brainy/docs/api-reference/search-methods.md

Search Methods API Reference

Complete API documentation for Brainy's search methods with MongoDB-style metadata filtering.

Overview

Brainy provides powerful search capabilities that combine vector similarity with sophisticated metadata filtering. All search methods support the new metadata parameter for advanced filtering using MongoDB-style operators.

Core Search Methods

search(queryVector, k, options)

Vector-based search with metadata filtering

async search<T = any>(
  queryVector: Vector | any,
  k: number = 10,
  options: SearchOptions<T> = {}
): Promise<SearchResult<T>[]>

Parameters

Parameter	Type	Default	Description
queryVector	Vector | any	Required	Query vector or data to be embedded
k	number	10	Maximum number of results to return
options	SearchOptions<T>	{}	Search configuration options

Options

interface SearchOptions<T> {
  nounTypes?: string[]           // Filter by entity types
  includeVerbs?: boolean         // Include relationships in results
  searchMode?: 'local' | 'remote' | 'combined'
  metadata?: MetadataFilter      // MongoDB-style metadata filtering 🆕
  service?: string              // Filter by service that created the data
  offset?: number               // Pagination offset
  forceEmbed?: boolean          // Force embedding even if input is a vector
}

Returns

interface SearchResult<T> {
  id: string
  score: number        // Similarity score (0-1, higher = more similar)
  vector: Vector
  metadata: T
  nounType?: string
  createdBy?: any
}

Example

const results = await brainy.search("smartphone", 10, {
  metadata: {
    category: { $in: ["electronics", "mobile"] },
    brand: "Apple",
    price: { $lt: 1000 }
  },
  nounTypes: ["product"],
  includeVerbs: true
})

---

searchText(query, k, options)

Text-based search with automatic embedding

async searchText(
  query: string,
  k: number = 10,
  options: TextSearchOptions = {}
): Promise<SearchResult<T>[]>

Parameters

Parameter	Type	Default	Description
query	string	Required	Text query to search for
k	number	10	Maximum number of results to return
options	TextSearchOptions	{}	Search configuration options

Options

interface TextSearchOptions {
  nounTypes?: string[]          // Filter by entity types
  includeVerbs?: boolean        // Include relationships in results
  searchMode?: 'local' | 'remote' | 'combined'
  metadata?: MetadataFilter     // MongoDB-style metadata filtering 🆕
}

Example

const results = await brainy.searchText("gaming laptop", 15, {
  metadata: {
    availability: { $in: ["in_stock", "preorder"] },
    price: { $lte: 2000 },
    specs: { $all: ["RTX4060", "16GB RAM"] }
  },
  nounTypes: ["product"]
})

---

searchByNounTypes(queryVector, k, nounTypes, options)

Search within specific entity types with metadata filtering

async searchByNounTypes(
  queryVectorOrData: Vector | any,
  k: number = 10,
  nounTypes: string[] | null = null,
  options: SearchByNounTypesOptions = {}
): Promise<SearchResult<T>[]>

Parameters

Parameter	Type	Default	Description
queryVectorOrData	Vector | any	Required	Query vector or data to be embedded
k	number	10	Maximum number of results to return
nounTypes	string[] | null	null	Specific entity types to search within
options	SearchByNounTypesOptions	{}	Search configuration options

Options

interface SearchByNounTypesOptions {
  forceEmbed?: boolean         // Force embedding even if input is a vector
  service?: string            // Filter by service that created the data
  metadata?: MetadataFilter   // MongoDB-style metadata filtering 🆕
  offset?: number            // Pagination offset
}

Example

const results = await brainy.searchByNounTypes(
  "organic coffee beans",
  20,
  ["product", "food_item"],
  {
    metadata: {
      $and: [
        { certification: "organic" },
        { origin: { $includes: "Ethiopia" } },
        { availability: { $ne: "out_of_stock" } }
      ]
    },
    service: "ecommerce_platform"
  }
)

---

Metadata Filtering

MetadataFilter Interface

The metadata filtering system supports MongoDB-style operators for complex queries:

type MetadataFilter = {
  [field: string]: any | {
    // Comparison operators
    $eq?: any
    $ne?: any
    $gt?: number | string | Date
    $gte?: number | string | Date
    $lt?: number | string | Date
    $lte?: number | string | Date
    
    // Array operators
    $in?: any[]
    $nin?: any[]
    $all?: any[]
    $includes?: any
    $size?: number
    
    // String operators
    $regex?: string
    $startsWith?: string
    $endsWith?: string
    $contains?: string
    
    // Existence operators
    $exists?: boolean
    $type?: 'string' | 'number' | 'boolean' | 'object' | 'array'
  }
  
  // Logical operators
  $and?: MetadataFilter[]
  $or?: MetadataFilter[]
  $not?: MetadataFilter
  $nor?: MetadataFilter[]
}

Operator Examples

Comparison Operators

// Equal (implicit)
{ category: "books" }

// Explicit comparison
{ 
  price: { $lte: 50 },
  pages: { $gt: 200 },
  rating: { $ne: null }
}

Array Operators

{
  genres: { $in: ["Fiction", "Mystery", "Thriller"] },  // Has any of these genres
  awards: { $all: ["Hugo", "Nebula"] },                // Has all awards
  chapters: { $size: 12 },                             // Exactly 12 chapters
  tags: { $includes: "bestseller" }                     // Array contains "bestseller"
}

String Operators

{
  isbn: { $regex: "^978-" },                      // ISBN starts with 978
  title: { $startsWith: "The" },                 // Title starts with "The"
  description: { $contains: "adventure" },       // Description contains "adventure"
  publisher: { $endsWith: "Press" }              // Publisher ends with "Press"
}

Logical Operators

{
  $and: [
    { category: "electronics" },
    { warranty: true }
  ],
  $or: [
    { brand: "Apple" },
    { brand: "Samsung" }
  ],
  $not: { status: "discontinued" }
}

Nested Fields (Dot Notation)

{
  "specs.display.size": { $gte: 15 },
  "specs.processor.brand": "Intel",
  "ratings.average": { $gt: 4.5 }
}

---

Advanced Search Options

Combining Multiple Filters

You can combine metadata filtering with other search options:

const results = await brainy.search("science textbook", 10, {
  // Entity type filtering
  nounTypes: ["book"],
  
  // Service filtering  
  service: "academic_platform",
  
  // Metadata filtering
  metadata: {
    subject: { $in: ["physics", "chemistry"] },
    format: { $includes: "hardcover" },
    condition: { $ne: "damaged" }
  },
  
  // Include relationships
  includeVerbs: true,
  
  // Pagination
  offset: 20
})

Search Modes

Control how search is performed:

const results = await brainy.searchText("cooking recipes", 10, {
  searchMode: "local",     // Search only local data
  // searchMode: "remote",    // Search only remote instances  
  // searchMode: "combined",  // Search local + remote (default)
  
  metadata: {
    cuisine: { $includes: "italian" }
  }
})

---

Performance Considerations

Index Optimization

Metadata filtering uses automatic indexing for optimal performance:

• Pre-filtering: Uses indexes to identify candidates before vector search
• Automatic maintenance: Indexes update when data changes
• Memory efficient: LRU caching with configurable limits

Query Performance Tips

1. Use specific filters first:

   // Faster: specific equality
   { category: "books" }
   
   // Slower: negation
   { category: { $ne: "magazines" } }
   

2. Combine filters efficiently:

   // Faster: most selective filter first
   {
     isbn: "978-0123456789",       // High selectivity
     genre: { $includes: "mystery" }, // Medium selectivity  
     in_stock: true                 // Low selectivity
   }
   

3. Use appropriate operators:

   // For arrays, use array operators
   { genres: { $includes: "mystery" } }   // ✅ Correct
   { genres: "mystery" }                  // ❌ Won't match arrays
   

Index Configuration

Configure indexing behavior:

const brainy = new BrainyData({
  metadataIndex: {
    maxIndexSize: 50000,           // Max entries per field+value
    rebuildThreshold: 0.05,        // Rebuild when 5% stale
    autoOptimize: true,            // Auto-cleanup unused entries
    indexedFields: ["category", "brand"],  // Only index specific fields
    excludeFields: ["internal_id", "temp"] // Never index sensitive fields
  }
})

---

Error Handling

Common Errors

try {
  const results = await brainy.search("query", 10, {
    metadata: { level: "senior" }
  })
} catch (error) {
  if (error.message.includes('MetadataIndexError')) {
    // Index-related error
    console.error('Metadata index error:', error)
  } else if (error.message.includes('ValidationError')) {
    // Invalid query format
    console.error('Invalid metadata query:', error)
  } else {
    // Other search errors
    console.error('Search error:', error)
  }
}

Query Validation

Brainy validates metadata queries and provides helpful error messages:

// Invalid operator
{ price: { $invalid: 25 } }
// Error: Unknown operator '$invalid'

// Type mismatch
{ pages: { $gt: "not_a_number" } }  
// Error: $gt operator requires number, got string

// Invalid regex
{ title: { $regex: "[invalid" } }
// Error: Invalid regular expression

---

Migration Guide

From Simple Filtering

// Before (v0.47.x and earlier)
const results = await brainy.search("laptop", 10, {
  filter: { brand: "Apple" }  // Simple object matching
})

// After (v0.48.x+) - Backward compatible!
const results = await brainy.search("laptop", 10, {
  metadata: { 
    brand: "Apple",                     // Same simple matching
    price: { $lte: 2000 },             // Plus MongoDB operators
    specs: { $includes: "SSD" }         // Plus array operations
  }
})

Automatic Migration

• No code changes required - existing searches continue to work
• Indexes build automatically - on first startup after upgrade
• Performance improves gradually - as indexes populate

---

Examples by Use Case

Academic Library

// Find advanced textbooks
const textbooks = await brainy.searchText("mathematics textbook", 20, {
  metadata: {
    level: { $in: ["undergraduate", "graduate", "advanced"] },
    subject: { $in: ["calculus", "algebra", "statistics"] },
    format: { $all: ["hardcover", "solutions_manual"] },
    availability: "in_stock"
  }
})

// Find research papers with specific citations
const researchPapers = await brainy.search(queryVector, 15, {
  metadata: {
    citations: { $gte: 10, $lte: 1000 },
    $or: [
      { "author.degree": { $in: ["PhD", "Masters"] } },
      { awards: { $size: { $gte: 1 } } }
    ]
  }
})

E-commerce Platform

// Product search with filters
const products = await brainy.searchText("wireless headphones", 25, {
  metadata: {
    category: "electronics",
    price: { $lte: 200 },
    rating: { $gte: 4.0 },
    availability: { $ne: "out_of_stock" },
    features: { $all: ["bluetooth", "noise_canceling"] }
  }
})

Content Management

// Find published articles
const articles = await brainy.searchText("climate change", 10, {
  metadata: {
    status: "published",
    publish_date: { $gte: "2023-01-01" },
    author: { $in: ["Dr. Green", "Prof. Earth"] },
    tags: { $includes: "environment" },
    word_count: { $gte: 1000 }
  }
})

---

Performance Monitoring

Index Statistics

// Get index performance metrics
const stats = await brainy.metadataIndex?.getStats()
console.log(`Index entries: ${stats.totalEntries}`)
console.log(`Fields indexed: ${stats.fieldsIndexed}`)
console.log(`Memory usage: ${stats.indexSize} bytes`)

Search Performance

// Monitor search performance
const start = Date.now()
const results = await brainy.search("query", 10, {
  metadata: { category: "electronics" }
})
const duration = Date.now() - start
console.log(`Search completed in ${duration}ms`)
console.log(`Found ${results.length} results`)

This API reference provides complete documentation for all search methods with metadata filtering. The MongoDB-style operators give you powerful querying capabilities while maintaining high performance through automatic indexing.