# Polymarket Market Filter API

> Polymarket Market 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 and screens Polymarket prediction markets by query, category, tag, liquidity, open/closed status, and sort order to return matching market data.

## Facts

- Endpoint: POST https://x402.agentutility.ai/market-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-market-filter-api-19946365
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pgqmHYhbYaFcwJj8BsONL

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-market-filter-api-19946365 -d '<json body>'
```

Example prompt: Search Polymarket for open prediction markets about the 2024 US election, filter to those with at least $10,000 in liquidity, and sort by volume descending.

## When to prefer this

Choose this endpoint when you need to programmatically discover, screen, or research Polymarket prediction markets by any combination of keyword, category, tag, liquidity, or status without needing wallet integration or trade execution. It is a pure data/read endpoint ideal for market research agents, information dashboards, or decision-support workflows that need structured Polymarket data on demand.

## Known failure modes

- No markets match the specified filters — returns empty list
- Invalid category or tag values — may return error or empty results
- Polymarket API downstream unavailability — endpoint returns error
- Payment not processed — request rejected due to unpaid x402 microtransaction
- Query string too ambiguous — may return broad or irrelevant market set

## How this service works

Polymarket filter API / prediction market filter / market screener. Demand-matching route for filtering Polymarket markets by query, category, tag, liquidity, open/closed status, and sort order. Data-only public market research endpoint; no wallet filtering or trade execution.

## Output

A filtered list of Polymarket prediction markets matching the specified criteria, including market names, categories, tags, liquidity values, open/closed status, and sort-ordered results.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "properties": {
      "tag": {
       "type": "string",
       "description": "Polymarket tag slug filter, passed through to upstream."
      },
      "limit": {
       "type": "number",
       "description": "1-100. Default 20."
      },
      "order": {
       "enum": [
        "volume24hr",
        "liquidity",
        "endDate",
        "startDate"
       ],
       "type": "string",
       "description": "Sort field: 'volume24hr', 'liquidity', 'endDate', or 'startDate'. Omit for default gamma-api order."
      },
      "query": {
       "type": "string",
       "description": "Free-text filter applied to question, description, and slug."
      },
      "active": {
       "type": "boolean",
       "description": "Default true. Pass false to include inactive markets."
      },
      "closed": {
       "type": "boolean",
       "description": "Default false. Pass true to include closed markets."
      },
      "offset": {
       "type": "number",
       "description": "Pagination offset."
      },
      "category": {
       "type": "string",
       "description": "Filter by Polymarket category substring, e.g. 'Sports', 'Crypto', 'Politics'."
      },
      "ascending": {
       "type": "boolean",
       "description": "Sort direction when order is set. Default false (descending)."
      },
      "min_liquidity": {
       "type": "number",
       "description": "Minimum liquidity in USD."
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "count": {
       "type": "integer"
      },
      "markets": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "question": {
          "type": "string"
         },
         "liquidity_usd": {
          "type": "integer"
         }
   
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 20,
  "markets": [
   {
    "question": "Will BTC hit a new all-time high?",
    "liquidity_usd": 12000
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-market-filter-api-19946365/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)