Load Dagster data to DuckDB
Build a Dagster to DuckDB pipeline with your coding agent. One prompt scaffolds it with the dltHub AI harness, plus the Dagster API base URL, auth, endpoints, and incremental loading.
Dagster REST API allows external systems to report asset materializations and checks to Dagster instances. Everything needed to build a working Dagster → DuckDB pipeline is on this page: the API's base URL, authentication, endpoints, pagination and incremental field — plus a prompt that hands the whole job to your coding agent.
Build your Dagster to DuckDB pipeline
Paste this prompt into Claude, Codex, or Cursor. The agent does the rest.
PromptRunuvx dlthub-init@latestto build a pipeline from Dagster to DuckDB and run it on dltHub
That scaffolds a dltHub workspace and installs the dltHub AI harness — the project rules, the secrets-management skill, and the dlt MCP server your agent needs to work safely. From there it reads the Dagster API, proposes the endpoints to load, then writes, runs and validates the pipeline while you review rather than type. Credentials are inspected through MCP tools, so your agent never reads secrets.toml itself. How the LLM-native workflow works →
Prefer to write it yourself? Every fact the agent uses is below.
Dagster API at a glance
| Base URL | For local: http://localhost:3000; For Dagster+: https://{ORGANIZATION}.dagster.cloud/{DEPLOYMENT_NAME} or https://{ORGANIZATION}.dagster.plus/{DEPLOYMENT_NAME}. |
| Example endpoint | GET /api/v1/assets |
| Authentication | Dagster+ instances require an API token sent in a header — sent in the Dagster-Cloud-Api-Token header |
| Pagination | Not paginated |
| Incremental field | cursor |
| Record id | asset_key |
| API reference | https://docs.dagster.io/api/rest-api |
These values come from the Dagster API reference — the authoritative source if anything here looks out of date.
How do I authenticate with the Dagster API?
Dagster+ requests require the 'Dagster-Cloud-Api-Token' header with a valid user token. For Dagster OSS/local instances, authentication is generally not required via headers for the REST API.
1. Get your credentials
To obtain an API token for Dagster+, log in to your Dagster+ organization. Navigate to 'Organization Settings' and locate the 'Tokens' section. Create a new user token, copy the generated token string, and store it securely. Ensure you have the necessary permissions within the organization to generate tokens.
2. Add them to .dlt/secrets.toml
[sources.dagster_source] dagster_cloud_api_token = "your_token_here"
dlt reads this file automatically at runtime. With the harness, the setup-secrets skill prompts you for the values and never handles the raw credential in chat. For production, see setting up credentials with dlt.
What Dagster data can I load into DuckDB?
These are the Dagster endpoints dlt can load into DuckDB:
| Resource | Endpoint | Method | Data selector | Description |
|---|---|---|---|---|
| asset | /api/v1/assets | GET | List assets | |
| asset_check | /api/v1/asset-checks | GET | List asset checks | |
| job | /api/v1/jobs | GET | List jobs | |
| run | /api/v1/runs | GET | List runs | |
| code_location | /api/v1/code-locations | GET | List code locations |
How do I load only new Dagster records?
Dagster exposes cursor on /api/v1/assets, so dlt can request only the records that changed since the last run. Set it as the cursor_path and dlt tracks the high-water mark for you between runs.
{"name": "asset", "endpoint": { "path": "/api/v1/assets", "incremental": {"cursor_path": "cursor", "initial_value": "2024-01-01T00:00:00Z"}, }}
On the first run dlt loads everything from initial_value; on every run after that it requests only what changed and appends with write_disposition="merge" if you set a primary key. See incremental loading.
What does the generated Dagster pipeline look like?
A standard dlt REST API pipeline — the same code you would write by hand, loading /report_asset_materialization/ and /report_asset_observation/ from the Dagster API into DuckDB:
import dlt from dlt.sources.rest_api import RESTAPIConfig, rest_api_resources @dlt.source def dagster_source(dagster_cloud_api_token=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "For local: http://localhost:3000; For Dagster+: https://{ORGANIZATION}.dagster.cloud/{DEPLOYMENT_NAME} or https://{ORGANIZATION}.dagster.plus/{DEPLOYMENT_NAME}.", "auth": {"type": "api_key", "api_key": dagster_cloud_api_token, "name": "Dagster-Cloud-Api-Token", "location": "header"}, }, "resources": [ {"name": "asset", "endpoint": {"path": "/api/v1/assets"}}, {"name": "run", "endpoint": {"path": "/api/v1/runs"}} ], } yield from rest_api_resources(config) def load_dagster_to_duckdb() -> None: pipeline = dlt.pipeline( pipeline_name="dagster_pipeline", destination="duckdb", dataset_name="dagster_data", ) load_info = pipeline.run(dagster_source()) print(load_info) if __name__ == "__main__": load_dagster_to_duckdb()
Run it with python dagster_pipeline.py. The agent iterates on this until it loads cleanly — you review and approve, rather than write it from scratch.
How do I query Dagster data in DuckDB?
dlt creates one table per resource. Query the loaded data with Python or SQL — or ask your agent to, through the MCP server's execute_sql_query tool.
Python (pandas DataFrame):
import dlt data = dlt.pipeline("dagster_pipeline").dataset() df = data.asset.df() print(df.head())
SQL:
SELECT * FROM dagster_data.asset LIMIT 10;
See querying your data with dataset and exploring it in marimo notebooks.
How do I deploy the Dagster to DuckDB pipeline in production?
The pipeline runs locally, which is ideal for prototyping and one-off analysis. When you need it on a schedule, monitored on every load, and shared with your team, deploy the same dlt code on the dltHub platform — no infrastructure to maintain. The prompt above already ends with "run it on dltHub", so your agent can take it there directly.
- Deploy & schedule — run the pipeline as a managed job with automatic retries.
- Monitor — observable job queues, alerting, and load metrics for every run.
- Transform — promote raw Dagster loads into governed, documented models.
- Visualize & share — explore data in notebooks and publish live dashboards instead of static screenshots.
What other destinations can I load Dagster data to?
dlt loads into any of these — only the destination argument changes:
| Destination | Example value |
|---|---|
| PostgreSQL | "postgres" |
| BigQuery | "bigquery" |
| Snowflake | "snowflake" |
| Redshift | "redshift" |
| Databricks | "databricks" |
| Filesystem (S3, GCS, Azure) | "filesystem" |
Set dlt.pipeline(destination="snowflake") and add credentials in .dlt/secrets.toml. On the dltHub platform the same pipeline runs against a managed Iceberg lakehouse. See the full destinations list.
Next steps
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