# Blockrun.ai Polymarket Market Open Interest History

> Blockrun.ai Polymarket Market Open Interest History is a paid API for AI agents from blockrun.ai, paid per call via x402, $0.0085/call, status unknown (last checked 2026-09-14).

Returns historical open interest data for a specific Polymarket prediction market identified by its hash

## Facts

- Endpoint: GET https://blockrun.ai/api/v1/pm/polymarket/markets/:hash/open_interest
- Price: $0.0085/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockrun-ai-polymarket-market-open-interest-history-037ca6f7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_S9WnPXP_VNFafT6nCgkOa

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 blockrun-ai-polymarket-market-open-interest-history-037ca6f7
```

Example prompt: Can you pull the historical open interest data for the Polymarket market with hash 0xabc123def456 so I can see how trader interest has changed over time?

## When to prefer this

Use this endpoint when you need historical open interest data specifically from Polymarket prediction markets and you have the market's hash identifier. Prefer this over general market data endpoints when your focus is on Polymarket's open interest trends rather than current prices or order books. Ideal for agents building analytics dashboards, monitoring market activity, or researching how trader interest has evolved for a specific prediction market.

## Known failure modes

- Invalid or unknown market hash returns an error or empty data
- Market hash not found on Polymarket returns 404 or null data
- Malformed hash parameter causes request failure
- Payment not provided or insufficient USDC results in 402 Payment Required
- Rate limiting or upstream Polymarket API downtime causes 503

## How this service works

Get historical open interest data for a market

## Output

Returns a data object containing historical open interest figures for the specified Polymarket market, indexed by the market's hash identifier. The response includes time-series open interest values showing how much capital has been committed to the market over time.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "query": {
     "type": "object",
     "required": [],
     "properties": {}
    }
   }
  },
  "output": {
   "type": "object",
   "properties": {
    "example": {
     "type": "object",
     "properties": {
      "data": {
       "type": "object"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/blockrun-ai-polymarket-market-open-interest-history-037ca6f7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from blockrun.ai](https://www.zero.xyz/host/blockrun.ai/llms.txt)