**Port SDL2 code to SDL3 without the bugs that still compile.** sdl3-porter is an agent skill that ports C and C++ code from SDL2 to SDL3, then checks the port for the changes that build cleanly but break at runtime.

SDL's rename scripts handle most of a port, and the compiler catches most of the rest. Neither catches code that still compiles but now means something else. SDL3 functions return `true` on success, so a leftover `if (SDL_Init(...) != 0)` exits on every launch. A device opened with `SDL_OpenAudioDeviceStream` starts paused, so the ported game plays no sound. Textures now filter linearly by default, so pixel art blurs. Coding agents make the same mistakes, because most of the SDL code they learned from is SDL2.

**Status:** v1.0.2, tested against SDL 3.2.0 and 3.4.18, and evaluated on Sonnet 5 and Haiku 4.5. [ROADMAP.md](ROADMAP.md) has what's next.


A real port of [`samples/bounce`](samples/bounce) with sdl3-porter 0.3.0 and Claude Opus 5.5, sped up 4×.

Before and after

This port compiles against SDL3 without a warning:

if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) != 0) {  // SDL3 returns true on success
    SDL_Log("SDL_Init failed: %s", SDL_GetError());
    return 1;                                          // so this runs on every launch
}

SDL_AudioStream *music = SDL_OpenAudioDeviceStream(
    SDL_AUDIO_DEVICE_DEFAULT_PLAYBACK, &spec, NULL, NULL);
SDL_PutAudioStreamData(music, samples, size);          // the device is paused: silence

The report after sdl3-porter fixes the port:

3 traps found, 3 fixed

src/main.c:14     bool-returns         SDL_Init returns true on success, so `!