Monzo Python API Docs | dltHub

Build a Monzo-to-database pipeline in Python using dlt with AI Workbench support for Claude Code, Cursor, and Codex.

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Monzo is a digital banking platform that offers a REST API for accessing account, transaction, pot, and Open Banking data. The REST API base URL is https://api.monzo.com and All requests require a Bearer access token obtained via OAuth2..

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 Monzo data in under 10 minutes.


What data can I load from Monzo?

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

ResourceEndpointMethodData selectorDescription
accounts/accountsGETaccountsReturns a list of the user's bank accounts.
pots/potsGETpotsReturns a list of the user's savings pots.
transactions/transactionsGETtransactionsReturns a list of transactions for an account.
balance/balanceGETbalanceReturns the current balance for an account.
feed/feedGETfeed_itemsReturns a chronological feed of account events.

How do I authenticate with the Monzo API?

Authentication is performed by sending the OAuth2 access token in the 'Authorization: Bearer <access_token>' header with every request.

1. Get your credentials

  1. Log in to the Monzo Developer Dashboard (https://developers.monzo.com).\n2. Create a new application and note the generated client_id and client_secret.\n3. Set a redirect URI for the OAuth2 flow.\n4. Direct a user to the authorization endpoint https://auth.monzo.com/authorize?client_id=<client_id>&response_type=code&redirect_uri=<your_redirect_uri>&scope=accounts:read,transactions:read.\n5. After the user authorizes, exchange the returned code for an access token by POSTing to https://api.monzo.com/oauth2/token with client_id, client_secret, grant_type=authorization_code, code, and redirect_uri.\n6. Store the received access_token for use in API calls.

2. Add them to .dlt/secrets.toml

[sources.monzo_source] access_token = "your_access_token_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.


How do I set up and run the pipeline?

Set up a virtual environment and install dlt:

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

1. Install the dlt AI Workbench:

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:

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 Monzo 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:

python monzo_pipeline.py

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

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

Inspect your pipeline and data:

dlt pipeline monzo_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.


Python pipeline example

This example loads accounts and transactions from the Monzo API into DuckDB. It mirrors the endpoint and data selector configuration from the table above:

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": "accounts", "endpoint": {"path": "accounts", "data_selector": "accounts"}}, {"name": "transactions", "endpoint": {"path": "transactions", "data_selector": "transactions"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="monzo_pipeline", destination="duckdb", dataset_name="monzo_data", ) load_info = pipeline.run(monzo_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.


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):

import dlt data = dlt.pipeline("monzo_pipeline").dataset() sessions_df = data.accounts.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM monzo_data.accounts LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("monzo_pipeline").dataset() data.accounts.df().head()

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


What destinations can I load Monzo data to?

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

DestinationExample value
DuckDB (local, default)"duckdb"
PostgreSQL"postgres"
BigQuery"bigquery"
Snowflake"snowflake"
Redshift"redshift"
Databricks"databricks"
Filesystem (S3, GCS, Azure)"filesystem"

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


Troubleshooting

Authentication Errors

  • 401 Unauthorized – The access token is missing, invalid, or expired. Obtain a fresh token via the OAuth2 flow.
  • 403 Forbidden – The token does not have the required scopes for the requested endpoint.

Rate Limiting

  • 429 Too Many Requests – Monzo enforces a rate limit per access token. Back‑off and retry after the Retry-After header interval.

Pagination

  • Endpoints that return large result sets (e.g., /transactions) use before and limit query parameters. Use the before cursor from the last item of the previous response to fetch the next page.

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


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

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