🗺️ SourceAtlas
🌐 sourceatlas.io | English | 繁體中文
Get project overview in ~3 minutes by scanning <5% of files
A set of AI-powered slash commands for Claude Code that help you understand any codebase quickly.
Have You Ever...
- Spent 3 days on a new project and still don't understand the architecture?
- Wanted to change one line, but afraid it might break everything?
- Asked a colleague "how do I write this", and got "just look at file XXX"?
- Needed to upgrade iOS 16 → 17, but had no idea how much work it would take?
SourceAtlas solves these in minutes, not days.
Before & After
| Task | Before | After |
|---|---|---|
| Understand project architecture | 2-3 days | ~3-15 minutes ✓ |
| Find API implementation examples | Ask colleagues / random searching | ~seconds |
| Analyze impact of code changes | Manual tracking, hope for the best | ~1-2 minutes |
| Plan framework upgrade | Weeks of research | ~15-30 minutes |
| Find code hotspots & experts | Ask around | ~5-10 minutes |
✓ = benchmarked on 5 open-source projects. Others are estimates based on usage.
How It Works
SourceAtlas uses information theory to prioritize high-entropy files (configs, READMEs, models) over implementation details. By scanning <5% of files, it achieves 70-80% understanding depth in minutes instead of days.
Core Commands
1. "I just joined the project, where do I start?"
/sourceatlas:overview
In ~3 minutes, get: Tech stack, architecture patterns, project scale, code quality signals
Example output: Detects Swift 5.10 + MVVM + Coordinator, 12K files, test coverage level
2. "I want to write an API, how does this project do it?"
/sourceatlas:pattern "api endpoint"
/sourceatlas:pattern "authentication"
/sourceatlas:pattern "database query"
In 0.1-30 seconds, get: 2-3 best example files with exact line numbers + implementation guide
Example output: Returns UserAPI.swift:45 with matching test file and implementation guide
221 patterns supported: MVVM, Networking, Core Data, React Hooks, Next.js API, Jetpack Compose, Vue Composable, FastAPI, Rails Controller...
3. "I want to change this file, what else will break?"
/sourceatlas:impact "src/api/users.ts"
/sourceatlas:impact api "/api/users/{id}"
In 1-2 minutes, get: All dependents, Breaking Change risks, test coverage, migration steps
Example output: Lists 23 dependent files, identifies 5 breaking change risks
4. "Who knows this code best? What's the danger zone?"
/sourceatlas:history
/sourceatlas:history src/
In 5-10 minutes, get: Hotspots (files that change constantly), Hidden Coupling, Knowledge Distribution
Example output: Shows PaymentService.swift with 47 changes, flags single-contributor bus factor risk
5. "How does the login flow actually work?"
/sourceatlas:flow "user login"
/sourceatlas:flow "checkout process"
In 3-5 minutes, get: Entry points, complete execution path, boundary identification (API/DB/Auth/Payment)
Example output: Traces LoginViewController → AuthService → APIClient → TokenManager
6. "We need to upgrade to iOS 17, how much work is that?"
/sourceatlas:deps "iOS 16 → 17"
/sourceatlas:deps "React 17 → 18"
/sourceatlas:deps "Python 3.11 → 3.12"
In 15-30 minutes, get: Deprecated APIs, version checks to remove, third-party compatibility, effort estimate
Example output: Migration checklist with removable version checks, deprecated APIs, effort estimate
Benchmark Results
Tested on 5 open-source projects: Firefox iOS, Discourse, Cal.com, Prefect, Thunderbird
| Command | Key Metric | Result | Report |
|---|---|---|---|
overview | Overall Accuracy | 93% (56/60) | ✓ |
pattern | Search Precision | 98.6% (7/7 cases) | ✓ |
impact | Internal Consistency | 100% (5/5 projects) | ✓ |
flow | Entry Point Detection | 100% (5/5 projects) | ✓ |
deps | Mode Detection | 100% (2/2 cases) | ✓ |
history | Hotspots Detection | 100% (Top 10) | ✓ |