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JavaScript (Flow)

The JavaScript/Flow indexer is built into the Flow system. It's also included in the Glean demo Docker image to try out.

Run the indexer

The indexer is run via the main glean CLI tool.

> cabal build exe:glean

And index your Flow repository with:

glean index flow DIR --repo name/hash


  • DIR is the root directory containing the Flow project (with .flowconfig)
  • name/hash is the name of the repository to create

Provide the usual --db-root and --schema or --service arguments to glean

Run the indexer (manually)

flow glean DIR --output-dir JSON --write-root PREFIX


  • DIR is the root directory containing the JavaScript/Flow files
  • JSON is the directory in which to write the output .json files
  • PREFIX is a prefix to add to the files in the Glean index (this can be empty if you don't need a prefix)

The generated files can be ingested into a Glean database using glean create.

Derived predicates

Several predicates should be derived after indexing. For each stored predicate in the schema you should glean derive the predicate.

In the shell

Flow source can also be indexed directly from the Glean shell:

:index flow DIR


The schema is in glean/schema/source/flow.angle