Firestore emulator

To work with the Google Firestore emulator you can use the environment variable:

export FIRESTORE_EMULATOR_HOST="localhost:8080"

or specify it as an option using FirestoreDb::with_options().

When FIRESTORE_EMULATOR_HOST is set, the library does not look up the Google credentials and uses a stub token instead, since the emulator does not authenticate the requests. This means you do not need any credentials configured to develop against it. Specifying credentials explicitly, with FirestoreDb::with_options_auth() for example, still takes precedence.

The emulator answers bulk delete and index management with UNIMPLEMENTED: .plan(), .sync(), the index calls list(), create(), delete() and update_field(), and the SQL index statements fail with it. SHOW COLLECTIONS works on the emulator.

On the Enterprise edition

The emulator acts as one edition, Standard by default. gcloud starts it, and needs a Java runtime (a JDK) for it:

gcloud emulators firestore start --host-port=127.0.0.1:8080 --edition=enterprise

The emulator prints Database Edition: STANDARD or Database Edition: ENTERPRISE as it starts.

Start the emulator with --edition=enterprise to run pipelines and SQL against it; the default Standard emulator answers them with INVALID_ARGUMENT, and neither edition of the emulator supports bulk delete. Core inserts and queries run on an emulator of either edition, and Core aggregations, transactions and listeners run on the Enterprise one as on a live database.

The Enterprise emulator runs SQL and pipelines, and ignores Query Explain: an EXPLAIN or EXPLAIN ANALYZE statement, and .explain(), return the rows and no plan. Check the plan of a query against a live database, see Explaining a pipeline.