Hookdeck Outpost vs RelayKit

Hookdeck Outpost is outbound webhook infrastructure for platforms sending events to destinations selected by their users. Hookdeck offers a managed service, while the open-source version can run on infrastructure you manage. That version is licensed under Apache-2.0, written in Go, and distributed as a binary and Docker container. Outpost supports event topics, topic-based subscriptions, destination filters based on event content, tenant isolation, and fan-out to multiple destinations. Destinations include webhooks, AWS services, Google Pub/Sub, Azure Service Bus, RabbitMQ, Kafka, Cloudflare Queues, and Hookdeck Event Gateway. Delivery is at least once, so consumers should deduplicate events by event ID. Failed deliveries retry automatically with exponential backoff by default, with customizable schedules and manual retries through the Retry API, tenant portal, or Admin UI. It supports webhook signatures, Standard Webhooks compatibility, secret rotation, destination-failure alerts, optional automatic disabling of failed destinations, and OpenTelemetry metrics. Self-hosting is always free; managed Starter is $10 a month, and Growth is $499 a month.

RelayKit is a cloud service and API for receiving, inspecting, verifying, storing, and forwarding webhook events from third-party services. One incoming event can be delivered to multiple destinations in parallel, with each destination tracked and retried independently. Failed deliveries receive automatic retries of up to 20 attempts, and users can replay events manually. Inbound signature verification supports Stripe, GitHub, Shopify, Twilio, SendGrid, Paddle, Clerk, and Resend. Security controls include IPv4 and IPv6 IP allowlisting, configurable rate limits, and audit records for rejected requests. RelayKit says it forwards the original request body and headers, except for specified hop-by-hop headers. The @relaykit/cli can send webhooks to a local development server and requires Node.js 18 or later. Hobby costs nothing for 1,000 webhooks monthly. Pro costs $9 a month for 100,000 webhooks, and Team costs $29 a month for 500,000. Team adds Schema Sentinel, Time Machine replay, and priority support.