Verify connectivity to RetroArch's Network Control Interface. Returns the RetroArch version string if reachable.

Get the current emulation status: playing/paused state, system identifier, game basename, and CRC32. Returns 'contentless' if no game is loaded.

Read a RetroArch configuration parameter by name. Useful values: savefile_directory, savestate_directory, system_directory, cache_directory, log_dir, runtime_log_directory, netplay_nickname, video_fullscreen. Note: screenshot_directory is NOT exposed via this command — RetroArch saves screenshots wherever it's configured but doesn't let the NCI report that path.

Read up to 4096 bytes from emulated memory via the loaded core's system memory map. Returns an array of byte values.

RetroArch exposes two distinct memory APIs:

• READ_CORE_MEMORY / WRITE_CORE_MEMORY (used by retroarch_read/write_memory): Goes through the libretro core's system memory map. Most reliable when the core advertises a memory map (most cores do). Errors with "no memory map defined" if the loaded core doesn't.

• READ_CORE_RAM / WRITE_CORE_RAM (used by retroarch_read/write_ram): Uses the achievement (CHEEVOS) address space. Works even when no core memory map is defined, but addresses follow CHEEVOS conventions, not the system bus. Use when read_memory returns "no memory map defined".

Write a byte sequence to emulated memory via the system memory map. Returns the number of bytes actually written (may be less than requested if a read-only descriptor is hit). Disables hardcore mode for the session.

RetroArch exposes two distinct memory APIs:

• READ_CORE_MEMORY / WRITE_CORE_MEMORY (used by retroarch_read/write_memory): Goes through the libretro core's system memory map. Most reliable when the core advertises a memory map (most cores do). Errors with "no memory map defined" if the loaded core doesn't.

• READ_CORE_RAM / WRITE_CORE_RAM (used by retroarch_read/write_ram): Uses the achievement (CHEEVOS) address space. Works even when no core memory map is defined, but addresses follow CHEEVOS conventions, not the system bus. Use when read_memory returns "no memory map defined".

Read memory via the CHEEVOS (achievements) address space. Use this if retroarch_read_memory reports 'no memory map defined' — some libretro cores don't advertise a memory map but DO support the older CHEEVOS read API.

Write to CHEEVOS memory address space. Fire-and-forget — RetroArch sends no acknowledgement for this command. Disables hardcore mode for the session.

Toggle the pause state. There's no separate pause/unpause command in the NCI — this single command flips the current state. Check retroarch_get_status first to know the current state.

Step exactly one frame forward. Only effective while paused; pause first with retroarch_pause_toggle.

Hard-reset the running game (equivalent to pressing the console's reset button).

Capture a screenshot of the current display. RetroArch saves it to its configured screenshot directory (which the NCI doesn't report — check RetroArch's settings). Fire-and-forget; returns immediately.

Display a notification message overlaid on the RetroArch window. Useful for debugging or telling the user something during a long-running script.

Save state to the currently-selected slot. RetroArch's NCI doesn't expose a 'save to slot N' command — you must walk the slot selector to N first using state_slot_plus/minus, then call this. The current slot is RetroArch's internal state and isn't reported back.

Load state from the currently-selected slot. Use retroarch_load_state_slot if you want to load from an explicit numbered slot without changing the current slot pointer.

Load state from an explicit numbered slot. Doesn't change the 'current slot' selector (unlike state_slot_plus/minus + load_state_current).

Increment the currently-selected save state slot. Combine with retroarch_save_state_current / retroarch_load_state_current to target a specific slot for SAVE.

Decrement the currently-selected save state slot.