Give Claude Code Access to Prediction Markets (One Command)

simplefunctions — Sat, 21 Mar 2026 11:00:43 +0000

If you use Claude Code or Cursor, you can query Kalshi and Polymarket prediction markets directly from your AI assistant:

claude mcp add simplefunctions --url https://simplefunctions.dev/api/mcp/mcp

That's it. 16 tools are now available.

What Can You Do?

Ask Claude: "What prediction markets exist for Fed rate decisions?"

Claude calls scan_markets and returns results from both Kalshi and Polymarket with prices, volumes, and liquidity.

Ask: "Show me the orderbook for KXWTIMAX-26DEC31-T135"

Claude calls inspect_book → bid/ask levels, spread, depth, liquidity score.

Ask: "Create a thesis that oil will exceed $120"

Claude calls create_thesis → builds a causal tree, scans both exchanges for mispriced contracts, identifies edges, sets up 24/7 monitoring.

Ask: "What if Hormuz shipping drops to 10% probability?"

Claude calls what_if → simulates how all your edges would change. Zero LLM cost — pure computation.

The 16 Tools

Tool	What it does
`scan_markets`	Search Kalshi + Polymarket by keyword
`inspect_book`	Orderbook depth for a specific market
`get_liquidity`	Liquidity scan across 18 topics
`get_context`	Full thesis snapshot (edges, confidence, evaluation)
`create_thesis`	Build causal model from a market conviction
`inject_signal`	Feed news/observations to thesis
`trigger_evaluation`	Force re-evaluation
`what_if`	Scenario analysis
`get_positions`	Kalshi + Polymarket positions
`get_balance`	Account balance
`get_orders`	Resting orders
`get_fills`	Trade history
`get_settlements`	Settled contracts
`get_milestones`	Upcoming events
`get_schedule`	Exchange status
`explore_public`	Browse public theses

CLI Alternative

If you prefer command-line:

npm install -g @spfunctions/cli
sf setup
sf scan "oil recession iran"
sf book KXWTIMAX-26DEC31-T135
sf liquidity geopolitics
sf edges --json

Kalshi vs Polymarket: A Developer's Guide to Both APIs

simplefunctions — Sat, 21 Mar 2026 11:00:15 +0000

If you're building anything on prediction markets — a bot, a dashboard, an AI agent — your first decision is: Kalshi or Polymarket? I've built on both. Here's what I wish I knew upfront.

The Basics

	Kalshi	Polymarket
Regulation	CFTC (US)	Unregulated (crypto)
Settlement	USD bank account	USDC on Polygon
Auth	RSA-PSS signatures	EIP-712 + HMAC
Main volume	Sports (90%)	Crypto + geopolitics
Rate limits	~100 req/10s	15,000 req/10s

Market Discovery

Kalshi uses Series → Events → Markets. Search by series ticker:

curl "https://api.elections.kalshi.com/trade-api/v2/series?include_volume=true"

Polymarket uses Events → Markets with the Gamma API:

curl "https://gamma-api.polymarket.com/events?active=true&limit=50"

Orderbook Data

Both expose full orderbook depth. The key difference:

Kalshi returns YES/NO dollar prices:

{ "yes_bid_dollars": "0.48", "no_bid_dollars": "0.53" }

YES ask = 100 - NO bid. Mental math required.

Polymarket returns direct probabilities:

{ "bids": [{"price": "0.48", "size": "500"}], "asks": [{"price": "0.52", "size": "300"}] }

Price History

Kalshi: authenticated candlestick API, OHLC, custom date ranges. Requires API keys.

Polymarket: public OHLC endpoint, no auth:

curl "https://clob.polymarket.com/ohlc?asset_id=TOKEN_ID&startTs=1710000000&fidelity=1h"

Liquidity Comparison

In practice, across 18 market categories:

Crypto: Polymarket wins (5-10x more depth)
Macro/geopolitics: Roughly equal
Sports: Kalshi dominates

The Practical Answer

Don't choose one. Use both. The best edges come from cross-venue comparison.

I built SimpleFunctions CLI for exactly this — one command to query both:

npm install -g @spfunctions/cli
sf scan "oil recession"          # search both venues
sf book KXWTIMAX-26DEC31-T135    # Kalshi orderbook depth
sf book --poly "oil price"       # Polymarket orderbook
sf liquidity crypto              # cross-venue liquidity scan

It's open source, handles all the auth/normalization, and also has an MCP server for Claude Code:

claude mcp add simplefunctions --url https://simplefunctions.dev/api/mcp/mcp

What are you building on prediction markets? Happy to answer questions.

DEV Community: simplefunctions