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Use this when setting up a BigQuery source or destination. Less connects with a Google Cloud service account JSON key — the standard approach for server-to-server data pipelines.
OAuth is not supported yet for BigQuery in Less. Google OAuth (sign in with your Google account) works for other Google connectors such as Google Sheets, but BigQuery requires a service account today. Service accounts are also what Google recommends for automated extract/load jobs.
1

Create or select a project

Open the Google Cloud Console and select the project that contains your BigQuery datasets, or create a new project.Copy the Project ID (not the project name) — you will enter this as Project ID in Less.
2

Enable the BigQuery API

In the Cloud Console, go to APIs & Services → Library, search for BigQuery API, and click Enable if it is not already enabled for the project.
3

Create a service account

Go to IAM & Admin → Service Accounts → Create service account.Enter a name (for example less-bigquery) and optional description, then select Create and continue.
4

Grant BigQuery roles

Assign roles depending on how you use Less:
  • Sources (read data) — add BigQuery Data Viewer and BigQuery Job User.
  • Destinations (write data) — add BigQuery Data Editor and BigQuery Job User.
You can grant roles at project level, or use dataset-level IAM for tighter access (see step 5).Select Continue, then Done.
5

Grant dataset access (recommended)

For least-privilege access, open BigQuery in the Cloud Console, select your dataset → Sharing → Permissions → Add principal.Enter the service account email (for example less-bigquery@my-project.iam.gserviceaccount.com) and assign:
  • BigQuery Data Viewer for sources
  • BigQuery Data Editor for destinations
The service account still needs BigQuery Job User at project level so Less can run queries and load jobs.
6

Create and download a JSON key

Return to IAM & Admin → Service Accounts, open the service account you created, go to the Keys tab → Add key → Create new key → JSON → Create.A JSON file downloads automatically. Upload that file in the Credentials step of the BigQuery wizard in Less.
Store the key securely. Anyone with this file can access BigQuery as the service account. Rotate or delete keys you no longer use under Keys in the service account settings.
7

Connect in Less

In the BigQuery wizard:
  1. Account — Project ID, optional default dataset, and optional location (for example US or EU).
  2. Credentials — upload the JSON key file from step 6.
  3. Tables (source) or Test Connection (destination) — click Connect to verify access.
BigQuery is accessed over HTTPS; you do not need to whitelist Less IP addresses for Google Cloud.

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Troubleshooting

Invalid service account JSON
  • Upload the original .json key file downloaded from Google Cloud.
  • The file must contain "type": "service_account" and a client_email field.
Access Denied or permission errors
  • Confirm BigQuery Job User is granted at project level.
  • Confirm BigQuery Data Viewer (source) or BigQuery Data Editor (destination) is granted on the dataset or project.
  • If you use a default dataset in Less, the service account must have access to that dataset.
Not found: Dataset or table
  • Check the Project ID matches the project where the dataset lives.
  • Dataset and table names are case-sensitive in BigQuery.
Location errors
  • If datasets use a regional location (for example europe-west1), set the same location in the Less Account step.
Further reading