Microsoft Exchange Online Python API Docs | dltHub

Build a Microsoft Exchange Online-to-database pipeline in Python using dlt with AI harness support for Claude Code, Cursor, and Codex.

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The Exchange Online Admin API is a REST-based management surface that allows programmatic execution of specific Exchange cmdlets to replace legacy EWS scenarios for organization and mailbox management. The REST API base URL is https://outlook.office365.com and all requests require a Bearer token.

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 Microsoft Exchange Online data in under 10 minutes.


What data can I load from Microsoft Exchange Online?

Here are some of the endpoints you can load from Microsoft Exchange Online:

ResourceEndpointMethodData selectorDescription
messages/me/messagesGETvalueList messages in the user's mailbox.
mail_folders/me/mailFoldersGETvalueList mail folders in the user's mailbox.
folder_messages/me/mailFolders/{id}/messagesGETvalueList messages in a specific folder.
message_delta/me/mailFolders/{id}/messages/deltaGETvalueGet incremental changes (delta) for messages in a folder.
user_messages/users/{id}/messagesGETvalueList messages for a specific user.

How do I authenticate with the Microsoft Exchange Online API?

All requests require an OAuth 2.0 access token passed in the Authorization header. Authentication is configured via Microsoft Entra ID using delegated or app-only flows with scopes such as 'https://outlook.office365.com/.default'.

1. Get your credentials

  1. Navigate to the Microsoft Entra admin center (https://entra.microsoft.com/). 2. Go to 'App registrations' and select 'New registration'. 3. Once registered, navigate to 'API permissions' and click 'Add a permission'. Select 'Microsoft Graph' and choose 'Application permissions'. 4. Select the required permissions (e.g., Mail.Read, Exchange.ManageAsApp). 5. Click 'Grant admin consent' for the configured permissions. 6. Go to 'Certificates & secrets' to generate a 'Client secret' or upload a public certificate (recommended for production). 7. Record the 'Application (client) ID', 'Directory (tenant) ID', and the 'Client secret' (or certificate thumbprint) for your dlt pipeline configuration.

2. Add them to .dlt/secrets.toml

[sources.microsoft_exchange_online_source] client_id = "your_application_client_id" client_secret = "your_client_secret_or_certificate_path" tenant_id = "your_directory_tenant_id"

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 harness:

dlthub 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:

dlthub 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 Microsoft Exchange Online 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 microsoft_exchange_online_pipeline.py

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

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

Inspect your pipeline and data:

dlt pipeline microsoft_exchange_online_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 v1.0/users and v1.0/me/messages from the Microsoft Exchange Online 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 microsoft_exchange_online_source(client_secret=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://outlook.office365.com", "auth": {"type": "bearer", "token": client_secret}, }, "resources": [ {"name": "message_delta", "endpoint": {"path": "me/mailFolders/{id}/messages/delta", "data_selector": "value"}}, {"name": "messages", "endpoint": {"path": "me/messages", "data_selector": "value"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="microsoft_exchange_online_pipeline", destination="duckdb", dataset_name="microsoft_exchange_online_data", ) load_info = pipeline.run(microsoft_exchange_online_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("microsoft_exchange_online_pipeline").dataset() sessions_df = data.message_delta.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM microsoft_exchange_online_data.message_delta LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("microsoft_exchange_online_pipeline").dataset() data.message_delta.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 Microsoft Exchange Online 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.


Next steps

Continue your data engineering journey with the other toolkits of the dltHub AI harness:

  • data-exploration — Build custom notebooks, charts, and dashboards for deeper analysis with marimo notebooks.
  • dlthub-platform — Deploy, schedule, and monitor your pipeline in production.
dlthub ai toolkit data-exploration install dlthub ai toolkit dlthub-platform install

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