sourceatlas

🗺️ 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.

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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.

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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.}

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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.

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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

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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...

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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

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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

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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

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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

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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)	✓