rerank()

The rerank() function provides advanced reranking capabilities for vector search results by combining semantic relevance, vector similarity, and position-based scoring.

function rerank(
  results: QueryResult[],
  query: string,
  modelConfig: ModelConfig,
  options?: RerankerFunctionOptions,
): Promise<RerankResult[]>;

Usage Example

import { openai } from "@ai-sdk/openai";
import { rerank } from "@mastra/rag";

const model = openai("gpt-4o-mini");

const rerankedResults = await rerank(
  vectorSearchResults,
  "How do I deploy to production?",
  model,
  {
    weights: {
      semantic: 0.5,
      vector: 0.3,
      position: 0.2,
    },
    topK: 3,
  },
);

Parameters

results:

QueryResult[]

The vector search results to rerank

query:

string

The search query text used to evaluate relevance

model:

MastraLanguageModel

The language Model to use for reranking

options?:

RerankerFunctionOptions

Options for the reranking model

The rerank function accepts any LanguageModel from the Vercel AI SDK. When using the Cohere model rerank-v3.5, it will automatically use Cohere's reranking capabilities.

Note: For semantic scoring to work properly during re-ranking, each result must include the text content in its metadata.text field.

RerankerFunctionOptions

weights?:

WeightConfig

Weights for different scoring components (must add up to 1)

number

semantic?:

number (default: 0.4)

Weight for semantic relevance

number

vector?:

number (default: 0.4)

Weight for vector similarity

number

position?:

number (default: 0.2)

Weight for position-based scoring

queryEmbedding?:

number[]

Embedding of the query

topK?:

number

= 3

Number of top results to return

Returns

The function returns an array of RerankResult objects:

result:

QueryResult

The original query result

score:

number

Combined reranking score (0-1)

details:

ScoringDetails

Detailed scoring information

ScoringDetails

semantic:

number

Semantic relevance score (0-1)

vector:

number

Vector similarity score (0-1)

position:

number

Position-based score (0-1)

queryAnalysis?:

object

Query analysis details

number

magnitude:

Magnitude of the query

number[]

dominantFeatures:

Dominant features of the query

Related

• createVectorQueryTool