Load Monzo data to DuckDB

Monzo is a banking service providing a REST API for individual developers to interact with Monzo accounts, including transactions, balances, and pots. Everything needed to build a working Monzo → 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 Monzo 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 Monzo 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 Monzo 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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Monzo API at a glance

These values come from the Monzo API reference — the authoritative source if anything here looks out of date.

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How do I authenticate with the Monzo API?

All API requests must be authenticated with an access token supplied in the Authorization header using the Bearer scheme. The header should be formatted as 'Authorization: Bearer <access_token>'.

1. Get your credentials

1. Log in to the Monzo Developer Dashboard at https://developers.monzo.com using your Monzo account. 2. Authorize the login in your Monzo app when prompted. 3. Navigate to the Clients section in the top right corner. 4. Click + New OAuth Client. 5. Fill out the form and ensure you select Confidential if you require refresh tokens. 6. Once created, note your Client ID, Client Secret, and Owner ID from the client details page. 7. To obtain an access token, perform an OAuth2 authorization code grant flow: redirect the user to https://auth.monzo.com/authorize with your client_id, redirect_uri, and scope; exchange the resulting code for an access token by POSTing to https://api.monzo.com/oauth2/token.

2. Add them to .dlt/secrets.toml

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[sources.monzo_source]
access_token = "your_access_token_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 Monzo data can I load into DuckDB?

These are the Monzo endpoints dlt can load into DuckDB:

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How do I load only new Monzo records?

Monzo exposes since on transactions, 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": "transactions", "endpoint": {
    "path": "transactions",
    "data_selector": "transactions",
    "incremental": {"cursor_path": "since", "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 Monzo pipeline look like?

A standard dlt REST API pipeline — the same code you would write by hand, loading /oauth2/token and /ping/whoami from the Monzo API into DuckDB:

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

@dlt.source
def monzo_source(access_token=dlt.secrets.value):
    config: RESTAPIConfig = {
        "client": {
            "base_url": "https://api.monzo.com",
            "auth": {"type": "bearer", "token": access_token},
        },
        "resources": [
            {"name": "transactions", "endpoint": {"path": "transactions", "data_selector": "transactions"}},
            {"name": "accounts", "endpoint": {"path": "accounts", "data_selector": "accounts"}}
        ],
    }
    yield from rest_api_resources(config)


def load_monzo_to_duckdb() -> None:
    pipeline = dlt.pipeline(
        pipeline_name="monzo_pipeline",
        destination="duckdb",
        dataset_name="monzo_data",
    )
    load_info = pipeline.run(monzo_source())
    print(load_info)


if __name__ == "__main__":
    load_monzo_to_duckdb()

Run it with python monzo_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 Monzo 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("monzo_pipeline").dataset()
df = data.transactions.df()
print(df.head())

SQL:

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SELECT * FROM monzo_data.transactions LIMIT 10;

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

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How do I deploy the Monzo 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 Monzo 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 Monzo 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