Getting Started

Fyrnheim lets data teams define business entities as typed Pydantic models and automatically generates Ibis transformation code from those definitions. The same entity runs on DuckDB for instant local development and deploys to BigQuery, ClickHouse, or Postgres in production with zero changes.

Install

pip install fyrnheim[duckdb]

Fyrnheim requires Python 3.11 or later.

Quick Start

1. Create a project

fyr init myproject && cd myproject

This scaffolds a project directory with everything you need:

Created myproject/
  created  entities/
  created  data/
  created  generated/
  created  fyrnheim.yaml
  created  entities/customers.py
  created  data/customers.parquet

2. Look at the sample entity

Open entities/customers.py to see a complete entity definition:

entity = Entity(
    name="customers",
    source=TableSource(..., duckdb_path="customers.parquet"),
    layers=LayersConfig(
        prep=PrepLayer(model_name="prep_customers", computed_columns=[
            ComputedColumn(name="email_hash", expression=hash_email("email")),
            ComputedColumn(name="amount_dollars", expression="t.amount_cents / 100.0"),
        ]),
        dimension=DimensionLayer(model_name="dim_customers", computed_columns=[
            ComputedColumn(name="is_paying", expression="t.plan != 'free'"),
        ]),
    ),
    quality=QualityConfig(checks=[NotNull("email"), Unique("email_hash")]),
)

An entity declares its source, transformation layers, and quality rules in one place.

3. Generate transformation code

fyr generate

Generating transforms from entities
  customers            generated/customers_transforms.py   written

Generated: 1 written, 0 unchanged

Fyrnheim reads your entity definitions and generates Ibis transformation code into the generated/ directory.

4. Run the pipeline

fyr run

Discovering entities... 1 found
Running on duckdb

  customers        prep -> dim            12 rows    0.1s  ok

Done: 1 success, 0 errors (0.2s)

Add your own entities to entities/ and data to data/. See the Core Concepts section to learn about entities, layers, sources, and more.