Perpetual Funding Rates API

Perpetual funding rates across Binance, Bybit and OKX. Scan every USDT perp ranked by funding in a single call, or query one asset with open interest and predicted next rate. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "funding-rates": {
      "url": "https://funding-rates.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

# Whole market, biggest funding first
curl -X POST "https://funding-rates.api.klymax402.com/api/rates"   -H "Content-Type: application/json" -d '{"sort":"abs","limit":20,"minVenues":2}'
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

perp_get_funding_rates

Two modes on the same route, at the same price.

Market scan -- omit symbol and every USDT perp on Binance and Bybit comes back ranked by funding, so an agent finds an opportunity in one paid call instead of probing symbol by symbol.

Single symbol -- pass symbol and Binance, Bybit and OKX come back side by side for that asset, with open interest, mark price, next funding time and a sentiment read.

Parameters

Returns (scan)

• markets -- ranked list, each with symbol, per-venue fundingRate and annualizedRate
• avgRate / annualizedRate -- mean funding across venues, annualized as rate * 3 * 365
• direction -- short opportunity when funding is positive, long opportunity when negative
• spread / spreadAnnualized -- gap between the cheapest and dearest venue
• longVenue / shortVenue -- where to take each leg of the cross-venue carry

Returns (single symbol)

• rates -- array per exchange with funding rate, annualized rate, next funding time
• summary -- average, min, max, spread, sentiment, total open interest, mark price

Example response (scan):

{"scan":true,"totalMarkets":600,"venues":["Binance","Bybit"],"sort":"abs","markets":[{"symbol":"PEPE","venueCount":2,"venues":{"Binance":{"fundingRate":0.0005,"annualizedRate":54.75},"Bybit":{"fundingRate":0.0003,"annualizedRate":32.85}},"avgRate":0.0004,"annualizedRate":43.8,"direction":"short opportunity (longs pay shorts)","spread":0.0002,"spreadAnnualized":21.9,"longVenue":"Bybit","shortVenue":"Binance"}]}

When to use: finding carry and basis trades, timing perp entries, monitoring funding costs on open positions.

Not for: spot prices (use dex_get_swap_quote), yields (use defi_find_best_yields), Hyperliquid-specific rates (use hyperliquid_get_funding_rates).

Note: market scans cover Binance and Bybit. OKX has no bulk funding-rate endpoint, so it is included only when you query a single symbol.

Example agent prompts

• "Which perps have the most extreme funding right now?"
• "Find the biggest cross-venue funding spread I can carry"
• "What is the funding rate for ETH across Binance, Bybit and OKX?"

Payment

• Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
• Network: Base L2 (eip155:8453)
• Asset: USDC
• Facilitator: Coinbase CDP (primary), PayAI (fallback)
• Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

• Catalog: https://klymax402.com/llms.txt
• Full API reference: https://klymax402.com/llms-full.txt
• Live stats: https://klymax402.com/stats

License

MIT