Prediction Market APIs
Markets, events, prices and order books from Polymarket and Kalshi, for research, dashboards and trading agents.
All Prediction Market APIs
Compare endpoints across providers, then open any API for parameters, pricing and a live request.
Kalshi Get Kalshi Markets
Get Kalshi Markets from Kalshi. Returns the official Kalshi API response unchanged.
Polymarket List events
List events with offset based pagination and filter parameters.
Kalshi Get Market Price
Get Market Price from Kalshi. Returns the official Kalshi API response unchanged.
Kalshi Get Kalshi Market OrderBook
Get Kalshi Market OrderBook from Kalshi. Returns the official Kalshi API response unchanged.
Kalshi Get Kalshi Trades
Get Kalshi Trades from Kalshi. Returns the official Kalshi API response unchanged.
Polymarket Wallet Activity
A wallet's activity feed: trades, splits, merges, redemptions, rewards and conversions, with time-range and type filters.
Polymarket Get order book
Retrieves the order book summary for a specific token ID. Includes bids, asks, market details, and last trade price.
Polymarket Builders Leaderboard
Leaderboard of Polymarket builders (apps routing orders) by volume for a time period.
Polymarket Builders Volume
Daily, weekly or monthly volume of Polymarket builders over time.
Polymarket Get CLOB market info
Returns all CLOB-level parameters for a market in a single call — tokens, tick size, base fees, rewards, RFQ status, and fee details.
Polymarket Closed Positions
A wallet's closed positions with realized PnL, newest first, from the Data API v2.
Polymarket List comments
List comments from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get comments by comment id
Get comments by comment id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get comments by user address
Get comments by user address from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get event by id
Get event by id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket List events (keyset pagination)
List events with cursor based keyset pagination. Use next_cursor as after_cursor to fetch the next page. The offset parameter is rejected.
Polymarket Get event by slug
Get event by slug from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get event tags
Get event tags from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get fee rate
Retrieves the base fee rate for a specific token ID. The fee rate can be provided either as a query parameter or as a path parameter.
Polymarket Get fee rate by path parameter
Retrieves the base fee rate for a specific token ID using the token ID as a path parameter.
Polymarket Market Holders
Top holders of each outcome token in a market by condition ID, with balances and optional PnL.
Polymarket Get last trade price
Retrieves the last trade price and side for a specific token ID. Returns default values of 0.5 for price and empty string for side if no trades found.
Polymarket Trader Leaderboard
Polymarket trader leaderboard by PnL or volume, for a time period and category.
Polymarket Live Event Volume
Live taker volume for an event by event ID, in total and per market.
Polymarket Market Positions
Positions held in one market by condition ID, with each holder wallet, size, value and PnL.
Polymarket List markets
List markets from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get market by id
Get market by id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get market by token
Get market by token from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket List markets (keyset pagination)
List markets (keyset pagination) from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get market by slug
Get market by slug from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get market tags by id
Get market tags by id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get midpoint price
Retrieves the midpoint price for a specific token ID. The midpoint is calculated as the average of the best bid and best ask prices.
Polymarket Open Interest
Open interest in USDC for one or more markets by condition ID.
Polymarket Wallet Positions
A wallet's positions across their lifecycle (open, redeemable, mergeable, closed), with size, average price, current value and PnL.
Polymarket Get market price
Retrieves the best market price for a specific token ID and side (bid or ask). Returns the best bid price for BUY side or best ask price for SELL side.
Polymarket Get prices history
Get prices history from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get public profile by wallet address
Get public profile by wallet address from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Search markets, events, and profiles
Search markets, events, and profiles from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get raw rewards for a specific market
Get raw rewards for a specific market from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get current active rewards configurations
Returns the current active rewards configurations for markets.
Polymarket Get multiple markets with rewards
Returns multiple markets with rewards and supports filtering and sorting.
Polymarket Get sampling markets
Returns sampling markets with richer descriptive metadata, token summaries, and tags.
Polymarket Get sampling simplified markets
Returns sampling simplified markets with reward and token summaries.
Polymarket List series
List series from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get series by id
Get series by id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get simplified markets
Returns simplified CLOB markets with token and reward summaries.
Polymarket Get sports metadata information
Get sports metadata information from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get valid sports market types
Get valid sports market types from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get spread
Retrieves the spread for a specific token ID. The spread is the difference between the best ask and best bid prices.
Polymarket Get supported assets
Get supported assets for deposits and withdrawals on the bridge.
Polymarket List tags
List tags from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get tag by id
Get tag by id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get related tags (relationships) by tag id
Get related tags (relationships) by tag id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get tags related to a tag id
Get tags related to a tag id from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get tag by slug
Get tag by slug from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get related tags (relationships) by tag slug
Get related tags (relationships) by tag slug from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get tags related to a tag slug
Get tags related to a tag slug from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket List teams
List teams from Polymarket. Returns the official Polymarket API response unchanged.
Polymarket Get tick size
Retrieves the minimum tick size (price increment) for a specific token ID. The tick size can be provided either as a query parameter or as a path parameter.
Polymarket Get tick size by path parameter
Retrieves the minimum tick size (price increment) for a specific token ID using the token ID as a path parameter.
Polymarket Get server time
Returns the current Unix timestamp of the server. This can be used to synchronize client time with server time.
Polymarket User Stats
A wallet's profile stats: total trades, biggest win, profile views and join date.
Polymarket Portfolio Value
Current USD value of a wallet's open positions, optionally limited to given markets.
Real-money odds as data
Prediction markets price the probability of future events. These endpoints read events, markets, prices and trading activity, so you can track sentiment or feed it to an agent.
- Polymarket: events, markets, prices, order books, trades, positions, holders and leaderboards.
- Kalshi: markets, order books and trades.
All endpoints use POST /v1/api/{vendor}/{endpoint} and are billed per call.
Start using Prediction Market APIs on SandBase
One key, one request pattern, billed per call.
- 01
Create an API key
Sign in to the SandBase Console and create a key on the API Keys page. Keep it in an environment variable and never commit it to source control.
TERMINALexport SANDBASE_API_KEY="YOUR_SANDBASE_API_KEY" - 02
Call an endpoint
POST a JSON body to /v1/api/polymarket/events. Every endpoint on this page uses the same pattern.
TERMINALcurl https://api.sandbase.ai/v1/api/polymarket/events \ -H "Authorization: Bearer $SANDBASE_API_KEY" \ -H "Content-Type: application/json" \ -d '{}' - 03
Let your agent call it
Connect the SandBase MCP server or CLI so an agent can discover and call these endpoints with your key.
TERMINALnpx -y @sandbaseai/cli@latest connect
Questions, answered
Can I place trades through these APIs?
No. These endpoints read public market data only.
How fresh are prices?
Freshness depends on the endpoint; check each endpoint description.
Which markets are covered?
Polymarket and Kalshi.
How am I billed?
Per call, at the price on each endpoint card.
Build with Prediction Market APIs.
One key, consistent APIs, and usage-based pricing across every API on this page.