Project configuration (ledgerloom.yaml)

ledgerloom.yaml controls how LedgerLoom interprets inputs and where it writes outputs.

Translation box

Accountant: This is where you set the period, default accounts, and “what counts as an error.”

Developer: This is the contract for build reproducibility: same config + same inputs ⇒ same outputs.

Data pro: This is where you standardize dimensions (e.g., department) and output locations.

A minimal example

schema_id: ledgerloom.project_config.v1

project:
  name: demo_books
  period: 2026-01

inputs:
  root: inputs

outputs:
  root: outputs

chart_of_accounts:
  path: config/chart_of_accounts.yaml

mappings:
  root: config/mappings

policy:
  # If true, unmapped rows fail the build/check (recommended once your rules are stable).
  strict_unmapped: false

  # Where to park truly-unknown rows if you choose to allow them.
  suspense_account: 9999

Key ideas

Period

The project.period value determines the default input folder:

inputs/<period>/

Strictness

policy.strict_unmapped controls whether unmapped rows are treated as errors.

Start with false while you’re building rules.
Switch to true once your mapping rules cover the expected input patterns.

Dimensions

LedgerLoom can attach optional “dimensions” (columns like department) to outputs. If you do not configure dimensions, LedgerLoom still emits a consistent schema for core artifacts.