DEV Community

RileyCraig14
RileyCraig14

Posted on • Edited on

I built a zero-auth Kalshi data relay with MCP — here's what's actually hitting it

The problem with Kalshi's API

Kalshi's API requires RSA-PSS key pairs, JWT tokens that expire every 30 minutes, and session refresh logic. For a trading bot that runs 24/7, that's a lot of auth plumbing before you even get to the data.

So I built NEXUS — a relay that handles all of that and exposes clean, zero-auth endpoints.

One curl, live Fed odds 

curl https://nexus-agent-xa12.onrender.com/kalshi?market=Fed
Enter fullscreen mode Exit fullscreen mode

Returns live Kalshi market data — Fed rate decisions, BTC, CPI, GDP — no API key, no RSA setup, no session refresh.

Works as an MCP server too

Paste this in Claude Desktop, Cursor, or Windsurf config:

{
  "mcpServers": {
    "nexus": {
      "url": "https://nexus-agent-xa12.onrender.com/mcp",
      "transport": "http"
    }
  }
}
Enter fullscreen mode Exit fullscreen mode

Then ask your agent: "what are the current Fed rate odds?" It calls NEXUS and gets live Kalshi data back.

WebSocket stream for bots that need continuous data 

wss://nexus-agent-xa12.onrender.com/stream/kalshi?market=Fed
Enter fullscreen mode Exit fullscreen mode

One persistent connection, live odds pushed as they update. At a 20-second poll interval that's 4,320 automatic hits/day from a single bot integration.

What's actually hitting it right now

From /health:

  • 81 MCP queries total
  • 3 external paid calls via x402 micropayments
  • $0.03 USDC earned — tiny, but proves the payment rail is live
  • Foreign IPs (GCP/AWS) crawling the manifest

If you're building a Kalshi bot, drop this in 

import requests

def get_fed_odds():
    return requests.get(
        'https://nexus-agent-xa12.onrender.com/kalshi',
        params={'market': 'Fed'}
    ).json()
Enter fullscreen mode Exit fullscreen mode

Free, no key, no setup. If something breaks or you want a specific market endpoint, open an issue: https://github.com/RileyCraig14/nexus-agent

Update: now also serving market signals at /v1/signals?symbol=BTC — returns BULLISH/BEARISH/NEUTRAL with confidence score. Free.

curl 'https://nexus-agent-xa12.onrender.com/v1/signals?symbol=BTC'
Enter fullscreen mode Exit fullscreen mode

Top comments (1)

Collapse
 
rileycraig14 profile image
RileyCraig14 •

Update since posting: First external paid call confirmed — reaworks-x402-paid-readback/1.0 paid $0.02 USDC on /arb/check via x402 on Base mainnet.

Also added /pay-guide: nexus-agent-xa12.onrender.com/pay-...

Shows the live 402 invoice, awal CLI steps, and @x402/fetch snippet. Any agent with a Base wallet can pay in ~60 seconds. Fed spread is currently 22.75pt live.