{"categories":[{"label":"Quality Assurance","url":"https://skillfed.io/packages/category/software-development-quality-assurance/3"}],"enrichment":{"capability":"Atheris is a coverage-guided fuzzer for Python code and native CPython extensions, using libFuzzer to generate and mutate test inputs that maximize code coverage and expose bugs.","skillfed_tags":["fuzzing","security-testing","coverage-guided"],"use_cases":["Discover crashes and uncaught exceptions in Python code by fuzzing parsing or processing functions.","Test native CPython extensions for memory safety bugs using Address Sanitizer or Undefined Behavior Sanitizer.","Validate input handling in code by generating diverse, coverage-guided test cases.","Fuzz complex data formats using custom mutators to generate valid inputs.","Measure code coverage of fuzzing campaigns and identify untested code paths."],"what_it_does":"Atheris is a coverage-guided fuzzer that automatically generates and mutates test inputs to find bugs in Python code and native CPython extensions. It instruments Python bytecode to track code coverage, then uses that feedback to guide libFuzzer's mutation engine toward unexplored code paths. This approach makes it effective at discovering crashes, uncaught exceptions, and undefined behavior in both pure Python and C/C++ extension code.\n\nThe fuzzer works by defining a single entry point function (TestOneInput) that accepts raw bytes, then running it repeatedly with mutated inputs. You control which code gets instrumented\u2014via context managers, decorators, or a blanket call\u2014and can optionally enable hooks for regex and string methods. It integrates with coverage.py for visualization and supports custom mutators for grammar-aware fuzzing of complex data formats.","worth_installing":"Yes, if you need automated bug detection in Python code or native extensions. Atheris is actively maintained, has no known vulnerabilities, and is well-suited for security testing and robustness validation. Install friction is moderate due to compiled dependencies, but prebuilt wheels ease setup for standard Python versions. Verify the license terms before use. Not necessary for basic unit testing, but valuable for finding edge-case bugs."},"id":"atheris","links":{"html":"https://skillfed.io/packages/atheris","md":"https://skillfed.io/packages/atheris.md","pypi":"https://pypi.org/project/atheris/"},"maintenance":{"status":"active"},"meta":{"latest_release":"2026-06-17","license_spdx":null,"license_treatment":"unclear","name":"atheris","python_support":"unspecified","summary":"A coverage-guided fuzzer for Python and Python extensions."},"popularity":{"monthly_downloads":269688,"position":8253,"tier":"top_15000"},"security":{"n_vulnerabilities":0},"version":"3.1.0"}