Briefing

API Resilience Tests: Rate Limiting, DoS, and Multilingual Support

security
by xiaoqiangapi · Cloudflare

Verify your API returns 429 on high‑frequency requests and handles long inputs and multilingual data without crashing.

What to do now

Patch your API to return a 429 status on excessive request rates; add explicit rate‑limit handling and monitor for DoS and multilingual input resilience.

Summary

The author performed three resilience tests on a custom API: 1) high‑frequency requests to check for rate limiting – the platform did not return 429 but Cloudflare protected against malicious traffic; 2) an extra‑long input (thousands of repeated characters) – the API returned 200 OK and did not crash; 3) special characters and multilingual input (Korean, emojis) – the API returned 200 OK and handled the content correctly. Two tests passed fully, one half‑passed due to lack of explicit 429 handling. The author plans to test HTTPS/TLS next and will publish a full 10‑test score sheet.

Key changes

  • High‑frequency requests did not trigger 429; Cloudflare mitigated malicious traffic
  • Extra‑long input of thousands of characters returned 200 OK, no crash
  • Special characters and Korean text returned 200 OK, no garbled output
  • Two tests passed fully, one half‑passed due to missing explicit rate‑limit response
  • Plan to test HTTPS/TLS next

Affects

internal

Customer impact

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