EmbedCache

Stop recomputing embeddings. Start shipping faster.

Website • Documentation • Skelf Research

EmbedCache is a Rust library and REST API that generates text embeddings locally and caches the results. No external API calls, no per-token billing, no rate limits. Just fast, local embeddings with 22+ models.

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Why EmbedCache?

Building RAG apps, semantic search, or anything with embeddings? You've probably hit these problems:

• Recomputing the same embeddings every time you restart your app
• Paying for API calls to embed text you've already processed
• Waiting on rate limits when you need to embed thousands of documents
• Vendor lock-in to a specific embedding provider

EmbedCache fixes all of this. Embeddings are generated locally using FastEmbed and cached in SQLite. Process a URL once, get instant results forever.

Features

• 22+ embedding models - BGE, MiniLM, Nomic, E5 multilingual, and more
• Local inference - No API keys, no costs, no rate limits
• Automatic caching - SQLite-backed, survives restarts
• LLM-powered chunking - Optional semantic chunking via Ollama/OpenAI
• Dual interface - Use as a Rust library or REST API
• Built-in docs - Swagger, ReDoc, RapiDoc, Scalar

Quick Start

As a Service

cargo install embedcache
embedcache

# Generate embeddings
curl -X POST http://localhost:8081/v1/embed \
  -H "Content-Type: application/json" \
  -d '{"text": ["Hello world", "Semantic search is cool"]}'

# Process a URL (fetches, chunks, embeds, caches)
curl -X POST http://localhost:8081/v1/process \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com/article"}'

As a Library

[dependencies]
embedcache = "0.1"
tokio = { version = "1", features = ["full"] }

use embedcache::{FastEmbedder, Embedder};
use fastembed::{InitOptions, EmbeddingModel};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let embedder = FastEmbedder {
        options: InitOptions::new(EmbeddingModel::BGESmallENV15),
    };

    let texts = vec![
        "First document to embed".to_string(),
        "Second document to embed".to_string(),
    ];

    let embeddings = embedder.embed(&texts).await?;
    println!("Generated {} embeddings of {} dimensions",
             embeddings.len(), embeddings[0].len());
    Ok(())
}

API Endpoints

Endpoint	Method	Description
/v1/embed	POST	Generate embeddings for text array
/v1/process	POST	Fetch URL, chunk, embed, and cache
/v1/params	GET	List available models and chunkers

Interactive docs at /swagger, /redoc, /rapidoc, or /scalar.

Configuration

Create a .env file or set environment variables:

SERVER_HOST=127.0.0.1
SERVER_PORT=8081
DB_PATH=cache.db
ENABLED_MODELS=BGESmallENV15,AllMiniLML6V2

# Optional: LLM-powered chunking
LLM_PROVIDER=ollama
LLM_MODEL=llama3
LLM_BASE_URL=http://localhost:11434

Supported Models

Model	Dimensions	Use Case
AllMiniLML6V2	384	Fast, general purpose
BGESmallENV15	384	Best quality/speed balance
BGEBaseENV15	768	Higher quality
BGELargeENV15	1024	Highest quality
MultilingualE5Base	768	100+ languages

See all 22+ models →

Chunking Strategies

Strategy	Description
words	Split by whitespace (fast, always available)
llm-concept	LLM identifies semantic boundaries
llm-introspection	LLM analyzes then chunks (highest quality)

Custom Chunkers

Implement the ContentChunker trait:

use embedcache::ContentChunker;
use async_trait::async_trait;

struct SentenceChunker;

#[async_trait]
impl ContentChunker for SentenceChunker {
    async fn chunk(&self, content: &str, _size: usize) -> Vec<String> {
        content.split(". ")
            .map(|s| s.to_string())
            .collect()
    }

    fn name(&self) -> &str { "sentences" }
}

Performance

• First request: ~100-500ms (model loading)
• Subsequent requests: ~10-50ms per text
• Cache hits: <5ms

Memory usage depends on enabled models (~200MB-800MB each).

Documentation

• Full Documentation
• API Reference
• Deployment Guide

Build docs locally:

cd documentation
pip install -r requirements.txt
mkdocs serve

Project Structure

src/
├── chunking/          # Text chunking (word, LLM-based)
├── embedding/         # Embedding generation (FastEmbed)
├── handlers/          # HTTP endpoints
├── cache/             # SQLite caching
├── models/            # Data types
└── utils/             # Hash generation, URL fetching

Contributing

git clone https://github.com/skelfresearch/embedcache
cd embedcache
cargo build
cargo test

PRs welcome. Please open an issue first for major changes.

License

GPL-3.0. See LICENSE.

Links

• GitHub
• Crates.io
• Documentation

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Built by Skelf Research with FastEmbed and Actix-web.

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Part of Skelf Research

embedcache is built by Skelf Research — an independent UK AI research lab publishing production-grade open-source projects.

🌐 Website · 📚 Documentation · 🔬 All projects · 🤗 Hugging Face

Related projects: memista (vector search for Rust) · polymathy (answer-engine service) · slorg (search that thinks first)

_{Released under MIT / Apache-2.0. © Skelf Research Limited.}