Reranking

Reranking reorders documents by relevance to a query, the second pass after similarity search narrows the field. Cohere, Jina, Bedrock, VoyageAI, and OpenRouter rerank; each returns scored documents in descending order.

Reranking documents

Pass plain strings; limit() caps the results, timeout() bounds the call, and the provider rides along per request:

use Crustum\Ai\Reranking;

$response = Reranking::of([
    'Django is a Python web framework.',
    'CakePHP is a PHP web application framework.',
    'React is a JavaScript library for building user interfaces.',
])->limit(2)->rerank('PHP frameworks');
echo count($response) . " documents\n";
echo $response->first()->document . PHP_EOL;

2 documents
React is a JavaScript library for building user interfaces.

first() is the top result; every entry carries document, score, and its original index. Collections rerank through the same call. Collections::of($posts)->rerank(query: '...', by: 'content', limit: 10) resolves each item's text with a field name, fields, or closure.

See also

• Providers — capability matrix
• Cohere — the rerank specialist
• Jina — search-stack reranking
• Bedrock — AWS-hosted rerank