Protonmail Python API Docs | dltHub

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

Last updated:

ProtonMail API is a client library and internal REST API for accessing ProtonMail email functionality. The REST API base URL is https://mail.proton.me/api and All requests require a Bearer token obtained via username/password login..

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 Protonmail data in under 10 minutes.


What data can I load from Protonmail?

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

ResourceEndpointMethodData selectorDescription
messages/messagesGETMessagesList email messages
contacts/contactsGETContactsList address book contacts
labels/labelsGETLabelsList message labels
calendars/calendarsGETCalendarsList user calendars
settings/settingsGETSettingsRetrieve user settings

How do I authenticate with the Protonmail API?

Include an HTTP header Authorization: Bearer <access_token> on each request. The token is obtained by logging in with your ProtonMail username and password via the auth endpoint.

1. Get your credentials

  1. Sign up for a ProtonMail account at https://mail.proton.me.
  2. Verify your email and enable two‑factor authentication if desired.
  3. Use the API login endpoint (e.g., POST /auth) with your username and password to receive an access token.
  4. Store the token for use in the Authorization header.

2. Add them to .dlt/secrets.toml

[sources.protonmail_source] api_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 Protonmail 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 protonmail_pipeline.py

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

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

Inspect your pipeline and data:

dlt pipeline protonmail_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 messages and contacts from the Protonmail 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 protonmail_source(api_token=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://mail.proton.me/api", "auth": { "type": "bearer", "token": api_token, }, }, "resources": [ {"name": "messages", "endpoint": {"path": "messages", "data_selector": "Messages"}}, {"name": "contacts", "endpoint": {"path": "contacts", "data_selector": "Contacts"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="protonmail_pipeline", destination="duckdb", dataset_name="protonmail_data", ) load_info = pipeline.run(protonmail_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("protonmail_pipeline").dataset() sessions_df = data.messages.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM protonmail_data.messages LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("protonmail_pipeline").dataset() data.messages.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 Protonmail 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 failures

  • Error 401 Unauthorized – Occurs when the Bearer token is missing, expired, or invalid. Refresh the token via the login endpoint and retry.

Rate limiting

  • Error 429 Too Many Requests – Proton API enforces request quotas. Respect the Retry-After header before retrying.

Pagination

  • Endpoints that return large result sets use a cursor (NextID or similar) in the response. Continue fetching pages by passing the cursor value as a query parameter until it is empty.

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

Was this page helpful?

Community Hub

Need more dlt context for Protonmail?

Request dlt skills, commands, AGENT.md files, and AI-native context.