socketio-wildcard is a small Node.js library that adds a wildcard event listener ('*') to socket.io, allowing developers to catch all incoming events in a single handler. The core implementation is a middleware that intercepts the `onevent` method of a socket, emitting a wildcard event before delegating to the specific event handler. It supports both server-side and client-side usage, with a single-file module that exports a factory function. The library is deprecated as socket.io 2.0.4+ includes native middleware for packet interception, which supersedes the wildcard pattern. The codebase is clean, well-tested, and follows modern JavaScript standards, but its functionality is largely redundant with current socket.io features. The repository includes comprehensive integration tests using mocha and power-assert, and CI configurations for Travis and CircleCI.