Polymarket API for AI agent

$0.006 USDC per call on Base · No signup · No API key · x402 v2

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What it does

Polymarket prediction market odds and volume. Live prices, implied probabilities, and 24h volume for Polymarket prediction markets. Feed your agent real crowd wisdom.

Data source: Polymarket

How to call (for AI agents)

No account. No API key. Every endpoint speaks x402 v2:

Call the endpoint → you get 402 Payment Required with the price
Pay $0.006 USDC on Base (eip155:8453)
Retry with the X-PAYMENT header → 200 with JSON

curl "https://inferencehub.taild7e69a.ts.net/polymarket/api/polymarket?limit=5"

Input

Param	Type	Description
`slug`	query param, optional	Market slug filter
`limit`	query param, optional	default 10

Example request & response

Request

GET /polymarket/api/polymarket?limit=5

Response

{
  "markets": [
    {"question": "Will BTC hit $100k by Dec?", "yes_price": 0.62,
     "no_price": 0.38, "volume_24h_usd": 1200000,
     "liquidity_usd": 340000}
  ]
}

Payment

x402 v2 · exact scheme · USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base (eip155:8453).
Facilitators: Coinbase CDP and PayAI (no API key needed for either).

FAQ

What is yes_price?
Price of a Yes share in USDC; equals implied probability (0.62 = 62%).

How fresh?
Updated every ~60 seconds.

Can I trade through this API?
No. Read-only market data.

Do I need an API key?
No. This API uses x402: call the endpoint, receive a 402 Payment Required with the price, pay in USDC on Base, and retry with proof of payment. No signup, no API key, no account.

Which facilitators are supported?
Both Coinbase CDP and PayAI facilitators are supported for x402 v2 exact payments on Base (eip155:8453).

What if my payment is too low?
The facilitator verifies the on-chain amount against the price. If underpaid, you get 402 again; pay the full amount and retry.

More APIs for AI agents

Part of the x402 API Collection — 37 pay-per-call endpoints, $0.0008–$1.50/call. Full catalog: https://inferencehub.taild7e69a.ts.net/.well-known/x402

Trust: every settlement is published in our public receipts log — verifiable on-chain, no wash trading.