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 agentmods add skills/curiouslearner/devkit/webhook-testernpx skills add CuriousLearner/devkit --skill webhook-testergit clone --depth 1 https://github.com/CuriousLearner/devkitWhat 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 | $0.00019 | $0.04798 |
| Opus 5 | $0.00010 | $0.02399 |
| Sonnet 5 | $0.00004 | $0.00960 |
| Haiku 4.5 | $0.00002 | $0.00480 |
Grade A, and why
webhook-tester scanned grade A with 1 finding 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 2d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
const response = await fetch(url, { How it starts
The opening of the file, as written. The whole thing — 839 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Webhook Tester Skill
Test webhook integrations locally with tunneling, inspection, and debugging tools.
Instructions
You are a webhook testing expert. When invoked:
-
Local Webhook Testing:
- Set up local webhook receivers
- Expose localhost to internet using tunnels
- Capture and inspect webhook payloads
- Verify webhook signatures
- Test retry mechanisms
-
Debugging Webhooks:
- Inspect request headers and body
- Validate webhook signatures
- Test different payload formats
- Simulate webhook failures
- Log and replay webhooks
-
Integration Testing:
- Test webhook delivery
- Verify idempotency
- Test retry logic
- Validate error handling
- Performance testing
-
Security Validation:
- Verify signature validation
- Test HTTPS requirements
- Validate origin checking
- Test replay attack prevention
Usage Examples
@webhook-tester
@webhook-tester --setup-tunnel
@webhook-tester --inspect
@webhook-tester --verify-signature
@webhook-tester --replay
Tunneling Tools
ngrok (Most Popular)
Basic Setup
# Install ngrok
# Download from https://ngrok.com/download
# Or use package manager
brew install ngrok/ngrok/ngrok # macOS
choco install ngrok # Windows
# Authenticate (get token from ngrok.com)
ngrok config add-authtoken YOUR_TOKEN
# Start tunnel to localhost:3000
ngrok http 3000
# Custom subdomain (requires paid plan)
ngrok http 3000 --subdomain=myapp
# Multiple ports
ngrok http 3000 3001
# Use specific region
ngrok http 3000 --region=us
# Enable inspection UI
ngrok http 3000 --inspect=true
ngrok Configuration File
# ~/.ngrok2/ngrok.yml
version: "2"
authtoken: YOUR_TOKEN
tunnels:
api:
addr: 3000
proto: http
subdomain: myapi
webhooks:
addr: 4000
proto: http
subdomain: webhooks
web:
addr: 8080
proto: http
bind_tls: true
# Start all tunnels
ngrok start --all
# Start specific tunnel
ngrok start api
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.
- 2d ago First seen · 839 lines · 19 tokens per session scan A 52668fdcadc0
webhook-tester is a skill published in the GitHub repository CuriousLearner/devkit (27 stars, last pushed 10mo ago), licensed MIT. It adds 19 tokens to every session and 4,798 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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