Axel vs Hookdeck Outpost

Axel captures third-party webhooks, routes them to data systems or HTTP services, and replays retained events. It stores an accepted event’s original payload before returning HTTP 202, then delivers it asynchronously. Declarative filters and field transformations can route one event to several destinations. Listed destinations include Postgres, MongoDB, S3, Cloudflare R2, Databricks, BigQuery, and signed HTTP webhooks; generic webhook and custom HMAC sources are also supported. The dashboard and CLI can replay retained events, while Axel Cloud provides 30 days of searchable event and delivery history. Data Contracts infer event and field types and check for schema changes every five minutes, but do not block delivery or guarantee destination acceptance. Delivery is at least once with a stable event ID across retries, so signed receivers should deduplicate. The Free plan includes 10,000 accepted inbound events monthly and community support. Pro costs $20 a month, with additional accepted events at 0.015 USD per 1,000; unused credit expires monthly. Axel is web, API, and self-hosted.

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.