# BlockRun Polymarket Market Open Interest Lookup

> BlockRun Polymarket Market Open Interest Lookup is a paid API for AI agents from blockrun.ai, paid per call via x402, $0.0085/call, status unknown (last checked 2026-10-19).

Fetches the open interest for a specific Polymarket prediction market by its contract address

## Facts

- Endpoint: GET https://blockrun.ai/api/v1/pm/polymarket/markets/0x0000000000000000000000000000000000000000000000000000000000000000/open_interest?utm_source=zero.xyz
- Price: $0.0085/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockrun-polymarket-market-open-interest-lookup-c7de62a5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yk9oyCqG5IeC2j0rujVeJ

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-polymarket-market-open-interest-lookup-c7de62a5
```

Example prompt: What is the open interest for the Polymarket market at contract address 0x1234...abcd?

## When to prefer this

Use this endpoint when you need on-chain open interest data for a specific Polymarket prediction market and want the lookup routed through BlockRun's payment layer settled in USDC — ideal for AI agents that need micro-payment-enabled DeFi data access without managing their own RPC infrastructure or API keys.

## Known failure modes

- Invalid or zero-padded contract address returns empty or null data
- Market address not found on Polymarket returns error or empty response
- Network or RPC issues cause timeouts
- Non-existent market addresses may return zero values without explicit errors

## How this service works

BlockRun lets AI agents use money well: pay for results, not for seats or subscriptions, and put every cent on the model or tool that actually does the job.

## Output

Returns open interest data for the specified Polymarket prediction market, indicating the total value of outstanding positions in the market as an on-chain data object.

## 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-polymarket-market-open-interest-lookup-c7de62a5/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)