Release Notes

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v2.5.0 --- March 24, 2026

• Automatic capture of funded payment sessions with a new explicit capture API for greater payment control.
• Fee computation service calculating Grain fees, network fees, and net payouts based on partner take rates and transaction status.
• Core data models for Users, Partners, Team Members, Take Rates, and Payments, establishing the foundation for partner management.
• Persistent payment records with rich details including currency, network/token info, fee breakdowns, and net payout — all normalized to cents with idempotent handling.
• Erebor KYB service integration for full business and person applicant management, onboarding flows, and document upload/retrieval.
• End-of-day Slack transaction report powered by Trigger.dev, delivering daily aggregated payment summaries.
• Threaded Slack notifications per payment transaction with persistent thread IDs for easier tracking.

• Multi-AZ Redis failover for production, ensuring high availability with automatic failover across availability zones.
• Optional custom domain support for API (ALB) and CDN (CloudFront) via Route53 alias records with ACM certificate integration.
• WAF rate-limiting rule protecting the ALB at 2,000 requests per 5 minutes per IP.
• VPC endpoints for S3, Secrets Manager, KMS, and STS to reduce NAT costs and improve latency.
• AWS Backup integration with daily automated backups (7-day retention for dev, 35-day for prod) and optional cross-region backup copy.
• GuardDuty findings forwarded to SNS via EventBridge and AWS Config recorder added for Vanta compliance.
• CloudWatch security alarms wired to SNS for root account usage, MFA-less console login, failed logins, and unauthorized API calls.
• Resource tagging across all CDK stacks (Environment, Project, ManagedBy) for compliance and cost attribution.
• Lambda reserved concurrency limits set per environment to prevent account-level exhaustion.
• SQS dead letter queue added for failed async Lambda invocations with KMS encryption and 14-day retention.

• Payment processing now uses the specified amount rather than a hardcoded default.
• Simplified API key handling in payment sessions and improved webhook error handling and logging.

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v2.4.0 --- March 10, 2026

• Support for USDC payments on the Arbitrum network, giving customers a lower-fee payment option.
• New payment.settlement.completed webhook event so you can track settlement in real time.
• Bulk export of transaction history as CSV from the Dashboard.

• Reduced average API response time for the /payments endpoint by 35%.
• Updated the Dashboard transaction detail view with clearer status labels and a timeline of payment lifecycle events.

• Resolved an issue where webhook signature verification failed intermittently when the payload contained non-ASCII characters.
• Fixed a display bug in the Dashboard that showed incorrect settlement amounts for refunded transactions.

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v2.3.0 --- February 14, 2026

• Multi-user access for merchant accounts with configurable roles (Owner, Admin, Viewer).
• Support for setting a preferred settlement currency per payment, overriding the account default.

• Sandbox environment now simulates realistic blockchain confirmation delays for more accurate integration testing.
• Webhook retry schedule adjusted to include a faster first retry (30 seconds instead of 5 minutes).

• Fixed a race condition that could cause duplicate payment.confirmed webhook deliveries under high throughput.
• Corrected exchange rate display rounding in the customer-facing payment page for JPY-denominated merchants.

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v2.2.0 --- January 20, 2026

• Introduced idempotency key support on the POST /payments endpoint to prevent duplicate payment creation.
• New status page integration for real-time service health visibility at status.grain.com.

• Upgraded on-chain monitoring to detect payments with zero confirmations, reducing perceived confirmation time for supported networks.
• Dashboard loading performance improved by 40% through optimized data fetching.

• Resolved an issue where expired payment sessions were not correctly marked as expired in the API response.
• Fixed CSV export encoding issue that affected merchants using special characters in product descriptions.