Artifacts

artifacts are “named URIs” you can reference from expressions and task scripts.

In v0.1, artifacts are not automatically downloaded/pulled. They are mainly used to:

• Normalize local paths (fs:// / file://) so you can reference them consistently
• Inject a convenient env var ${NAME} into every task (the artifact's resolved path)
• Automatically mount path when running with containers inside slurm cluster

Minimal example

version: "0.1"

artifacts:
  MODEL_DIR:
    uri: fs://./models/qwen

workflow:
  name: wf
  tasks:
    - name: show_paths
      script:
        - echo "env=${MODEL_DIR}"
        - echo "expr=${{ artifacts.MODEL_DIR.path }}"

Supported URI schemes (v0.1)

Artifacts are exposed as:

• ${{ artifacts.NAME.uri }}
• ${{ artifacts.NAME.path }}
• ${NAME} (env var injected into tasks)

Rules in v0.1:

• fs://<path> and file://<path> become a real local filesystem path
  • relative paths are resolved relative to --workspace-dir (default: current directory)
• other schemes keep path as the raw URI string (no download/pull yet)

Override artifacts at runtime (--artifact)

sflow run --file sflow.yaml --artifact MODEL_DIR=fs:///mnt/models/qwen

Notes:

• --artifact can only override artifacts that already exist in artifacts: (otherwise it errors).

Variable expressions in artifact URIs

Artifact URIs can use ${{ }} expressions to reference variables:

variables:
  MODEL_DIR:
    value: /data/models/Qwen3-8B-FP8

artifacts:
  - name: LOCAL_MODEL_PATH
    uri: fs://${{ variables.MODEL_DIR }}

The expression is resolved before the artifact path is validated. This means:

• If the variable resolves to a valid path, the fs:// path check verifies it exists
• If the variable itself is an unresolved expression (e.g. references another computed variable), the path check is skipped and deferred to runtime
• Shell variable references (e.g. $HOME) in URIs are also skipped during validation

Path validation

fs:// artifact paths are validated during dry-run to catch missing paths early (before allocating Slurm nodes):

• fs:// paths: must exist on disk. If missing, the dry-run fails with an error.
• file:// paths with content: skipped (the file is generated at runtime from the inline content).
• URIs with unresolved expressions: skipped (validated later during full resolution).

To override an artifact path at runtime:

sflow run -f workflow.yaml --artifact LOCAL_MODEL_PATH=fs:///actual/path/to/model

Inline content

The schema allows:

artifacts:
  CONFIG_YAML:
    uri: file://config.yaml
    content: |
      key: value

Artifacts with content are materialized to disk under the workflow output directory at runtime. The content can use ${{ }} expressions that are resolved before writing.