| CApplication | The main application class that coordinates application-wide functionality |
| C<ApplicationDelegate> | A protocol that defines the methods for an application delegate |
| C<CollectionProtocol> | A protocol that defines collection methods for an Object |
| Cdriver_bme280_t | BME280 sensor driver structure |
| Cdriver_st7789_rect_t | ST7789 display rectangle for window operations |
| Cdriver_st7789_t | ST7789 display driver structure |
| Cdriver_uc8151_rect_t | UC8151 display rectangle for partial updates |
| Cdriver_uc8151_t | UC8151 display driver structure |
| Cfs_file_t | File and directory metadata |
| CGPIO | The GPIO class |
| C<GPIODelegate> | A protocol that defines the methods for a GPIO delegate |
| Chw_adc_t | ADC channel |
| Chw_gpio_t | GPIO logical pin structure |
| Chw_i2c_t | I2C adapter |
| Chw_infrared_rx_t | Infrared receiver |
| Chw_led_t | LED structure definition for hardware control |
| Chw_pwm_config_t | PWM configuration structure for setup parameters |
| Chw_pwm_t | PWM structure representing a PWM instance |
| Chw_spi_t | SPI adapter |
| Chw_wifi_network_t | Describes a discovered Wi‑Fi network (scan result) |
| C<InputManagerDelegate> | A protocol that defines the methods for an input manager delegate |
| C<InputManagerSource> | A protocol that defines the methods for an input manager source |
| C<JSONProtocol> | A protocol that defines JSON methods for an Object |
| CLED | The LED class |
| CMQTT | An MQTT client |
| C<MQTTDelegate> | Protocol for receiving MQTT events |
| Cnet_mqtt_t | Opaque MQTT handle |
| C<NetworkTimeDelegate> | Protocol for receiving network time update events |
| CNXArray | The NXArray classNXArray represents an array that can store ordered objects |
| CNXAutoreleasePool | A class for managing autorelease pools |
| CNXConstantString | A constant string class |
| C<NXConstantStringProtocol> | Protocol for constant string objects |
| CNXData | The NXData classNXData represents a structure for storing binary data |
| CNXDate | A class for representing and manipulating dates |
| CNXMap | The NXMap class |
| CNXNetworkTime | A class for managing network time synchronization |
| CNXNull | The NXNull classNXNull represents a null value that can be inserted into collections |
| CNXNumber | The base class for NXNumber instances |
| CNXObject | The base class for objects in the Foundation framework |
| CNXPoint | A structure representing a point in 2D space |
| CNXString | A class for managing and manipulating string objects |
| CNXThread | A class for managing and interacting with threads |
| CNXTimer | The NXTimer class |
| CNXWireless | A class for managing wireless connections |
| CNXWirelessNetwork | A class for representing a wireless network |
| CNXZone | A class for managing memory zones |
| CObject | The root class of all Objective-C classes |
| CObject(Description) | A category that adds a description method to the Object class |
| C<ObjectProtocol> | Protocol for objects |
| Cpix_display_t | Display context structure |
| Cpix_frame_t | Frame structure containing pixel data and drawing operations |
| Cpix_point_t | Point structure representing X,Y coordinates |
| Cpix_size_t | Size structure representing width and height dimensions |
| CProtocol | Protocol class definition |
| C<RetainProtocol> | Protocol for retaining and releasing objects |
| Csys_atomic_t | Underlying atomic uint32_t value |
| Csys_cond_t | Condition variable context structure |
| Csys_date_t | Represents a system date and time structure |
| Csys_event_queue_t | Event queue structure for producer/consumer patterns |
| Csys_hash_t | Hash context structure |
| Csys_hashtable_entry_t | Hash table entry |
| Csys_hashtable_iterator | Iterator state for hash table traversal |
| Csys_mutex_t | Mutex context structure |
| Csys_timer_t | Timer context structure |
| Csys_waitgroup_t | Waitgroup context structure |
| C<TimerDelegate> | A protocol that defines the methods for a timer delegate |
| C<WirelessDelegate> | Protocol for receiving wireless scan events |