Here is a list of all files with brief descriptions:

docs
api.h	General-purpose definitions for Banjo API
assert.h	Assertion facility for Banjo API
audio.h	Basic audio library interface
bitmap.h	Header file for Bitmap type
draw.h	Header file for Bitmap drawing functions
error.h	Recoverable error handling
event.h	Sytem event management API
geometry_2d.h	2D Geometry helpers
log.h	Logging utility functions
main.h	Portable main substitution and application callback facilities
mat.h	C99 math shim with bj_real precision type and scalar utilities
math.h	C99 math shim with bj_real precision type and scalar utilities
memory.h	All memory-related functions, including custom allocators
physics.h	Physics helpers (SI units, but dimensionally consistent with any unit system)
physics_2d.h	Physics helpers (SI units, but dimensionally consistent with any unit system)
pixel.h	Header file for general pixel manipulation facilities
quat.h	Quaternion manipulation API (by-value, bj_vec4_t-based)
random.h	Pseudo-random number generation API
rect.h	Defines the bj_rect struct representing a rectangle with position and dimensions
shader.h	Basic shader-like bitmap manipulation
stream.h	Header file for bj_stream_t struct and related functions
string.h
system.h	Header file for system interactions
time.h	Header file for time manipulation utilities
vec.h	Vector manipulation API
video.h
window.h	Header file for bj_window type