GCS

The GCS connector exposes objects in a Google Cloud Storage bucket as datasets. Summation reads Parquet, CSV, JSON, JSONL, and TSV files directly from the bucket.

What you’ll need

A Cloud Storage bucket and optional prefix.
A Google Cloud service account with read access to the bucket. The roles/storage.objectViewer role includes object read and list permissions. See IAM roles for Cloud Storage.
A service account JSON key. See Create and delete service account keys.
Optional HMAC keys if your setup requires S3-compatible Cloud Storage credentials. See Manage HMAC keys for service accounts.

Grant the service account access only to the bucket that Summation should read.

Form fields

Field	Required	Stored as	Notes
Base Path	Yes	Config	A `gcs://` prefix that scopes the connection, e.g. `gcs://my-bucket/path`. `gs://` paths are also accepted. Browsing starts from this prefix.
Service Account Key	Yes	Secret	The full service account JSON key, including the surrounding `{` and `}`.
HMAC Access ID	Optional	Secret	Cloud Storage HMAC access ID. If set, HMAC Secret must also be set.
HMAC Secret	Optional	Secret	Cloud Storage HMAC secret. If set, HMAC Access ID must also be set.

Grant read access

Grant the service account object viewer access to the bucket you want Summation to read.

PROJECT_ID=my-gcp-project-123
BUCKET_NAME=my-bucket
SERVICE_ACCOUNT=summation@$PROJECT_ID.iam.gserviceaccount.com

gcloud storage buckets add-iam-policy-binding "gs://$BUCKET_NAME" \
  --member="serviceAccount:$SERVICE_ACCOUNT" \
  --role="roles/storage.objectViewer"

Generate a JSON key for the service account and paste the full file contents into Service Account Key.

gcloud iam service-accounts keys create summation-gcs-key.json \
  --iam-account="$SERVICE_ACCOUNT"

The downloaded summation-gcs-key.json is a credential. Paste it into Summation, then delete the local copy. See Best practices for managing service account keys.

Adding datasets

Each dataset is a single file or folder in the bucket. Supported file formats are parquet, csv, json, jsonl, and tsv. Source references use the form:

gcs://bucket/path/to/data/

Common problems

Error or symptom	Likely cause
`GCS base path is required`	Base Path is blank or doesn’t include a bucket.
`Invalid GCS service account key`	The pasted JSON is incomplete or malformed. Paste the full key file contents.
`GCS authentication failed`	The service account key is invalid, disabled, or lacks bucket access.
`GCS bucket does not exist`	The bucket name in Base Path is wrong, or the service account cannot see it.
HMAC validation error	Only one HMAC field is filled. Provide both HMAC Access ID and HMAC Secret, or leave both blank.

Get started

Features

API & Integrations

What you’ll need

Form fields

Grant read access

Adding datasets

Common problems

​What you’ll need

​Form fields

​Grant read access

​Adding datasets

​Common problems

What you’ll need

Form fields

Grant read access

Adding datasets

Common problems