Load JSON:API data to DuckDB

JSON:API is a specification for building APIs that defines how clients should request and modify resources and how servers should respond to those requests. Everything needed to build a working JSON:API → 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 JSON:API 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 JSON:API 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 JSON:API 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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JSON:API API at a glance

These values come from the JSON:API API reference — the authoritative source if anything here looks out of date.

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How do I authenticate with the JSON:API API?

Authentication methods vary by implementation; common approaches include passing an 'Authorization' header with 'Bearer ' for OAuth/JWT or 'Basic <base64_encoded_credentials>' for Basic Authentication. Requests typically require the 'Content-Type: application/vnd.api+json' and 'Accept: application/vnd.api+json' headers.

1. Get your credentials

To obtain API credentials for a JSON:API service (such as Drupal), navigate to your application's administrative dashboard, typically under Configuration > People > API Authentication or similar settings. Depending on the service, you can either generate an API Key directly for a specific user or configure an OAuth2 client to retrieve a Bearer Token via an authentication endpoint (e.g., /oauth/token). Store these credentials securely outside of your codebase.

2. Add them to .dlt/secrets.toml

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[sources.json_api_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 JSON:API data can I load into DuckDB?

These are the JSON:API endpoints dlt can load into DuckDB:

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How do I load only new JSON:API records?

The JSON:API 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": "resources", "endpoint": {
    "path": "resources",
    # 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 JSON:API pipeline look like?

A standard dlt REST API pipeline — the same code you would write by hand, loading /oauth/token and /entity/user from the JSON:API API into DuckDB:

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

@dlt.source
def json_api_source(token=dlt.secrets.value):
    config: RESTAPIConfig = {
        "client": {
            "base_url": "the base URL is implementation-specific and is not defined by the JSON:API specification itself",
            "auth": {"type": "bearer", "token": token},
        },
        "resources": [
            {"name": "resources", "endpoint": {"path": "resources", "data_selector": "data"}},
            {"name": "resource_detail", "endpoint": {"path": "resources/:id", "data_selector": "data"}}
        ],
    }
    yield from rest_api_resources(config)


def load_json_api_to_duckdb() -> None:
    pipeline = dlt.pipeline(
        pipeline_name="json_api_pipeline",
        destination="duckdb",
        dataset_name="json_api_data",
    )
    load_info = pipeline.run(json_api_source())
    print(load_info)


if __name__ == "__main__":
    load_json_api_to_duckdb()

Run it with python json_api_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 JSON:API 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("json_api_pipeline").dataset()
df = data.resources.df()
print(df.head())

SQL:

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SELECT * FROM json_api_data.resources LIMIT 10;

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

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How do I deploy the JSON:API 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 JSON:API 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 JSON:API 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