AGENTS.md

Project

XiaoZhi is an ESP-IDF C/C++ voice-assistant firmware supporting many chips, boards, displays, audio devices, and network transports. A build selects exactly one board implementation.

Use the ESP-IDF release/v6.1 branch when possible. The minimum supported SDK is ESP-IDF v6.0.1. IDF 5.x is not supported.

Architecture

• main/application.*: main event loop, protocol lifecycle, and high-level behavior.
• main/device_state_machine.*: legal runtime state transitions.
• main/boards/common/: board interfaces and reusable hardware/network helpers.
• main/boards/**/: board-specific pins, initialization, and build variants.
• main/audio/: codecs, audio tasks, engines, wake words, and queues.
• main/protocols/: transport-neutral API plus WebSocket and MQTT/UDP.
• main/display/ and main/led/: reusable UI implementations.
• main/mcp_server.*: common device-side MCP tools and dispatch.
• main/Kconfig.projbuild: board and feature configuration.
• main/CMakeLists.txt: source, board, locale, font, and asset selection.
• scripts/build.py: canonical board/variant build entry point.

Read the closest existing implementation before adding a new one. Prefer the narrowest owning layer; do not put board-specific behavior into core modules.

Required Rules

• Preserve unrelated worktree changes and keep patches focused.
• A build must export exactly one board factory through DECLARE_BOARD(...).
• Never alter an existing board's pins to support different hardware. Add a uniquely named board or release variant; board identity affects OTA compatibility.
• Core code depends on Board interfaces, never a concrete board class or board config.h.
• Treat camera, backlight, display, LED, battery, and similar capabilities as optional.
• Change runtime state through Application::SetDeviceState() and the state machine.
• Callbacks may run outside the main task. Schedule application mutations with Application::Schedule() or event bits.
• Do not block the main event loop or audio tasks. Avoid unbounded queues and repeated large allocations in audio paths.
• Keep shared message semantics in Protocol; verify both transports when changing its contract.
• Validate network input and preserve cJSON ownership. NVS keys are persistent API and require migration when changed.
• Guard target-specific features with Kconfig/component rules. Do not assume every target has PSRAM or S3/P4 resources.
• Do not manually edit generated/vendor output: build/, releases/, managed_components/, components/, sdkconfig*, main/assets/lang_config.h, or generated mmap headers.
• Format only touched C/C++ files with the repository .clang-format; avoid unrelated mass formatting.

Boards and Configuration

Board selection is a coupled chain:

config.json -> scripts/build.py -> main/Kconfig.projbuild -> main/CMakeLists.txt -> board source and config.h.

When adding a board or variant, update every relevant link in that chain. Include a unique board identity, correct chip target, flash/partition settings, exactly one DECLARE_BOARD, and board documentation. Follow docs/custom-board.md.

Commands

Source the intended ESP-IDF environment first:

source /path/to/esp-idf/export.sh
idf.py --version

# Discover exact board and variant names
python3 scripts/build.py --list-boards

# Canonical variant build
python3 scripts/build.py <board-directory> --name <variant-name>

# Host-side build tests
python3 -m unittest discover -s scripts/tests -v

# Format/check touched files
clang-format -i <files>
clang-format --dry-run -Werror <files>

The build script changes local sdkconfig and build state. Do not assume the build directory still represents a previous target.

Validation

• Board-only change: build affected variants and smoke-test changed hardware.
• Core, common-board, audio, protocol, display, dependency, Kconfig, or CMake change: run host tests and build representative affected chip/network paths.
• Protocol changes: verify WebSocket and MQTT/UDP when shared behavior changes.
• Audio changes: verify capture, playback, wake/VAD, interruption, reconnect, and applicable AEC modes.
• UI/assets changes: verify applicable no-display/OLED/LVGL paths and partition size.
• Always report what was tested and what still needs physical hardware. A successful build is not hardware validation.

Authoritative Documentation

• Overview and SDK policy: README.md
• Board guide: docs/custom-board.md
• Audio design: main/audio/README.md
• Code style: docs/code_style.md
• Protocols: docs/websocket.md, docs/mqtt-udp.md, docs/mcp-protocol.md
• CI matrix: .github/workflows/build.yml

Keep detailed or fast-changing information in those files, not here. Add a nested AGENTS.md only when a subsystem needs specialized instructions.