How to Get a Google Sheets API Key

A Google Sheets API key lets you read and write a spreadsheet from the command line or from code. This guide follows the video above step by step. You'll enable the Sheets API in Google Cloud, create a service account with write access, mint an access token with a short shell script, and call the API with curl to read and update a sheet.

Step 1: Create a test sheet

Create a spreadsheet in Google Drive to test against. In the video the sheet is named "YouTube API key demo" and one cell holds "hello, YouTube."

Step 2: Open the Google Cloud console

Google Sheets has no settings page with a ready-made key. API access runs through Google Cloud, so go to console.cloud.google.com. Your first visit may ask you to accept the terms. The API access itself costs nothing or pennies.

Step 3: Create a project

Create a new project and select it. The video names it "Google Sheets API Key Project."

Step 4: Enable the Google Sheets API

Search for "Google Sheets" in the bar at the top and open the Google Sheets API, which lives in the Marketplace. Click Enable.

Step 5: Create a service account

A read-only path with a plain API key exists, but write access needs a service account. Search for "service accounts," click Create service account, and name it. The video uses "Google Sheets API Service Account." Click through Create and continue, then Continue, then Done.

Step 6: Create a JSON key

On the service account, open Manage keys, then Add key, Create new key, and choose JSON. The key file downloads to your computer. You can't paste this file into a request as a key. The script in step 8 reads it to mint one.

Step 7: Share the sheet with the service account

This is the step everyone misses. Copy the service account's email address, which looks like name@project-id.iam.gserviceaccount.com, and share the target sheet with it as an Editor. That share is what gives the API access to the sheet.

Step 8: Mint an access token

Save the script below as mint_token.sh and make it executable. It uses only jq, openssl, and curl. No Python, no gcloud. Tokens expire after one hour; run the script again for a fresh one.

#!/usr/bin/env bash
# Mint a Google OAuth access token from a service account key.
# Pure shell: needs only jq, openssl, and curl. No Python, no gcloud.
#
#   ./mint_token.sh <key.json> [scope]
set -euo pipefail

KEY="$1"
SCOPE="${2:-https://www.googleapis.com/auth/spreadsheets}"

b64url() { openssl base64 -A | tr '+/' '-_' | tr -d '='; }

EMAIL=$(jq -r .client_email "$KEY")
NOW=$(date +%s)

HEADER=$(printf '{"alg":"RS256","typ":"JWT"}' | b64url)
CLAIMS=$(jq -nc \
  --arg iss "$EMAIL" --arg scope "$SCOPE" \
  --argjson iat "$NOW" --argjson exp "$((NOW + 3600))" \
  '{iss:$iss, scope:$scope, aud:"https://oauth2.googleapis.com/token",
    iat:$iat, exp:$exp}' | b64url)

# Sign "<header>.<claims>" with the key's RSA private key.
SIG=$(printf '%s.%s' "$HEADER" "$CLAIMS" \
  | openssl dgst -sha256 -sign <(jq -r .private_key "$KEY") | b64url)

curl -s https://oauth2.googleapis.com/token \
  -d grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer \
  --data-urlencode "assertion=${HEADER}.${CLAIMS}.${SIG}" \
  | jq -r .access_token

Step 9: Call the API with curl

Set three variables, then run any of the commands below. The sheet ID is the long string in the middle of the spreadsheet URL.

export KEY=~/Downloads/your-service-account-key.json
export SHEET=your_sheet_id_from_the_url
export TOKEN=$(./mint_token.sh $KEY)

# Read a range
curl -s -H "Authorization: Bearer $TOKEN" "https://sheets.googleapis.com/v4/spreadsheets/$SHEET/values/Sheet1!A1:D10"

# Sheet metadata (title + tab names)
curl -s -H "Authorization: Bearer $TOKEN" "https://sheets.googleapis.com/v4/spreadsheets/$SHEET?fields=properties.title,sheets.properties.title"

# Read several ranges in one request
curl -s -H "Authorization: Bearer $TOKEN" "https://sheets.googleapis.com/v4/spreadsheets/$SHEET/values:batchGet?ranges=Sheet1!A1:B5&ranges=Sheet1!D1:D5"

# Overwrite a range
curl -s -X PUT -H "Authorization: Bearer $TOKEN" -H 'Content-Type: application/json' "https://sheets.googleapis.com/v4/spreadsheets/$SHEET/values/Sheet1!B1?valueInputOption=USER_ENTERED" -d '{"values":[["hello","from curl"]]}'

# Append a row after the last populated row
curl -s -X POST -H "Authorization: Bearer $TOKEN" -H 'Content-Type: application/json' "https://sheets.googleapis.com/v4/spreadsheets/$SHEET/values/Sheet1!A1:append?valueInputOption=USER_ENTERED" -d '{"values":[["appended","row"]]}'

Two-way sync without the shell script

Whalesync syncs Google Sheets two-way with Webflow, Notion, Supabase, Salesforce, HubSpot, and more. Scratch downloads your data locally so AI can edit it, then publishes it back safely. This video was recorded by Curtis, founder of Whalesync.