Faxplus Python API Docs | dltHub

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

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Fax.Plus API is a programmable online fax service API to send, receive, and manage faxes, files, numbers, and account resources. The REST API base URL is https://restapi.fax.plus/v3 and All requests require an 'Authorization' header formatted as 'Bearer '. OAuth2 authentication additionally requires an 'x-fax-clientid' header..

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 add "dlt[hub]" and start loading Faxplus data in under 10 minutes.


What data can I load from Faxplus?

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

ResourceEndpointMethodData selectorDescription
faxes/accounts/{user_id}/faxesGETdata.recordsList fax records
outbox/accounts/{user_id}/outboxGETList faxes in the outbox
contacts/accounts/{user_id}/contactsGETdata.recordsList contacts
contact_groups/accounts/{user_id}/contact-groupsGETdata.recordsList contact groups
account_info/accounts/{user_id}GETGet account information

How do I authenticate with the Faxplus API?

All requests require an 'Authorization' header with the value 'Bearer {token}'. When using OAuth2 authentication, an additional required header 'x-fax-clientid' must be provided with the client ID.

1. Get your credentials

To obtain credentials for the Fax.plus REST API, log in to your Fax.plus account and navigate to Settings > Integrations. Under the Fax.plus API section, you can manage and generate Personal Access Tokens (PATs) or set up OAuth2 credentials (Client ID and Client Secret). PATs are the recommended method for most integrations.

2. Add them to .dlt/secrets.toml

[sources.faxplus_source] faxplus_access_token = "your_personal_access_token_here" faxplus_client_id = "your_client_id_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 init uv add "dlt[hub]"

1. Install the dlt AI harness:

uv run 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:

uv run dlthub ai toolkit install rest-api-pipeline

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 Faxplus 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:

uv run python faxplus_pipeline.py

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

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

Inspect your pipeline and data:

uv run dlthub 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/{user_id}/outbox and /accounts/{user_id}/faxes/{fax_id} from the Faxplus 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 faxplus_source(api_key=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://restapi.fax.plus/v3", "auth": {"type": "bearer", "token": api_key}, }, "resources": [ {"name": "faxes", "endpoint": {"path": "accounts/self/faxes", "data_selector": "data.records"}}, {"name": "contacts", "endpoint": {"path": "accounts/self/contacts", "data_selector": "data.records"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="faxplus_pipeline", destination="duckdb", dataset_name="faxplus_data", ) load_info = pipeline.run(faxplus_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("faxplus_pipeline").dataset() sessions_df = data.faxes.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM faxplus_data.faxes LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("faxplus_pipeline").dataset() data.faxes.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 Faxplus 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.
uv run dlthub ai toolkit install data-exploration uv run dlthub ai toolkit install dlthub-platform

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