# Hook0

> Open-source webhook platform that delivers events with HMAC signatures, configurable retries, dead letter queues, and a built-in subscriber portal. Cloud (EU-hosted, France) or self-hosted under SSPL-1.0. Editor: FGRibreau SARL (France), no US parent. CDN: Cloudflare (US), disclosed in our DPA.

## Product
- [Webhook Platform](https://www.hook0.com/webhook-platform): Sign, retry, replay, and monitor webhooks. Two-phase retries, dead letter queue, subscriber portal, drop-in HMAC.
- [Webhook Service](https://www.hook0.com/webhook-service): Managed delivery with HMAC signing, two-phase retries, and per-attempt logs. EU data plane on every plan. The same SSPL-1.0 code self-hosts when you want to leave.
- [Pricing](https://www.hook0.com/pricing): Free forever tier, paid tiers unlock higher volume only. No feature gating. Self-hosted free under SSPL-1.0.
- [Free Webhooks](https://www.hook0.com/webhook-free): Three free paths. Test webhooks in the browser with no account, self-host the SSPL-1.0 server with no Hook0 volume cap, or run the free cloud tier at 100 events/day, no credit card.
- [Open-Source Webhooks](https://www.hook0.com/open-source-webhooks): SSPL-1.0, no open-core, same code in cloud and self-hosted.
- [Self-Hosted Webhooks](https://www.hook0.com/self-hosted-webhooks): Docker Compose and Kubernetes manifests, free, same feature set as the cloud.
- [Webhook API](https://www.hook0.com/webhook-api): One API call sends an event, Hook0 handles signing, fan-out, retries, replay.
- [Webhook MCP Server](https://www.hook0.com/webhooks-for-ai-agents): MCP server that gives Claude, Cursor, and Windsurf tools to create subscriptions, emit events, and replay failed deliveries on the webhooks you send.
- [Security & Compliance](https://www.hook0.com/security): EU data residency (France, Clever Cloud), GDPR-aligned process, DPA on request.
- [EU Webhook Infrastructure](https://www.hook0.com/eu-webhook-infrastructure): Webhook data plane on Clever Cloud in France, from the free tier up. French-law company, public sub-processor list, self-host or on-prem anytime.
- [Sovereign Webhooks](https://www.hook0.com/sovereign-webhooks): Digital sovereignty as who can be legally compelled to produce your data, not just where it sits. French-law editor with no US parent, EU data plane, open-source (SSPL-1.0) and reversible, Cloudflare (US) edge disclosed. The CLOUD Act lens and a seven-question vendor checklist.

## Proof
- Production customers include Coinbase, GEODIS, WoodWing, Optery, Eudonet, Alteos, ActiveAnts, and Apizee.
- Coinbase is on the record. Ian Mukherjee (Coinbase): "Thank you for all of your help, we appreciate your partnership."
- Platon Samuel left a 5/5 review on Product Hunt, and the GitHub star count is public and verifiable.

## Compliance
- [Data Processing Agreement (DPA)](https://www.hook0.com/data-processing-addendum): The GDPR data processing agreement covering how Hook0 handles customer data. Sign it before going live.
- [GDPR Subprocessors](https://www.hook0.com/gdpr-subprocessors): Every subprocessor Hook0 relies on, what each one processes, and where it runs.

## Free tools
- [Webhook Tester](https://www.hook0.com/webhook-playground): Send test events, inspect payloads, and verify HMAC signatures in the browser. No signup. Handles Stripe, GitHub, and Shopify webhooks.
- [GitHub Webhook Tester](https://www.hook0.com/github-webhook-tester): Inspect a GitHub delivery: the payload, the X-GitHub-Event header, and the X-Hub-Signature-256 you have to verify.
- [Shopify Webhook Tester](https://www.hook0.com/shopify-webhook-tester): Inspect a Shopify delivery: the payload, the X-Shopify-Topic header, and the base64 X-Shopify-Hmac-Sha256 signature.
- [Stripe Webhook Tester](https://www.hook0.com/stripe-webhook-tester): Read the raw body and the exact Stripe-Signature header so your whsec_ verification matches.

## Localized
- [Webhook-Plattform (DE)](https://www.hook0.com/de/webhook-plattform): German page, EU-hosting and DSGVO angle for DACH.
- [Webhook-MCP-Server für KI-Agenten (DE)](https://www.hook0.com/de/mcp-server-fuer-webhooks): German page, MCP-Server und Webhooks für KI-Agenten.
- [Plateforme de webhooks (FR)](https://www.hook0.com/fr/plateforme-webhook): Page française, hébergement UE et conformité RGPD.
- [Serveur MCP webhook pour agents IA (FR)](https://www.hook0.com/fr/serveur-mcp-webhook): Page française, serveur MCP et webhooks pour agents IA.
- [Webhook gratuit (FR)](https://www.hook0.com/fr/webhook-gratuit): Page française, les trois options gratuites (testeur sans compte, serveur SSPL-1.0 auto-hébergé, offre cloud gratuite).
- [Kostenlose Webhooks (DE)](https://www.hook0.com/de/webhook-kostenlos): German page, die drei kostenlosen Wege (Tester ohne Konto, selbst gehosteter SSPL-1.0-Server, kostenloser Cloud-Tarif).

## Comparisons
- [Hook0 vs Svix](https://www.hook0.com/hook0-vs-svix)
- [Hook0 vs Hookdeck](https://www.hook0.com/hook0-vs-hookdeck)
- [Hook0 vs Convoy](https://www.hook0.com/hook0-vs-convoy)
- [Hook0 vs Requeue](https://www.hook0.com/hook0-vs-requeue): Requeue is an inbound dead-letter inbox that catches webhooks you receive and failed cron/worker jobs to replay into your app. Hook0 is outbound webhooks-as-a-service: it sends webhooks to your users with per-attempt logs, free retries, HMAC, and replay from the dashboard or API. Opposite directions on the same reliability problem; Hook0 does not offer a production inbound dead-letter today.
- [Hook0 vs ngrok](https://www.hook0.com/hook0-vs-ngrok): ngrok is a general-purpose ingress for any local HTTP, TCP or TLS service. The Hook0 CLI ships hook0 listen, a WebSocket tunnel that forwards webhooks to localhost with no account, backed by an open-source relay (SSPL-1.0) you can self-host with --relay-url. They overlap only on receiving webhooks during development.
- [Hook0 vs Webhook Relay](https://www.hook0.com/hook0-vs-webhook-relay): Webhook Relay is an inbound gateway that receives third-party webhooks and forwards them to localhost, private servers, Kubernetes or cloud queues. Hook0 is outbound webhooks-as-a-service that sends your events to your users, EU-hosted by default and open source. Opposite directions; they meet only on local development.
- [Build vs Buy Webhooks](https://www.hook0.com/build-vs-buy-webhooks)
- [Hookdeck Alternatives](https://www.hook0.com/hookdeck-alternatives): Hookdeck runs inbound gateway and outbound delivery as two separate products. Weighs Hook0, Svix, and Convoy for sending and monitoring webhooks.
- [Svix Alternatives](https://www.hook0.com/svix-alternatives): Hook0, Hookdeck, and Convoy measured against Svix on pricing, self-hosting, and source-available licensing.
- [Webhook.site Alternative](https://www.hook0.com/migrate-from-webhook-site): Move from webhook.site debugging to production delivery. HMAC signatures, configurable retries, delivery logs, and a subscriber portal.
- [Webhook Cost Comparison](https://www.hook0.com/webhook-cost-comparison): Public prices for Hook0, Svix, Hookdeck Outpost, and Convoy from 100k to 10M events per month, billing models side by side.
- [Hook0 Alternatives](https://www.hook0.com/hook0-alternatives): Honest comparison of Hook0 against other webhook platforms.

## Learn
- [How Webhooks Work](https://www.hook0.com/how-webhooks-work): Rebuilds GitLab's push webhook from scratch (the HTTP POST, the X-Gitlab-Event and X-Gitlab-Token headers, shared-token auth versus HMAC-SHA256 signatures), then shows how GitLab.com would run multitenant delivery on Hook0: one event published with labels fans out to project, group, and instance subscribers by label containment, with retries, signatures, and delivery logs per subscriber.

## Docs
- [Documentation](https://documentation.hook0.com/): Full reference, guides, API, deploy.
- [Documentation index for assistants](https://documentation.hook0.com/llms.txt): Every published documentation page, with a one-line summary each.
- [Getting Started](https://documentation.hook0.com/tutorials/getting-started): 30-minute setup, free tier.
- [CLI](https://documentation.hook0.com/reference/cli): Command-line client. Send and replay events, manage subscriptions and event types, and receive webhooks on localhost through a built-in tunnel, no exposed ports.
- [MCP Server](https://documentation.hook0.com/reference/mcp): 17 tools (9 read, 8 write) that let Claude, Cursor, or Windsurf create subscriptions, emit events, and replay failed deliveries against a Hook0 account. Runs locally over stdio, or as an SSE service.

## Optional
- [Built to Last](https://www.hook0.com/built-to-last): Why Hook0 is built as durable, open-source webhook infrastructure.
- [Open-Source Friends](https://www.hook0.com/oss-friends): Other open-source projects Hook0 supports.
- [GitHub](https://github.com/hook0/hook0): Source code (SSPL-1.0).
- [GitLab](https://gitlab.com/hook0/hook0): Mirror.
- [Playground](https://play.hook0.com): Free webhook testing tool, no signup.