API Documentation

One unified API to access all prediction markets. Get started in minutes with our simple REST interface.

API Key for Testing

Enter your API key to test endpoints directly from the docs

Quick Start

1Get your API key from the dashboard or create one via the API.

2Include your API key in the Authorization header:

text

Authorization: Bearer YOUR_API_KEY

3Make your first request:

bash

curl "bash-flag">-H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.propheseer.com/v1/markets?limit=5"

Base URL

Production

text

https://api.propheseer.com/v1

Local Development

text

http://localhost:3000/v1

Currently testing against: https://api.propheseer.com

Rate Limits

Plan	Daily Limit	Per-Minute Limit	Price
Free	100 req/day	10 req/min	$0/mo
Pro	10,000 req/day	100 req/min	$29/mo
Business	100,000 req/day	1,000 req/min	$99/mo

Rate limit headers are included in all authenticated responses: X-RateLimit-Remaining-Day, X-RateLimit-Remaining-Minute

Endpoints

GET/v1/markets

Retrieve a paginated list of prediction markets from all connected platforms. Filter by source, category, status, or search by question text.

Parameters

Name	Type	Description	Default
`source`	string	Filter by platform	all
`category`	string	Filter by topic category	-
`status`	string	Filter by market status	-
`q`	string	Search query to filter by question text	-
`limit`	number	Results per page (max: 200)	50
`offset`	number	Pagination offset for retrieving additional results	0

Example Request

bash

curl "bash-flag">-H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.propheseer.com/v1/markets?category=politics&limit=10"

Example Response

JSON

{
  "data": [
    {
      "id": "pm_abc123",
      "source": "polymarket",
      "question": "Will the Fed cut rates in January 2025?",
      "category": "finance",
      "status": "open",
      "outcomes": [
        { "name": "Yes", "probability": 0.35 },
        { "name": "No", "probability": 0.65 }
      ],
      "url": "https://polymarket.com/event/..."
    }
  ],
  "meta": { "total": 1234, "limit": 50, "offset": 0 }
}

GET/v1/markets/:id

Retrieve detailed information about a specific market including historical data, trading volume, and resolution criteria.

Parameters

Name	Type	Description	Default
`id`*	string	Unique market identifier (e.g., pm_abc123 or ks_xyz789)	-

Example Request

bash

curl "bash-flag">-H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.propheseer.com/v1/markets/pm_abc123"

Example Response

JSON

{
  "data": {
    "id": "pm_abc123",
    "source": "polymarket",
    "question": "Will the Fed cut rates in January 2025?",
    "description": "This market resolves YES if...",
    "category": "finance",
    "status": "open",
    "outcomes": [
      { "name": "Yes", "probability": 0.35, "volume24h": 125000 },
      { "name": "No", "probability": 0.65, "volume24h": 98000 }
    ],
    "resolutionDate": "2025-01-30",
    "url": "https://polymarket.com/event/..."
  }
}

GET/v1/categories

List all available market categories and their subcategories. Use these values to filter markets by topic.

Example Request

bash

curl "bash-flag">-H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.propheseer.com/v1/categories"

Example Response

JSON

{
  "data": [
    { "id": "politics", "name": "Politics", "subcategories": ["elections", "policy"] },
    { "id": "sports", "name": "Sports", "subcategories": ["nfl", "nba", "soccer"] },
    { "id": "finance", "name": "Finance", "subcategories": ["crypto", "stocks", "fed"] }
  ],
  "meta": { "total": 6 }
}

GET/v1/arbitrage

Discover cross-platform arbitrage opportunities where the same market trades at different prices. Perfect for building trading bots or alerts.

Parameters

Name	Type	Description	Default
`min_spread`	number	Minimum price spread to consider (0-1, e.g., 0.05 = 5%)	0.03
`category`	string	Filter opportunities by category	-

Example Request

bash

curl "bash-flag">-H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.propheseer.com/v1/arbitrage?min_spread=0.05"

Example Response

JSON

{
  "data": [
    {
      "question": "Will Trump win 2024 election?",
      "spread": 0.05,
      "potentialReturn": "5.3%",
      "markets": [
        { "source": "polymarket", "yesPrice": 0.52, "url": "..." },
        { "source": "kalshi", "yesPrice": 0.47, "url": "..." }
      ]
    }
  ],
  "meta": { "total": 3 }
}

POST/v1/keys

Create a new API key for your application. Choose a plan based on your expected usage. Keys are generated immediately and can be used right away.

Parameters

Name	Type	Description	Default
`name`	string	A friendly name to identify this key (e.g., 'Production App')	Unnamed Key
`plan`	string	Rate limit tier for this key	free

Example Request

bash

curl "bash-flag">-X POST "bash-flag">-H "Content">-Type: application/json" \
  "bash-flag">-d '{"name": "My App", "plan": "free"}' \
  "https://api.propheseer.com/v1/keys"

Example Response

JSON

{
  "message": "API key created successfully",
  "data": {
    "key": "pk_test_abc123xyz...",
    "name": "My App",
    "plan": "free",
    "limits": { "requestsPerDay": 100, "requestsPerMinute": 10 }
  }
}

GET/v1/keys/me

Retrieve information about your API key including current usage statistics, rate limits, and plan details.

Example Request

bash

curl "bash-flag">-H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.propheseer.com/v1/keys/me"

Example Response

JSON

{
  "data": {
    "id": "key_abc123",
    "name": "My App",
    "plan": "free",
    "limits": { "requestsPerDay": 100, "requestsPerMinute": 10 },
    "usage": { "daily": 45, "minute": 3, "total": 1250 },
    "createdAt": "2025-01-15T10:30:00Z"
  }
}

Error Codes

Code	Status	Description
`UNAUTHORIZED`	401	Missing or invalid API key in Authorization header
`NOT_FOUND`	404	The requested resource does not exist
`RATE_LIMITED`	429	You have exceeded your rate limit. Upgrade your plan or wait.
`INTERNAL_ERROR`	500	An unexpected server error occurred. Please try again.

Data Sources

Polymarket

Crypto-native prediction market with high liquidity, particularly on political and current events.

Market IDs prefixed with pm_

Kalshi

CFTC-regulated exchange, legal for US residents. Diverse categories including economics and weather.

Market IDs prefixed with ks_