modules

mdvdb modules

Inspect and run the built-in modules that materialize computed frontmatter fields declared in .markdownvdb.schema.yml.

Module ID	Owns	Execution order
formula	Formula fields calculated from the current document	First
lookup_rollup	Lookup fields copied from related documents and Rollup aggregations	Second

Both modules are always on during ingest, watch updates, and schema changes. modules run is the explicit recomputation surface.

Usage

mdvdb modules <COMMAND> [OPTIONS]

Command	Description
list	List compiled-in modules, versions, and hooks
validate <MODULE>	Validate a Formula or Rollup expression without changing files or the index
run <MODULE>	Recompute persisted derived data
status <MODULE>	Read cached diagnostics without running expressions

Valid module IDs are formula and lookup_rollup.

List modules

mdvdb modules list
mdvdb modules list --json

JSON output is an array of descriptors:

[
  {
    "id": "formula",
    "name": "Formula",
    "version": 1,
    "always_on": true,
    "hooks": ["full_ingest", "files_changed", "schema_changed", "manual_run"]
  },
  {
    "id": "lookup_rollup",
    "name": "Lookup & Rollup",
    "version": 1,
    "always_on": true,
    "hooks": ["full_ingest", "files_changed", "schema_changed", "manual_run"]
  }
]

Validate an expression

mdvdb modules validate <MODULE> \
  --formula <EXPRESSION> \
  --result-type <TYPE>

Supported result types are string, number, boolean, date, datetime, list, and json. Use the formula module for a document Formula and lookup_rollup for a Rollup expression, where values is the reserved input list.

# Formula expression
mdvdb modules validate formula \
  --formula 'price * quantity' \
  --result-type number

# Rollup expression
mdvdb modules validate lookup_rollup \
  --formula 'values.reduce((sum, value) => sum + Number(value), 0)' \
  --result-type number \
  --json