---
name: "dagster-software-defined-assets"
description: "Declare data pipelines as Software-Defined Assets with integrated column-level lineage."
metadata:
  author: "Dagster Labs"
  version: "1.0.0"
  runtime_compatibility:
    - "codex"
    - "claude-code"
    - "cursor"
    - "windsurf"
triggers:
  - "create dagster asset"
  - "setup dagster partitions"
  - "configure dagster io manager"
permissions:
  fs_read: true
  fs_write: "workspace"
  shell_exec: false
  net_access: false
---

# Dagster Software-Defined Assets & Data Lineage

Implements data platforms using Dagster: declaring assets with @asset, defining upstream dependencies, partition definitions (DailyPartitionsDefinition), I/O managers, and declarative freshness policies.

## When to Invoke
Invoke this skill whenever you need to:
- create dagster asset
- setup dagster partitions
- configure dagster io manager

## Execution SOP & Rules
1. Define assets using @asset(deps=[upstream_asset]) or accept upstream assets directly as function parameters.
2. Assign partitions_def = DailyPartitionsDefinition(start_date='2025-01-01') for date-partitioned tables.
3. Declare auto-materialize policies with AutoMaterializePolicy.eager() for real-time asset freshness.
4. Launch the Dagit/Dagster web UI to inspect the asset graph, execution history, and data lineage.

## Verification Checklist
- Run local linting, syntax validation, and type-checks before reporting completion.
- Ensure all created or modified files adhere to workspace boundaries and avoid uncommitted secrets.
- Verify tests or build commands exit cleanly with return code 0.