zendesk-webhooks

zendesk-webhooks is a skill for Claude Code, Codex from hookdeck/webhook-skills. It costs 63 tokens per session (1,556 once invoked), scanned A, a copy of adyen-webhooks, MIT.

A guide for receiving Zendesk webhooks, which are messages Zendesk sends to your application when support events occur, and checking that those messages are genuine.

In plain words
What is it for?
Use it when building or debugging handlers for ticket, user, organization, comment, trigger, and automation events.
Why use it?
It explains the exact signature checks needed to reject forged or incorrectly processed requests.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/hookdeck/webhook-skills/zendesk-webhooks
Any agent
npx skills add hookdeck/webhook-skills --skill zendesk-webhooks
Clone the repo
git clone --depth 1 https://github.com/hookdeck/webhook-skills

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin zendesk-webhooks/plugin install zendesk-webhooks after adding the marketplace above.

Wrote 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.

agentmods badge for zendesk-webhooks

README.md
[![agentmods](https://agentmods.dev/badge/skills/hookdeck/webhook-skills/zendesk-webhooks.svg)](https://agentmods.dev/skills/hookdeck/webhook-skills/zendesk-webhooks)
Your own site
<a href="https://agentmods.dev/skills/hookdeck/webhook-skills/zendesk-webhooks"><img src="https://agentmods.dev/badge/skills/hookdeck/webhook-skills/zendesk-webhooks.svg" alt="Measured on agentmods" height="20"></a>
Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,556 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 77% copy Near-identical to another mod in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00063 $0.01556
Opus 5 $0.00032 $0.00778
Sonnet 5 $0.00013 $0.00311
Haiku 4.5 $0.00006 $0.00156

Measured yesterday against content hash 70b8d25b6130, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

zendesk-webhooks 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 yesterday.

The scan reads SKILL.md. This mod also ships 7 executable files (examples/express/src/index.js, examples/express/test/webhook.test.js, examples/fastapi/main.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Origin

This is a copy

77% identical to adyen-webhooks — 171 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/zendesk-webhooks/SKILL.md · 136 lines

How it starts

The opening of the file, as written. The whole thing — 136 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Zendesk Webhooks

When to Use This Skill

  • Setting up Zendesk webhook handlers
  • Debugging Zendesk signature verification failures
  • Understanding Zendesk event subscriptions vs. trigger/automation webhooks
  • Handling ticket, user, or organization events like zen:event-type:ticket.created

Verification (core)

Zendesk signs every webhook with HMAC-SHA256, base64-encoded. The signed message is the timestamp concatenated directly with the raw request body (no separator): base64(HMAC_SHA256(timestamp + body)). Zendesk does not follow the Standard Webhooks spec and ships no official verification SDK, so verify manually with the language's crypto primitives.

Two headers are sent:

  • X-Zendesk-Webhook-Signature — the base64 signature
  • X-Zendesk-Webhook-Signature-Timestamp — the timestamp that is prepended to the body

Use the raw body — don't JSON.parse first. Some requests (e.g. GET/DELETE methods on a webhook) have no body, so account for an empty body.

const crypto = require('crypto');

function verifyZendeskWebhook(rawBody, signature, timestamp, secret) {
  const hmac = crypto.createHmac('sha256', secret);
  hmac.update(timestamp);        // timestamp first...
  hmac.update(rawBody);          // ...then the raw body (Buffer), no separator
  const expected = hmac.digest('base64');
  try {
    return crypto.timingSafeEqual(Buffer.from(expected), Buffer.from(signature));
  } catch {
    return false;                // length mismatch = invalid
  }
}

The signing secret comes from GET /api/v2/webhooks/{webhook_id}/signing_secret (or Admin Center → the webhook → Reveal secret). Test webhooks (before creation) always use the static secret dGhpc19zZWNyZXRfaXNfZm9yX3Rlc3Rpbmdfb25seQ==.

For complete handlers with route wiring, event dispatch, and tests, see:

Two Webhook Models

Read the full file on GitHub · 136 lines

Changes

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.

  1. yesterday First seen · 136 lines · 63 tokens per session scan A 70b8d25b6130

Subscribe to this mod's changes

zendesk-webhooks is a skill published in the GitHub repository hookdeck/webhook-skills (84 stars, last pushed yesterday), licensed MIT. It adds 63 tokens to every session and 1,556 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 77% identical to adyen-webhooks, differing in 171 lines, and is treated as a copy.

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