Here are the classes, structs, unions and interfaces with brief descriptions:

[detail level 12]

AudioFileUtilities	A collection of functions for loading and storing audio files
ConfigFileUtils
IoUtils
PinmuxUtils
StringUtils
_BelaHwConfig
_InternalBelaContext
ADSR
AudioCodec
AudioCodecParams
AudioFile
AudioFileReader
AudioFileWriter
AudioSystemClass
AuxTaskNonRT
AuxTaskRT
BelaChannelGain
BelaChannelGainArray
BelaContext	Structure holding audio and sensor settings and pointers to I/O data buffers
BelaContextFifo
BelaContextSplitter
BelaCpuData
BelaDebounce
Settings
BelaEncoder	Connect a quadrature rotary encoder, and handle it at audio rate from Bela
Pins
Settings
BelaInitSettings	Structure containing initialisation parameters for the real-time audio control system
BelaSteppedPot	Connect a stepped potentiometer and handle it at audio rate from Bela
Biquad
BiquadCoeff
Settings
BiquadCoeffT
bufferDescription
CentroidDetection
CalculateCentroids
Command
Convolver
ConvolverChannel
CsData
DataBuffer
DataFifo
Debounce	Debounce a boolean reading
Settings
DelayLine
DigitalChannelManager
DigitalToMessage
Eeprom
Settings
Encoder	Connect a quadrature rotary encoder
EnvelopeDetector
Es9080_Codec
Fft
GlottisClass
Gpio
GpioDebounce
Gui
GuiController
guiControlMessageHeader
GuiSlider
I2c
I2c_Codec
I2C_MPR121
I2c_MultiI2sCodec
I2c_MultiTdmCodec
I2c_MultiTLVCodec
TdmConfig
IirFilter
IirFilterStage
JSON
JSONValue
McaspConfig
Parameters
McaspRegisters
Midi
MidiChannelMessage
MidiParser
Mmap
MovingAverage
OnePole
Oscillator
OscillatorBank
OscReceiver	OscReceiver provides functions for receiving OSC messages in Bela
OscSender	OscSender provides functions for sending OSC messages from Bela
Pipe
PRU
PruManager
PulseIn	A class to measure the duration of a pulse on a digital pin
QuadBiquad
SampleData
SampleStream
Scope	An oscilloscope which allows data to be visualised in a browser in real time
Serial
ShiftRegister	A class to drive a shift register using Bela's digital I/O
Pins
ShiftRegisterIn
ShiftRegisterOut
SimplexNoise	A Perlin Simplex Noise C++ Implementation (1D, 2D, 3D, 4D)
Spi
Settings
Spi_Codec
SteppedPot	Connect a stepped potentiometer
Tlv320_Es9080_Codec
Touch
TractClass
TractUIClass
Trill	A class to use the Trill family of capacitive sensors. http://bela.io/trill
TrillDefaults
trillRescaleFactors_t
TrillStatusByte
UdpClient
UdpServer
UIClass
WriteFile
WSServer
WSServerDataHandler