- Updated: March 19, 2026
- 3 min read
Step‑by‑Step Performance Tuning for the OpenClaw Rating API on Cloudflare Workers
Step‑by‑Step Performance Tuning for the OpenClaw Rating API on Cloudflare Workers
Optimising the OpenClaw Rating API on Cloudflare Workers can dramatically improve response times, reduce costs, and increase reliability. This guide walks you through the most effective techniques, from worker configuration to request batching.
1. Worker Configuration
- Set appropriate CPU time limits: Cloudflare Workers offer up to 50 ms of CPU time per request on the free tier and 100 ms on paid plans. Use
setTimeoutsparingly and avoid heavy synchronous loops. - Enable WebAssembly (Wasm) for computationally intensive rating calculations. Compile the rating algorithm to Wasm and call it from the worker to gain near‑native performance.
- Use environment variables for API keys and configuration values. This keeps secrets out of the code and allows you to change settings without redeploying.
2. Caching Strategies
Cache both static assets and API responses to minimise origin calls.
- Edge Cache with
Cache API: Store rating responses for a short TTL (e.g., 30 seconds) when the data is unlikely to change per request.const cache = caches.default; await cache.put(request, new Response(json, { headers: { "Cache-Control": "public, max-age=30" } })); - Cache‑Control Headers: Add
Cache‑Control: public, max-age=30, stale‑while‑revalidate=60to allow stale content while a fresh version is fetched. - Cache‑First vs Network‑First: Use a cache‑first strategy for read‑only rating look‑ups and a network‑first approach when you need the latest data after a rating update.
3. Memory Limits
Workers have a 128 MB memory limit. To stay within this bound:
- Avoid loading large JSON payloads into memory; stream the response when possible.
- Use
JSON.parseonly on the required subset of data. - Release references to large objects as soon as they are no longer needed, allowing the runtime to garbage‑collect them.
4. Request Batching
When the API receives multiple rating queries in quick succession, batch them into a single origin request.
let batch = [];
addEventListener('fetch', event => {
batch.push(event.request);
if (batch.length === 1) {
setTimeout(processBatch, 50); // wait 50 ms for more requests
}
});
async function processBatch() {
const requests = batch.splice(0, batch.length);
const ids = requests.map(r => new URL(r.url).searchParams.get('id')).join(',');
const response = await fetch(`https://origin.example.com/ratings?ids=${ids}`);
const data = await response.json();
// split response back to individual requests
requests.forEach((req, i) => {
const result = data[i];
req.respondWith(new Response(JSON.stringify(result), { headers: { 'Content-Type': 'application/json' } }));
});
}
5. Cost‑Optimization
- Reduce CPU time by off‑loading heavy calculations to Wasm or external services.
- Minimise data transfer with gzip compression and by sending only the fields required by the client.
- Leverage free tier limits: Keep each request under the free‑tier CPU and bandwidth quotas. Use the caching strategies above to lower the number of origin hits.
Conclusion
By configuring workers correctly, implementing smart caching, staying within memory limits, batching requests, and monitoring cost‑driving factors, you can deliver a fast, reliable, and economical OpenClaw Rating API.
For a deeper dive into hosting OpenClaw on UBOS, see the guide Host OpenClaw on UBOS.