Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add finsilabs/awesome-ecommerce-skills --skill webhook-architecturegit clone --depth 1 https://github.com/finsilabs/awesome-ecommerce-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/finsilabs/awesome-ecommerce-skills/webhook-architecture)<a href="https://agentmods.dev/skills/finsilabs/awesome-ecommerce-skills/webhook-architecture"><img src="https://agentmods.dev/badge/skills/finsilabs/awesome-ecommerce-skills/webhook-architecture/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/finsilabs/awesome-ecommerce-skills/webhook-architecture"><img src="https://agentmods.dev/badge/skills/finsilabs/awesome-ecommerce-skills/webhook-architecture.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00030 | $0.02732 |
| Opus 5 | $0.00015 | $0.01366 |
| Sonnet 5 | $0.00006 | $0.00546 |
| Haiku 4.5 | $0.00003 | $0.00273 |
Grade A, and why
webhook-architecture scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 240 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Webhook Architecture
Overview
Webhooks are HTTP callbacks used by commerce platforms (Shopify, Stripe) to push real-time event notifications to your application. Reliable webhook infrastructure requires: HMAC signature verification to prevent spoofed events, idempotent handlers that tolerate duplicate delivery, exponential backoff retry logic, and a dead-letter queue for events that exhaust all retries. This skill covers building a reliable webhook receiver and, for custom platforms, a webhook sender using the Outbox Pattern.
When to Use This Skill
- When receiving webhooks from Shopify, Stripe, Square, or other platforms
- When debugging missed events or duplicate processing caused by webhook delivery issues
- When building a commerce platform or app that needs to notify external systems of events
- When designing event-driven architecture between commerce microservices
- When setting up webhook fanout (single event delivered to multiple consumers)
Core Instructions
Step 1: Determine your platform and what webhooks you need to handle
| Platform | Where Webhooks Are Configured | Most Important Topics to Subscribe |
|---|---|---|
| Shopify | Settings → Notifications → Webhooks (or via Admin API) | orders/create, orders/paid, orders/cancelled, inventory_levels/update, refunds/create |
| WooCommerce | Install WP Webhooks plugin (free, wordpress.org) or use WooCommerce's built-in webhooks under WooCommerce → Settings → Advanced → Webhooks | Order status changes (processing, completed, refunded), stock updates |
| BigCommerce | Advanced Settings → Legacy API Settings → Webhooks or via API | store/order/statusUpdated, store/product/inventory/updated, store/cart/abandoned |
| Custom / Headless | Build your own webhook system | Use the Outbox Pattern for sending; HMAC verification + idempotency for receiving; see implementation below |
Step 2: Platform-specific webhook setup
What ships with it
7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- evals/outbox-pattern-sender-with-retry-and-dlq/criteria.json 3.6 KB
- evals/outbox-pattern-sender-with-retry-and-dlq/task.md 2.0 KB
- evals/secure-idempotent-webhook-receiver/criteria.json 2.8 KB
- evals/secure-idempotent-webhook-receiver/task.md 1.7 KB
- evals/webhook-subscription-management-api/criteria.json 2.8 KB
- evals/webhook-subscription-management-api/task.md 1.7 KB
- tile.json 232 B
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 240 lines · 30 tokens per session scan A e3bb7b31e6e3
webhook-architecture is a skill published in the GitHub repository finsilabs/awesome-ecommerce-skills (52 stars, last pushed 6mo ago), licensed MIT. It adds 30 tokens to every session and 2,732 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
webhook-handler-patterns
Best practices for webhook handlers: verify → parse → handle idempotently. Covers idempotency, error handling, retry logic, framework-specific gotchas (Express, Next.js, FastAPI). Use when implementing any webhook receiver.
api-rate-limit-handler
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distributed-systems
Distributed systems patterns for locking, resilience, idempotency, and rate limiting. Use when implementing distributed locks, circuit breakers, retry policies, idempotency keys, token bucket rate limiters, or fault tolerance patterns.
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error-handling
Use when designing the reaction to a class of failures — typed error taxonomies, retry/backoff/timeout policy, circuit breakers, React/Next error boundaries, and the user-message vs operator-log split. NOT diagnosing one specific crash (that is debug), NOT logs/metrics/traces (that is observability), NOT the wire…
llm-pipeline
Use when wiring several LLM calls into a production flow: typed contracts between steps, a router/gateway so 429s, timeouts and outages fail over instead of taking you down, and cost control via caching, model tiers and abort caps. NOT single-prompt wording (that is prompt-engineering), NOT a model-driven tool loop…