webhook-handler-patterns

Best practices for webhook handlers. Use when implementing the handler sequence (verify first, parse second, handle idempotently), idempotency, error handling, retry logic, or framework-specific issues with Express, Next.js, or FastAPI.

1.12x

Quality

87%

Does it follow best practices?

Impact

89%

1.12x

Average score across 3 eval scenarios

Securityby

Advisory

Suggest reviewing before use

Evaluation results

95%

15%

Add Stripe Webhook Support to an Existing Express API

Express raw body and middleware ordering

Criteria

Without context

With context

Uses express.raw()

100%

Raw middleware before JSON parser

100%

Verify before parse

100%

Parse after verify

100%

4xx on invalid signature

100%

Correct content-type in express.raw

100%

2xx on success

100%

Idempotency check present

100%

Async processing pattern

50%

No express.json() on webhook route

100%

92%

Fix Duplicate Order Fulfillments Caused by Webhook Retries

Idempotent webhook handler with deduplication

Criteria

Without context

With context

Extracts event ID

100%

Checks for prior processing

100%

2xx for duplicate events

83%

100%

Stores event ID after processing

100%

Processed events schema

100%

Race condition handling

100%

83%

Side effects only once

100%

Handler sequence followed

87%

100%

2xx on first success

100%

No duplicate side effects in test

30%

40%

82%

14%

Build a GitHub Webhook Receiver in FastAPI

FastAPI webhook patterns and response codes

Criteria

Without context

With context

Uses request.body()

100%

Dependency injection for verification

100%

Verify before parse

100%

4xx for invalid signature

100%

BackgroundTasks for async processing

100%

Returns 200 quickly

100%

5xx or 503 for server errors

50%

Handler sequence

100%

Idempotency present

Structured logging

25%

No request.json() first

100%

Repository: hookdeck/webhook-skills
Commit: f8a4801

Evaluated: about 1 month ago
Agent: Claude Code
Model: Claude Sonnet 4.6

Table of Contents

Add Stripe Webhook Support to an Existing Express API Fix Duplicate Order Fulfillments Caused by Webhook Retries Build a GitHub Webhook Receiver in FastAPI

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