Adapters

Knowledge Engine uses a pluggable adapter system for extensibility.

Database Adapters

PostgreSQL (Default)

The primary database adapter using PostgreSQL with pgvector extension.

Features:

• Vector similarity search (pgvector)
• Full-text search with BM25
• Chinese text support (zhparser)
• Connection pooling

Configuration:

DatabaseURL: "postgres://user:pass@host:5432/dbname?sslmode=disable"

Embedding Adapters

OpenAI

Embedding: knowledge.EmbeddingConfig{
    Provider: "openai",
    APIKey:   "sk-...",
    Model:    "text-embedding-3-small",
}

Gemini

Embedding: knowledge.EmbeddingConfig{
    Provider: "gemini",
    APIKey:   "your-gemini-key",
    Model:    "text-embedding-004",
}

Ollama (OpenAI-compatible)

Embedding: knowledge.EmbeddingConfig{
    Provider:  "ollama",
    BaseURL:   "http://localhost:11434/v1",
    Model:     "nomic-embed-text",
}

Storage Adapters

Local Filesystem

Storage: knowledge.StorageConfig{
    Type: "local",
    Path: "./uploads",
}

MinIO / S3

Storage: knowledge.StorageConfig{
    Type:      "minio",
    Bucket:    "knowledge",
    Endpoint:  "localhost:9000",
    AccessKey: "minioadmin",
    SecretKey: "minioadmin",
    UseSSL:    false,
}

Auth Adapters

JWT

Auth: knowledge.AuthConfig{
    Type:      "jwt",
    JWTSecret: "your-secret-key",
}

No-op (Development)

Auth: knowledge.AuthConfig{
    Type: "noop",
}

Custom Adapters

Implement the corresponding interface to create custom adapters:

// Custom Embedding Provider
type Embedder interface {
    Embed(ctx context.Context, texts []string) ([][]float32, error)
}

// Custom Storage Backend
type Storage interface {
    Upload(ctx context.Context, path string, reader io.Reader) error
    Download(ctx context.Context, path string) (io.ReadCloser, error)
    Delete(ctx context.Context, path string) error
}

// Custom Auth Provider
type Authenticator interface {
    Authenticate(ctx context.Context, token string) (string, error)
}

Register custom adapters in the adapter registry:

knowledge.RegisterEmbedder("custom", func(cfg knowledge.EmbeddingConfig) (Embedder, error) {
    return NewCustomEmbedder(cfg), nil
})