From ad6a1667730e6838af93ef50c028ba8014147bf6 Mon Sep 17 00:00:00 2001 From: Dhiraj Kumar Azad Date: Tue, 14 Oct 2025 17:05:45 +0530 Subject: [PATCH 1/3] Added semantic kernel tutorial --- .../semantic-kernel-tutorial.md | 387 ++++++++++++++++++ 1 file changed, 387 insertions(+) create mode 100644 tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md diff --git a/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md b/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md new file mode 100644 index 0000000..eaa56fd --- /dev/null +++ b/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md @@ -0,0 +1,387 @@ +--- +# frontmatter +path: "/tutorial-csharp-semantic-kernel-vector-search" +# title and description do not need to be added to markdown, start with H2 (##) +title: Build Vector Search with Couchbase .NET Semantic Kernel Connector and OpenAI +short_title: Vector Search with Semantic Kernel +description: + - Build a semantic search application using Couchbase BHIVE vector index with Semantic Kernel. + - Learn to use the Couchbase .NET Vector Store Connector for Microsoft Semantic Kernel. + - Discover how to generate embeddings with OpenAI and store them in Couchbase. + - Perform vector similarity searches with filtering using SQL++ and ANN_DISTANCE. +content_type: tutorial +filter: sdk +technology: + - vector-search + - kv +tags: + - Semantic Kernel + - OpenAI + - Vector Search +sdk_language: + - csharp +length: 30 Mins +--- + +## Repository Links + +- **Connector Repository**: [couchbase-semantic-kernel](https://github.com/Couchbase-Ecosystem/couchbase-semantic-kernel) - The official Couchbase .NET Vector Store Connector for Microsoft Semantic Kernel +- **This Example**: [CouchbaseVectorSearchDemo](https://github.com/Couchbase-Ecosystem/couchbase-semantic-kernel/tree/Support-Bhive-and-Composite-Index/CouchbaseVectorSearchDemo) - Complete working example demonstrating vector search with Couchbase + +## Introduction + +This demo showcases the **Semantic Kernel Couchbase connector** - a .NET library that bridges Microsoft's Semantic Kernel framework with Couchbase's vector search capabilities. The connector provides a seamless integration that allows developers to build AI-powered applications using familiar Semantic Kernel abstractions while leveraging Couchbase's vector indexing for high-performance semantic search. + +The connector supports three index types: +- **BHIVE** (Hyperscale Vector Index) - for pure vector search at scale ← *Used in this demo* +- **Composite Vector Index** - for vector search with heavy scalar filtering +- **FTS** (Full-Text Search) - for hybrid text + semantic search + +This makes the connector ideal for RAG (Retrieval-Augmented Generation) applications, semantic search engines, hybrid search, and recommendation systems. + +## Prerequisites + +### 1. Couchbase Server Setup +- **Couchbase Server 8.0+** +- Local installation or Couchbase Cloud/Capella +- Bucket with proper read/write permissions +- Query service enabled for SQL++ operations + +### 2. OpenAI API Access +- **OpenAI API Key** - Get one from: https://platform.openai.com/api-keys +- Used for generating text embeddings with `text-embedding-ada-002` model +- Ensure you have sufficient API quota for embedding generation + +### 3. Development Environment +- **.NET 8.0** or later +- Visual Studio, VS Code, or JetBrains Rider +- Basic understanding of C# and vector databases + + +## Setting Up the Environment + +### 1. Clone and Navigate +```bash +git clone https://github.com/Couchbase-Ecosystem/couchbase-semantic-kernel.git +cd couchbase-semantic-kernel/CouchbaseVectorSearchDemo +``` + +### 2. Install Dependencies +```bash +dotnet restore +``` + +### 3. Configuration Setup + +Update `appsettings.Development.json` with your credentials: + +```json +{ + "OpenAI": { + "ApiKey": "your-openai-api-key-here", + "EmbeddingModel": "text-embedding-ada-002" + }, + "Couchbase": { + "ConnectionString": "couchbase://localhost", + "Username": "Administrator", + "Password": "your-password", + "BucketName": "demo", + "ScopeName": "semantic-kernel", + "CollectionName": "glossary" + } +} +``` + +## Understanding the Data Model + +The demo uses a `Glossary` class that demonstrates Semantic Kernel's vector store data model. The model uses attributes to define how properties are stored and indexed in the vector database. + +For a comprehensive guide on data modeling in Semantic Kernel, refer to [Defining your data model](https://learn.microsoft.com/en-us/semantic-kernel/concepts/vector-store-connectors/defining-your-data-model?pivots=programming-language-csharp) in the official documentation. + +### The Glossary Model + +```csharp +internal sealed class Glossary +{ + [VectorStoreKey] + public string Key { get; set; } + + [VectorStoreData(IsIndexed = true)] + public string Category { get; set; } + + [VectorStoreData] + public string Term { get; set; } + + [VectorStoreData] + public string Definition { get; set; } + + [VectorStoreVector(Dimensions: 1536)] + public ReadOnlyMemory DefinitionEmbedding { get; set; } +} +``` + +## Step-by-Step Tutorial + +### Step 1: Prepare Couchbase + +Ensure you have the bucket, scope, and collection ready in Couchbase: +- **Bucket**: `demo` +- **Scope**: `semantic-kernel` +- **Collection**: `glossary` + +### Step 2: Data Ingestion and Embedding Generation + +This step demonstrates how the connector works with Semantic Kernel's vector store abstractions: + +**Getting the Collection** - The demo uses `CouchbaseVectorStore.GetCollection()` to obtain a collection reference configured for BHIVE index: +```csharp +var vectorStore = new CouchbaseVectorStore(scope); +var collection = vectorStore.GetCollection( + "glossary", + new CouchbaseQueryCollectionOptions + { + IndexName = "bhive_glossary_index", // BHIVE index name + SimilarityMetric = "cosine" + } +); +``` + +The `CouchbaseQueryCollectionOptions` works with both BHIVE and composite indexes - simply specify the appropriate index name. For FTS indexes, use `CouchbaseSearchCollection` with `CouchbaseSearchCollectionOptions` instead. + +**Automatic Embedding Generation** - The connector integrates with Semantic Kernel's `IEmbeddingGenerator` interface to automatically generate embeddings from text. When you provide an embedding generator (in this case, OpenAI's `text-embedding-ada-002`), the text is automatically converted to vectors: + +```csharp +// Generate embedding from text +var embedding = await embeddingGenerator.GenerateAsync(glossary.Definition); +glossary.DefinitionEmbedding = embedding.Vector; +``` + +For more details on embedding generation in Semantic Kernel, see [Embedding Generation Documentation](https://learn.microsoft.com/en-us/semantic-kernel/concepts/vector-store-connectors/embedding-generation?pivots=programming-language-csharp). + +**Upserting Records** - The demo uses the connector's `UpsertAsync()` method to insert or update records in the collection: +```csharp +await collection.UpsertAsync(glossaryEntries); +``` + +This creates 6 sample glossary entries with technical terms, generates embeddings for each definition, and stores them in Couchbase with the following structure: + +**Document ID:** `"1"` (from Key field) +**Document Content:** +```json +{ + "Category": "Software", + "Term": "API", + "Definition": "Application Programming Interface. A set of rules...", + "DefinitionEmbedding": [0.123, -0.456, 0.789, ...] // 1536 floats +} +``` + +### Step 3: BHIVE Index Creation + +This demo uses a **BHIVE (Hyperscale Vector Index)** - optimized for pure vector searches without heavy scalar filtering. After documents are inserted, the demo creates the BHIVE index: + +```sql +CREATE VECTOR INDEX `bhive_glossary_index` +ON `demo`.`semantic-kernel`.`glossary` (DefinitionEmbedding VECTOR) +INCLUDE (Category, Term, Definition) +USING GSI WITH { + "dimension": 1536, + "similarity": "cosine", + "description": "IVF,SQ8" +} +``` + +**BHIVE Index Configuration:** +- **Index Type**: BHIVE (Hyperscale Vector Index) - best for pure vector similarity searches +- **Vector Field**: `DefinitionEmbedding` (1536 dimensions) +- **Similarity**: `cosine` (optimal for OpenAI embeddings) +- **Include Fields**: Non-vector fields for faster retrieval +- **Quantization**: `IVF,SQ8` (Inverted File with 8-bit scalar quantization) + +> **Note**: Composite vector indexes can be created similarly by adding scalar fields to the index definition. Use composite indexes when your queries frequently filter on scalar values before vector comparison. For this demo, we use BHIVE since we're demonstrating pure semantic search capabilities. + +### Step 4: Vector Search Operations + +The demo performs two types of searches using the connector's `SearchAsync()` method with the BHIVE index: + +#### Pure Vector Search + +Using the connector's search API: +```csharp +// Generate embedding from search query +var searchVector = (await embeddingGenerator.GenerateAsync( + "What is an Application Programming Interface?")).Vector; + +// Search using the connector +var results = await collection.SearchAsync(searchVector, top: 1) + .ToListAsync(); +``` + +Behind the scenes, this executes a SQL++ query with `ANN_DISTANCE`: +```sql +SELECT META().id AS _id, Category, Term, Definition, + ANN_DISTANCE(DefinitionEmbedding, [0.1,0.2,...], 'cosine') AS _distance +FROM `demo`.`semantic-kernel`.`glossary` +ORDER BY _distance ASC +LIMIT 1 +``` + +**Expected Result**: Finds "API" entry with high similarity + +#### Filtered Vector Search + +Even with a BHIVE index (designed for pure vector search), the connector supports filtering using LINQ expressions with `VectorSearchOptions`: +```csharp +// Search with scalar filter +var results = await collection.SearchAsync( + searchVector, + top: 1, + new VectorSearchOptions + { + Filter = g => g.Category == "AI" + }).ToListAsync(); +``` + +This translates to SQL++ with a WHERE clause: +```sql +SELECT META().id AS _id, Category, Term, Definition, + ANN_DISTANCE(DefinitionEmbedding, [0.1,0.2,...], 'cosine') AS _distance +FROM `demo`.`semantic-kernel`.`glossary` +WHERE Category = 'AI' +ORDER BY _distance ASC +LIMIT 1 +``` + +**Query**: *"How do I provide additional context to an LLM?"* +**Expected Result**: Finds "RAG" entry within AI category + +> **Note**: While BHIVE indexes support filtering as shown above, for scenarios where you frequently filter on scalar values with highly selective filters, consider using a **composite vector index** instead. The index creation syntax is similar - just add the scalar fields to the index definition. The connector's `SearchAsync()` method works identically with both index types. + +## Understanding Vector Index Configuration + +Couchbase offers three types of vector indexes optimized for different use cases: + +### Index Types + +**1. Hyperscale Vector Indexes (BHIVE)** ← *This demo uses BHIVE* +- Uses SQL++ queries via `CouchbaseQueryCollection` +- Best for pure vector searches without complex scalar filtering +- Designed to scale to billions of vectors with low memory footprint +- Optimized for high-performance concurrent operations +- Ideal for: Large-scale semantic search, recommendations, content discovery +- **Creation**: Using SQL++ `CREATE VECTOR INDEX` as shown in Step 3 + +**2. Composite Vector Indexes** +- Uses SQL++ queries via `CouchbaseQueryCollection` +- Best for filtered vector searches combining vector similarity with scalar filters +- Efficient when scalar filters significantly reduce the search space +- Ideal for: Compliance filtering, user-specific searches, time-bounded queries +- **Creation**: Similar to BHIVE but includes scalar fields in the index definition + +**3. FTS (Full-Text Search) Indexes** +- Uses Couchbase Search API via `CouchbaseSearchCollection` +- Best for hybrid search scenarios combining full-text search with vector similarity +- Supports text search, faceting, and vector search in a single query +- Ideal for: Hybrid search, text + semantic search, moderate scale deployments +- **Creation**: Using Search Service index configuration with vector field support + + +All three index types work with the same Semantic Kernel abstractions (`SearchAsync()`, `UpsertAsync()`, etc.). The main difference is which collection class you instantiate and the underlying query engine. + +**Choosing the Right Type**: +- Start with **BHIVE** for pure vector searches and large datasets +- Use **Composite** when scalar filters eliminate large portions of data before vector comparison +- Use **FTS** when you need hybrid search combining full-text and semantic search + +For more details, see the [Couchbase Vector Index Documentation](https://preview.docs-test.couchbase.com/docs-server-DOC-12565_vector_search_concepts/server/current/vector-index/use-vector-indexes.html). + + +### Index Configuration (Couchbase 8.0+) + +The `description` parameter in the index definition controls vector storage optimization through centroids and quantization: + +**Format**: `IVF[],{PQ|SQ}` + +**Centroids (IVF - Inverted File)** +- Controls dataset subdivision for faster searches +- More centroids = faster search, slower training +- If omitted (e.g., `IVF,SQ8`), Couchbase auto-selects based on dataset size + +**Quantization Options** +- **SQ** (Scalar Quantization): `SQ4`, `SQ6`, `SQ8` (4, 6, or 8 bits per dimension) +- **PQ** (Product Quantization): `PQx` (e.g., `PQ32x8`) +- Higher values = better accuracy, larger index size + +**Common Examples**: +- `IVF,SQ8` - Auto centroids, 8-bit quantization (good default) +- `IVF1000,SQ6` - 1000 centroids, 6-bit quantization (faster, less accurate) +- `IVF,PQ32x8` - Auto centroids, product quantization (better accuracy) + +For detailed configuration options, see the [Quantization & Centroid Settings](https://preview.docs-test.couchbase.com/docs-server-DOC-12565_vector_search_concepts/server/current/vector-index/hyperscale-vector-index.html#algo_settings) documentation. + +## Running the Demo + +### Build and Execute +```bash +cd CouchbaseVectorSearchDemo +dotnet build +dotnet run +``` + +### Expected Output +``` +Couchbase BHIVE Vector Search Demo +==================================== +Using OpenAI model: text-embedding-ada-002 +Step 1: Ingesting data into Couchbase vector store... +Data ingestion completed + +Step 2: Creating BHIVE vector index manually... +Executing BHIVE index creation query... +BHIVE vector index 'bhive_glossary_index' already exists. + +Step 3: Performing vector search... + Found: API + Definition: Application Programming Interface. A set of rules and specifications that allow software components to communicate and exchange data. + Score: 0.1847 + +Step 4: Performing filtered vector search... + Found (AI category only): RAG + Definition: Retrieval Augmented Generation - a term that refers to the process of retrieving additional data to provide as context to an LLM to use when generating a response (completion) to a user's question (prompt). + Score: 0.4226 + + Demo completed successfully! +``` + +## How the Connector Works + +The Couchbase Semantic Kernel connector provides a seamless integration between Semantic Kernel's vector store abstractions and Couchbase's vector search capabilities: + +### Data Flow +1. **Initialize** - Create a `CouchbaseVectorStore` instance using a Couchbase scope +2. **Get Collection** - Use `GetCollection()` to get a typed collection reference +3. **Generate Embeddings** - Use Semantic Kernel's `IEmbeddingGenerator` to convert text to vectors +4. **Upsert Records** - Call `UpsertAsync()` to insert/update records with embeddings +5. **Create Index** - Set up a vector index using SQL++ for optimal search performance +6. **Search** - Use `SearchAsync()` with optional `VectorSearchOptions` for filtered searches +7. **Results** - Receive ranked results with similarity scores (lower = more similar) + +### Key Connector Classes & Methods + +**Vector Store Classes:** +- **`CouchbaseVectorStore`** - Main entry point for vector store operations +- **`CouchbaseQueryCollection`** - Collection class for BHIVE and Composite indexes (SQL++) +- **`CouchbaseSearchCollection`** - Collection class for FTS indexes (Search API) + +**Common Methods (all index types):** +- **`GetCollection()`** - Returns a typed collection for CRUD operations +- **`UpsertAsync()`** - Inserts or updates records in the collection +- **`SearchAsync()`** - Performs vector similarity search with optional filters +- **`VectorSearchOptions`** - Configures search behavior including filters and result count + +**Configuration Options:** +- **`CouchbaseQueryCollectionOptions`** - For BHIVE and Composite indexes +- **`CouchbaseSearchCollectionOptions`** - For FTS indexes + +For more documentation, visit the [connector repository](https://github.com/Couchbase-Ecosystem/couchbase-semantic-kernel). + From e1e7502574961ab8891f3b4ab20c6659738406e2 Mon Sep 17 00:00:00 2001 From: Dhiraj Kumar Azad Date: Tue, 14 Oct 2025 17:14:30 +0530 Subject: [PATCH 2/3] Added tags --- test/test-markdown-frontmatter.js | 2 +- .../markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/test/test-markdown-frontmatter.js b/test/test-markdown-frontmatter.js index f34018e..f80a510 100644 --- a/test/test-markdown-frontmatter.js +++ b/test/test-markdown-frontmatter.js @@ -6,7 +6,7 @@ const chalk = require('chalk') // accepted data field values const sdk_languages = ['nodejs', 'scala', 'python', 'swift', 'csharp', 'objective-c', 'android-java', 'any', 'java', 'kotlin', 'dart', 'golang', 'c++'] -const tags = ['Ottoman', 'Ktor', 'REST API', 'Express', 'Flask', 'TLS', 'Configuration', 'Next.js', 'iOS', 'Xcode', '.NET', 'Xamarin', 'Authentication', 'OpenID', 'Keycloak', 'Android', 'P2P', 'UIKit', 'Installation', 'Spring Boot', 'Spring Data', 'Transactions', 'SQL++ (N1QL)', 'Optimization', 'Community Edition', 'Docker', 'Data Modeling', 'Metadata', 'Best Practices', 'Data Ingestion', 'Kafka', 'Support', 'Customer', 'Prometheus', 'Monitoring', 'Observability', 'Metrics', 'Query Workbench', 'ASP.NET', 'linq', 'DBaaS', 'App Services', 'Flutter', 'Gin Gonic', 'FastAPI', 'LangChain', "OpenAI", "Streamlit", 'Google Gemini', 'Nvidia NIM', 'LLama3', 'AWS', 'Artificial Intelligence', 'Cohere', 'Jina AI', 'Mistral AI', 'Ragas', 'Haystack', 'LangGraph', 'Amazon Bedrock', 'CrewAI', 'PydanticAI', 'C++', 'C++ SDK', 'smolagents', 'Ag2', 'Autogen', 'Couchbase Edge Server', 'Deepseek', 'OpenRouter', 'mastra', 'Looker Studio', 'Google Data Studio', 'Connector', 'Couchbase Columnar', 'TAVs', 'Custom Queries', 'Data API'] +const tags = ['Ottoman', 'Ktor', 'REST API', 'Express', 'Flask', 'TLS', 'Configuration', 'Next.js', 'iOS', 'Xcode', '.NET', 'Xamarin', 'Authentication', 'OpenID', 'Keycloak', 'Android', 'P2P', 'UIKit', 'Installation', 'Spring Boot', 'Spring Data', 'Transactions', 'SQL++ (N1QL)', 'Optimization', 'Community Edition', 'Docker', 'Data Modeling', 'Metadata', 'Best Practices', 'Data Ingestion', 'Kafka', 'Support', 'Customer', 'Prometheus', 'Monitoring', 'Observability', 'Metrics', 'Query Workbench', 'ASP.NET', 'linq', 'DBaaS', 'App Services', 'Flutter', 'Gin Gonic', 'FastAPI', 'LangChain', "OpenAI", "Streamlit", 'Google Gemini', 'Nvidia NIM', 'LLama3', 'AWS', 'Artificial Intelligence', 'Cohere', 'Jina AI', 'Mistral AI', 'Ragas', 'Haystack', 'LangGraph', 'Amazon Bedrock', 'CrewAI', 'PydanticAI', 'C++', 'C++ SDK', 'smolagents', 'Ag2', 'Autogen', 'Couchbase Edge Server', 'Deepseek', 'OpenRouter', 'mastra', 'Looker Studio', 'Google Data Studio', 'Connector', 'Couchbase Columnar', 'TAVs', 'Custom Queries', 'Data API', 'Semantic Kernel'] const technologies = ['connectors', 'kv', 'query', 'capella', 'server', 'index', 'mobile', 'fts', 'sync gateway', 'eventing', 'analytics', 'udf', 'vector search', 'react', 'edge-server', 'app-services'] diff --git a/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md b/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md index eaa56fd..0416b8d 100644 --- a/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md +++ b/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md @@ -17,7 +17,7 @@ technology: tags: - Semantic Kernel - OpenAI - - Vector Search + - Artificial Intelligence sdk_language: - csharp length: 30 Mins From 2c5f798a2a188b6b080d244c6d06fcdf698c4e74 Mon Sep 17 00:00:00 2001 From: Dhiraj Kumar Azad Date: Tue, 14 Oct 2025 17:16:39 +0530 Subject: [PATCH 3/3] corrected formatter --- .../markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md b/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md index 0416b8d..2dcf6b1 100644 --- a/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md +++ b/tutorial/markdown/aspnet/semantic-kernel/semantic-kernel-tutorial.md @@ -12,7 +12,7 @@ description: content_type: tutorial filter: sdk technology: - - vector-search + - fts - kv tags: - Semantic Kernel