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redis-vl-dotnet

Vectorizer Abstractions

RedisVL.Vectorizers.Abstractions defines the provider-neutral contracts used by caches and workflow APIs.

Core interfaces

  • ITextVectorizer exposes VectorizeAsync(string input, CancellationToken cancellationToken = default) for single-input embedding generation.

  • IBatchTextVectorizer extends ITextVectorizer with VectorizeAsync(IReadOnlyList<string> inputs, CancellationToken cancellationToken = default) for providers that can embed a batch in one request.

  • TextVectorizerExtensions.VectorizeManyAsync(…​) is the compatibility helper for callers that only know about ITextVectorizer. It uses native batch support when available and otherwise falls back to sequential single-input calls.

Input and batching behavior

These contracts are intentionally minimal:

  • Callers own model selection, provider credentials, and HTTP client lifetime.

  • Providers are expected to reject null or empty inputs before making a remote request.

  • Empty batch requests should return an empty collection without calling the provider.

Use TextVectorizerExtensions.VectorizeManyAsync(…​) when higher-level code should accept either a batch-capable provider or a single-input provider without branching.

Relationship to older APIs

RedisVL.Caches.ITextEmbeddingGenerator remains in the core package as an obsolete migration shim over ITextVectorizer.

Prefer new code to depend on ITextVectorizer directly so vectorizer packages can plug into SemanticCache, SemanticRouter, and SemanticMessageHistory without adapter code.

Examples and tests

  • OpenAI vectorizer is the batch-capable reference implementation under src/RedisVL.Vectorizers.OpenAI.

  • Hugging Face vectorizer is the HTTP-based reference implementation under src/RedisVL.Vectorizers.HuggingFace.

  • /examples/OpenAiVectorizerExample and /examples/HuggingFaceVectorizerExample show environment-based provider setup.

  • tests/RedisVL.Tests/Vectorizers/TextVectorizerExtensionsTests.cs captures the batch fallback contract.