Polymarket Midpoints API

Retrieves midpoint prices for multiple token IDs using query parameters. The midpoint is calculated as the average of the best bid and best ask prices.

Data from Polymarket.

Category: Prediction Markets

Input schema is not available in the local snapshot. Call inspect first; fill body and queryParams as required and replace any pathParams placeholders before running.

Discover

curl https://keepbal.com/apis/v1/discover -H 'Authorization: Bearer YOUR_KEEPBAL_KEY' -H 'Content-Type: application/json' -d '{"query":"Polymarket"}'

Inspect

curl https://keepbal.com/apis/v1/inspect -H 'Authorization: Bearer YOUR_KEEPBAL_KEY' -H 'Content-Type: application/json' -d '{"publicId":"polymarket/midpoints"}'

curl

curl https://keepbal.com/apis/v1/polymarket/midpoints \
  -H 'Authorization: Bearer YOUR_KEEPBAL_KEY' \
  -H 'Content-Type: application/json' \
  -d '{}'

MCP run_tool

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run_tool",
    "arguments": {
      "tool": "polymarket/midpoints",
      "input": {}
    }
  }
}

Python

import json, os, requests

# Inspect first and replace input_data with the required parameters.
input_data = json.loads("{}")
response = requests.post(
    "https://keepbal.com/apis/v1/polymarket/midpoints",
    headers={"Authorization": "Bearer " + os.environ["KEEPBAL_API_KEY"]},
    json=input_data,
)
response.raise_for_status()
print(response.json())

Errors and billing

Failed provider calls are not charged. HTTP 400 invalid_request means invalid JSON or parameters, including missing pathParams. HTTP 401 missing_api_key or invalid_api_key means authentication is required. HTTP 402 insufficient_credits means insufficient balance; top up before retrying. HTTP 503 provider_unavailable means the provider is unavailable. A pending run can settle later; poll GET /apis/v1/runs/{id} instead of starting another execution.

Frequently asked questions

How much does this API cost?

$0.0162 per successful call

How do I start?

Create a KeepBal account with $1 free credit, obtain an API key, and inspect this tool before running it.

Related tools

MCP documentation

Start with $1 free credit