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Jack Loh
Jack Loh

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9 paid x402 agent endpoints on Base USDC — wallet, Polymarket, token info

9 paid x402 agent endpoints on Base USDC

Building AI agents that earn USDC per call. Stack is live on Base L2.

What works

  • wallet-scan — POST {address:"0x..."} → ETH + USDC balance, single RPC hop
  • polymarket-odds — Live prediction market odds by slug
  • polymarket-list — 10 hottest markets right now
  • token-info — Token metadata + price (Blockscout + DefiLlama)
  • contract-risk — Heuristic risk flags for any Base contract
  • swap-quote — Indicative swap rate
  • gas — Current Base gas price
  • address-validate — Checksum + EIP-55
  • echo — Round-trip debug

Pricing

  • $0.005–$0.01 USDC per call
  • 500 free trials for Founding Agents
  • Pay per call via x402 (HTTP 402, USDC on Base, gasless via EIP-3009)

Try it

curl -X POST https://api.kachangsia.com/api \
  -H "Content-Type: application/json" \
  -d '{"action":"wallet-scan","address":"0xd8da6bf26964af9d7eed9e03e53415d37aa96045"}'
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Returns:

{"address":"0xd8da6bf26964af9d7eed9e03e53415d37aa96045","chain":"base",
 "native_eth":3.12759802,"usdc":30.06,"scanned_at":1785290965.04}
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Stack

  • FastAPI on Python 3.11
  • viem for wallet signing (x402 EIP-3009 transferWithAuthorization)
  • Base RPC fallback chain (1rpc → publicnode → drpc)
  • Cloudflare named tunnel at api.kachangsia.com
  • Live on minia2a.uk marketplace (22 services)

For agent builders

If your agent needs wallet balance, token metadata, or Polymarket odds as a primitive — call these endpoints instead of running your own RPC. Pay per call in USDC, no signup.

Open for hire-agent contracts via Virtuals ACP: agent ID 0x13B5B41DD68e950e021DBA99dF65bF849d84cDcF.

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