Load OpenAPI Generators data to DuckDB

OpenAPI Generator is an open-source tool that automatically generates API client libraries, server stubs, documentation, and configuration from OpenAPI Specification files. Everything needed to build a working OpenAPI Generators → 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.

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Build your OpenAPI Generators to DuckDB pipeline

Paste this prompt into Claude, Codex, or Cursor. The agent does the rest.

PromptCopy prompt
Run uvx dlthub-init@latest to build a pipeline from OpenAPI Generators 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 OpenAPI Generators 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.

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OpenAPI Generators API at a glance

These values come from the OpenAPI Generators API documentation. Check them against the vendor's current reference before relying on them in production.

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How do I authenticate with the OpenAPI Generators API?

OpenAPI Generator is a tool that generates client libraries based on an OpenAPI specification, meaning there is no single REST API or authentication mechanism; rather, authentication is determined by the specific security schemes defined within your own OpenAPI document (e.g., API Key, OAuth2, or Bearer Token). Generated clients typically handle these via configuration objects or header injections defined in your OpenAPI definition.

1. Get your credentials

OpenAPI Generator is an open-source code generation tool, not a hosted service requiring centralized API credentials or a dashboard account. For its public online generator service (api.openapi-generator.tech), no authentication or API keys are required; users directly POST their OpenAPI specification or URL to the endpoint to trigger SDK generation. If you are self-hosting the generator, you manage your own environment and access controls.

2. Add them to .dlt/secrets.toml

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[sources.openapi_generators_source]
api_key = "your_api_key_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.

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What OpenAPI Generators data can I load into DuckDB?

These are the OpenAPI Generators endpoints dlt can load into DuckDB:

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How do I load only new OpenAPI Generators records?

The OpenAPI Generators API reference does not document a timestamp or sequence field for these endpoints, so there is nothing to advertise here as verified. Pick a field from the endpoints table above that increases with every write, then set it as the cursor_path.

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{"name": "generators_list", "endpoint": {
    "path": "api/gen/clients",
    # Replace with a field that increases on every write.
    "incremental": {"cursor_path": "REPLACE_ME", "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.

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What does the generated OpenAPI Generators pipeline look like?

A standard dlt REST API pipeline — the same code you would write by hand, loading /gen/clients/{generator} and /gen/servers/{generator} from the OpenAPI Generators API into DuckDB:

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

@dlt.source
def openapi_generators_source(api_token=dlt.secrets.value):
    config: RESTAPIConfig = {
        "client": {
            "base_url": "The base URL is derived from the 'servers' object in the provided OpenAPI specification, though it can be overridden during generation or via the generated client's configuration.",
            "auth": {"type": "bearer", "token": api_token},
        },
        "resources": [
            {"name": "generators_list", "endpoint": {"path": "api/gen/clients"}},
            {"name": "generate_client", "endpoint": {"path": "gen/clients/{generator}"}}
        ],
    }
    yield from rest_api_resources(config)


def load_openapi_generators_to_duckdb() -> None:
    pipeline = dlt.pipeline(
        pipeline_name="openapi_generators_pipeline",
        destination="duckdb",
        dataset_name="openapi_generators_data",
    )
    load_info = pipeline.run(openapi_generators_source())
    print(load_info)


if __name__ == "__main__":
    load_openapi_generators_to_duckdb()

Run it with python openapi_generators_pipeline.py. The agent iterates on this until it loads cleanly — you review and approve, rather than write it from scratch.

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How do I query OpenAPI Generators 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):

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import dlt

data = dlt.pipeline("openapi_generators_pipeline").dataset()
df = data.generators.df()
print(df.head())

SQL:

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SELECT * FROM openapi_generators_data.generators LIMIT 10;

See querying your data with dataset and exploring it in marimo notebooks.

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How do I deploy the OpenAPI Generators 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 OpenAPI Generators loads into governed, documented models.
• Visualize & share — explore data in notebooks and publish live dashboards instead of static screenshots.

Book a demo →

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What other destinations can I load OpenAPI Generators data to?

dlt loads into any of these — only the destination argument changes:

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.

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Next steps

• Ready for production? Book a demo of the dltHub platform →
• dlt LLM-native workflow docs
• REST API source reference
• Join the dlt community on Slack