Chaos & Fault Injection

Rate-Limit Simulation (HTTP 429)

Test client-side exponential backoff, retry throttles, and user toast notifications when API quotas are exceeded. Simulates sliding-window rate limiters and returns compliant Retry-After and X-RateLimit-* headers.

Interactive Rate-Limit Workbench

Choose a quota preset and send repeated requests to observe rate limiting in action:

Rate-Limited Request (Immediate 429)

Send repeatedly to exhaust remaining calls and observe HTTP 429 response.

GET

response.json

{

// Click "Send" above to execute this request against the live server.

}

Rate-Limit Response Headers Reference

Header	Format	Example	Description
Retry-After	Integer (seconds)	3	Recommended pause duration in seconds before the client should attempt a retry.
X-RateLimit-Limit	Integer	5	The maximum permitted request ceiling within the configured time window.
X-RateLimit-Remaining	Integer	0	The number of remaining permitted calls before rejection occurs.
X-RateLimit-Reset	Unix Timestamp	1759165200	Epoch timestamp in seconds marking when the sliding window resets.

Client-Side Exponential Backoff Recipe

A resilient TypeScript implementation that parses Retry-After and retries automatically:

fetchWithRetry.ts

// Client-side fetch wrapper that honors Retry-After headers

async function fetchWithRetry(url: string, options: RequestInit = {}, maxRetries = 3): Promise<Response> {

let attempt = 0;

while (attempt < maxRetries) {

const response = await fetch(url, options);

if (response.status === 429) {

attempt++;

// Parse standard Retry-After header (in seconds), fallback to exponential backoff

const retryAfterHeader = response.headers.get('Retry-After');

const waitSeconds = retryAfterHeader ? parseInt(retryAfterHeader, 10) : Math.pow(2, attempt);

console.warn(Rate limited (429)! Retrying after ${waitSeconds}s (attempt ${attempt}/${maxRetries})...);

await new Promise((resolve) => setTimeout(resolve, waitSeconds * 1000));

continue;

}

return response;

}

throw new Error('Request failed after maximum rate limit retries.');

}

Need to test intermittent packet drops?

Simulate probabilistic failure rates and randomized network jitter.

View Flaky Network Engine

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Rate-Limit Simulation (HTTP 429)

Interactive Rate-Limit Workbench

Immediate 429

3 calls / 10s window

5 calls / 60s window

Rate-Limited Request (Immediate 429)

Rate-Limit Response Headers Reference

Client-Side Exponential Backoff Recipe

Need to test intermittent packet drops?

Rate-Limit Simulation (HTTP 429)

Interactive Rate-Limit Workbench

Immediate 429

3 calls / 10s window

5 calls / 60s window

Rate-Limited Request (Immediate 429)

Rate-Limit Response Headers Reference

Client-Side Exponential Backoff Recipe

Need to test intermittent packet drops?