# Polymarket Best Markets to Watch

> Polymarket Best Markets to Watch is a paid API for AI agents from x402.botsmith.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Returns the top Polymarket prediction markets ranked by a composite watch-score based on volume, liquidity, competitiveness, momentum, and time-to-resolution, with optional tag filtering.

## Facts

- Endpoint: GET https://x402.botsmith.dev/polymarket/markets
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polymarket-best-markets-to-watch-923e9b70
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8dSYQGwhyi1YXA218YYw3

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-best-markets-to-watch-923e9b70
```

Example prompt: Show me the top 5 crypto prediction markets on Polymarket right now, ranked by the composite watch-score, with their implied probabilities and a quick reason why each is worth watching.

## When to prefer this

Use this endpoint when you want a curated, ranked discovery view of Polymarket markets — especially when you don't know which specific market to look at and want algorithmically scored recommendations. Prefer over the sibling Market Intel endpoint when you need broad discovery rather than deep analysis of one market.

## Known failure modes

- Invalid tag slug returns empty markets array or 404
- Limit outside 1-25 range causes validation error
- Sort value not in enum causes 400 bad request
- Polymarket data temporarily unavailable causes 503 or stale data
- Payment failure (x402) blocks request before reaching endpoint

## How this service works

Best Markets to Watch ($0.02/call): The best Polymarket prediction markets to watch right now, ranked by a composite watch-score (24h volume, liquidity, competitiveness, momentum, time-to-resolution). Filter by tag. Returns implied probability, volume, liquidity, spread and a plain-English reason for each. Live data, no account needed.

## Output

A ranked list of Polymarket prediction markets, each including the question, URL, implied probability (yes price 0-1), 24h volume, liquidity, bid-ask spread, 24h price change, days until resolution, a 0-100 composite watch-score, and a plain-English sentence explaining why the market ranks. The response includes the count and the sort method used.

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "limit",
      "sort"
     ],
     "properties": {
      "tag": {
       "type": "string",
       "description": "Filter by a Polymarket tag slug, e.g. 'politics', 'crypto', 'sports'"
      },
      "sort": {
       "enum": [
        "watch",
        "volume",
        "liquidity"
       ],
       "type": "string",
       "default": "watch",
       "description": "Ranking: 'watch' = composite watch-score (default), or raw volume/liquidity"
      },
      "limit": {
       "type": "integer",
       "default": 10,
       "maximum": 25,
       "minimum": 1,
       "description": "How many markets to return"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "count",
      "sort",
      "markets"
     ],
     "properties": {
      "sort": {
       "type": "string"
      },
      "count": {
       "type": "integer",
       "maximum": 9007199254740991,
       "minimum": -9007199254740991
      },
      "markets": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "question",
         "slug",
         "url",
         "yesPrice",
         "volume24hr",
         "liquidity",
         "spread",
         "priceChange24h",
         "daysToResolution",
         "watchScore",
         "why"
        ],
        "properties": {
         "url": {
          "type": "string"
         },
         "why": {
          "type": "string",
          "description": "Short human-readable reason this market ranks"
         },
         "slug": {
          "type": "string"
         },
         "spread": {
          "anyOf": [
           {
            "type": "number"
           },
           {
            "type": "null"
           }
          ]
         },
         "question": {
          "type": "string"
         },
         "yesPrice": {
          "anyOf": [
     
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-best-markets-to-watch-923e9b70/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.botsmith.dev](https://www.zero.xyz/host/x402.botsmith.dev/llms.txt)