This page covers the advanced configuration options available in the Upstash Search. These parameters allow you to fine-tune search behavior for your specific use case and requirements.

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Reranking

The reranking parameter enables enhanced search result reranking using advanced AI models. It’s disabled by default (false) and incurs additional costs when enabled. 
const results = await index.search({
  query: "complex technical documentation",
  reranking: true // Enable reranking
});
Reranking Options:
  • Standard Reranking (reranking: false, default): Uses a simpler, faster model with no additional cost
  • Advanced Reranking (reranking: true): Uses state-of-the-art models for highest quality results at $1 per 1K operations
Learn more about how reranking works in our Algorithm documentation.

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Semantic Weight

The semanticWeight parameter controls the balance between semantic search and full-text search in the hybrid search process. It accepts values from 0 to 1, with a default of 0.75 (75% semantic, 25% full-text). 
// More semantic matching (better for conceptual searches)
const semanticResults = await index.search({
  query: "artificial intelligence concepts",
  semanticWeight: 0.9 // 90% semantic, 10% full-text
});

// More keyword matching (better for exact terms)
const keywordResults = await index.search({
  query: "API documentation React hooks",
  semanticWeight: 0.3 // 30% semantic, 70% full-text
});
Optimization Guidelines:
  • Higher semantic weight (0.7-1.0): Better for conceptual searches, finding related content, and handling synonyms
  • Lower semantic weight (0.0-0.4): Better for exact keyword matching, technical queries, and specific terms
Read more about hybrid search in our Algorithm documentation.

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Input Enrichment

The inputEnrichment parameter controls whether queries are enhanced using AI before searching. It’s enabled by default (true) and significantly improves search quality at the cost of some additional latency. 
// Disable input enrichment for faster responses
const results = await index.search({
  query: "space opera",
  inputEnrichment: false // Faster but less enhanced results
});

// Default behavior (enrichment enabled)
const enrichedResults = await index.search({
  query: "space opera"
  // inputEnrichment: true is the default
});
When to Disable Input Enrichment:
  • When you need the fastest possible response times
  • When you want to preserve the exact user query for full-text search
Benefits of Input Enrichment:
  • Handles typos and alternative phrasings
  • Expands queries with related terms and context
  • Improves understanding of user intent
  • Adds semantic context to ambiguous queries
Learn more about input enrichment in our Algorithm documentation.

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Filter

The filter parameter allows you to restrict search results based on content criteria. It accepts either a string expression (SQL-like syntax) or a structured filter object (TypeScript SDK only). 
// String filter expression (SQL-like syntax)
const results = await index.search({
  query: "wireless headphones",
  filter: "category = 'Electronics' AND in_stock > 0"
});

// TypeSafe structured filter (TypeScript SDK only)
const results2 = await index.search({
  query: "wireless headphones",
  filter: {
    AND: [
      { category: { equals: 'Electronics' } },
      { in_stock: { greaterThan: 0 } }
    ]
  }
});
For detailed information about filter syntax, operators, and examples, see the Filtering documentation.

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Example: Complete Configuration

Here’s an example showing all parameters configured together: 
const results = await index.search({
  query: "machine learning algorithms for data analysis",
  limit: 15,
  filter: "category = 'data-science' AND difficulty_level <= 'intermediate'",
  reranking: true,
  semanticWeight: 0.8,
  inputEnrichment: true
});
This configuration:
  • Searches for ML content with enhanced query processing
  • Returns up to 15 results
  • Filters for data science content at beginner to intermediate levels
  • Uses premium reranking for best quality results
  • Emphasizes semantic matching (80%) over keyword matching (20%)
  • Enables input enrichment for better intent understanding