eider

A declarative pipeline compiler for DuckDB. Models are plain SELECT files; eider owns every statement that writes to the warehouse, so the layer contract holds by construction.

No templating. Dependencies are read from the SQL itself. A model is valid DuckDB as written, so any DuckDB tool can run, format or lint it.
One static binary, no runtime dependencies. eider check runs offline, so CI needs no database and no credentials.
Medallion layers with a Data Vault silver tier. Data flows one way: sources → staging → silver → gold.

Early. eider check and eider order work today; compiling and running models against DuckDB comes next.

Install

cargo install eider

A project

eider.toml
models/
  staging/birds/stg_birds__fieldbook_species.sql
  silver/birds/birds__hub_species.sql
  silver/birds/birds__sat_species__fieldbook.sql
  gold/atlas/species_tallies.sql

A model’s path is its declaration: models/<layer>/<domain>/<name>.sql, referenced elsewhere as <layer>.<name>. eider.toml declares the source relations eider reads but never writes:

[sources]
bronze   = ["fieldbook__species"]
reference = ["birds__taxonomy"]

See examples/birds for a complete project: a birding atlas built from a field-notes app’s sightings. It is written in the house style, clean under every grebe rule and formatted by it.

Usage

eider check [DIR]    check the project in DIR (default: .)
eider order [DIR]    print models in build order
eider --version

Each finding is one line, path:line:col: CODE message, sorted by file and position. order prints nothing while there are findings.

Exit codes: 0 clean, 1 findings, 2 usage or project error.

Rules

Code	Rule
`PRJ001`	a `.sql` file under `models/` is not at `<layer>/<domain>/`
`PRS001`	a model is not valid DuckDB SQL
`LAY001`	a model reads a layer it may not read
`LAY002`	a model is not exactly one `SELECT`
`LAY003`	a relation is not qualified by a known catalog
`LAY004`	a source relation is not declared in `eider.toml`
`LAY005`	a model reads files directly (`read_parquet`, `'x.csv'`, …)
`NAM001`	a model name does not follow its layer’s pattern
`NAM002`	two models in one layer share a name
`DAG001`	a model reads a model that does not exist
`DAG002`	models depend on each other in a cycle

Who may read what: staging reads sources; silver reads sources, staging and silver; gold reads silver and non-raw sources (any source catalog other than bronze). Nothing reads gold.

Naming: staging stg_<domain>__<name>; silver <domain>__hub_<entity>, <domain>__lnk_<name> or <domain>__sat_<entity>__<system>; gold any snake_case name.

License

MIT