# HARS-Zero Polymarket Market Brief

> HARS-Zero Polymarket Market Brief is a paid API for AI agents from hars.cryptotavern.xyz, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-18).

Returns a concise AI-generated signal brief summarizing current Polymarket prediction market activity and trends

## Facts

- Endpoint: GET https://hars.cryptotavern.xyz/paid/market-brief?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hars-zero-polymarket-market-brief-e9d39407
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fjiO-Xls6k0vWTq4wTh1E

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 hars-zero-polymarket-market-brief-e9d39407
```

Example prompt: Can you pull the latest HARS-Zero market brief for Polymarket and show me the top 5 signals?

## When to prefer this

Choose this endpoint when you need a quick, pre-processed AI signal brief about current Polymarket prediction market conditions without building your own Polymarket data pipeline. Ideal for agents that need to summarize or act on prediction market intelligence on demand, especially in crypto trading or event-driven automation contexts.

## Known failure modes

- Payment not included or invalid x402 payment header — returns 402 Payment Required
- Polymarket data unavailable or stale — may return empty items array
- Rate limiting if called too frequently
- Network timeout if upstream Polymarket data feed is slow

## How this service works

HARS-Zero Polymarket signal: market-brief

## Output

Returns a structured market brief object containing a count of market items, an array of Polymarket market signal items, a product identifier, and a generated_at timestamp indicating when the brief was produced — essentially a snapshot summary of current Polymarket prediction market signals.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "markets"
 ],
 "properties": {
  "markets": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "slug",
     "question",
     "volatility",
     "spread_bps",
     "volume_24h"
    ],
    "properties": {
     "slug": {
      "type": "string",
      "description": "Market identifier slug"
     },
     "no_price": {
      "type": "number",
      "description": "Current NO probability (0–1)"
     },
     "question": {
      "type": "string",
      "description": "Market question text"
     },
     "yes_price": {
      "type": "number",
      "description": "Current YES probability (0–1)"
     },
     "spread_bps": {
      "type": "number",
      "description": "Bid-ask spread in basis points"
     },
     "updated_at": {
      "type": "string",
      "description": "ISO-8601 timestamp"
     },
     "volatility": {
      "type": "number",
      "description": "Volatility score 0–1"
     },
     "volume_24h": {
      "type": "number",
      "description": "24h volume in USDC"
     },
     "narrative_tags": {
      "type": "array",
      "items": {
       "type": "string"
      }
     }
    }
   },
   "description": "Array of up to 20 market objects"
  },
  "generated_at": {
   "type": "string"
  }
 },
 "description": "Top 20 active Polymarket markets with volatility + spread + volume."
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hars-zero-polymarket-market-brief-e9d39407/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from hars.cryptotavern.xyz](https://www.zero.xyz/host/hars.cryptotavern.xyz/llms.txt)