Kalshi API vs Polymarket API
Plans, limits and coverage side by side. No winner is declared where data is missing.
Comparison
| Field | Kalshi API | Polymarket API |
|---|---|---|
| Free tier | unknown | unknown |
| Lowest paid $/mo | unknown | unknown |
| Plans | unknown | unknown |
| Rate limits | Token buckets per tier (Basic, Advanced, Premier, higher); default cost 10 tokens/request; separate Read and Write budgets. Example: Premier Write refills 1,200 tokens/s (≈120 orders/s), capacity 3,600. Balance endpoint 1/s (Basic/Advanced) or 5/s (higher). Basic/Advanced per-second budgets not captured. | IP-based (Cloudflare), sliding windows: general 15,000 req/10s; Gamma API 4,000/10s; Data API v1 1,000/10s; CLOB 9,000/10s (/book 1,500/10s); POST /order burst 5,000/10s, sustained 120,000/10min |
| History | unknown | unknown |
| Assets | prediction-markets | prediction-markets |
| Real-time | unknown | unknown |
| WebSocket | yes (user fills websocket channel referenced) | yes (Market/User/Sports channels) |
Facts only from official pages. — means not stated there.
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