The esp_wifi_remote component provides transparent WiFi connectivity for ESP chips through external WiFi hardware while keeping the public esp_wifi API compatible. It routes esp_wifi calls from a host device to a WiFi-capable slave via RPC, enabling WiFi on chips without native WiFi or adding a second WiFi interface alongside local esp_wifi.

Remote connectivity is provided by backend solutions such as esp_hosted, wifi_remote_over_eppp, and wifi_remote_over_at.

Directory Structure and Auto-Generation

The esp_wifi_remote component relies heavily on auto-generated code to maintain synchronization with the native esp_wifi API. The generation is handled by scripts/generate_and_check.py, which parses the original esp_wifi headers and produces the necessary remote wrappers, mocked C implementations, and Kconfig files.

Key Directories and Files

include/: Contains the generated header files defining the remote API (e.g., esp_wifi_remote_api.h, esp_eap_client_remote_api.h).
include/injected/: Contains modified copies of the native ESP-IDF headers (like esp_wifi.h, esp_mesh.h, esp_now.h). The generator script copies these from the native esp_wifi/include directory and "injects" changes into them—specifically replacing native Kconfig macros (e.g., CONFIG_ESP_WIFI_, CONFIG_SOC_WIFI_) with remote-specific macros (e.g., CONFIG_WIFI_RMT_, CONFIG_SLAVE_SOC_WIFI_). This allows the remote component to reuse the native data structures while relying on different Kconfig selections corresponding to the slave device.
scripts/generate_and_check.py: The core Python script responsible for generating the remote wrappers, injected headers, Kconfig mappings, and default implementations. This script is run as part of the CI pipeline (check_wif_remote_api job) to ensure the generated files are always up-to-date with any changes to the native WiFi API.
esp_wifi_remote_weak.c & esp_eap_client_remote_weak.c: Auto-generated C files containing weakly linked default implementations for the remote APIs. By default, these functions log a warning and return an unsupported error (ESP_ERR_NOT_SUPPORTED). Backend solutions (like esp_hosted) provide the actual strong implementations for these functions to route the calls over RPC.
Kconfig.*.in: Template Kconfig files used by the generator script. They bridge standard Wi-Fi configuration selections to the slave targets, enabling the host to configure the remote WiFi hardware seamlessly