Use Case: tiangolo/fastapi - The FastAPI Framework

Repository: https://github.com/tiangolo/fastapi Stack: Python Test Date: 2025-12-08 Loctree Version: 0.6.2-dev

Overview

Testing loctree on FastAPI - the popular Python web framework with heavy decorator usage.

Repository Scale

Metric	Value
Python Files	1,184
Analysis Time	20.69 seconds
Throughput	57 files/sec

Findings

Dead Code Detection

High Confidence: 0
False Positive Rate: 0%

Route Detection

loct routes    # 451 FastAPI routes detected!

Loctree correctly identifies all FastAPI route decorators:

@app.get(), @app.post(), etc.
@router.get(), @router.post(), etc.
Nested routers and includes

Version History

Version	FP Rate	Status
0.5.16	100%	BROKEN (decorators)
0.6.1-dev	0%	FIXED
0.6.2-dev (pre-fix)	CRASH	UTF-8 bug
0.6.2-dev (post-fix)	0%	PERFECT

Commands Used

cd FastAPI
loct                              # Create snapshot
loct dead --confidence high       # Dead code analysis
loct routes                       # Route detection (451 found!)
loct twins                        # Duplicate detection

Verdict

PERFECT - FastAPI analysis is production-ready after UTF-8 fix.

Key Insights

Decorator Tracking: response_model=X correctly parsed
Route Detection: 451 endpoints found automatically
UTF-8 Fixed: Emoji in strings no longer crash

Special Feature: `loct routes`

Perfect for FastAPI projects:

loct routes              # List all endpoints
loct routes --json       # Export for documentation
loct routes --unused     # Find orphaned handlers