# Polymarket Price History

> Polymarket Price History is a paid API for AI agents from agent402.tools, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Returns historical implied probability samples for a Polymarket outcome token, including timestamped price series and first/last/min/max summary statistics.

## Facts

- Endpoint: POST https://agent402.tools/api/polymarket-price-history
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polymarket-price-history-17f0c4ad
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HTSoIlLPLHkwbOD97UXCU

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-price-history-17f0c4ad -d '<json body>'
```

Example prompt: Show me the hourly probability history for Polymarket token 12345678 over the past week — I want to see the first, last, min, and max prices and all the timestamped samples.

## When to prefer this

Use this endpoint when you need historical probability timeseries data for a specific Polymarket outcome token — particularly for analyzing how market sentiment shifted around events, computing volatility, or backtesting prediction strategies. Prefer this over the live orderbook endpoint when historical context matters rather than current bids/asks.

## Known failure modes

- Invalid or unknown tokenId returns an error or empty result
- fidelity value outside 1-720 range rejected
- Unrecognized interval string returns an error
- Polymarket CLOB data unavailable for the requested window
- Network timeout or upstream API failure

## How this service works

Historical odds (implied probabilities) for a Polymarket outcome token. Returns timestamped price samples with first/last/min/max summary. Useful for: tracking probability shifts around events, computing realized volatility, backtesting prediction strategies.

## Output

A list of timestamped price samples (implied probabilities between 0 and 1) for the specified Polymarket outcome token, plus a summary with first, last, minimum, and maximum values across the requested lookback window.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tokenId": {
   "type": "string",
   "description": "CLOB token id (decimal string) from market.clobTokenIds."
  },
  "fidelity": {
   "type": "number",
   "description": "Sample granularity in minutes (1-720, default 60)."
  },
  "interval": {
   "type": "string",
   "description": "Lookback window: 1h, 6h, 1d, 1w, 1m, max (default 1d)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "max": 0.67,
  "min": 0.55,
  "last": 0.62,
  "count": 24,
  "first": 0.58,
  "points": [
   {
    "price": 0.58,
    "timestamp": 1751200000
   },
   {
    "price": 0.59,
    "timestamp": 1751203600
   }
  ],
  "source": "polymarket-clob",
  "tokenId": "72909...",
  "interval": "1d",
  "fidelityMinutes": 60
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-price-history-17f0c4ad/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)