Google Cloud Datastore Emulator

To develop and test your application locally, you can use theGoogle CloudDatastoreEmulator,which provideslocalemulation of theproduction Google Cloud Datastore environment. You can start the Google CloudDatastore emulator using thegcloud command-line tool.

When you run the Cloud Datastore emulator you will see a message similar to thefollowing printed:

If you are using a library that supports the DATASTORE_EMULATOR_HOSTenvironment variable, run:  export DATASTORE_EMULATOR_HOST=localhost:8978

Now you can connect to the emulator using theDATASTORE_EMULATOR_HOSTenvironment variable:

require"google/cloud/datastore"# Make Datastore use the emulatorENV["DATASTORE_EMULATOR_HOST"]="localhost:8978"datastore=Google::Cloud::Datastore.newproject:"emulator-project-id"task=datastore.entity"Task","emulatorTask"do|t|t["type"]="Testing"t["done"]=falset["priority"]=5t["description"]="Use Datastore Emulator"enddatastore.savetask

Or by providing theemulator_host argument:

require"google/cloud/datastore"datastore=Google::Cloud::Datastore.newemulator_host:"localhost:8978"task=datastore.entity"Task","emulatorTask"do|t|t["type"]="Testing"t["done"]=falset["priority"]=5t["description"]="Use Datastore Emulator"enddatastore.savetask

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Last updated 2025-11-04 UTC.