MCP - Radion

The MCP server lets your AI agent talk to Radion through tools. Connect it to Claude Code, Codex, Cursor, VS Code, or any MCP-compatible tool. Each tool maps to one Radion REST endpoint, so your agent can read on-chain Polymarket data — markets, traders, events, search, and the orderbook — without writing any HTTP code.

Endpoint

https://mcp.radion.app/mcp

Authentication

Every request needs an API key. Send it in the X-API-Key header (or as an Authorization: Bearer token). If your client can’t set custom headers (for example, Claude Cowork), pass the key as an api_key query string instead:

https://mcp.radion.app/mcp?api_key=YOUR_API_KEY

Use the header when your client supports it. Keys in URLs can leak through proxies and client history, so rotate any key you put in a query string if it may have been seen. Get an API key from the dashboard.

Setup

Claude Code
Codex
Cursor
VS Code
Claude Cowork

claude mcp add --transport http "Radion" "https://mcp.radion.app/mcp" \
  --header "X-API-Key: YOUR_API_KEY"

export RADION_API_KEY=your_api_key
codex mcp add "Radion" --url "https://mcp.radion.app/mcp" --bearer-token-env-var RADION_API_KEY

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project):

{
  "mcpServers": {
    "Radion": {
      "url": "https://mcp.radion.app/mcp",
      "headers": {
        "X-API-Key": "${env:RADION_API_KEY}"
      }
    }
  }
}

Set the env var in your shell profile: export RADION_API_KEY=your_api_key

Add to .vscode/mcp.json:

{
  "servers": {
    "Radion": {
      "type": "http",
      "url": "https://mcp.radion.app/mcp",
      "headers": {
        "X-API-Key": "${input:radionApiKey}"
      }
    }
  }
}

VS Code will ask for the key the first time you use it.

Claude Cowork can’t set custom headers, so put the key in the URL:

https://mcp.radion.app/mcp?api_key=YOUR_API_KEY

Available tools

Each tool returns the same JSON as the matching REST endpoint.

Events and search

Tool	What it does
`list_events`	List events (groups of related markets). Pages with a cursor.
`get_event`	Get one event by its numeric id or slug.
`list_markets`	List markets. Pages with a cursor.
`get_market`	Get one market by its condition id or slug.
`search`	Search Polymarket markets, topics, and profiles by text.

Orderbook

Tool	What it does
`get_orderbook`	Get the full orderbook depth (bids and asks) for a `token_id`.
`get_midpoint`	Get the midpoint price (between best bid and ask) for a token.
`get_spread`	Get the bid-ask spread for a token.
`get_price`	Get the best bid or ask price for a token (`side` = buy/sell).
`get_last_trade_price`	Get the last executed trade price for a token.

Health

Tool	What it does
`health`	Check whether the MCP server is up.

Example prompts

Once connected, try these in your AI tool:

“List the top 10 Polymarket markets by volume.”
“What is the PnL for trader 0x1234…?”
“Search Polymarket for markets about the election.”
“Show the most recent trades for this market slug.”
“Who is on the Polymarket profit leaderboard right now?”

Rate limits and plans

Rate limits match the REST API rate limits. Your API key plan applies.

​Endpoint

​Authentication

​Setup

​Available tools

​Events and search

​Orderbook

​Health

​Example prompts

​Rate limits and plans