Browse Polymarket prediction markets. Filter by active/closed, order by volume/liquidity/endDate, page with limit/offset. Each market returns its question, outcomes + live outcome prices (implied probabilities), CLOB token ids (use with predict.price / predict.orderbook / predict.price-history), USD volume + liquidity, open/close dates, and the Polymarket URL. Read-only mirror of Polymarket's public market list.
/api/predict/marketsPAYMENT-SIGNATURE.The markets API is a pay-per-call predict endpoint built for AI agents and autonomous software. Browse Polymarket prediction markets.
There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in markets data source for an agent tool-use loop, an MCP host, or a backend that needs predict data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
limit | integer | min 1 · max 100 |
offset | integer | min 0 |
active | boolean | |
closed | boolean | |
order | string | one of: volume | liquidity | endDate | startDate |
ascending | boolean | |
tagId | integer |
# 1. Probe with no auth → 402 envelope with PaymentRequirements curl -sS 'https://2s.io/api/predict/markets?limit=1&offset=0&active=false&closed=false&order=volume&ascending=false&tagId=1' # 2. Sign + retry with PAYMENT-SIGNATURE: curl -sS 'https://2s.io/api/predict/markets?limit=1&offset=0&active=false&closed=false&order=volume&ascending=false&tagId=1' \ -H 'PAYMENT-SIGNATURE: <base64-json-payload>' # Or use the canonical runner (handles probe → sign → retry): # EVM_PRIVATE_KEY=0x... node --env-file=.env.local \ # --experimental-strip-types scripts/x402-pay.ts \ # 'https://2s.io/api/predict/markets?limit=1&offset=0&active=false&closed=false&order=volume&ascending=false&tagId=1'
import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.predict.markets({
"limit": 1,
"offset": 0,
"active": false,
"closed": false,
"order": "volume",
"ascending": false,
"tagId": 1
})
console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)import os
from twosio import TwoS
client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])
result = client.predict.markets(limit=1, offset=0, active=False, closed=False, order="volume", ascending=False, tagId=1)
print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
// EVM_PRIVATE_KEY funds x402 payments per call.
// claude_desktop_config.json
{
"mcpServers": {
"2sio": {
"command": "npx",
"args": ["-y", "@2sio/mcp"],
"env": { "EVM_PRIVATE_KEY": "0x..." }
}
}
}
// 2. Once the server is running, agents call this tool via standard MCP:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "predict.markets",
"arguments": {
"limit": 1,
"offset": 0,
"active": false,
"closed": false,
"order": "volume",
"ascending": false,
"tagId": 1
}
}
}| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object | |
meta | object |
{
"ok": true,
"items": [
{
"id": "example",
"question": "example",
"slug": "example",
"conditionId": "example",
"outcomes": [
"example"
],
"outcomePrices": [
1
],
"clobTokenIds": [
"example"
],
"volumeUsd": 1,
"liquidityUsd": 1,
"active": false,
"closed": false,
"startDate": "example",
"endDate": "example",
"description": "example",
"url": "example"
}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
},
"meta": {
"count": 1
}
}