Prediction Markets API

API ID 14541

Live Polymarket, Kalshi and Manifold odds, price history, arbitrage scanner, consensus fair value and Kelly sizing in one JSON API.

API Documentation

Endpoints

Request
Liveness check that also lists the prediction market venues this API covers.
Endpoint ID: 37137
GET https://zylalabs.com/api/14541/prediction+markets+api/37137/health+check
INPUT PARAMETERS

Free test requests remaining: 3 of 3.

This endpoint does not require any input parameters.

API EXAMPLE RESPONSE
JSON
{
    "data": {
        "status": "ok",
        "time": "2026-10-26T19:05:56.599Z",
        "venues": [
            "polymarket",
            "kalshi",
            "manifold"
        ]
    },
    "error": false,
    "message": "OK"
}
Health Check — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37137/health+check' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Lists the prediction market venues supported by this API, with the exact venue values accepted by other endpoints.
Endpoint ID: 37138
GET https://zylalabs.com/api/14541/prediction+markets+api/37138/list+venues
INPUT PARAMETERS

Free test requests remaining: 3 of 3.

This endpoint does not require any input parameters.

API EXAMPLE RESPONSE
JSON
{
    "data": {
        "venues": [
            "polymarket",
            "kalshi",
            "manifold"
        ]
    },
    "error": false,
    "message": "OK"
}
List Venues — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37138/list+venues' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Normalized market listing across Polymarket, Kalshi and Manifold with title, status, volume, liquidity, bid, ask and outcome odds. Omit venue to merge all three.
Endpoint ID: 37139
GET https://zylalabs.com/api/14541/prediction+markets+api/37139/list+markets
INPUT PARAMETERS

List Markets — Endpoint Features

Object Description
venue Optional Optional venue filter: polymarket, kalshi or manifold.
q Optional Optional title filter, for example bitcoin or fed.
limit Optional Maximum markets to return per venue, up to 200.

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

venue
q
limit
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "count": 1,
        "markets": [
            {
                "bestAsk": 0.921,
                "bestBid": 0.92,
                "category": "fomc",
                "closeTime": "2026-10-29T03:59:00Z",
                "id": "2589812",
                "liquidity": 267606.65,
                "outcomes": [
                    {
                        "ask": 0.921,
                        "bid": 0.92,
                        "name": "Yes",
                        "odds": {
                            "american": -1158,
                            "decimal": 1.086,
                            "probability": 0.9205
                        }
                    },
                    {
                        "ask": 0.08,
                        "bid": 0.079,
                        "name": "No",
                        "odds": {
                            "american": 1158,
                            "decimal": 12.579,
                            "probability": 0.0795
                        }
                    }
                ],
                "status": "open",
                "ticker": "will-there-be-no-change-in-fed-interest-rates-after-the-october-2026-meeting",
                "title": "Will there be no change in Fed interest rates after the October 2026 meeting?",
                "venue": "polymarket",
                "volume": 23357574.46
            }
        ],
        "warnings": null
    },
    "error": false,
    "message": "OK"
}
List Markets — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37139/list+markets?venue=polymarket&q=bitcoin&limit=5' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Returns one normalized market. The id accepts the native identifier of each venue: id or slug for Polymarket and Manifold, ticker for Kalshi.
Endpoint ID: 37140
GET https://zylalabs.com/api/14541/prediction+markets+api/37140/get+market
INPUT PARAMETERS

Free test requests remaining: 3 of 3.

API EXAMPLE RESPONSE
JSON
{
    "data": {
        "bestAsk": 0.11,
        "bestBid": 0.09,
        "id": "KXHIGHNY-26OCT27-T67",
        "outcomes": [
            {
                "name": "Yes",
                "odds": {
                    "american": 900,
                    "decimal": 10,
                    "probability": 0.1
                }
            },
            {
                "name": "No",
                "odds": {
                    "american": -900,
                    "decimal": 1.111,
                    "probability": 0.9
                }
            }
        ],
        "status": "open",
        "title": "Highest temperature in NYC above 67 on Oct 27",
        "venue": "kalshi",
        "volume": 295
    },
    "error": false,
    "message": "OK"
}
Get Market — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37140/get+market&venue=Required&/=Required&id=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Live order book with bids and asks for a market. For Manifold, which uses an AMM, it returns the current probability and liquidity pool instead.
Endpoint ID: 37141
GET https://zylalabs.com/api/14541/prediction+markets+api/37141/get+order+book
INPUT PARAMETERS

Free test requests remaining: 3 of 3.

API EXAMPLE RESPONSE
JSON
{
    "data": {
        "asks": [
            {
                "price": 0.11,
                "size": 73.59
            },
            {
                "price": 0.12,
                "size": 28.6
            }
        ],
        "bids": [
            {
                "price": 0.08,
                "size": 1540.73
            },
            {
                "price": 0.07,
                "size": 2236.48
            }
        ],
        "ticker": "KXELONMARS-99",
        "venue": "kalshi"
    },
    "error": false,
    "message": "OK"
}
Get Order Book — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37141/get+order+book&venue=Required&/=Required&id=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Returns just the outcomes and odds of one market in probability, decimal and American formats.
Endpoint ID: 37142
GET https://zylalabs.com/api/14541/prediction+markets+api/37142/get+market+odds
INPUT PARAMETERS

Free test requests remaining: 3 of 3.

API EXAMPLE RESPONSE
JSON
{
    "data": {
        "outcomes": [
            {
                "name": "Yes",
                "odds": {
                    "american": 733,
                    "decimal": 8.333,
                    "probability": 0.12
                }
            },
            {
                "name": "No",
                "odds": {
                    "american": -733,
                    "decimal": 1.136,
                    "probability": 0.88
                }
            }
        ],
        "title": "Will Kylian Mbappe win the 2026 Ballon d Or?",
        "venue": "polymarket"
    },
    "error": false,
    "message": "OK"
}
Get Market Odds — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37142/get+market+odds&venue=Required&/=Required&id=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Side-by-side odds for a topic across every venue in one call, the fastest way to compare lines between exchanges.
Endpoint ID: 37143
GET https://zylalabs.com/api/14541/prediction+markets+api/37143/compare+odds+by+topic
INPUT PARAMETERS

Compare Odds By Topic — Endpoint Features

Object Description
q Required Topic to compare across venues, for example fed rate.

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

q
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "query": "fed rate",
        "results": [
            {
                "probability": 0.92,
                "title": "Fed decision in October?",
                "venue": "polymarket"
            },
            {
                "probability": 0.9,
                "title": "Fed holds rates in October",
                "venue": "kalshi"
            }
        ]
    },
    "error": false,
    "message": "OK"
}
Compare Odds By Topic — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37143/compare+odds+by+topic?q=fed rate' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Normalized OHLC candles for one market outcome. Each candle has open, high, low, close as probabilities between 0 and 1, plus volume and timestamp.
Endpoint ID: 37144
GET https://zylalabs.com/api/14541/prediction+markets+api/37144/get+price+history
INPUT PARAMETERS

Get Price History — Endpoint Features

Object Description
interval Optional Candle size: 1m, 5m, 15m, 1h, 4h, 1d or 1w.
lookback Optional History window: 1d, 7d, 30d, 90d, 180d or 365d.
outcome Optional Outcome name, Yes or No.
venue Required
id Required

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

interval
lookback
outcome
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "candles": [
            {
                "c": 0.09,
                "h": 0.11,
                "l": 0.09,
                "o": 0.11,
                "t": 1790467200000,
                "time": "2026-09-27T00:00:00.000Z",
                "v": 295
            }
        ],
        "interval": "1d",
        "lookback": "30d",
        "outcome": "Yes",
        "ticker": "KXHIGHNY-26OCT27-T67",
        "venue": "kalshi"
    },
    "error": false,
    "message": "OK"
}
Get Price History — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37144/get+price+history?interval=1d&lookback=30d&outcome=Yes&venue=Required&/=Required&id=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Free-text search merged across Polymarket, Kalshi and Manifold. Returns matching markets with normalized odds.
Endpoint ID: 37145
GET https://zylalabs.com/api/14541/prediction+markets+api/37145/search+markets
INPUT PARAMETERS

Search Markets — Endpoint Features

Object Description
q Required Search term, for example world cup.
venue Optional Optional venue filter: polymarket, kalshi or manifold.
limit Optional Maximum results per venue, up to 100.

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

q
venue
limit
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "count": 1,
        "markets": [
            {
                "id": "abc123",
                "outcomes": [
                    {
                        "name": "Yes",
                        "odds": {
                            "american": 614,
                            "decimal": 7.143,
                            "probability": 0.14
                        }
                    }
                ],
                "title": "Will Brazil win the 2026 World Cup?",
                "venue": "manifold"
            }
        ],
        "warnings": null
    },
    "error": false,
    "message": "OK"
}
Search Markets — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37145/search+markets?q=world cup&venue=manifold&limit=5' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Scans two or more venues for the same binary question priced differently and reports the guaranteed edge, with optional Kalshi trading fee modeling.
Endpoint ID: 37146
GET https://zylalabs.com/api/14541/prediction+markets+api/37146/cross+venue+arbitrage+scanner
INPUT PARAMETERS

Cross Venue Arbitrage Scanner — Endpoint Features

Object Description
q Optional Topic to narrow the scan, recommended for speed and precision.
minEdge Optional Minimum edge between 0 and 1, for example 0.02 for 2 percent.
feeAware Optional Set true to subtract Kalshi taker fees from the edge.
limit Optional Maximum opportunities to return, up to 100.

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

q
minEdge
feeAware
limit
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "count": 1,
        "minEdge": 0.02,
        "opportunities": [
            {
                "buy": [
                    {
                        "price": 0.115,
                        "side": "Yes",
                        "venue": "polymarket"
                    },
                    {
                        "price": 0.84,
                        "side": "No",
                        "venue": "kalshi"
                    }
                ],
                "cost": 0.955,
                "edge": 0.045,
                "edgePct": 4.5,
                "markets": [
                    {
                        "title": "Will Naftali Bennett be the next Prime Minister of Israel?",
                        "venue": "polymarket"
                    },
                    {
                        "title": "Will Naftali Bennett be the next Prime Minister of Israel?",
                        "venue": "kalshi"
                    }
                ],
                "similarity": 1
            }
        ],
        "scanned": {
            "kalshi": 150,
            "manifold": 75,
            "polymarket": 100
        }
    },
    "error": false,
    "message": "OK"
}
Cross Venue Arbitrage Scanner — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37146/cross+venue+arbitrage+scanner?q=bitcoin&minEdge=0.02&feeAware=true&limit=20' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Same-venue dutch book check for one multi-outcome event: when the Yes prices of all mutually exclusive outcomes sum to less than 1, buying the whole field is profitable.
Endpoint ID: 37147
GET https://zylalabs.com/api/14541/prediction+markets+api/37147/dutch+book+scanner+single+event
INPUT PARAMETERS

Dutch Book Scanner Single Event — Endpoint Features

Object Description
feeAware Optional Set true to subtract Kalshi modeled trading fees from each leg.
venue Required
eventId Required

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

feeAware
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "buyTheField": {
            "edge": 0.005,
            "edgePct": 0.5,
            "profitable": true,
            "totalCost": 0.995
        },
        "event": {
            "id": "81557",
            "mutuallyExclusive": true,
            "title": "Prime Minister of Israel after the next election?"
        },
        "legs": [
            {
                "ask": 0.54,
                "bid": 0.536,
                "id": "682708",
                "title": "Will Gadi Eizenkot be the next Prime Minister of Israel?"
            }
        ],
        "outcomeCount": 19,
        "venue": "polymarket"
    },
    "error": false,
    "message": "OK"
}
Dutch Book Scanner Single Event — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37147/dutch+book+scanner+single+event?feeAware=false&venue=Required&/=Required&eventId=Required' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Runs the same-venue dutch book check across every event found by a search term, on one or more venues.
Endpoint ID: 37148
GET https://zylalabs.com/api/14541/prediction+markets+api/37148/dutch+book+scanner+search+events
INPUT PARAMETERS

Dutch Book Scanner Search Events — Endpoint Features

Object Description
q Required Search term used to find multi-outcome events.
minEdge Optional Minimum edge between 0 and 1 to report.
feeAware Optional Set true to subtract Kalshi modeled trading fees.

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

q
minEdge
feeAware
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "count": 1,
        "events": [
            {
                "buyTheField": {
                    "edge": 0.005,
                    "edgePct": 0.5,
                    "profitable": true
                },
                "event": {
                    "title": "Prime Minister of Israel after the next election?"
                },
                "outcomeCount": 19,
                "venue": "polymarket"
            }
        ]
    },
    "error": false,
    "message": "OK"
}
Dutch Book Scanner Search Events — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37148/dutch+book+scanner+search+events?q=prime minister of israel&minEdge=0.01&feeAware=true' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Volume-weighted fair value probability for one question built from every venue with a matching market, plus a disagreement score between venues.
Endpoint ID: 37149
GET https://zylalabs.com/api/14541/prediction+markets+api/37149/consensus+fair+value
INPUT PARAMETERS

Consensus Fair Value — Endpoint Features

Object Description
q Required The question to build a consensus for, for example fed rate cut october.
minSimilarity Optional How strictly titles must match, between 0 and 1.

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

q
minSimilarity
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "agreement": {
            "spreadPct": 4.2,
            "stdDev": 0.021,
            "venuesMatched": 3
        },
        "consensus": {
            "american": 144,
            "decimal": 2.439,
            "probability": 0.41
        },
        "pivotVenue": "polymarket",
        "query": "fed rate cut october",
        "venues": [
            {
                "deviationFromConsensus": -0.01,
                "probability": 0.4,
                "venue": "polymarket",
                "volume": 23000000
            },
            {
                "deviationFromConsensus": 0.03,
                "probability": 0.44,
                "venue": "kalshi",
                "volume": 58000
            }
        ]
    },
    "error": false,
    "message": "OK"
}
Consensus Fair Value — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37149/consensus+fair+value?q=fed rate cut october&minSimilarity=0.55' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request
Kelly criterion stake sizing from your own probability estimate and the market price, with optional fractional Kelly to reduce variance.
Endpoint ID: 37150
GET https://zylalabs.com/api/14541/prediction+markets+api/37150/kelly+criterion+calculator
INPUT PARAMETERS

Kelly Criterion Calculator — Endpoint Features

Object Description
probability Required Your own probability estimate between 0 and 1.
price Optional Market price between 0 and 1, or use venue and id instead.
bankroll Optional Your stake budget in any currency unit.
fraction Optional Kelly fraction, 1 for full Kelly, 0.5 for half Kelly.

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

probability
price
bankroll
fraction
API EXAMPLE RESPONSE
JSON
{
    "data": {
        "appliedFraction": 0.1364,
        "edge": 0.15,
        "evPerDollarStaked": 0.3333,
        "expectedProfit": 22.73,
        "fullKellyFraction": 0.2727,
        "hasEdge": true,
        "inputs": {
            "bankroll": 500,
            "fraction": 0.5,
            "price": 0.45,
            "probability": 0.6
        },
        "recommendedStake": 68.18
    },
    "error": false,
    "message": "OK"
}
Kelly Criterion Calculator — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/14541/prediction+markets+api/37150/kelly+criterion+calculator?probability=0.6&price=0.45&bankroll=500&fraction=0.5' --header 'Authorization: Bearer YOUR_API_KEY' 


    

API Access Key & Authentication

After signing up, every developer is assigned a personal API access key, a unique combination of letters and digits provided to access to our API endpoint. To authenticate with the Prediction Markets API simply include your bearer token in the Authorization header.

Headers
Header Description
Authorization Required Should be Bearer access_key. See "Your API Access Key" above when you are subscribed.

No long-term commitment. Upgrade, downgrade, or cancel anytime.

Starts at
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Overview

Live Polymarket, Kalshi and Manifold odds, price history, arbitrage scanner, consensus fair value and Kelly sizing in one JSON API.

Prediction Markets API FAQs

No. It is an independent API that aggregates and normalizes public market data from the three venues into one format. It is not affiliated with or endorsed by any of them.

No. Your Zyla API key is all you need.

Yes. Every response is computed live at request time. A few seconds of client-side caching is recommended if you poll often.

No. It is a read-only data and analytics API. Trade on the venues themselves.

It compares binary markets across venues that look like the same question and reports the guaranteed edge. A separate dutch book scanner checks multi-outcome events on a single venue.

No. Arbitrage, consensus and Kelly outputs are informational tools. Always verify live prices and liquidity before trading.

General FAQs

To obtain your API key, first sign in to your account and navigate to the API you want to use. From the API's Pricing section, choose a plan and complete the subscription process. Once subscribed, return to the API page and you will see your API Access Key displayed at the top of the documentation page. You can use this key to authenticate your requests.

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