AI Engineering Toolkit: A Complete Guide for Building Better LLM Applications
Large Language Models (LLMs) are transforming how we build software. From chatbots and document analysis to autonomous agents, they are becoming the foundation of a new era of applications. But building production-ready LLM systems is far from simple. Engineers face challenges with data, workflows, evaluation, deployment, and security.
This guide introduces the AI Engineering Toolkit—a curated collection of 100+ libraries and frameworks designed to make your LLM development faster, smarter, and more reliable. Each tool has been battle-tested in real-world environments, and together they cover the full lifecycle: from data collection to inference, from experimentation to production.
Whether you are building a prototype or managing enterprise-grade AI services, this toolkit gives you practical building blocks to succeed.
Table of Contents
- ❀
Why This Toolkit Matters - ❀
Vector Databases - ❀
Orchestration and Workflows - ❀
PDF Extraction Tools - ❀
Retrieval-Augmented Generation (RAG) - ❀
Evaluation and Testing - ❀
Model Management - ❀
Data Collection and Web Scraping - ❀
Agent Frameworks - ❀
LLM Training and Fine-Tuning - ❀
Open Source LLM Inference - ❀
LLM Safety and Security - ❀
AI Application Development Frameworks - ❀
Local Development and Serving - ❀
LLM Inference Platforms - ❀
Contribution Guidelines - ❀
Frequently Asked Questions
Why This Toolkit Matters
Building with LLMs is not like building traditional applications.
- ❀
Data handling is complex: You need ways to transform unstructured documents into usable formats. - ❀
Workflows are multi-step: Prompts, retrieval, generation, and evaluation must all connect smoothly. - ❀
Deployment has high demands: Models are resource-heavy, requiring scalable infrastructure. - ❀
Reliability is critical: Outputs must be accurate, safe, and consistent.
This toolkit gives engineers a roadmap. Instead of searching the internet for tools and piecing them together, you can explore proven options organized by category.
Vector Databases
Vector databases store embeddings—numerical representations of text, images, or other data—so that similar items can be retrieved efficiently. They are the backbone of semantic search, question answering, and RAG systems.
| Tool | Description | Language | License |
|---|---|---|---|
| Pinecone | Managed vector database for production-grade applications | API/SDK | Commercial |
| Weaviate | Open-source database with GraphQL API | Go | BSD-3 |
| Qdrant | Vector similarity search with filtering | Rust | Apache-2.0 |
| Chroma | Embedding database tailored for LLM apps | Python | Apache-2.0 |
| Milvus | Cloud-native and scalable similarity search | Go/C++ | Apache-2.0 |
| FAISS | High-performance similarity search and clustering | C++/Python | MIT |
These databases are essential when building applications such as enterprise knowledge bases, AI-powered document search, or multimodal retrieval systems.
Orchestration and Workflows
Orchestration tools help engineers connect different steps of an AI pipeline. They let you design workflows that include prompt engineering, document retrieval, and model execution.
| Tool | Description | Language | License |
|---|---|---|---|
| LangChain | Widely used framework for LLM applications | Python/JS | MIT |
| LlamaIndex | Focuses on connecting data to LLMs | Python | MIT |
| Haystack | End-to-end NLP framework for production | Python | Apache-2.0 |
| DSPy | Optimizes prompts algorithmically | Python | MIT |
| Semantic Kernel | SDK for integrating AI into programming workflows | C#/Python/Java | MIT |
| Langflow | Visual no-code LLM workflow builder | Python/TypeScript | MIT |
| Flowise | Drag-and-drop UI for building LLM chains | TypeScript | MIT |
If you are building your first agent or retrieval pipeline, LangChain and LlamaIndex are natural starting points. For visual workflows, Langflow and Flowise reduce coding overhead.
PDF Extraction Tools
Working with PDFs is a common challenge. These tools help extract text, tables, and layout from documents.
| Tool | Description | Language | License |
|---|---|---|---|
| Docling | Converts PDFs, DOCX, PPTX, HTML, images into structured JSON/Markdown | Python | MIT |
| pdfplumber | Extracts text and tables with visual debugging | Python | MIT |
| PyMuPDF (fitz) | Lightweight, high-performance parser | Python/C | AGPL-3.0 |
| PDF.js | Browser-based renderer with extraction features | JavaScript | Apache-2.0 |
| Camelot | Extracts tabular data into DataFrames/CSVs | Python | MIT |
Retrieval-Augmented Generation (RAG)
RAG combines retrieval with generation, making models more accurate by grounding them in external data.
| Tool | Description | Language | License |
|---|---|---|---|
| RAGFlow | Deep document understanding for RAG | Python | Apache-2.0 |
| Verba | Open-source RAG chatbot | Python | BSD-3 |
| PrivateGPT | Local interaction with documents | Python | Apache-2.0 |
| AnythingLLM | General-purpose LLM application | JavaScript | MIT |
| Quivr | “Second brain” for personal knowledge | Python/TypeScript | Apache-2.0 |
| Jina | Cloud-native multimodal search framework | Python | Apache-2.0 |
| txtai | All-in-one embeddings database and search | Python | Apache-2.0 |
RAG is now a standard method for enterprise QA systems, compliance tools, and specialized assistants.
Evaluation and Testing
Evaluation frameworks ensure that your system produces reliable and useful outputs.
| Tool | Description | Language | License |
|---|---|---|---|
| Ragas | Evaluation for RAG pipelines | Python | Apache-2.0 |
| LangSmith | Debugging, testing, monitoring platform | API/SDK | Commercial |
| Phoenix | ML observability for LLM and multimodal models | Python | Apache-2.0 |
| DeepEval | Unit testing for LLM outputs | Python | Apache-2.0 |
| TruLens | Evaluation and tracking framework | Python | MIT |
| Inspect | Evaluation tools for LLM experiments | Python | Apache-2.0 |
| UpTrain | Improve and evaluate LLM applications | Python | Apache-2.0 |
These frameworks help detect hallucinations, measure consistency, and track system improvements.
Model Management
Managing models and experiments is key when moving from prototype to production.
| Tool | Description | Language | License |
|---|---|---|---|
| Hugging Face Hub | Model and dataset repository | Python | Apache-2.0 |
| MLflow | Lifecycle management for ML | Python | Apache-2.0 |
| Weights & Biases | Experiment tracking and collaboration | Python | MIT |
| DVC | Data version control | Python | Apache-2.0 |
| Comet ML | Experiment management platform | Python | MIT |
| ClearML | MLOps platform with LLM support | Python | Apache-2.0 |
A typical workflow: DVC for data versioning, MLflow for tracking experiments, and Hugging Face Hub for sharing models.
Data Collection and Web Scraping
Applications often rely on external data. Scraping tools help collect and structure this information.
| Tool | Description | Language | License |
|---|---|---|---|
| Firecrawl | AI-powered crawler for LLM pipelines | TypeScript | MIT |
| Scrapy | Fast, high-level framework | Python | BSD-3 |
| Playwright | Web automation with headless browsers | Multiple | Apache-2.0 |
| BeautifulSoup | Simple HTML/XML parser | Python | MIT |
| Selenium | Browser automation framework | Multiple | Apache-2.0 |
| Apify SDK | Web scraping SDK | Python/JS | Apache-2.0 |
| Newspaper3k | News and article extraction | Python | MIT |
Agent Frameworks
Agents are autonomous systems built on LLMs. These frameworks support memory, tools, and multi-agent collaboration.
| Framework | Description | Language | License |
|---|---|---|---|
| AutoGen | Multi-agent conversations | Python | CC-BY-4.0 |
| CrewAI | Role-playing autonomous agents | Python | MIT |
| LangGraph | Graph-based agent framework | Python | MIT |
| AgentOps | Monitoring and benchmarking for agents | Python | MIT |
| Swarm | Lightweight orchestration | Python | MIT |
| Agency Swarm | Automates workflows | Python | MIT |
| Multi-Agent Systems | Research into agent collaboration | Python | MIT |
| Auto-GPT | Autonomous task execution | Python | MIT |
| BabyAGI | Task-driven autonomous agent | Python | MIT |
| SuperAGI | Infrastructure for managing agents | Python | MIT |
| Phidata | Agents with memory and tools | Python | MIT |
| MemGPT | Infinite context via memory management | Python | MIT |
LLM Training and Fine-Tuning
Training and fine-tuning allow customization for specific tasks.
| Tool | Description | Language | License |
|---|---|---|---|
| PyTorch Lightning | High-level training interface | Python | Apache-2.0 |
| unsloth | Faster fine-tuning with low memory | Python | Apache-2.0 |
| Axolotl | Post-training pipeline | Python | Apache-2.0 |
| LLaMA-Factory | Efficient fine-tuning of LLaMA models | Python | Apache-2.0 |
| PEFT | Parameter-efficient fine-tuning | Python | Apache-2.0 |
| DeepSpeed | Distributed training and inference | Python | MIT |
| TRL | Reinforcement learning for transformers | Python | Apache-2.0 |
| Transformers | Pretrained models for multiple modalities | Python | Apache-2.0 |
| LLMBox | Unified training pipeline | Python | MIT |
| LitGPT | Fast training and fine-tuning | Python | Apache-2.0 |
| Mergoo | Merge multiple experts | Python | Apache-2.0 |
| Ludwig | Low-code custom LLM training | Python | Apache-2.0 |
| txtinstruct | Instruction-tuned training | Python | Apache-2.0 |
| xTuring | Fast fine-tuning of open-source models | Python | Apache-2.0 |
| RL4LMs | RL fine-tuning for language models | Python | Apache-2.0 |
| torchtune | PyTorch-native fine-tuning | Python | BSD-3 |
| Accelerate | Multi-GPU/TPU training | Python | Apache-2.0 |
| BitsandBytes | 8-bit optimization and quantization | Python | MIT |
Open Source LLM Inference
Efficient inference is critical for production systems.
| Tool | Description | Language | License |
|---|---|---|---|
| LLM Compressor | Compression algorithms for deployment | Python | Apache-2.0 |
| LightLLM | Lightweight inference and serving | Python | Apache-2.0 |
| vLLM | High-throughput, memory-efficient serving | Python | Apache-2.0 |
| torchchat | Run PyTorch LLMs locally | Python | MIT |
| TensorRT-LLM | NVIDIA library for optimized inference | C++/Python | Apache-2.0 |
| WebLLM | In-browser inference | TypeScript/Python | Apache-2.0 |
LLM Safety and Security
Safety tools protect systems from malicious prompts, jailbreaks, and vulnerabilities.
| Tool | Description | Language | License |
|---|---|---|---|
| JailbreakEval | Automated jailbreak assessment | Python | MIT |
| EasyJailbreak | Generate adversarial prompts | Python | Apache-2.0 |
| Guardrails | Add safety guardrails | Python | MIT |
| LLM Guard | Toolkit for secure interactions | Python | Apache-2.0 |
| AuditNLG | Reduce risks in generative AI | Python | MIT |
| NeMo Guardrails | Programmable safety toolkit | Python | Apache-2.0 |
| Garak | Vulnerability scanner | Python | MIT |
| DeepTeam | Red-teaming framework | Python | Apache-2.0 |
AI Application Development Frameworks
Frameworks for building interactive AI-powered applications.
| Tool | Description | Language | License |
|---|---|---|---|
| Reflex | Full-stack LLM apps with Python | Python | Apache-2.0 |
| Gradio | Interactive demos and prototypes | Python | Apache-2.0 |
| Streamlit | Dashboard and app framework | Python | Apache-2.0 |
| Taipy | End-to-end production apps | Python | Apache-2.0 |
Local Development and Serving
Tools for running LLMs on local machines.
| Tool | Description | Language | License |
|---|---|---|---|
| Ollama | Local deployment of LLMs | Go | MIT |
| LM Studio | Desktop app for local models | – | Commercial |
| GPT4All | Open-source chatbot ecosystem | C++ | MIT |
| LocalAI | Self-hosted API | Go | MIT |
LLM Inference Platforms
Cloud services offering model inference and scaling.
| Platform | Description | Pricing | Features |
|---|---|---|---|
| Clarifai | High-speed AI model hosting | Free tier + pay-as-you-go | Pretrained models, custom deployment |
| Modal | Serverless AI/ML workloads | Pay-per-use | GPU auto-scaling |
| Replicate | Run open-source models via API | Pay-per-use | Prebuilt models, custom training |
| Together AI | Cloud platform for open-source LLMs | Various | Open models, fine-tuning |
| Anyscale | Ray-based AI platform | Enterprise | Distributed training, serving |
Contribution Guidelines
Community contributions keep the toolkit strong.
Steps to contribute:
-
Fork the repository -
Create a new branch -
Add your tool, template, or tutorial -
Submit a pull request
Principles:
- ❀
Focus on quality, not quantity - ❀
Tools should be production-ready - ❀
Documentation must be clear - ❀
Only include actively maintained projects
Frequently Asked Questions
Q1. I am new to LLMs. Where should I start?
Start with LangChain or LlamaIndex, paired with Chroma for vector storage. Build a simple Q&A system to learn the basics.
Q2. I need enterprise-grade reliability. Which tools are best?
Use Milvus for vector storage, LangChain for orchestration, and MLflow for model management.
Q3. Should I run models locally or on the cloud?
It depends. If privacy is critical, run locally with Ollama or GPT4All. If speed and scalability matter, cloud platforms like Replicate or Anyscale are better.
Q4. How can I test the reliability of my RAG pipeline?
Use Ragas or DeepEval to measure correctness and stability of outputs.
Q5. Can I combine these tools into a single project?
Yes. A common stack is: LangChain + Milvus + Ragas + Gradio. This covers retrieval, orchestration, evaluation, and interface.
Final Thoughts
This toolkit is more than a list—it is a structured map for navigating the complex landscape of LLM application development. By selecting the right tools at each stage, you can move from prototype to production with confidence.
For engineers, researchers, and product teams alike, the AI Engineering Toolkit provides clarity and direction. Explore it, experiment with it, and contribute to its growth.
