Datastreamer Python API Docs | dltHub

DataStream is a public OData v4 API providing water‑related datasets (metadata, locations, observations, records) for research and analysis. The REST API base URL is https://api.datastream.org/v1/odata/v4 and All requests require an x-api-key header for authentication..

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 pip install "dlt[workspace]" and start loading Datastreamer data in under 10 minutes.

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What data can I load from Datastreamer?

Here are some of the endpoints you can load from Datastreamer:

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How do I authenticate with the Datastreamer API?

Provide your API key in the HTTP header 'x-api-key: YOUR_KEY'. For browser requests, ensure your domain is whitelisted for CORS.

1. Get your credentials

1. Request an API key via the DataStream public API key request form (see API docs). 2) The DataStream team issues a private API key tied to your account. 3) Store this key and send it in every request header as 'x-api-key'.

2. Add them to .dlt/secrets.toml

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[sources.datastreamer_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.

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How do I set up and run the pipeline?

Set up a virtual environment and install dlt:

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uv venv && source .venv/bin/activate
uv pip install "dlt[workspace]"

1. Install the dlt AI Workbench:

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dlt 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:

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dlt ai toolkit rest-api-pipeline install

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 Datastreamer 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:

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python datastreamer_pipeline.py

If everything is configured correctly, you'll see output like this:

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Pipeline datastreamer_pipeline load step completed in 0.26 seconds
1 load package(s) were loaded to destination duckdb and into dataset datastreamer_data
The duckdb destination used duckdb:/datastreamer.duckdb location to store data
Load package 1749667187.541553 is LOADED and contains no failed jobs

Inspect your pipeline and data:

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dlt pipeline datastreamer_pipeline show

This opens the Pipeline Dashboard where you can verify pipeline state, load metrics, schema (tables, columns, types), and query the loaded data directly.

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Python pipeline example

This example loads metadata and observations from the Datastreamer API into DuckDB. It mirrors the endpoint and data selector configuration from the table above:

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import dlt
from dlt.sources.rest_api import RESTAPIConfig, rest_api_resources

@dlt.source
def datastreamer_source(api_key=dlt.secrets.value):
    config: RESTAPIConfig = {
        "client": {
            "base_url": "https://api.datastream.org/v1/odata/v4",
            "auth": {
                "type": "api_key",
                "api_key": api_key,
            },
        },
        "resources": [
            {"name": "metadata", "endpoint": {"path": "Metadata", "data_selector": "value"}},
            {"name": "observations", "endpoint": {"path": "Observations", "data_selector": "value"}}
        ],
    }
    yield from rest_api_resources(config)


def get_data() -> None:
    pipeline = dlt.pipeline(
        pipeline_name="datastreamer_pipeline",
        destination="duckdb",
        dataset_name="datastreamer_data",
    )
    load_info = pipeline.run(datastreamer_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.

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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):

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import dlt

data = dlt.pipeline("datastreamer_pipeline").dataset()
sessions_df = data.observations.df()
print(sessions_df.head())

SQL (DuckDB example):

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SELECT * FROM datastreamer_data.observations LIMIT 10;

In a marimo or Jupyter notebook:

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import dlt

data = dlt.pipeline("datastreamer_pipeline").dataset()
data.observations.df().head()

See how to explore your data in marimo Notebooks and how to query your data in Python with dataset.

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What destinations can I load Datastreamer data to?

dlt supports loading into any of these destinations — only the destination parameter changes:

Change the destination in dlt.pipeline(destination="snowflake") and add credentials in .dlt/secrets.toml. See the full destinations list.

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Troubleshooting

Authentication failures

If you receive 401/403 or no data, verify that the x-api-key header is present and correct. For browser requests ensure your domain is whitelisted for CORS by DataStream support.

Rate limits / 429 Too Many Requests

The API enforces a limit of 2 requests per second. Exceeding this limit returns a 429 Too Many Requests error. Throttle your calls accordingly.

Pagination and large result errors

Responses include a top‑level value array and an @odata.nextLink (or Link header) for additional pages. Use $top (max 10000) and $skiptoken to paginate. Very large requests may return 408/504 timeouts or 413 Payload Too Large; reduce $top, narrow $filter, or partition requests by year or location.

Common API errors

• 400 Bad Request – often caused by unencoded $ characters ($ should be %24).
• 408/504 Timeout – query too complex or exceeds the 30 s limit; retry with narrower filters.
• 413 Payload Too Large – result set exceeds size limits; lower $top or select fewer fields.
• 429 Too Many Requests – exceed rate limit; throttle to ≤2 req/s.

Ensure that the API key is valid to avoid 401 Unauthorized errors. Also, verify endpoint paths and parameters to avoid 404 Not Found errors.

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Next steps

Continue your data engineering journey with the other toolkits of the dltHub AI Workbench:

• data-exploration — Build custom notebooks, charts, and dashboards for deeper analysis with marimo notebooks.
• dlthub-runtime — Deploy, schedule, and monitor your pipeline in production.

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dlt ai toolkit data-exploration install
dlt ai toolkit dlthub-runtime install

• How to deploy a pipeline
• How to explore your data in marimo Notebooks
• How to query your data in Python with dataset
• Join the dlt community on Slack