent sockets/keys | no | — |
| provenance | Enable provenance attestation | no | false |
| sbom | Generate SBOM attestation | no | false |
| buildx_version | Buildx version (e.g., v0.3.0, latest, https://github.com/docker/buildx.git#master) | no | — |
| buildx_name | Name of the builder (auto-generated if not specified) | no | — |
| buildx_driver | Builder driver (docker-container, docker, kubernetes, remote) | no | — |
| buildx_driver_opts | List of additional driver-specific options (e.g., image=moby/buildkit:master) | no | — |
| buildx_buildkitd_flags | BuildKit daemon flags | no | — |
| buildx_buildkitd_config | BuildKit daemon config file | no | — |
| buildx_buildkitd_config_inline | BuildKit daemon config inline | no | — |
| buildx_install | Set up docker build command as an alias to docker buildx | no | — |
| buildx_use | Switch to this builder instance | no | — |
| buildx_endpoint | Optional address for docker socket or context from docker context ls | no | — |
| buildx_platforms | Fixed platforms for current node (overrides detected ones) | no | — |
| buildx_append | Append additional nodes to the builder (YAML format) | no | — |
| buildx_keep_state | Keep BuildKit state on cleanup (useful for persistent self-hosted runners) | no | — |
| buildx_cache_binary | Cache buildx binary to GitHub Actions cache backend | no | — |
| buildx_cleanup | Cleanup temp files and remove builder at the end of a job | no | — |