Opinionated local CI that checks your code before it leaves your machine. After every commit a git hook runs four stages in a worktree at that commit: lint and build in parallel, then a fast suite, with a slow suite in the background, each held to a strict time budget (30 s, 30 s, 10 s and 5 minutes). The pre-push hook stops a push whose lint, build or fast suite failed. There are two ways in. People watch fun-ci console, a terminal dashboard drawn in 24-bit colour by a Rust renderer (included in the Linux and macOS gems), where each milestone of a run plays a scene of its own: a rocket while it runs, gears when the build passes, fireworks or a sunrise when the whole run does, an explosion when it fails, and a quiet night scene when nothing has run for a while. Coding agents and scripts ask with commands that answer in exit codes: fun-ci wait blocks until a commit's verdict is in, and fun-ci why prints what was kept about a failure (the failures a test runner reported, excerpts picked out by presets for 34 tools, log lines, the end of the output, with secrets masked), so nobody has to run a suite again to see what broke. Results are kept in SQLite. Any language works, since the stages are shell scripts; fun-ci init writes them for Ruby, Gradle, Maven, Rust, Go, Elixir, Dart, Swift, PHP, .NET, Python, Deno, Bun, Node, Perl, and C and C++ built with CMake or make.