Load OpenAPI Specification data to DuckDB

The OpenAPI Specification (OAS) is a standard, language-agnostic interface description for RESTful APIs that allows humans and computers to discover and understand service capabilities without access to source code or internal documentation. Everything needed to build a working OpenAPI Specification → 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 Specification 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 Specification 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 Specification 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 Specification API at a glance

These values come from the OpenAPI Specification 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 Specification API?

Authentication is defined via the securitySchemes section; common methods include HTTP Bearer tokens (Authorization header), API keys (headers, query parameters, or cookies), and OAuth2. The specific implementation depends on the individual API definition.

1. Get your credentials

Log in to the service's dashboard interface. Navigate to the API settings or profile section (commonly found under Settings > API Keys, API & Webhooks, or My Profile > API Access). Click the button to create, generate, or add a new API key. Assign a descriptive name if prompted. Copy the displayed API key immediately, as it may be hidden or only shown once for security purposes. Store it securely using environment variables or a secrets manager.

2. Add them to .dlt/secrets.toml

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[sources.openapi_specification_source]
api_key = "your_actual_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 Specification data can I load into DuckDB?

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

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How do I load only new OpenAPI Specification records?

OpenAPI Specification exposes updated_at on users, 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.

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{"name": "users", "endpoint": {
    "path": "users",
    "data_selector": "data",
    "incremental": {"cursor_path": "updated_at", "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 Specification pipeline look like?

A standard dlt REST API pipeline — the same code you would write by hand, loading organizations and nodes (or users) from the OpenAPI Specification API into DuckDB:

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

@dlt.source
def openapi_specification_source(api_key=dlt.secrets.value):
    config: RESTAPIConfig = {
        "client": {
            "base_url": "The base URL is defined in the servers array; if omitted, it defaults to /.",
            "auth": {"type": "bearer", "token": api_key},
        },
        "resources": [
            {"name": "users", "endpoint": {"path": "users", "data_selector": "data"}},
            {"name": "issues", "endpoint": {"path": "issues", "data_selector": "items"}}
        ],
    }
    yield from rest_api_resources(config)


def load_openapi_specification_to_duckdb() -> None:
    pipeline = dlt.pipeline(
        pipeline_name="openapi_specification_pipeline",
        destination="duckdb",
        dataset_name="openapi_specification_data",
    )
    load_info = pipeline.run(openapi_specification_source())
    print(load_info)


if __name__ == "__main__":
    load_openapi_specification_to_duckdb()

Run it with python openapi_specification_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 Specification 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_specification_pipeline").dataset()
df = data.users.df()
print(df.head())

SQL:

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SELECT * FROM openapi_specification_data.users LIMIT 10;

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

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How do I deploy the OpenAPI Specification 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 Specification 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 Specification 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