{"library":"nest-asyncio","title":"nest-asyncio Library","description":"nest-asyncio is a Python library that patches the `asyncio` module to allow nested event loops. This addresses the `RuntimeError: This event loop is already running` issue encountered in environments like web servers, GUI applications, and Jupyter notebooks where an event loop is already active. It is currently at version 1.6.0 and maintains a stable release cadence.","language":"python","status":"active","last_verified":"Tue May 12","install":{"commands":["pip install nest-asyncio"],"cli":null},"imports":["import nest_asyncio\nnest_asyncio.apply()"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"import asyncio\nimport nest_asyncio\n\n# Apply the patch to allow nested event loops\nnest_asyncio.apply()\n\nasync def my_async_function():\n    await asyncio.sleep(0.1)\n    return \"Hello, Nested World!\"\n\n# This works even in environments with existing event loops\nresult = asyncio.run(my_async_function())\nprint(result)","lang":"python","description":"This quickstart demonstrates how to apply the `nest-asyncio` patch and then run an `asyncio` coroutine using `asyncio.run()`, even if an event loop is already running.","tag":"verified","tag_description":"quickstart runs on critical runtimes, recently tested","last_tested":"2026-04-23","results":[{"runtime":"python:3.10-alpine","exit_code":0},{"runtime":"python:3.10-slim","exit_code":0},{"runtime":"python:3.11-alpine","exit_code":0},{"runtime":"python:3.11-slim","exit_code":0},{"runtime":"python:3.12-alpine","exit_code":0},{"runtime":"python:3.12-slim","exit_code":0},{"runtime":"python:3.13-alpine","exit_code":0},{"runtime":"python:3.13-slim","exit_code":0},{"runtime":"python:3.9-alpine","exit_code":0},{"runtime":"python:3.9-slim","exit_code":0}]},"compatibility":{"tag":"verified","tag_description":"installs cleanly on critical runtimes, fast import, recently tested","last_tested":"2026-05-12","installed_version":null,"pypi_latest":null,"is_stale":null,"summary":{"python_range":"3.10–3.9","success_rate":100,"avg_install_s":null,"avg_import_s":0.27,"wheel_type":null},"results":[{"runtime":"python:3.10-alpine","python_version":"3.10","os_libc":"alpine (musl)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.12,"mem_mb":4,"disk_size":"17.8M"},{"runtime":"python:3.10-slim","python_version":"3.10","os_libc":"slim (glibc)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.09,"mem_mb":4,"disk_size":"18M"},{"runtime":"python:3.11-alpine","python_version":"3.11","os_libc":"alpine (musl)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.21,"mem_mb":4.9,"disk_size":"19.6M"},{"runtime":"python:3.11-slim","python_version":"3.11","os_libc":"slim (glibc)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.2,"mem_mb":4.9,"disk_size":"20M"},{"runtime":"python:3.12-alpine","python_version":"3.12","os_libc":"alpine (musl)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.5,"mem_mb":8.2,"disk_size":"11.5M"},{"runtime":"python:3.12-slim","python_version":"3.12","os_libc":"slim (glibc)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.43,"mem_mb":8.2,"disk_size":"12M"},{"runtime":"python:3.13-alpine","python_version":"3.13","os_libc":"alpine (musl)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.43,"mem_mb":8.7,"disk_size":"11.1M"},{"runtime":"python:3.13-slim","python_version":"3.13","os_libc":"slim (glibc)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.49,"mem_mb":8.7,"disk_size":"12M"},{"runtime":"python:3.9-alpine","python_version":"3.9","os_libc":"alpine (musl)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.13,"mem_mb":3.9,"disk_size":"17.3M"},{"runtime":"python:3.9-slim","python_version":"3.9","os_libc":"slim (glibc)","variant":"nest-asyncio","exit_code":0,"wheel_type":null,"failure_reason":null,"import_side_effects":null,"install_time_s":null,"import_time_s":0.11,"mem_mb":3.9,"disk_size":"18M"}]}}