> ## Documentation Index
> Fetch the complete documentation index at: https://docs.polynode.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Global Open Interest

> Total platform-wide open interest from onchain data.

Returns the total open interest across the entire Polymarket platform, sourced from onchain data.

## Request

```
GET /v2/onchain/oi
```

No parameters required.

## Response

```json theme={null}
{
  "source": "onchain",
  "open_interest_usdc": 488484168.103811
}
```

| Field                | Type   | Description                          |
| -------------------- | ------ | ------------------------------------ |
| `open_interest_usdc` | number | Total platform open interest in USDC |

## Example

```bash theme={null}
curl "https://api.polynode.dev/v2/onchain/oi" \
  -H "x-api-key: YOUR_KEY"
```


## OpenAPI

````yaml GET /v2/onchain/oi
openapi: 3.1.0
info:
  title: PolyNode API
  description: >-
    Real-time Polymarket data API with decoded mempool settlements, OHLCV
    candles, and full Polygon JSON-RPC proxy.
  contact:
    name: PolyNode
    url: https://polynode.dev
  license:
    name: ''
  version: 2.0.0
servers:
  - url: https://api.polynode.dev
    description: Production
security:
  - api_key: []
paths:
  /v2/onchain/oi:
    get:
      tags:
        - Onchain
      summary: Global open interest (onchain)
      description: Total platform-wide open interest from onchain data.
      operationId: onchain_global_oi
      parameters: []
      responses:
        '200':
          description: Global open interest
        '401':
          description: Unauthorized
      security:
        - apiKey: []
components:
  securitySchemes:
    api_key:
      type: apiKey
      in: header
      name: x-api-key

````