# Polymarket Filter API

> Polymarket Filter API is a paid API for AI agents from x402.agentutility.ai, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Filters Polymarket prediction markets by category, query text, tag, status, liquidity, and sort order to return matching market listings

## Facts

- Endpoint: POST https://x402.agentutility.ai/polymarket-filter
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polymarket-filter-api-88fb5f89
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RH-7RFhtPgNK5tVOEYkVv

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability polymarket-filter-api-88fb5f89 -d '<json body>'
```

Example prompt: Can you find me open Polymarket prediction markets about the 2024 US presidential election, sorted by highest liquidity?

## When to prefer this

Choose this endpoint when an agent needs to discover or browse Polymarket prediction markets programmatically by category, tag, or keyword — especially useful for research, monitoring, or surfacing relevant markets to users. Prefer this over scraping Polymarket directly because it handles filtering, sorting, and normalization in one call and is designed for autonomous agent consumption with USDC micropayment settlement.

## Known failure modes

- Invalid or unsupported category value returns empty results or error
- Overly restrictive liquidity filter returns zero markets
- Payment not processed — x402 USDC payment failure prevents response
- Malformed query string causes 400 error
- Polymarket upstream data unavailable causes 503 or stale results

## How this service works

Polymarket filter API / filter prediction markets by category, query, tag, status, liquidity, and sort order. Market-data filter only; it does not filter wallets by trade history.

## Output

Returns a filtered list of Polymarket prediction market objects including market names, current probabilities, liquidity values, status (open/closed/resolved), tags, and category metadata matching the specified filter criteria.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 25,
  "markets": [
   {
    "question": "Will team X win?",
    "outcome_prices": [
     0.51,
     0.49
    ]
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-filter-api-88fb5f89/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentutility.ai](https://www.zero.xyz/host/x402.agentutility.ai/llms.txt)