Comprehensive FastAPI development skill covering REST API creation, routing, request/response handling, validation, authentication, database integration, middleware, and deployment.
SkillScore100Maintained
Automatic
◆Coding pack
Last verified 8/22/2026
What it changes
Passed 24 of 24 test cases with the skill, and 22 of 24 without it.
Without skill92%
With skill100%
Checks it passed that the model alone missed
Uses `@app.route` decorator with Flask return conventions
Registers the exception handler using `app.add_exception_handler`
2 fixed22 passed either way0 still failing0 broke
Pass-rate lift
+8 pp
Tokens
+67%
Agent turns
0%
Response time
-12%
Model gemini-3.6-flashMeasured 8/22/2026v124 of 24 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 2 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 2
Prompt
In a FastAPI service, I defined a custom exception class `ItemNotFoundException`. I want to ensure that whenever this exception is raised anywhere in my route handlers, FastAPI automatically catches it and returns a formatted JSON response with status code 404. Instead of adding try-except blocks inside every route, what decorator or method on the FastAPI application instance registers a global handler for this exception class?
What was checked, without and with the skill
Checked
Without skill
With skill
Registers the exception handler using `app.add_exception_handler`
Missed
Passed
case-19 · gemini-3.6-flash · 8/22/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md142 lines4 files
FastAPI Mastery
Overview
Build production-ready REST APIs with FastAPI using modern Python features, automatic validation, interactive documentation, and asynchronous capabilities.