# HARS-Zero Signal API – Breaking Markets

> HARS-Zero Signal API – Breaking Markets is a paid API for AI agents from hars.cryptotavern.xyz, paid per call via x402, $0.008/call, status unknown (last checked 2026-10-18).

Fetches Polymarket prediction-market intelligence, surfacing breaking or high-signal markets for AI agents via pay-per-call USDC payments.

## Facts

- Endpoint: GET https://hars.cryptotavern.xyz/paid/breaking-markets?utm_source=zero.xyz
- Price: $0.008/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-signal-api-breaking-markets-d6345463
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_wan76JrMtgCxgUvRYwEw1

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-signal-api-breaking-markets-d6345463
```

Example prompt: Pull the latest breaking markets from the HARS-Zero Polymarket signal feed and tell me which prediction markets are trending right now.

## When to prefer this

Choose this endpoint when you need real-time Polymarket prediction market intelligence specifically around breaking or trending markets, and you are comfortable with pay-per-call USDC micropayments via the x402 protocol on Base or Solana. Prefer this over building direct Polymarket integrations when you need a simple, agent-ready REST interface without managing exchange credentials or raw API complexity.

## Known failure modes

- Payment not included or insufficient USDC — 402 Payment Required response
- No breaking markets currently available — returns count:0 and empty markets array
- Invalid properties filter parameter — may return empty results or error
- Network timeout if Polymarket data feed is slow
- Rate limiting if too many calls are made in rapid succession

## How this service works

Polymarket prediction-market intelligence for AI agents. Pay-per-call in USDC via x402 protocol. Multi-chain: Base + Solana.

## Output

Returns a JSON object with a count of matching markets and an array of market objects from Polymarket, each representing a prediction market with associated metadata and probability signals. When no matching markets are found, returns count 0 and an empty markets array.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "example": {
  "count": 0,
  "markets": []
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hars-zero-signal-api-breaking-markets-d6345463/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)