Load MailerQ data in Python using dltHub

Build a MailerQ-to-database or-dataframe pipeline in Python using dlt with automatic Cursor support.

In this guide, we'll set up a complete MailerQ data pipeline from API credentials to your first data load in just 10 minutes. You'll end up with a fully declarative Python pipeline based on dlt's REST API connector, like in the partial example code below:

Example code
@dlt.source
def mailerq_suppressions_source(access_token=dlt.secrets.value):
    config: RESTAPIConfig = {
        "client": {
            "base_url": "/v1/",
            "auth": {
                "type": "bearer",
                "token": access_token,
            },
        },
        "resources": [
            errors, externalmtas
        ],
    }
    [...]
    yield from rest_api_resources(config)


def get_data() -> None:
    # Connect to destination
    pipeline = dlt.pipeline(
        pipeline_name='mailerq_suppressions_pipeline',
        destination='duckdb',
        dataset_name='mailerq_suppressions_data', 
    )
    # Load the data
    load_info = pipeline.run(mailerq_suppressions_source())
    print(load_info)

Why use dltHub Workspace with LLM Context to generate Python pipelines?

  • Accelerate pipeline development with AI-native context
  • Debug pipelines, validate schemas and data with the integrated Pipeline Dashboard
  • Build Python notebooks for end users of your data
  • Low maintenance thanks to Schema evolution with type inference, resilience and self documenting REST API connectors. A shallow learning curve makes the pipeline easy to extend by any team member
  • dlt is the tool of choice for Pythonic Iceberg Lakehouses, bringing mature data loading to pythonic Iceberg with or without catalogs

What you’ll do

We’ll show you how to generate a readable and easily maintainable Python script that fetches data from mailerq_suppressions’s API and loads it into Iceberg, DataFrames, files, or a database of your choice. Here are some of the endpoints you can load:

  • Errors: Manage and retrieve error logs and error information
  • External MTAs: Handle external mail transfer agents configuration and data
  • Pauses: Control and view pause states for sending operations
  • Pool IPs: Manage IP pool assignments and retrieve pool IP details
  • Pools: Configure and retrieve mail sending pools
  • Suppressions: Manage suppressed email addresses and retrieve suppression lists

You will then debug the MailerQ pipeline using our Pipeline Dashboard tool to ensure it is copying the data correctly, before building a Notebook to explore your data and build reports.

Setup & steps to follow

💡
Before getting started, let's make sure Cursor is set up correctly:

Now you're ready to get started!

  1. ⚙️ Set up dlt Workspace

    Install dlt with duckdb support:

    pip install dlt[workspace]

    Initialize a dlt pipeline with MailerQ support.

    dlt init dlthub:mailerq_suppressions duckdb

    The init command will setup the necessary files and folders for the next step.

  2. 🤠 Start LLM-assisted coding

    Here’s a prompt to get you started:

    Prompt
    Please generate a REST API Source for MailerQ API, as specified in @mailerq_suppressions-docs.yaml 
Start with endpoint(s) errors and externalmtas and skip incremental loading for now. 
Place the code in mailerq_suppressions_pipeline.py and name the pipeline mailerq_suppressions_pipeline. 
If the file exists, use it as a starting point. 
Do not add or modify any other files. 
Use @dlt rest api as a tutorial. 
After adding the endpoints, allow the user to run the pipeline with python mailerq_suppressions_pipeline.py and await further instructions.

  3. 🔒 Set up credentials

    A POST request allows you to create a new error, or to update an existing one. For the request format, see the table below. All fields are optional.

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

Do note that not all fields may be passed at the same time. pool and mta are mutually exclusive. That means that they may not be supplied together, or they will result in a 400 response.

For example, the request below will install a Forced Error with code 421 to hotmail.com for a single campaign.


POST /v1/errors HTTP/1.0
Content-Type: application/json
Authorization: Bearer ...

{
    "domain": "hotmail.com",
    "code": 421,
    "tag": "Campaign1"
}

and equivalently, with urlencoded body


POST /v1/errors HTTP/1.0
Content-Type: application/x-www-form-urlencoded
Authorization: Bearer ...

domain=hotmail.com&code=421&tag=Campaign1

DELETE

A DELETE request allows you to

This API uses Bearer token authentication. The token must be passed in the Authorization header as "Bearer ". Include the header Authorization: Bearer ... in all requests to authenticate.

To get the appropriate API keys, please visit the original source at www.mailerq.com.
If you want to protect your environment secrets in a production environment, look into [setting up credentials with dlt](https://dlthub.com/docs/walkthroughs/add_credentials).

4. 🏃‍♀️ Run the pipeline in the Python terminal in Cursor

```shell
python mailerq_suppressions_pipeline.py
```

If your pipeline runs correctly, you’ll see something like the following:

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

5. 📈 Debug your pipeline and data with the Pipeline Dashboard

Now that you have a running pipeline, you need to make sure it’s correct, so you do not introduce silent failures like misconfigured pagination or incremental loading errors. By launching the dlt Workspace Pipeline Dashboard, you can see various information about the pipeline to enable you to test it. Here you can see:
- Pipeline overview: State, load metrics
- Data’s schema: tables, columns, types, hints
- You can query the data itself

```shell
dlt pipeline mailerq_suppressions_pipeline show 
```

6. 🐍 Build a Notebook with data explorations and reports

With the pipeline and data partially validated, you can continue with custom data explorations and reports. To get started, paste the snippet below into a new marimo Notebook and ask your LLM to go from there. Jupyter Notebooks and regular Python scripts are supported as well.


```python
import dlt

data = dlt.pipeline("mailerq_suppressions_pipeline").dataset()

get errors table as Pandas frame

data.errors.df().head() ```

Extra resources:

Next steps