Data DC Python API Docs | dltHub
Build a Data DC-to-database pipeline in Python using dlt with AI harness support for Claude Code, Cursor, and Codex.
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Data DC is the District of Columbia's open data portal providing access to government datasets and GIS services via REST APIs. The REST API base URL is https://opendata.dc.gov and API key or token authentication via query parameter or Authorization header is used for protected services..
dlt is an open-source Python library that handles authentication, pagination, and schema evolution automatically. dlthub provides AI context files that enable code assistants to generate production-ready pipelines. Install with uv add "dlt[hub]" and start loading Data DC data in under 10 minutes.
What data can I load from Data DC?
Here are some of the endpoints you can load from Data DC:
| Resource | Endpoint | Method | Data selector | Description |
|---|---|---|---|---|
| datasets | datasets | GET | List of published datasets on the portal | |
| dataset_metadata | datasets/{id}/api | GET | Dataset metadata and API explorer page | |
| arcgis_services_list | maps2.dcgis.dc.gov/dcgis/rest/services | GET | services | List of ArcGIS services |
| arcgis_feature_query | maps2.dcgis.dc.gov/dcgis/rest/services/{service}/FeatureServer/0/query | GET | features | ArcGIS FeatureService query endpoint |
| mar_locations | datagate.dc.gov/mar/open/api/v2.2/locations | GET | DC Master Address Repository location data |
How do I authenticate with the Data DC API?
Authentication is required for protected ArcGIS REST services and can be provided either as an 'apikey' query parameter or via an Authorization header, depending on the specific service requirements. Public datasets on the Open Data portal are generally accessible without credentials.
1. Get your credentials
To obtain an API key for the Data Commons REST API, navigate to the official API key management portal at https://apikeys.datacommons.org. Sign in or create an account if prompted, then request a key for the relevant hostnames (such as api.datacommons.org). You can manage and enable access for the specific APIs you intend to use through this dashboard.
2. Add them to .dlt/secrets.toml
[sources.data_dc_source] api_key = "your_api_key_here"
dlt reads this automatically at runtime — never hardcode tokens in your pipeline script. For production environments, see setting up credentials with dlt for environment variable and vault-based options.
How do I set up and run the pipeline?
Set up a virtual environment and install dlt:
uv init uv add "dlt[hub]"
1. Install the dlt AI harness:
uv run dlthub ai init --agent <your-agent> # <agent>: claude | cursor | codex
This installs project rules, a secrets management skill, appropriate ignore files, and configures the dlt MCP server for your agent. Learn more →
2. Install the rest-api-pipeline toolkit:
uv run dlthub ai toolkit install rest-api-pipeline
This loads the skills and context about dlt the agent uses to build the pipeline iteratively, efficiently, and safely. The agent uses MCP tools to inspect credentials — it never needs to read your secrets.toml directly. Learn more →
3. Start LLM-assisted coding:
Use /find-source to load data from the Data DC API into DuckDB.
The rest-api-pipeline toolkit takes over from here — it reads relevant API documentation, presents you with options for which endpoints to load, and follows a structured workflow to scaffold, debug, and validate the pipeline step by step.
4. Run the pipeline:
uv run python data_dc_pipeline.py
If everything is configured correctly, you'll see output like this:
Pipeline data_dc_pipeline load step completed in 0.26 seconds 1 load package(s) were loaded to destination duckdb and into dataset data_dc_data The duckdb destination used duckdb:/data_dc.duckdb location to store data Load package 1749667187.541553 is LOADED and contains no failed jobs
Inspect your pipeline and data:
uv run dlthub show
This opens the Pipeline Dashboard where you can verify pipeline state, load metrics, schema (tables, columns, types), and query the loaded data directly.
Python pipeline example
This example loads node and resolve from the Data DC API into DuckDB. It mirrors the endpoint and data selector configuration from the table above:
import dlt from dlt.sources.rest_api import RESTAPIConfig, rest_api_resources @dlt.source def data_dc_source(apikey=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://opendata.dc.gov", "auth": {"type": "api_key", "api_key": apikey, "name": "X-API-Key", "location": "header"}, }, "resources": [ {"name": "arcgis_feature_query", "endpoint": {"path": "maps2.dcgis.dc.gov/dcgis/rest/services/{service}/FeatureServer/0/query", "data_selector": "features"}}, {"name": "datasets", "endpoint": {"path": "datasets", "data_selector": "datasetRecords"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="data_dc_pipeline", destination="duckdb", dataset_name="data_dc_data", ) load_info = pipeline.run(data_dc_source()) print(load_info)
To add more endpoints, append entries from the resource table to the "resources" list using the same name, path, and data_selector pattern.
How do I query the loaded data?
Once the pipeline runs, dlt creates one table per resource. You can query with Python or SQL.
Python (pandas DataFrame):
import dlt data = dlt.pipeline("data_dc_pipeline").dataset() sessions_df = data.arcgis_feature_query.df() print(sessions_df.head())
SQL (DuckDB example):
SELECT * FROM data_dc_data.arcgis_feature_query LIMIT 10;
In a marimo or Jupyter notebook:
import dlt data = dlt.pipeline("data_dc_pipeline").dataset() data.arcgis_feature_query.df().head()
See how to explore your data in marimo Notebooks and how to query your data in Python with dataset.
What destinations can I load Data DC data to?
dlt supports loading into any of these destinations — only the destination parameter changes:
| Destination | Example value |
|---|---|
| DuckDB (local, default) | "duckdb" |
| PostgreSQL | "postgres" |
| BigQuery | "bigquery" |
| Snowflake | "snowflake" |
| Redshift | "redshift" |
| Databricks | "databricks" |
| Filesystem (S3, GCS, Azure) | "filesystem" |
Change the destination in dlt.pipeline(destination="snowflake") and add credentials in .dlt/secrets.toml. See the full destinations list.
Next steps
Continue your data engineering journey with the other toolkits of the dltHub AI harness:
data-exploration— Build custom notebooks, charts, and dashboards for deeper analysis with marimo notebooks.dlthub-platform— Deploy, schedule, and monitor your pipeline in production.
uv run dlthub ai toolkit install data-exploration uv run dlthub ai toolkit install dlthub-platform
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