motherduck-build-data-pipeline ยท diff

git:20260827.1ff9a10 to git:20260905.e700746

15 added, 76 removed. Audit A to A.

---
name: motherduck-build-data-pipeline
- description: Design an end-to-end MotherDuck data pipeline. Use for ETL/ELT workflows -- choosing raw, staging, and analytics boundaries, bulk ingestion paths, transformation sequencing, dlt/dbt integration, publication targets, or whether DuckLake is actually required.
+ description: Build ingestion-to-serving pipelines on MotherDuck, including stage boundaries, transformations, and publication.
argument-hint: [pipeline-goal]
license: MIT
---
# Build a Data Pipeline with MotherDuck
- Use this skill when the user needs an ingestion-to-serving workflow, not just a single load step.
-
- This is a use-case skill. It orchestrates `motherduck-connect`, `motherduck-load-data`, `motherduck-model-data`, `motherduck-query`, `motherduck-share-data`, `motherduck-ducklake`, and `motherduck-manage-guides`.
-
## Start Here: Is a MotherDuck Server Active?
- - If a **remote MotherDuck MCP server** or **local MotherDuck server** is active, use it.
- - If the user names the destination database, use it without adding a confirmation step.
- - Explore the live environment:
- - current databases and schemas
- - raw, staging, and analytics boundaries if they already exist
- - source tables, target tables, and table grain
- - key columns, date fields, and join keys
-
- Use that discovery to decide whether the pipeline is:
-
- - landing into an empty workspace
- - extending an existing warehouse layout
- - publishing into an existing analytics model
+ Use an active remote MotherDuck MCP server or local MotherDuck server to inspect the in-scope database, schema, grain, keys, and relevant metrics. Reuse known context and narrow discovery to the requested work; do not scan the whole workspace by default. Let the actual data model shape the result.
- If no server is active, use any supplied source and target context. For planning work, proceed with explicit assumptions when safe; ask for missing details only when they block a reliable result.
+ Resolve the target from the request or active context. Ask only if ambiguity materially affects the result. Without a server, use supplied schema and explicit assumptions for planning; do not imply live validation.
## Pipeline Defaults
- batch over streaming
- raw landing before curation
- explicit raw -> staging -> analytics boundaries
- bulk ingest paths over row-by-row writes
- idempotent stage rebuilds or append contracts before scheduled automation
- verify the MotherDuck-supported DuckDB client version before recommending upstream-only write, checkpoint, or lakehouse features
- native MotherDuck storage unless DuckLake is explicitly required
- MotherDuck CLI for Flight source and large file-shaped output when the agent has a shell; MCP for chat-only operation
- a `flights` Guide for reusable scheduling, naming, secret, and ingestion conventions when the organization has them
## Workflow
1. Inspect the available MotherDuck server or supplied source and target context.
2. Inspect the current workspace and target data model.
3. Define raw, staging, and analytics boundaries.
4. Ingest raw data.
5. Deduplicate, type, and promote into staging.
6. Materialize analytics-ready outputs.
7. Validate counts, freshness, uniqueness, and business metrics before publishing downstream assets.
- 8. Capture stable business definitions and operating caveats in referenced Guides; keep executable transformation logic in source control.
+ 8. When durable context is part of delivery, capture stable business definitions and operating caveats in referenced Guides; keep executable transformation logic in source control.
Match execution to the request: answer, review, or planning work returns the requested pipeline artifacts; build or change work creates the requested in-scope files and warehouse objects and validates them. Ask before destructive actions, unrelated external writes, or a material expansion of scope.
When this skill produces a native DuckDB (`md:`) connection, watermark it with `custom_user_agent=agent-skills/2.6.0(harness-<harness>;llm-<llm>)`. If metadata is missing, fall back to `harness-unknown` and `llm-unknown`.
## Output
- The output of this skill should be:
+ For a full engagement, cover the following as relevant to the request:
- the stage layout
- the ingestion method
- the transformation sequence
- the serving tables or views
- the validation checks
- If the caller explicitly asks for structured JSON, return raw JSON only with no Markdown fences or prose before/after it.
- This is mainly for automated tests, regression checks, or downstream tooling that needs a stable machine-readable shape. Normal human-facing use of the skill can stay in prose unless JSON is explicitly requested.
-
- Use this exact top-level shape when JSON is requested:
-
- ```json
- {
- "summary": {},
- "assumptions": [],
- "implementation_plan": [],
- "validation_plan": [],
- "risks": []
- }
- ```
+ For explicit structured JSON requests, read [the output contract](references/EXECUTION_REFERENCE.md#structured-output). Otherwise use the format that fits the requested deliverable.
## References
+ Read only the sections relevant to the task; these are guidance, not a mandatory itinerary.
+
- `references/dlt-dbt-motherduck-project/` -- fully runnable MotherDuck reference project using `dlt`, `dbt-duckdb`, and validation queries
- - `references/PIPELINE_IMPLEMENTATION_GUIDE.md` -- preserved detailed pipeline guidance that used to live in this skill
+ - `references/PIPELINE_IMPLEMENTATION_GUIDE.md` -- stage design, transformation sequencing, and ingestion-to-serving examples
- `../motherduck-load-data/references/INGESTION_PATTERNS.md` -- lower-level ingestion patterns
- ## Runnable Artifact
-
- - `artifacts/pipeline_stage_example.py` -- MotherDuck-backed Python example that stages a Parquet extract, lands it into raw, deduplicates it, and publishes analytics output across raw/staging/analytics databases
- - `artifacts/pipeline_stage_example.ts` -- TypeScript companion artifact with the same stage layout and output contract
- - `references/dlt-dbt-motherduck-project/` -- end-to-end MotherDuck example that bootstraps the target database, lands raw data with `dlt`, builds staging and analytics models with `dbt`, and validates the final mart
-
- Run it with:
-
- ```bash
- uv run --with duckdb python skills/motherduck-build-data-pipeline/artifacts/pipeline_stage_example.py
- ```
-
- Run the same stage pattern against temporary MotherDuck databases:
-
- ```bash
- MOTHERDUCK_ARTIFACT_USE_MOTHERDUCK=1 \
- uv run --with duckdb python skills/motherduck-build-data-pipeline/artifacts/pipeline_stage_example.py
- ```
-
- Validate the TypeScript companion artifact:
-
- ```bash
- uv run scripts/test_typescript_artifacts.py
- ```
-
- For the full MotherDuck project:
-
- ```bash
- cd skills/motherduck-build-data-pipeline/references/dlt-dbt-motherduck-project
- export MOTHERDUCK_TOKEN=...
- export MOTHERDUCK_PIPELINE_DB=md_skills_pipeline_demo
- uv sync --python 3.12
- uv run python pipeline/run_all.py
- uv run python pipeline/cleanup.py
- ```
+ ## Examples
- ## Verified Notes
+ Read [the execution reference](references/EXECUTION_REFERENCE.md) only to run the bundled examples or reproduce their validation.
- - Bootstrap the target MotherDuck database before running `dlt`. The `motherduck` destination does not create the database for you.
- - Use Python 3.11 or 3.12 to reproduce this reference project; its tested `dbt-duckdb` path did not run reliably on Python 3.14.
- - If you want exact schema names like `raw`, `staging`, and `analytics` in dbt, override `generate_schema_name`.
- - When a long-lived Python process loads data and a separate `dbt` subprocess builds models, run post-build validation in a fresh process or refresh database state before reading new relations.
+ - [pipeline_stage_example.py](artifacts/pipeline_stage_example.py)
+ - [pipeline_stage_example.ts](artifacts/pipeline_stage_example.ts)
## Related Skills
+
+ Load related skills only for missing capabilities; reuse established context.
- `motherduck-connect` -- choose the right connection path
- `motherduck-load-data` -- ingestion mechanics
- `motherduck-model-data` -- shape the analytics layer
- `motherduck-query` -- write transformations and validations
- `motherduck-share-data` -- publish curated outputs
- `motherduck-ducklake` -- only when open-table-format storage is a real requirement