api-webhook-signer

Sign and verify HMAC-SHA256 webhooks with optional retry scheduling.

17|45|Updated Jan 23, 2026
One-click install
npx skills add https://github.com/XSpoonAi/spoon-awesome-skill --skill api-webhook-signer
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: api-webhook-signer
Source: https://github.com/XSpoonAi/spoon-awesome-skill/tree/main/ai-productivity/api-webhook-signer
Command: npx skills add https://github.com/XSpoonAi/spoon-awesome-skill --skill api-webhook-signer

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) components.

What problem does it solve?

Signatures for webhook payloads are essential for secure API integrations; this skill provides a reliable HMAC-SHA256 signing and verification workflow with retry scheduling.

Core Features & Use Cases

  • Sign webhooks: Generate HMAC-SHA256 signatures for webhook payloads.
  • Verify webhooks: Validate incoming webhook signatures using constant-time comparison.
  • Retry queue: Create exponential backoff retry schedules for failed webhook deliveries.
  • Usage: Integrates via a simple CLI and JSON-like parameter input for automation.

Quick Start

Run the demo mode to sign a sample payload, verify the signature, and inspect the generated retry queue.

Frequently Asked Questions about api-webhook-signer

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I verify webhook signatures using HMAC-SHA256?▼

Verify webhook signatures by computing HMAC-SHA256 over the payload and comparing it against the incoming signature using constant-time comparison. This prevents timing attacks and ensures secure API integration.

What's the best way to handle failed webhook deliveries with retry logic?▼

Handle failed webhook deliveries by generating a retry queue with exponential backoff. This schedules subsequent attempts at increasing intervals to avoid overwhelming the receiving service during outages.

Can I automate signing and verifying webhooks via a CLI?▼

Automate signing and verifying webhooks via a simple CLI accepting JSON-like parameters. This enables automated workflows for backend systems integrating with external services without manual intervention.

Why do I need constant-time comparison for webhook signature verification?▼

Constant-time comparison for webhook signature verification is needed to prevent timing attacks where attackers exploit response time differences to forge HMAC-SHA256 signatures and bypass security checks.

Does this webhook signer and verifier work for backend systems integrating with external services?▼

This webhook signer and verifier works for backend systems integrating with external services by providing HMAC-SHA256 sign and verify flows for events with optional retry scheduling.