Fastfield Python API Docs | dltHub

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

Last updated:

FastField is a mobile forms platform that allows users to create, submit, and retrieve form data via RESTful APIs. The REST API base URL is https://api.fastfieldforms.com/v1 and all requests require a Bearer token in the Authorization 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 Fastfield data in under 10 minutes.


What data can I load from Fastfield?

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

ResourceEndpointMethodData selectorDescription
formsformsGETformsList all forms.
submissionssubmissionsGETsubmissionsList all submissions.
dispatchesdispatchesGETdispatchesList dispatches.
global_listsglobal_listsGETglobal_listsList global lists.
lookup_listslookup_listsGETlookup_listsList lookup lists.

How do I authenticate with the Fastfield API?

FastField uses Bearer token authentication, which requires including the token in the Authorization header as 'Authorization: Bearer '.

1. Get your credentials

To obtain FastField API credentials, log in to the FastField portal (https://app.fastfieldforms.com). Navigate to the API or Integrations section to locate your User Token or API Key details. If these are not directly visible in your profile/settings, navigate to the Help Center or submit a support ticket via the FastField Help Center to request access to the API and receive your credentials.

2. Add them to .dlt/secrets.toml

[sources.fastfield_source] token = "your_fastfield_user_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 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 Fastfield 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 fastfield_pipeline.py

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

Pipeline fastfield_pipeline load step completed in 0.26 seconds 1 load package(s) were loaded to destination duckdb and into dataset fastfield_data The duckdb destination used duckdb:/fastfield.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 /forms and /submissions from the Fastfield 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 fastfield_source(token=dlt.secrets.value): config: RESTAPIConfig = { "client": { "base_url": "https://api.fastfieldforms.com/v1", "auth": {"type": "bearer", "token": token}, }, "resources": [ {"name": "forms", "endpoint": {"path": "forms", "data_selector": "forms"}}, {"name": "submissions", "endpoint": {"path": "submissions", "data_selector": "submissions"}} ], } yield from rest_api_resources(config) def get_data() -> None: pipeline = dlt.pipeline( pipeline_name="fastfield_pipeline", destination="duckdb", dataset_name="fastfield_data", ) load_info = pipeline.run(fastfield_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("fastfield_pipeline").dataset() sessions_df = data.forms.df() print(sessions_df.head())

SQL (DuckDB example):

SELECT * FROM fastfield_data.forms LIMIT 10;

In a marimo or Jupyter notebook:

import dlt data = dlt.pipeline("fastfield_pipeline").dataset() data.forms.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 Fastfield 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

Was this page helpful?

Community Hub

Need more dlt context for Fastfield?

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

Available Pipelines