List Markets - Adjacent News API

Comprehensive Market Discovery & Filtering

This endpoint is your gateway to exploring prediction markets across multiple platforms with unprecedented flexibility and control. Whether you’re building market dashboards, conducting research, or developing trading applications, this endpoint provides powerful filtering, sorting, and pagination capabilities to help you find exactly the markets you need.

Key Features & Capabilities

🎯 Multi-Platform Access

Access markets from all major prediction market platforms:

Kalshi - Regulated US prediction markets
Polymarket - Crypto-based prediction markets
Manifold Markets - Community-driven forecasting
Metaculus - Research-focused forecasting platform

🔍 Advanced Filtering

Filter markets by virtually any attribute:

Platform & Type: Specific platforms, market types
Content: Keywords in questions, descriptions, rules
Status & Dates: Active, resolved, creation dates, end dates
Numerical Values: Probability ranges, volume thresholds, liquidity levels
Categories: Politics, economics, technology, sports, entertainment
Geography: Region-specific markets

📊 Flexible Sorting

Sort results by any field in ascending or descending order:

Recency: created_at, updated_at
Activity: volume, trades_count
Market Metrics: probability, liquidity, open_interest
Engagement: comments_count

📄 Smart Pagination

Efficient pagination with metadata for building interfaces:

Total count information
Pagination state tracking
“Has more” indicators
Configurable page sizes

Query Parameters Reference

Core Parameters

limit

integer

default:50

Maximum number of markets to return per request.

Range: 1-1000 (unauthenticated max: 100)
Default: 50
Tip: Use 10-20 for UI components, 100-500 for data analysis

offset

integer

default:0

Number of markets to skip (for pagination).

Usage: offset = page * limit
Example: Page 3 with 50 per page = offset=100

sort

string

default:"created_at:desc"

Sort order for results.Format: field:directionPopular Sort Options:

created_at:desc - Newest first (default)
updated_at:desc - Recently updated
volume:desc - Highest volume
probability:desc - Highest probability
end_date:asc - Ending soonest
liquidity:desc - Most liquid

Platform & Type Filters

platform

string

Filter by specific platforms.Supported Values:

kalshi - Kalshi markets
polymarket - Polymarket
manifold - Manifold Markets
metaculus - Metaculus

Format: "kalshi,polymarket" for multiple platforms

market_type

string

Filter by market type.Common Types:

binary - Yes/No markets
multiple_choice - Multiple outcome markets
numerical - Numerical prediction markets
conditional - Conditional prediction markets

Status & Date Filters

status

string

Filter by market status.Status Values:

active - Currently active for trading
resolved - Market has been resolved
closed - Closed but not yet resolved
suspended - Temporarily suspended
cancelled - Cancelled market

created_after

string

Include markets created after this date.Format: ISO 8601 date string (2024-01-01T00:00:00Z) Example: created_after=2024-01-01 for markets from 2024

created_before

string

Include markets created before this date.Format: ISO 8601 date string Use Case: Historical analysis, specific time periods

end_date_after

string

Include markets ending after this date.Format: ISO 8601 date string Use Case: Find markets ending in a specific timeframe

end_date_before

string

Include markets ending before this date.Format: ISO 8601 date string Use Case: Find markets ending soon or in the past

Content Search Filters

string

Search within market questions, descriptions, and rules.Search Capabilities:

Full-text search across all market content
Supports partial matches and stemming
Case-insensitive search

Examples:

q=presidential election - Find election-related markets
q=climate change - Environmental markets
q=AI artificial intelligence - Technology markets

question_contains

string

Search specifically within market questions.Use Case: More targeted search than general q parameter Example: question_contains=Will Trump for specific question patterns

Numerical Filters

probability_min

number

Minimum probability (0.0 to 1.0).Example: probability_min=0.7 for high-probability markets Use Case: Find markets with strong conviction

probability_max

number

Maximum probability (0.0 to 1.0).Example: probability_max=0.3 for low-probability markets Use Case: Find contrarian opportunities

volume_min

number

Minimum trading volume.Use Case: Filter for liquid, actively traded markets Example: volume_min=10000 for markets with significant activity

liquidity_min

number

Minimum liquidity/open interest.Use Case: Ensure markets have sufficient depth for trading Example: liquidity_min=5000 for well-funded markets

Category & Tag Filters

Response Format

Successful Response Structure

{
  "data": [
    {
      "market_id": "kalshi_KXSECPRESSMENTION-25JUN30-HOAX",
      "platform": "kalshi",
      "platform_id": "KXSECPRESSMENTION-25JUN30-HOAX",
      "adj_ticker": "HOAX-MENTION-JUNE-2025",
      "question": "Will the White House Press Secretary say 'Hoax' at her next press briefing?",
      "description": "This market resolves to 'Yes' if the White House Press Secretary uses the word 'hoax' during any official press briefing...",
      "rules": "Market resolves based on official White House press briefing transcripts...",
      "status": "active",
      "market_type": "binary",
      "category": "politics",
      "probability": 0.23,
      "volume": 45000,
      "liquidity": 8500,
      "open_interest": 12000,
      "trades_count": 156,
      "comments_count": 89,
      "created_at": "2025-01-15T10:30:00Z",
      "updated_at": "2025-01-24T14:22:00Z",
      "end_date": "2025-06-30T23:59:59Z",
      "resolution_date": null,
      "link": "https://kalshi.com/events/KXSECPRESSMENTION-25JUN30-HOAX",
      "tags": ["politics", "white-house", "press-briefing", "communication"],
      "event": "White House Communications",
      "settlement_sources": ["whitehouse.gov", "c-span.org"]
    }
    // ... more markets
  ],
  "meta": {
    "count": 1247,        // Total matching markets
    "limit": 50,          // Requested limit  
    "offset": 0,          // Current offset
    "hasMore": true,      // Whether more results exist
    "page": 1,            // Current page (calculated)
    "totalPages": 25,     // Total pages (calculated) 
    "filters": {          // Applied filters summary
      "status": "active",
      "platform": ["kalshi", "polymarket"],
      "category": "politics"
    },
    "sort": "created_at:desc"
  }
}

Field Descriptions

Field	Type	Description
`market_id`	string	Unique identifier across all platforms
`platform`	string	Source platform (kalshi, polymarket, etc.)
`platform_id`	string	Platform-specific identifier
`adj_ticker`	string	Adjacent News standardized ticker
`question`	string	Market question or title
`description`	string	Detailed market description
`rules`	string	Resolution rules and conditions
`status`	string	Current market status
`market_type`	string	Type of market (binary, multiple_choice, etc.)
`category`	string	Market category
`probability`	number	Current probability (0.0-1.0)
`volume`	number	Total trading volume
`liquidity`	number	Current liquidity/open interest
`trades_count`	integer	Number of trades
`comments_count`	integer	Number of comments
`created_at`	string	Market creation timestamp
`updated_at`	string	Last update timestamp
`end_date`	string	Market end/close date
`resolution_date`	string	Actual resolution date (if resolved)
`link`	string	Direct link to market on platform
`tags`	array	Associated tags
`event`	string	Parent event (if applicable)

Comprehensive Examples

Basic Market Discovery

# Get 20 most recent active markets
curl "https://api.data.adj.news/api/markets?status=active&limit=20&sort=created_at:desc"

# Browse markets by category
curl "https://api.data.adj.news/api/markets?category=politics&limit=25"

# Find high-volume markets
curl "https://api.data.adj.news/api/markets?volume_min=50000&sort=volume:desc"

Platform-Specific Queries

# Get all Kalshi markets
curl "https://api.data.adj.news/api/markets?platform=kalshi"

# Compare markets across platforms
curl "https://api.data.adj.news/api/markets?platform=kalshi,polymarket&q=presidential%20election"

# Manifold Markets community predictions
curl "https://api.data.adj.news/api/markets?platform=manifold&sort=comments_count:desc"

Time-Based Filtering

# Markets created in the last 7 days
curl "https://api.data.adj.news/api/markets?created_after=2025-01-17T00:00:00Z"

# Markets ending in the next 30 days
curl "https://api.data.adj.news/api/markets?end_date_after=2025-01-24T00:00:00Z&end_date_before=2025-02-24T00:00:00Z"

# Historical markets from 2024
curl "https://api.data.adj.news/api/markets?created_after=2024-01-01&created_before=2024-12-31" \
  -H "Authorization: Bearer YOUR_API_KEY"

Advanced Filtering Combinations

# High-conviction political markets
curl "https://api.data.adj.news/api/markets?category=politics&probability_min=0.8&volume_min=10000"

# Low-probability opportunities with good liquidity
curl "https://api.data.adj.news/api/markets?probability_max=0.2&liquidity_min=5000&status=active"

# Technology markets ending soon
curl "https://api.data.adj.news/api/markets?category=technology&end_date_before=2025-02-01T00:00:00Z&status=active"

Content-Based Search

# Search for election-related markets
curl "https://api.data.adj.news/api/markets?q=presidential%20election%202024"

# Find AI and technology markets
curl "https://api.data.adj.news/api/markets?question_contains=artificial%20intelligence&category=technology"

# Climate change predictions
curl "https://api.data.adj.news/api/markets?q=climate%20change%20global%20warming&tags=environment,climate"

Pagination Strategies

Standard Pagination

# Page 1 (first 50 markets)
curl "https://api.data.adj.news/api/markets?limit=50&offset=0"

# Page 2 (next 50 markets)  
curl "https://api.data.adj.news/api/markets?limit=50&offset=50"

# Page 3 (next 50 markets)
curl "https://api.data.adj.news/api/markets?limit=50&offset=100"

Cursor-Based Pagination

For real-time applications, use timestamp-based pagination:

# Initial request
curl "https://api.data.adj.news/api/markets?sort=created_at:desc&limit=50"

# Next page using last item's timestamp
curl "https://api.data.adj.news/api/markets?created_before=2025-01-24T10:30:00Z&sort=created_at:desc&limit=50"

Use Cases & Applications

1. Market Discovery Dashboards

# Featured markets widget
curl "https://api.data.adj.news/api/markets?volume_min=25000&sort=volume:desc&limit=10"

# Trending markets (high recent activity)
curl "https://api.data.adj.news/api/markets?sort=updated_at:desc&limit=15"

# Ending soon section
curl "https://api.data.adj.news/api/markets?status=active&end_date_before=2025-02-07T00:00:00Z&sort=end_date:asc&limit=8"

2. Research & Analysis

# Dataset for political market analysis
curl "https://api.data.adj.news/api/markets?category=politics&created_after=2024-01-01&limit=1000" \
  -H "Authorization: Bearer YOUR_API_KEY"

# Technology market trends
curl "https://api.data.adj.news/api/markets?category=technology&volume_min=5000&sort=created_at:desc&limit=500"

# Cross-platform comparison dataset
curl "https://api.data.adj.news/api/markets?q=artificial%20intelligence&platform=kalshi,polymarket,metaculus"

3. Trading Applications

# High-liquidity opportunities
curl "https://api.data.adj.news/api/markets?status=active&liquidity_min=10000&sort=liquidity:desc"

# Arbitrage opportunities (same events across platforms)
curl "https://api.data.adj.news/api/markets?q=Trump%202024&platform=kalshi,polymarket"

# Portfolio monitoring
curl "https://api.data.adj.news/api/markets?market_id=kalshi_EVENT1,polymarket_EVENT2,manifold_EVENT3"

4. Content Curation

# Weekly newsletter content
curl "https://api.data.adj.news/api/markets?created_after=2025-01-17T00:00:00Z&volume_min=5000&sort=volume:desc&limit=20"

# Category-specific feeds
curl "https://api.data.adj.news/api/markets?category=sports&status=active&end_date_after=2025-01-24T00:00:00Z"

# Community highlights
curl "https://api.data.adj.news/api/markets?comments_count_min=50&sort=comments_count:desc&limit=10"

Performance & Optimization

Response Time Guidelines

Typical Performance:

Simple queries: 50-200ms
Complex filtering: 200-500ms
Large datasets: 500ms-2s
Historical data: 1-3s (authenticated)

Optimization Strategies

Use Appropriate Limits:

# Good for UI components
curl "https://api.data.adj.news/api/markets?limit=20"

# Good for data analysis
curl "https://api.data.adj.news/api/markets?limit=500"

Leverage Sorting:

# Pre-sorted data reduces client processing
curl "https://api.data.adj.news/api/markets?sort=volume:desc&limit=100"

Strategic Filtering:

# Filter on indexed fields for better performance
curl "https://api.data.adj.news/api/markets?platform=kalshi&status=active"

Caching Recommendations

// Example caching strategy
function getCacheKey(params) {
  const sorted = Object.keys(params).sort().reduce((result, key) => {
    result[key] = params[key];
    return result;
  }, {});
  return `markets:${JSON.stringify(sorted)}`;
}

// Cache duration based on query type
const getCacheDuration = (params) => {
  if (params.status === 'resolved') return 3600; // 1 hour for resolved
  if (params.sort === 'created_at:desc') return 300; // 5 min for recent
  return 600; // 10 min default
};

Error Handling & Troubleshooting

Common Issues

1. No Results Found

{
  "data": [],
  "meta": {
    "count": 0,
    "filters": {...},
    "suggestion": "Try removing some filters or broadening search terms"
  }
}

Solutions:

Remove restrictive filters one by one
Check for typos in filter values
Verify date formats are correct
Try broader search terms

2. Rate Limiting

{
  "error": {
    "code": "RATE_LIMIT_EXCEEDED",
    "message": "Rate limit exceeded. Please try again later.",
    "details": {
      "reset_time": "2025-01-24T15:35:00Z",
      "limit": 300,
      "window": "60s"
    }
  }
}

Solutions:

Implement exponential backoff
Cache results to reduce API calls
Consider upgrading to authenticated access
Batch requests more efficiently

3. Invalid Parameters

{
  "error": {
    "code": "INVALID_PARAMETER",
    "message": "Invalid value for 'probability_min' parameter",
    "details": {
      "parameter": "probability_min",
      "value": "1.5",
      "valid_range": "0.0-1.0"
    }
  }
}

Solutions:

Check parameter value ranges
Verify date format (ISO 8601)
Ensure numeric parameters are numbers
Review API documentation for valid options

Authentication Requirements

Remember that enhanced access requires authentication:

# Unauthenticated (limited)
curl "https://api.data.adj.news/api/markets?limit=50"

# Authenticated (full access)
curl "https://api.data.adj.news/api/markets?limit=1000&created_after=2023-01-01" \
  -H "Authorization: Bearer YOUR_API_KEY"

Authentication Provides:

Access to historical data (>1 day old)
Higher rate limits (1000/min vs 300/min)
Larger result sets (>100 items)
Priority support

Best Practices

1. Efficient Querying

Start with broad queries, then narrow down
Use specific platforms when possible
Leverage sorting to reduce client-side processing
Cache frequently accessed data

2. Pagination Strategy

Use reasonable page sizes (20-100 items)
Implement “load more” for user interfaces
Consider cursor-based pagination for real-time data
Track pagination state in your application

3. Error Handling

Always handle rate limiting gracefully
Implement retry logic with exponential backoff
Provide fallback options for users
Log errors for monitoring and debugging

4. User Experience

Show loading states for slower queries
Implement search suggestions based on popular queries
Provide filter explanations in your UI
Cache and persist user preferences

Need Assistance? Contact our team at lucas@adj.news with:

Specific query patterns that aren’t performing well
Feature requests for additional filtering options
Integration questions or optimization guidance

Authorizations

Authorization

string

header

required

Enter your API key as the bearer token

Query Parameters

limit

integer

default:5

Number of results to return, default is 5 results

offset

integer

default:0

Number of results to skip

platform

string

Filter by platform (e.g., kalshi, polymarket, etc.)

status

string

Filter by status (e.g., active, resolved, etc.)

Response

200

application/json

List of markets

The response is of type object.

Markets API

Search API

News API

Trade API

Indices API

​Comprehensive Market Discovery & Filtering

​Key Features & Capabilities

​🎯 Multi-Platform Access

​🔍 Advanced Filtering

​📊 Flexible Sorting

​📄 Smart Pagination

​Query Parameters Reference

​Core Parameters

​Platform & Type Filters

​Status & Date Filters

​Content Search Filters

​Numerical Filters

​Category & Tag Filters

​Response Format

​Successful Response Structure

​Field Descriptions

​Comprehensive Examples

​Basic Market Discovery

​Platform-Specific Queries

​Time-Based Filtering

​Advanced Filtering Combinations

​Content-Based Search

​Pagination Strategies

​Standard Pagination

​Cursor-Based Pagination

​Use Cases & Applications

​1. Market Discovery Dashboards

​2. Research & Analysis

​3. Trading Applications

​4. Content Curation

​Performance & Optimization

​Response Time Guidelines

​Optimization Strategies

​Caching Recommendations

​Error Handling & Troubleshooting

​Common Issues

​1. No Results Found

​2. Rate Limiting

​3. Invalid Parameters

​Authentication Requirements

​Best Practices

​1. Efficient Querying

​2. Pagination Strategy

​3. Error Handling

​4. User Experience

Authorizations

Query Parameters

Response

Comprehensive Market Discovery & Filtering

Key Features & Capabilities

🎯 Multi-Platform Access

🔍 Advanced Filtering

📊 Flexible Sorting

📄 Smart Pagination

Query Parameters Reference

Core Parameters

Platform & Type Filters

Status & Date Filters

Content Search Filters

Numerical Filters

Category & Tag Filters

Response Format

Successful Response Structure

Field Descriptions

Comprehensive Examples

Basic Market Discovery

Platform-Specific Queries

Time-Based Filtering

Advanced Filtering Combinations

Content-Based Search

Pagination Strategies

Standard Pagination

Cursor-Based Pagination

Use Cases & Applications

1. Market Discovery Dashboards

2. Research & Analysis

3. Trading Applications

4. Content Curation

Performance & Optimization

Response Time Guidelines

Optimization Strategies

Caching Recommendations

Error Handling & Troubleshooting

Common Issues

1. No Results Found

2. Rate Limiting

3. Invalid Parameters

Authentication Requirements

Best Practices

1. Efficient Querying

2. Pagination Strategy

3. Error Handling

4. User Experience