# HARS-Zero Historical Mispricing API

> HARS-Zero Historical Mispricing API is a paid API for AI agents from hars.cryptotavern.xyz, paid per call via x402, $0.04/call, status unknown (last checked 2026-10-18).

Retrieves historical mispricing signals for Polymarket prediction markets, identifying past instances where market prices diverged from fair value

## Facts

- Endpoint: GET https://hars.cryptotavern.xyz/paid/historical-mispricing?utm_source=zero.xyz
- Price: $0.04/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-historical-mispricing-api-733bc35c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_v_ogmGcEbAcvaehpP1ktp

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-historical-mispricing-api-733bc35c
```

Example prompt: Pull up the historical mispricing data from HARS-Zero for Polymarket — I want to see which markets have had significant price divergences from fair value in the past so I can spot patterns.

## When to prefer this

Choose this endpoint when you need historical intelligence on Polymarket prediction market mispricings specifically — ideal for backtesting, identifying recurring inefficiencies, or evaluating market quality before trading. Prefer this over real-time market data endpoints when the goal is pattern analysis of past price divergences rather than current signals.

## Known failure modes

- Empty markets array returned if no historical mispricings match the filter criteria (count: 0)
- Payment failure via x402 protocol if USDC balance is insufficient or wallet not connected
- Invalid properties filter format may return empty results or an error
- Rate limiting or timeout if Polymarket data source is temporarily unavailable

## 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 containing a count of mispriced markets found and an array of market objects with historical mispricing details from Polymarket, indicating where market prices diverged from fair value over time.

## 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-historical-mispricing-api-733bc35c/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)