# MimiClaw Architecture > ESP32-S3 AI Agent firmware — a C/FreeRTOS reimplementation of [nanobot](../nanobot/)'s core agent capabilities. --- ## 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) │ │ └──────┬───────┘ │ │ ┌─────────────┐ │ │ │ │ Serial CLI │ ▼ │ │ │ (Core 0) │ ┌──────────────┐ │ │ └─────────────┘ │ 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 + SSE) ▼ ┌───────────┐ │ Claude API │ └───────────┘ ``` --- ## 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) c. Build messages array (history + current message) d. Call Claude API via HTTPS (SSE streaming) e. Accumulate streamed response tokens f. Save user + assistant messages to session file g. 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 in one place │ ├── 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() API │ └── llm_proxy.c Anthropic Messages API, SSE stream parser │ ├── agent/ │ ├── agent_loop.h Agent task init/start │ ├── agent_loop.c Main processing loop: inbound → context → LLM → outbound │ ├── context_builder.h System prompt + messages builder API │ └── context_builder.c Reads bootstrap files + memory, assembles prompt │ ├── 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 │ ├── cli/ │ ├── serial_cli.h CLI init API │ └── serial_cli.c esp_console REPL with 12 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 | 8 KB | Telegram long polling (30s timeout) | | `agent_loop` | 1 | 6 | 8 KB | Message processing + Claude API call | | `outbound` | 0 | 5 | 4 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-4-5-20251101) | All configured via Serial CLI commands: `wifi_set`, `set_tg_token`, `set_api_key`, `set_model`. --- ## 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, not OpenAI): ```json { "model": "claude-opus-4-5-20251101", "max_tokens": 4096, "stream": true, "system": "", "messages": [ {"role": "user", "content": "Hello"}, {"role": "assistant", "content": "Hi!"}, {"role": "user", "content": "How are you?"} ] } ``` Key difference from OpenAI: `system` is a top-level field, not inside the `messages` array. SSE streaming response events: ``` event: content_block_delta data: {"type":"content_block_delta","delta":{"type":"text_delta","text":"Hello"}} event: message_stop data: {"type":"message_stop"} ``` The SSE parser in `llm_proxy.c` accumulates `text_delta` tokens into a response buffer. --- ## 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 ├── telegram_bot_init() Load bot token from NVS ├── llm_proxy_init() Load API key + model from NVS ├── agent_loop_init() ├── serial_cli_init() Start REPL (works without WiFi) │ ├── wifi_manager_start() Connect using 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 | | `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 | --- ## Nanobot Reference Mapping | Nanobot Module | MimiClaw Equivalent | Notes | |-----------------------------|--------------------------------|------------------------------| | `agent/loop.py` | `agent/agent_loop.c` | Simplified: no tool use loop | | `agent/context.py` | `agent/context_builder.c` | Loads SOUL.md + USER.md + memory | | `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` + NVS | Compile-time + NVS storage | | `cli/commands.py` | `cli/serial_cli.c` | esp_console REPL | | `agent/tools/*` | *(not yet implemented)* | See TODO.md | | `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 |