Fastspring Slack Bridge

A lightweight Go service that receives Fastspring webhook events and sends notifications to Slack. Also provides a weekly payment digest. Designed for deployment on Google Cloud Run.

Features

• Real-time webhooks: Receive Fastspring events and post to Slack instantly
• Weekly digest: Summarize payments per customer with subscription history and open quotes

Supported Webhook Events

Orders

Event	Description
order.completed	Order/payment completed
order.canceled	Order canceled
order.failed	Order failed
order.payment.pending	Payment processed but not yet received
order.approval.pending	Invoice order awaiting approval

Subscriptions

Event	Description
subscription.activated	New subscription created
subscription.deactivated	Subscription deactivated
subscription.canceled	Subscription canceled
subscription.uncanceled	Subscription reactivated
subscription.updated	Subscription modified
subscription.paused	Subscription paused
subscription.resumed	Subscription resumed
subscription.charge.completed	Recurring payment received
subscription.charge.failed	Recurring payment failed
subscription.trial.reminder	Trial ending soon
subscription.payment.reminder	Upcoming payment reminder
subscription.payment.overdue	Payment overdue

Other

Event	Description
return.created	Refund processed
invoice.reminder.email	Invoice reminder sent
quote.created	Quote created
quote.updated	Quote updated

Weekly Digest

The /digest endpoint generates a weekly payment summary including:

• All subscriptions grouped by customer
• Last 5 payment cycles per subscription (with invoice links)
• Deduplication of pending/completed entries for the same date
• Open and awaiting-payment quotes

The digest posts to Slack as a threaded message: header with quotes as the parent, each customer as a reply.

Environment Variables

Variable	Required	Description
SLACK_WEBHOOK_URL	Yes	Slack incoming webhook URL (for real-time webhooks)
SLACK_BOT_TOKEN	For digest	Slack Bot token for threaded digest messages
SLACK_CHANNEL_ID	For digest	Slack channel ID for digest (e.g., C01234ABCDE)
FASTSPRING_HMAC_SECRET	No	HMAC secret for webhook signature verification
FASTSPRING_API_USERNAME	For digest	Fastspring API username
FASTSPRING_API_PASSWORD	For digest	Fastspring API password
PORT	No	Server port (default: 8080)

Setup

1. Slack Incoming Webhook (for real-time events)

1. Go to https://api.slack.com/apps
2. Create a new app or use existing
3. Enable Incoming Webhooks
4. Add a new webhook to your workspace
5. Choose the channel for notifications
6. Copy the webhook URL

2. Slack Bot Token (for digest threading)

1. Go to https://api.slack.com/apps and select your app
2. Go to OAuth & Permissions
3. Under Scopes → Bot Token Scopes, add:
   • chat:write - Post messages
4. Install/reinstall the app to your workspace
5. Copy the Bot User OAuth Token (starts with xoxb-)
6. Invite the bot to your channel: /invite @YourBotName

3. Get Slack Channel ID

1. Open Slack in a browser
2. Navigate to the channel
3. The URL will be: https://app.slack.com/client/TXXXXX/C01234ABCDE
4. The channel ID is the last part (e.g., C01234ABCDE)

4. Fastspring API Credentials

1. Go to Developer Tools → APIs in Fastspring dashboard
2. Create new API credentials
3. Note the username and password

5. Configure Fastspring Webhooks

1. Go to Developer Tools → Webhooks → Configuration in Fastspring dashboard
2. Click Add Webhook
3. Enter your Cloud Run URL: https://fastspring-slack-bridge-xxxxx.run.app/webhooks/fastspring
4. Set HMAC SHA256 secret (same as FASTSPRING_HMAC_SECRET)
5. Select events (all supported events listed above)
6. Save

Local Development

# Run locally
export SLACK_WEBHOOK_URL="https://hooks.slack.com/services/..."
export FASTSPRING_HMAC_SECRET="your-secret"
export FASTSPRING_API_USERNAME="your-api-username"
export FASTSPRING_API_PASSWORD="your-api-password"
export SLACK_BOT_TOKEN="xoxb-your-bot-token"
export SLACK_CHANNEL_ID="C01234ABCDE"
go run main.go

# Test webhook endpoint
curl -X POST http://localhost:8080/webhooks/fastspring \
  -H "Content-Type: application/json" \
  -d '{"events":[{"id":"test","type":"order.completed","live":false,"data":{"reference":"TEST-123","totalDisplay":"$99.00","customer":{"first":"John","last":"Doe","email":"john@example.com","company":"Acme"},"items":[]}}]}'

# Test digest endpoint
curl http://localhost:8080/digest

Deploy to Cloud Run

gcloud run deploy fastspring-slack-bridge \
  --source . \
  --region europe-west3 \
  --allow-unauthenticated \
  --set-env-vars "SLACK_WEBHOOK_URL=https://hooks.slack.com/services/..."

For production with secrets, use Google Secret Manager:

# Create secrets
echo -n "your-webhook-url" | gcloud secrets create fastspring-slack-webhook --data-file=-
echo -n "your-hmac-secret" | gcloud secrets create fastspring-hmac-secret --data-file=-
echo -n "your-api-username" | gcloud secrets create fastspring-api-username --data-file=-
echo -n "your-api-password" | gcloud secrets create fastspring-api-password --data-file=-
echo -n "xoxb-your-bot-token" | gcloud secrets create slack-bot-token --data-file=-
echo -n "C01234ABCDE" | gcloud secrets create slack-channel-id --data-file=-

# Deploy with secrets
gcloud run deploy fastspring-slack-bridge \
  --source . \
  --region europe-west3 \
  --allow-unauthenticated \
  --set-secrets "SLACK_WEBHOOK_URL=fastspring-slack-webhook:latest,FASTSPRING_HMAC_SECRET=fastspring-hmac-secret:latest,FASTSPRING_API_USERNAME=fastspring-api-username:latest,FASTSPRING_API_PASSWORD=fastspring-api-password:latest,SLACK_BOT_TOKEN=slack-bot-token:latest,SLACK_CHANNEL_ID=slack-channel-id:latest"

Schedule Weekly Digest

Use Cloud Scheduler to trigger the digest weekly:

gcloud scheduler jobs create http fastspring-weekly-digest \
  --location=europe-west3 \
  --schedule="0 14 * * 4" \
  --time-zone="Europe/Berlin" \
  --uri="https://your-service-url.run.app/digest" \
  --http-method=GET

This runs every Thursday at 14:00 Berlin time.

To trigger manually:

gcloud scheduler jobs run fastspring-weekly-digest --location=europe-west3