∆ Delta Context Engine
Only send what changed. 85% fewer tokens. 6× more tasks on the same weekly budget.
What is Delta?
Delta is an open-source context intelligence engine that sits between your editor and Claude. Instead of re-reading your entire codebase on every task, Delta indexes it once, watches for changes, and surgically assembles the minimum possible context payload.
Every AI coding task today sends your entire codebase to the LLM — even when only one file changed. Delta fixes this.
WITHOUT DELTA: WITH DELTA ∆:
───────────────────────────── ─────────────────────────────
auth.ts 1,800 tokens ←unused Task instruction 200 tok
user.model.ts 1,200 tokens ←unused login.ts 800 tok ← changed
api/routes.ts 3,100 tokens ←unused Direct deps 600 tok ← symbols
utils/... 2,400 tokens ←unused Compressed summary 328 tok
config/db.ts 800 tokens ←unused ─────────────────────────────
types/... 1,905 tokens ←unused TOTAL: 1,928 tokens ✅
login.ts 800 tokens ←changed
─────────────────────────────
TOTAL: 12,005 tokens ❌ 6.2× fewer tokens
Key Features
| Feature | Description |
|---|---|
| Context Intelligence | 4-layer pipeline: change detection → AST extraction → dependency graph → context assembly |
| Graph Intelligence | Leiden community detection, execution flow tracing, blast radius, risk scoring, hub/bridge detection |
| Hybrid Search | FTS5 full-text + semantic vector search with Reciprocal Rank Fusion across symbols, files, memory, flows, and communities |
| Memory System | Persistent memory across sessions — architectural decisions, bug fixes, and edge cases auto-captured |
| 56+ Languages | Full AST parsing (6 languages), pattern extraction (15+), notebook support, and minimal indexing for 30+ more |
| 14 MCP Tools + 5 Prompts | blast_radius, codebase_compass, fault_tracer, first_day, merge_guardian |
| Multi-Provider Embeddings | Ollama (local), OpenAI, Azure OpenAI — with automatic fallback |
| Universal Tool Support | Claude Code (MCP stdio), HTTP MCP server, OpenAI-compatible proxy, Cursor, VS Code |
| Zero Config | Works out of the box. Customize when you need to. |
Token Reduction
| Scenario | Before | After | Saved | Multiple |
|---|---|---|---|---|
| Single bug fix | 13,205 | 1,928 | 11,277 | 6.8× |
| Add new feature | 18,400 | 2,800 | 15,600 | 6.5× |
| Write unit tests | 11,200 | 1,600 | 9,600 | 7.0× |
| Refactor a module | 22,000 | 4,100 | 17,900 | 5.3× |
| Config file update | 8,400 | 900 | 7,500 | 9.3× |
| Average | 16,213 | 2,466 | 13,747 | 6.6× |
Quick Start
npm install -g delta-ctx
delta init
delta run "fix the JWT expiry bug in login"