Perpetual Funding Rates API

Live perpetual funding rates across Binance, Bybit, OKX -- open interest and predicted next rate included. 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)

curl "https://funding-rates.api.klymax402.com/api/rates?symbol=BTC"
# -> 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

Use this when you need current perpetual futures funding rates for a single asset across exchanges. Returns rates comparison in JSON.

Parameters

Returns

• symbol -- trading pair symbol
• rates -- array per exchange with exchange name, current funding rate, annualized rate
• openInterest -- open interest in USD per exchange
• predictedNextRate -- predicted next funding rate per exchange
• nextFundingTime -- timestamp of next funding event

Example response:

{"symbol":"ETH","rates":[{"exchange":"Binance","rate":0.0082,"annualized":8.98},{"exchange":"Bybit","rate":0.0075,"annualized":8.21},{"exchange":"OKX","rate":0.0091,"annualized":9.97}],"openInterest":{"Binance":2150000000},"nextFundingTime":"2026-04-13T16:00:00Z"}

When to use: monitoring funding costs on your perpetual positions and timing entries. Essential for basis trading and funding cost management.

Not for: spot prices (use dex_get_swap_quote), yields (use defi_find_best_yields).

Example agent prompts

• "Current perpetual futures funding rates for a single asset across exchanges"

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