predict.search

Cross-venue prediction-market keyword search across Polymarket, Kalshi, and Limitless Exchange in one call. Pass q (required); filter by status (open/closed) and cap per-venue with limit. Each hit is tagged with its venue and returns the question, live YES/NO price (0-1 implied probability), USD volume, close date, and the venue URL — for finding the same real-world question wherever it trades. Read-only, keyless.

price
$0.0048 USDC per call
method
GET/api/predict/search
payment
x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)
auth
None. Sign the payment, retry with PAYMENT-SIGNATURE.

Overview

The search API is a pay-per-call predict endpoint built for AI agents and autonomous software. Cross-venue prediction-market keyword search across Polymarket, Kalshi, and Limitless Exchange in one call.

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 search 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.

Use cases

Parameters

NameTypeDescription
qrequiredstringKeyword(s) to search market questions for.
min 2 chars · max 120 chars
limitintegerMax results per venue (default 15).
min 1 · max 50
statusstringFilter by market status.
one of: open | closed

Code samples

cURLbash
# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/predict/search?q=xx&limit=1&status=open'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/predict/search?q=xx&limit=1&status=open' \
  -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/search?q=xx&limit=1&status=open'
TypeScript / Node — @2sio/sdktypescript
import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.predict.search({
  "q": "xx",
  "limit": 1,
  "status": "open"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)
Python — 2siopython
import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.predict.search(q="xx", limit=1, status="open")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)
MCP — Claude Desktop / AgentKit / any MCP hostjson
// 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.search",
    "arguments": {
      "q": "xx",
      "limit": 1,
      "status": "open"
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
metaobject
Example response datajson
{
  "ok": true,
  "items": [
    {
      "venue": "polymarket",
      "title": "example",
      "slug": "example",
      "yesPrice": 1,
      "noPrice": 1,
      "volumeUsd": 1,
      "closed": false,
      "endDate": "example",
      "ticker": "example",
      "conditionId": "example",
      "url": "example"
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  },
  "meta": {
    "q": "example",
    "byVenue": {}
  }
}

FAQ

Do I need an API key to use the search API?
No. predict.search is x402-native — there is no signup and no API key. Your client makes the call, receives a 402 with payment requirements, signs a USDC payment, and retries. Funds come from a wallet you control.
How much does the search API cost?
$0.0048 USDC per call, charged per request. There are no monthly fees, seats, or minimums — you pay only for the calls you make.
Can I try the search API for free first?
Yes. Add ?trial=1 (or the header X-2s-Trial: 1) to get a free real call per endpoint per hour, so you can verify the response shape before wiring payment.
Which networks and tokens are supported?
USDC on Base (via EIP-3009 transferWithAuthorization) or Solana (SPL transfer), using the open x402 payment protocol.
How do I call predict.search from an AI agent or MCP host?
Use @2sio/sdk (TypeScript), 2sio (Python), or the @2sio/mcp server for any MCP host — each handles the probe → sign → retry loop for you. See the code samples on this page.

Discovery

Related: search api · predict search api · search api for ai agents · x402 predict api · search api no api key · pay per call search api · predict api