Ultra performant document intelligence engine for RAG, with written in Rust. Zero vector database, zero embedding model — just LLM-powered tree navigation. Incremental indexing and multi-format support out-of-box.
Early Development: This project is in active development. The API and features are likely to evolve, and breaking changes may occur.
Why Vectorless?
Traditional RAG systems have a fundamental problem: they lose document structure.
When you chunk a document into vectors, you lose:
- The hierarchical relationship between sections
- The context of where information lives
- The ability to navigate based on reasoning
Vectorless takes a different approach:
It preserves your document's tree structure and uses an LLM to navigate it — just like a human would skim a table of contents, then drill into relevant sections.
Result: More accurate retrieval with zero infrastructure complexity.
How It Works
Vectorless preserves your document's hierarchical structure and uses a multi-stage pipeline for intelligent retrieval:
Index Pipeline
Transforms documents into a navigable tree structure:
- Parse — Parse documents (Markdown, PDF, DOCX, HTML) into structured content
- Build — Construct document tree with metadata
- Enhance — Add table of contents and section detection
- Enrich — Generate AI summaries for tree nodes
- Optimize — Optimize tree structure for efficient retrieval
Retrieval Pipeline
Uses adaptive, multi-stage retrieval with backtracking:
- Analyze — Detect query complexity, extract keywords
- Plan — Select optimal strategy (keyword/semantic/LLM) and algorithm
- Search — Execute tree traversal (greedy/beam/MCTS)
- Judge — Evaluate sufficiency, trigger backtracking if needed
This mimics how humans navigate documentation: skim the TOC, drill into relevant sections, and backtrack when needed.
Pilot: The Brain
Pilot is the intelligence layer that guides retrieval:
-
Intervention Points — Pilot acts at key decision moments:
- START — Analyze query intent, set initial direction
- FORK — Rank candidates at branch points
- BACKTRACK — Suggest alternatives when search fails
- EVALUATE — Assess content sufficiency
-
Score Merging — Combines algorithm scores with LLM reasoning:
final_score = α × algorithm_score + β × llm_score -
Fallback Strategy — 4-level degradation (Normal → Retry → Simplified → Algorithm-only)
-
Budget Control — Token and call limits with intelligent allocation
Comparison
| Aspect | Vectorless | Traditional RAG |
|---|---|---|
| Infrastructure | Zero | Vector DB + Embedding Model |
| Setup Time | Minutes | Hours to Days |
| Reasoning | Native navigation | Similarity search only |
| Document Structure | Preserved | Lost in chunking |
| Incremental Updates | Supported | Full re-index required |
| Debugging | Traceable navigation path | Black box similarity scores |
| Best For | Structured documents | Unstructured text |
Installation
Add to your Cargo.toml:
[]
= "0.1"
Quick Start
Create a configuration file vectorless.toml in your project root:
Basic usage:
use Engine;
async
Examples
See the examples/ directory for complete working examples.
Architecture
Contributing
Contributions are welcome!
If you find this project useful, please consider giving it a star on GitHub — it helps others discover it and supports ongoing development.
Star History
License
Licensed under the Apache License, Version 2.0. See LICENSE for details.