RAG/llm/ — LLM Provider Abstraction
Multi-provider chat, embedding, and specialized models
Chat models, embedding models, reranking, OCR, vision, sequence-to-text, text-to-speech.
❓ What is this & why?
The llm module abstracts multiple LLM providers (OpenAI, Claude, local models) behind a unified interface. This prevents vendor lock-in: swapping from OpenAI to Claude requires changing one config line, not refactoring code.
💡 Real-world analogy
Like a translator agency. You don't need to hire a specific translator; the agency routes your request to whoever is available. If your usual translator is busy or expensive, the agency can swap in another without you noticing.
🤔 Why Is It Designed This Way?
{{DESIGN_RATIONALE}} — 150+ words explaining the design choices: what pattern does this follow and why? What constraints shaped the implementation? What trade-offs were made and what was sacrificed?
| Design Choice | What Was Chosen | What Was Rejected | Why |
|---|---|---|---|
| Example: data layout | Array of structs | Struct of arrays | Random access pattern dominates; cache locality for single items matters more than SIMD sweeps |
Contents
Architecture
flowchart TD
subgraph Chat["Chat Models"]
C1["OpenAI"]
C2["Claude"]
C3["Local LLM"]
end
subgraph Embed["Embedding Models"]
E1["BGE"]
E2["OpenAI Embed"]
E3["Local ONNX"]
end
subgraph Other["Specialized"]
O1["Reranker"]
O2["OCR"]
O3["TTS"]
end
Key Classes
| Class / Function | File | Purpose |
|---|---|---|
ClassName | file.h | Brief description |
Data Structures
| Type | Name | Description |
|---|---|---|
| enum | EnumName | Brief description |
Interactions
| Direction | Partner | Interface | Description |
|---|---|---|---|
| → | Other Module | methodName() | Brief description |
Configuration
| Knob / Parameter | Default | Description |
|---|---|---|
param_name | value | What it controls |
Directory Map
Source tree for llm
submod_name/
├── file_a.ext ← Role: brief annotation
├── file_b.ext ← Role: brief annotation
├── file_c.ext ← Role: brief annotation
└── index.ext ← Role: entry point
📑 Annotated Code Walkthrough
The most important code in this sub-module, annotated with WHY each piece exists:
{{KEY_FUNCTION_NAME}}
// Replace with actual code from the source
void key_function() {
// ← WHY: Explain the purpose of this line
// ← WHY: What constraint or requirement drives this?
}
Line-by-line:
- Line N: What this does and WHY — what would break if removed
- Line M: The design choice here — why this approach over the obvious alternative
⚠️ Edge Cases & Boundaries
| Edge Case | What Happens | Where in Code | Risk Level |
|---|---|---|---|
| Empty input | How it's handled | function_name:line | 🟢 Low |
| Concurrent access | How it's handled | function_name:line | 🔴 High |
Deep-Dive Highlights
Core mechanisms from this sub-module have been extracted into dedicated focus pages for in-depth exploration. Each page covers one algorithm, protocol, or subsystem with diagrams, code walks, and configuration details.
Deep-Dive Pages
Provider Dispatch
sequenceDiagram
participant Code as Application
participant Factory as Factory
participant OpenAI as OpenAI
participant Claude as Claude
Code->>Factory: create("openai")
Factory->>OpenAI: Initialize
OpenAI->>Code: Provider
Code->>Code: Switch config
Code->>Factory: create("claude")
Factory->>Claude: Initialize
Claude->>Code: Provider
Code Examples
Example: Typical Usage
// Replace with actual code example
void example() {
// ...
}