# MimiClaw Architecture > ESP32-S3 AI Agent firmware — C/FreeRTOS implementation running on bare metal (no Linux). --- ## System Overview ``` Telegram App (User) │ │ HTTPS Long Polling │ ▼ ┌──────────────────────────────────────────────────┐ │ ESP32-S3 (MimiClaw) │ │ │ │ ┌─────────────┐ ┌──────────────────┐ │ │ │ Telegram │──────▶│ Inbound Queue │ │ │ │ Poller │ └────────┬─────────┘ │ │ │ (Core 0) │ │ │ │ └─────────────┘ ▼ │ │ ┌────────────────────────┐ │ │ ┌─────────────┐ │ Agent Loop │ │ │ │ WebSocket │─▶│ (Core 1) │ │ │ │ Server │ │ │ │ │ │ (:18789) │ │ Context ──▶ LLM Proxy │ │ │ └─────────────┘ │ Builder (HTTPS) │ │ │ │ ▲ │ │ │ │ ┌─────────────┐ │ │ tool_use? │ │ │ │ Serial CLI │ │ │ ▼ │ │ │ │ (Core 0) │ │ Tool Results ◀─ Tools │ │ │ └─────────────┘ │ (web_search)│ │ │ └──────────┬─────────────┘ │ │ │ │ │ ┌──────▼───────┐ │ │ │ Outbound Queue│ │ │ └──────┬───────┘ │ │ │ │ │ ┌──────▼───────┐ │ │ │ Outbound │ │ │ │ Dispatch │ │ │ │ (Core 0) │ │ │ └──┬────────┬──┘ │ │ │ │ │ │ Telegram WebSocket │ │ sendMessage send │ │ │ │ ┌──────────────────────────────────────────┐ │ │ │ SPIFFS (12 MB) │ │ │ │ /spiffs/config/ SOUL.md, USER.md │ │ │ │ /spiffs/memory/ MEMORY.md, YYYY-MM-DD │ │ │ │ /spiffs/sessions/ tg_.jsonl │ │ │ └──────────────────────────────────────────┘ │ └───────────────────────────────────────────────────┘ │ │ Anthropic Messages API (HTTPS) │ + Brave Search API (HTTPS) ▼ ┌───────────┐ ┌──────────────┐ │ Claude API │ │ Brave Search │ └───────────┘ └──────────────┘ ``` --- ## Data Flow ``` 1. User sends message on Telegram (or WebSocket) 2. Channel poller receives message, wraps in mimi_msg_t 3. Message pushed to Inbound Queue (FreeRTOS xQueue) 4. Agent Loop (Core 1) pops message: a. Load session history from SPIFFS (JSONL) b. Build system prompt (SOUL.md + USER.md + MEMORY.md + recent notes + tool guidance) c. Build cJSON messages array (history + current message) d. ReAct loop (max 10 iterations): i. Call Claude API via HTTPS (non-streaming, with tools array) ii. Parse JSON response → text blocks + tool_use blocks iii. If stop_reason == "tool_use": - Execute each tool (e.g. web_search → Brave Search API) - Append assistant content + tool_result to messages - Continue loop iv. If stop_reason == "end_turn": break with final text e. Save user message + final assistant text to session file f. Push response to Outbound Queue 5. Outbound Dispatch (Core 0) pops response: a. Route by channel field ("telegram" → sendMessage, "websocket" → WS frame) 6. User receives reply ``` --- ## Module Map ``` main/ ├── mimi.c Entry point — app_main() orchestrates init + startup ├── mimi_config.h All compile-time constants + build-time secrets include ├── mimi_secrets.h Build-time credentials (gitignored, highest priority) ├── mimi_secrets.h.example Template for mimi_secrets.h │ ├── bus/ │ ├── message_bus.h mimi_msg_t struct, queue API │ └── message_bus.c Two FreeRTOS queues: inbound + outbound │ ├── wifi/ │ ├── wifi_manager.h WiFi STA lifecycle API │ └── wifi_manager.c NVS credentials, event handler, exponential backoff │ ├── telegram/ │ ├── telegram_bot.h Bot init/start, send_message API │ └── telegram_bot.c Long polling loop, JSON parsing, message splitting │ ├── llm/ │ ├── llm_proxy.h llm_chat() + llm_chat_tools() API, tool_use types │ └── llm_proxy.c Anthropic Messages API (non-streaming), tool_use parsing │ ├── agent/ │ ├── agent_loop.h Agent task init/start │ ├── agent_loop.c ReAct loop: LLM call → tool execution → repeat │ ├── context_builder.h System prompt + messages builder API │ └── context_builder.c Reads bootstrap files + memory + tool guidance │ ├── tools/ │ ├── tool_registry.h Tool definition struct, register/dispatch API │ ├── tool_registry.c Tool registration, JSON schema builder, dispatch by name │ ├── tool_web_search.h Web search tool API │ └── tool_web_search.c Brave Search API via HTTPS (direct + proxy) │ ├── memory/ │ ├── memory_store.h Long-term + daily memory API │ ├── memory_store.c MEMORY.md read/write, daily .md append/read │ ├── session_mgr.h Per-chat session API │ └── session_mgr.c JSONL session files, ring buffer history │ ├── gateway/ │ ├── ws_server.h WebSocket server API │ └── ws_server.c ESP HTTP server with WS upgrade, client tracking │ ├── proxy/ │ ├── http_proxy.h Proxy connection API │ └── http_proxy.c HTTP CONNECT tunnel + TLS via esp_tls │ ├── cli/ │ ├── serial_cli.h CLI init API │ └── serial_cli.c esp_console REPL with 15 commands │ └── ota/ ├── ota_manager.h OTA update API └── ota_manager.c esp_https_ota wrapper ``` --- ## FreeRTOS Task Layout | Task | Core | Priority | Stack | Description | |--------------------|------|----------|--------|--------------------------------------| | `tg_poll` | 0 | 5 | 12 KB | Telegram long polling (30s timeout) | | `agent_loop` | 1 | 6 | 12 KB | Message processing + Claude API call | | `outbound` | 0 | 5 | 8 KB | Route responses to Telegram / WS | | `serial_cli` | 0 | 3 | 4 KB | USB serial console REPL | | httpd (internal) | 0 | 5 | — | WebSocket server (esp_http_server) | | wifi_event (IDF) | 0 | 8 | — | WiFi event handling (ESP-IDF) | **Core allocation strategy**: Core 0 handles I/O (network, serial, WiFi). Core 1 is dedicated to the agent loop (CPU-bound JSON building + waiting on HTTPS). --- ## Memory Budget | Purpose | Location | Size | |------------------------------------|----------------|----------| | FreeRTOS task stacks | Internal SRAM | ~40 KB | | WiFi buffers | Internal SRAM | ~30 KB | | TLS connections x2 (Telegram + Claude) | PSRAM | ~120 KB | | JSON parse buffers | PSRAM | ~32 KB | | Session history cache | PSRAM | ~32 KB | | System prompt buffer | PSRAM | ~16 KB | | LLM response stream buffer | PSRAM | ~32 KB | | Remaining available | PSRAM | ~7.7 MB | Large buffers (32 KB+) are allocated from PSRAM via `heap_caps_calloc(1, size, MALLOC_CAP_SPIRAM)`. --- ## Flash Partition Layout ``` Offset Size Name Purpose ───────────────────────────────────────────── 0x009000 24 KB nvs WiFi creds, TG token, API key, model 0x00F000 8 KB otadata OTA boot state 0x011000 4 KB phy_init WiFi PHY calibration 0x020000 2 MB ota_0 Firmware slot A 0x220000 2 MB ota_1 Firmware slot B 0x420000 12 MB spiffs Markdown memory, sessions, config 0xFF0000 64 KB coredump Crash dump storage ``` Total: 16 MB flash. --- ## Storage Layout (SPIFFS) SPIFFS is a flat filesystem — no real directories. Files use path-like names. ``` /spiffs/config/SOUL.md AI personality definition /spiffs/config/USER.md User profile /spiffs/memory/MEMORY.md Long-term persistent memory /spiffs/memory/2026-02-05.md Daily notes (one file per day) /spiffs/sessions/tg_12345.jsonl Session history (one file per Telegram chat) ``` Session files are JSONL (one JSON object per line): ```json {"role":"user","content":"Hello","ts":1738764800} {"role":"assistant","content":"Hi there!","ts":1738764802} ``` --- ## NVS Configuration | Namespace | Key | Description | |-----------------|--------------|-----------------------------------------| | `wifi_config` | `ssid` | WiFi SSID | | `wifi_config` | `password` | WiFi password | | `tg_config` | `bot_token` | Telegram Bot API token | | `llm_config` | `api_key` | Anthropic API key | | `llm_config` | `model` | Model ID (default: claude-opus-4-6) | | `proxy_config` | `host` | HTTP proxy hostname/IP | | `proxy_config` | `port` | HTTP proxy port | | `search_config` | `api_key` | Brave Search API key | **Configuration priority**: `mimi_secrets.h` (build-time) > NVS (CLI-set) > defaults. All configurable via Serial CLI or build-time config file (`mimi_secrets.h`). --- ## Message Bus Protocol The internal message bus uses two FreeRTOS queues carrying `mimi_msg_t`: ```c typedef struct { char channel[16]; // "telegram", "websocket", "cli" char chat_id[32]; // Telegram chat ID or WS client ID char *content; // Heap-allocated text (ownership transferred) } mimi_msg_t; ``` - **Inbound queue**: channels → agent loop (depth: 8) - **Outbound queue**: agent loop → dispatch → channels (depth: 8) - Content string ownership is transferred on push; receiver must `free()`. --- ## WebSocket Protocol Port: **18789**. Max clients: **4**. **Client → Server:** ```json {"type": "message", "content": "Hello", "chat_id": "ws_client1"} ``` **Server → Client:** ```json {"type": "response", "content": "Hi there!", "chat_id": "ws_client1"} ``` Client `chat_id` is auto-assigned on connection (`ws_`) but can be overridden in the first message. --- ## Claude API Integration Endpoint: `POST https://api.anthropic.com/v1/messages` Request format (Anthropic-native, non-streaming, with tools): ```json { "model": "claude-opus-4-6", "max_tokens": 4096, "system": "", "tools": [ { "name": "web_search", "description": "Search the web for current information.", "input_schema": {"type": "object", "properties": {"query": {"type": "string"}}, "required": ["query"]} } ], "messages": [ {"role": "user", "content": "Hello"}, {"role": "assistant", "content": "Hi!"}, {"role": "user", "content": "What's the weather today?"} ] } ``` Key difference from OpenAI: `system` is a top-level field, not inside the `messages` array. Non-streaming JSON response: ```json { "id": "msg_xxx", "type": "message", "role": "assistant", "content": [ {"type": "text", "text": "Let me search for that."}, {"type": "tool_use", "id": "toolu_xxx", "name": "web_search", "input": {"query": "weather today"}} ], "stop_reason": "tool_use" } ``` When `stop_reason` is `"tool_use"`, the agent loop executes each tool and sends results back: ```json {"role": "assistant", "content": []} {"role": "user", "content": [{"type": "tool_result", "tool_use_id": "toolu_xxx", "content": "..."}]} ``` The loop repeats until `stop_reason` is `"end_turn"` (max 10 iterations). --- ## Startup Sequence ``` app_main() ├── init_nvs() NVS flash init (erase if corrupted) ├── esp_event_loop_create_default() ├── init_spiffs() Mount SPIFFS at /spiffs ├── message_bus_init() Create inbound + outbound queues ├── memory_store_init() Verify SPIFFS paths ├── session_mgr_init() ├── wifi_manager_init() Init WiFi STA mode + event handlers ├── http_proxy_init() Load proxy config (secrets > NVS) ├── telegram_bot_init() Load bot token (secrets > NVS) ├── llm_proxy_init() Load API key + model (secrets > NVS) ├── tool_registry_init() Register tools, build tools JSON ├── agent_loop_init() ├── serial_cli_init() Start REPL (works without WiFi) │ ├── wifi_manager_start() Connect (secrets > NVS credentials) │ └── wifi_manager_wait_connected(30s) │ └── [if WiFi connected] ├── telegram_bot_start() Launch tg_poll task (Core 0) ├── agent_loop_start() Launch agent_loop task (Core 1) ├── ws_server_start() Start httpd on port 18789 └── outbound_dispatch task Launch outbound task (Core 0) ``` If WiFi credentials are missing or connection times out, the CLI remains available for configuration. --- ## Serial CLI Commands | Command | Description | |--------------------------------|--------------------------------------| | `wifi_set ` | Save WiFi credentials to NVS | | `wifi_status` | Show connection status and IP | | `set_tg_token ` | Save Telegram bot token | | `set_api_key ` | Save Anthropic API key | | `set_model ` | Set LLM model identifier | | `set_search_key ` | Save Brave Search API key | | `set_proxy ` | Set HTTP CONNECT proxy | | `clear_proxy` | Remove proxy, use direct connection | | `memory_read` | Print MEMORY.md contents | | `memory_write ` | Overwrite MEMORY.md | | `session_list` | List all session files | | `session_clear ` | Delete a session file | | `heap_info` | Show internal + PSRAM free bytes | | `restart` | Reboot the device | | `help` | List all available commands | > **Note**: CLI-set values are stored in NVS but are overridden by `mimi_secrets.h` build-time values if set. --- ## Nanobot Reference Mapping | Nanobot Module | MimiClaw Equivalent | Notes | |-----------------------------|--------------------------------|------------------------------| | `agent/loop.py` | `agent/agent_loop.c` | ReAct loop with tool use | | `agent/context.py` | `agent/context_builder.c` | Loads SOUL.md + USER.md + memory + tool guidance | | `agent/memory.py` | `memory/memory_store.c` | MEMORY.md + daily notes | | `session/manager.py` | `memory/session_mgr.c` | JSONL per chat, ring buffer | | `channels/telegram.py` | `telegram/telegram_bot.c` | Raw HTTP, no python-telegram-bot | | `bus/events.py` + `queue.py`| `bus/message_bus.c` | FreeRTOS queues vs asyncio | | `providers/litellm_provider.py` | `llm/llm_proxy.c` | Direct Anthropic API only | | `config/schema.py` | `mimi_config.h` + `mimi_secrets.h` + NVS | Build-time secrets > NVS | | `cli/commands.py` | `cli/serial_cli.c` | esp_console REPL | | `agent/tools/*` | `tools/tool_registry.c` + `tool_web_search.c` | web_search via Brave API | | `agent/subagent.py` | *(not yet implemented)* | See TODO.md | | `agent/skills.py` | *(not yet implemented)* | See TODO.md | | `cron/service.py` | *(not yet implemented)* | See TODO.md | | `heartbeat/service.py` | *(not yet implemented)* | See TODO.md |