Performance

Caching

JustKalm intelligently caches valuations to improve performance and reduce costs. Understand our caching strategy to optimize your integration.

<50ms

Cache hit latency

1 hour

Default TTL

Global

Edge distribution

Cache Headers

Every API response includes cache headers that indicate the caching status and remaining validity.

Header	Description
X-JustKalm-Cache	HIT or MISS
X-JustKalm-Cache-Age	Seconds since cached
X-JustKalm-Cache-TTL	Seconds until expiry
ETag	Unique content identifier
Cache-Control	Standard HTTP cache directives

Response Headers Example

HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: public, max-age=3600, stale-while-revalidate=86400
ETag: "abc123xyz"
X-JustKalm-Cache: HIT
X-JustKalm-Cache-Age: 1823
X-JustKalm-Cache-TTL: 1777

{
  "price_min": 150,
  "price_max": 250,
  ...
}

TTL Policies

Cache duration varies based on item type and market volatility:

Stable Items

24h

Everyday clothing, accessories. Low price volatility.

Standard Items

Designer goods, popular brands. Moderate volatility.

Volatile Items

15m

Limited editions, hyped releases. High market activity.

Conditional Requests

Use ETags for conditional requests to minimize bandwidth and costs. A 304 response means your cached data is still valid.

304 Not Modified

No body returned, use your local cache

Reduced API usage

304 responses don't count against quotas

Lower latency

Minimal response size means faster transfers

Conditional Request

// Use ETag for conditional requests
const response = await fetch('https://api.justkalm.com/v2/valuate', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer jk_live_xxx',
    'If-None-Match': '"abc123xyz"',  // ETag from previous response
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ url: 'https://example.com/item' })
});

if (response.status === 304) {
  // Cached data is still valid, use local cache
  console.log('Using cached valuation');
} else {
  // New data available
  const valuation = await response.json();
}

Cache Invalidation

Force Fresh Data

// Force cache refresh
const response = await fetch('https://api.justkalm.com/v2/valuate', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer jk_live_xxx',
    'Cache-Control': 'no-cache',  // Bypass cache
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({ url: 'https://example.com/item' })
});

// Or use the refresh parameter
const fresh = await client.valuate({
  url: 'https://example.com/item',
  refresh: true,  // Force fresh valuation
});

When to Bypass Cache

Real-time pricing needed

For checkout flows where accuracy is critical

Known product changes

When you know the listing was updated

Use sparingly

Fresh requests cost more and are slower

Global Edge Cache

Infrastructure

Edge Locations50+ worldwide
Cache ProviderCloudflare Enterprise
Origin ShieldUS-East, EU-West, AP-Tokyo
Avg Cache Hit Rate94%

Cache Layers

Edge Cache

Closest to user, 50+ locations

Regional Cache

Origin shields, 3 regions

Application Cache

Redis cluster, computed results

Need Custom Caching?

Enterprise plans include custom TTL configuration and cache purge APIs.

Enterprise Pricing Rate Limits