5-Minute Quickstart

Answer "Is this a good deal?" in 5 minutes

One API call. Three answers: price fairness, resale prediction, authenticity risk. Perfect for resale marketplaces and AI shopping assistants.

< 5 min

Time to First Value

98.6%

Accuracy (±5%)

< 200ms

API Response

Choose your language

Select your preferred SDK or use the REST API directly

Free tier includes 1,000 API calls/month

No credit card required to get started

Get API Key

export JUSTKALM_API_KEY="jk_live_..."

Streaming for Real-Time Copilots

Recommended

For AI shopping assistants and real-time UIs, stream results as they arrive. Show price fairness, then resale prediction, then authenticity—all within 200ms.

// Stream for real-time UI in shopping assistants
const stream = await client.valueDecision({
  url: 'https://example.com/listing/nike-dunks-sz10',
  stream: true
});

for await (const chunk of stream) {
  // Show each insight as it arrives
  console.log(chunk.type, chunk.data);
  // 'price_fairness' { fairPriceRange: [170, 195], ... }
  // 'resale_prediction' { estimatedValue12m: 145, ... }
  // 'authenticity_risk' { score: 92, ... }
  // 'verdict' { verdict: 'FAIR_DEAL', confidence: 0.87 }
}