rbt — Rust lake build tool

Medallion SQL DAGs for filesystem / object-storage lakes: bronze files → silver → gold, with dbt-shaped models, frontmatter contracts, and in-process DataFusion execution.

Status: 0.0.1 experimental. The spine works (compile / run / test / --select). Default materialization is full Parquet rewrite. Filesystem Iceberg-style tables are supported via --format iceberg (data + metadata layout; not a full multi-catalog OCC product yet). APIs may break between 0.0.x releases.

Why rbt


Niche	Bronze → silver → gold on a lake, not warehouse-dbt
Stack	Rust + Arrow + DataFusion + optional Iceberg-style FS tables + jshift
UX	Models, `ref` / `source`, frontmatter tests, CLI select
Claim	Replace ad-hoc scripts / Spark for team-scale medallion jobs

Install / build

git clone <repo> && cd rbt
cargo build -p rbt-cli --release
# binary: ./target/release/rbt

Requires a matching rustc/cargo pair (see rust-toolchain.toml).

Quick start (smoke fixture)

Tiny JSONL bronze → staging → dim:

./target/release/rbt compile -p examples/smoke_fixture --bronze-check fail
./target/release/rbt run -p examples/smoke_fixture --select dim_ticker --format parquet
./target/release/rbt test -p examples/smoke_fixture --select dim_ticker

Full market example (large Arrow IPC bronze):

./target/release/rbt compile -p examples/full_e2e_rbt_example --bronze-check fail
./target/release/rbt run -p examples/full_e2e_rbt_example --format parquet

See examples/smoke_fixture/README.md and examples/full_e2e_rbt_example/README.md.

CLI

Command	Purpose
`rbt compile -p <proj> [--select …]`	DAG + bronze path checks
`rbt run -p <proj> [--select …] [--format parquet\|iceberg\|…]`	Execute subgraph (ancestors always included)
`rbt test -p <proj> [--select …]`	Run subgraph + frontmatter tests
`rbt bench`	In-memory throughput microbench

`--select` (dbt-like)

Spec	Meaning
`dim_ticker`	That model + all ancestors on `run`/`test`
`stg_trades+`	Model + descendants (+ ancestors on execute)
`+fact_x`	Model + ancestors
`a,b`	Union of selectors

`--format`

Value	Output
`parquet`	Single `.parquet` file per model (default)
`iceberg`	Table dir: `data/part-*.parquet` + `metadata/v1.metadata.json`
`parquet-and-iceberg`	Flat parquet and sibling `.iceberg/` dir
`jsonl` / `csv`	Line/CSV files

Iceberg here is a filesystem table layout written by rbt (full refresh), not Glue/REST multi-writer production yet.

Project shape

my_project/
  rbt_project.yml
  models/staging|transforms|marts/*.sql   # YAML frontmatter + SQL
  lake/bronze/…                           # external landing
  lake/silver/…                           # rbt outputs
  lake/gold/…

Staging frontmatter example: scan_path, source_format, grain, tests, columns.*.description/context.

Workspace crates

Crate	Role
`rbt-cli`	Binary `rbt`
`rbt-core`	Project, frontmatter, DAG, select
`rbt-engine`	DataFusion + bronze registration + run
`rbt-scan` / `rbt-json`	Bronze multi-format / jshift
`rbt-materializer`	Parquet / Iceberg-FS / JSONL / CSV writers
`rbt-testing`	Arrow assertions
`rbt-catalog` / `rbt-models`	Thin / evolving

Docs

CONTRIBUTING.md — priorities and positioning
thesis.md — product thesis
docs/ADR_003_UDF_RSMODELS.md — polyglot roadmap

CI

bash scripts/smoke.sh

GitHub Actions: .github/workflows/ci.yml.

Version / publish

See CHANGELOG.md and PUBLISHING.md.
crates.io: set a real repository URL in root Cargo.toml, then publish in dependency order at 0.0.1.

License

Apache-2.0 — see LICENSE.

rbt-core 0.0.1