Aggregate Optimizely Graph results using the C# SDK

Use .Facet() to retrieve value counts for one or more fields alongside query results. Facets power category navigation, filter-by-author panels, and other UI patterns that require aggregated counts.

Retrieve facet counts

var result = await client
    .QueryContent<BlogPostPage>()
    .Facet(x => x.Author!)
    .Facet(x => x.ViewCount!)
    .GetAsContentAsync();

Read the counts back from the result:

var authorFacet = result.Facets?.GetFacet(x => x.Author);
var viewCountFacet = result.Facets?.GetFacet(x => x.ViewCount);

Each facet entry contains a value and its count.

Use facets with full-text search

Facet counts reflect the current search results, not the full content set:

var result = await client
    .QueryContent<BlogPostPage>()
    .SearchFor("api")
    .UsingFullText()
    .Facet(x => x.ViewCount)
    .GetAsContentAsync();

Filter within facets

Pass filters to apply a value filter while keeping the full facet list. This is essential for faceted navigation. Users can refine or change their selection without losing the other options:

var result = await client
    .QueryContent<BlogPostPage>()
    .Facet(x => x.Author, filters: ["John Developer"])
    .GetAsContentAsync();

The result set is filtered to posts by John Developer, but the facet still shows counts for all authors so the user can switch.

Multi-select facets

To let users select multiple values within a single facet, use OR logic. Selections across multiple facets combine using AND logic. Pass an empty string ("") as a placeholder for facets with no active selection:

var result = await client
    .QueryContent<BlogPostPage>()
    .Facet(x => x.BlogCategory!, filters: [""])
    .Facet(x => x.Author!, filters: ["John Developer"])
    .GetAsContentAsync();

var categoryFacet = result.Facets?.GetFacet(x => x.BlogCategory);
var authorFacet = result.Facets?.GetFacet(x => x.Author);