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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 --db NAME/INSTANCE


  • 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