VectorFilter

VectorFilter is a fluent API for filtering vector store queries by metadata. It applies to IVectorStore.SearchAsync, HybridSearchAsync, and RAG queries.

Basic Equality

var filter = new VectorFilter()
    .Where("source", "manual.pdf")
    .Where("language", "en");

Comparison Operators

var filter = new VectorFilter()
    .WhereGreaterThan("date", "2024-01-01")
    .WhereLessThanOrEqual("priority", "3")
    .WhereNot("status", "archived");

Method	SQL Equivalent
`.Where(key, value)`	`key = value`
`.WhereNot(key, value)`	`key != value`
`.WhereGreaterThan(key, value)`	`key > value`
`.WhereGreaterThanOrEqual(key, value)`	`key >= value`
`.WhereLessThan(key, value)`	`key < value`
`.WhereLessThanOrEqual(key, value)`	`key <= value`
`.WhereLike(key, pattern)`	`key LIKE pattern`

Set Membership

var filter = new VectorFilter()
    .WhereIn("category", "legal", "compliance", "policy")
    .WhereNotIn("type", "draft", "archived");

Key Existence

var filter = new VectorFilter()
    .WhereExists("reviewed_by")      // Key must be present
    .WhereNotExists("deprecated");   // Key must be absent

Logical Grouping (AND / OR)

Conditions at the same level are combined with AND by default. Use .Or() to create OR groups:

var filter = new VectorFilter()
    .Where("source", "manual.pdf")
    .Or(f => f
        .Where("type", "urgent")
        .Where("priority", "high")
    );
// source = "manual.pdf" AND (type = "urgent" OR priority = "high")

Nested AND:

var filter = new VectorFilter()
    .Or(f => f
        .And(a => a.Where("lang", "en").Where("region", "us"))
        .And(a => a.Where("lang", "ko").Where("region", "kr"))
    );
// (lang = "en" AND region = "us") OR (lang = "ko" AND region = "kr")

Score Threshold

var filter = new VectorFilter()
    .Where("source", "faq.pdf")
    .WithMinScore(0.75);

Using with Vector Store

var filter = new VectorFilter()
    .Where("document_type", "contract")
    .WhereGreaterThan("year", "2023");

var results = await vectorStore.SearchAsync(
    queryVector: embedding,
    topK: 5,
    filter: filter
);

Using with RAG

Pass as StoreFilter in RagQueryOptions:

var options = new RagQueryOptions
{
    StoreFilter = new VectorFilter()
        .Where("source", "product-manual.pdf")
        .WithMinScore(0.7)
};

var response = await ragService.GetCompletionAsync("How do I reset the device?", options);

Merging Filters

Use AppendConditionsFrom to combine two filters (e.g., merging a pipeline-level filter with a per-query filter):

var baseFilter = new VectorFilter().Where("tenant", "acme");
var queryFilter = new VectorFilter().Where("language", "en");

baseFilter.AppendConditionsFrom(queryFilter);
// baseFilter now has both conditions

Table of Contents