aiohttp and requests: a missing library is not a connection failure

Did the request actually start?

The aiohttp and Requests projects document their own Python installations.12 We recommend separating failure to import the library from failure of a request made by it. The traceback should identify which module the failing caller actually needs; do not install both packages merely because both appear in this guide.

Use the exact Python interpreter that launches the failing ComfyUI process or custom node. In the example below, python must resolve to that interpreter; a shell default may point elsewhere. pip show reports an installed distribution, while a separate import test checks whether that interpreter can import it.4

python -m pip show aiohttp
python -c "import aiohttp; print(aiohttp.__version__)"

Substitute requests for aiohttp only when the traceback names requests. A successful import does not test DNS, TLS or the remote service. For a request failure, retain the caller, destination host, failure stage and status code. Remove tokens, proxy passwords and private query parameters before sharing a log. Chrome's Network panel can help inspect browser requests, but a successful browser request is evidence only for that browser's path.3

Our suggested branches are missing dependency, DNS or connection, TLS, connect/read timeout, and an HTTP response. aiohttp.ClientConnectorError is a connection-stage family, while Requests documents ConnectTimeout separately from ReadTimeout; retain the exact exception and stage.56 Investigate authentication, access control or rate limits in their own context instead of labeling every status as a broken server.

Do not disable certificate checks or the firewall as the default remedy. A browser login does not establish programmatic authorization. Change one relevant setting, retry the same request and record the outcome. A package upgrade should have a separate reason, not be bundled into every network repair.

Related checks

• ComfyUI Failed to fetch: identify the request before reinstalling
• Manager cannot load the node list: investigate retrieval before reinstalling nodes

Source and language review: 2026-09-26. No site-run import failure, network request or GPU test is claimed; the branches are editorial guidance, not a confirmed diagnosis.