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zclaw

zclaw is the smallest possible AI personal assistant, running on ESP32 in pure C with an all-in firmware budget of 888 KiB. GPIO control, cron scheduling, custom tools, persistent memory, and Telegram chat.

Key takeaways

  • All-in firmware under 888 KiB including ESP-IDF/FreeRTOS runtime, Wi-Fi, TLS, and cert bundle — the smallest AI personal assistant
  • GPIO read/write control with guardrails turns any ESP32 into a natural-language-controlled IoT device
  • Persistent memory across reboots with timezone-aware scheduling (daily, periodic, one-shot)
  • Supports Anthropic, OpenAI, OpenRouter, and Ollama — no cloud lock-in

FAQ

What is zclaw?

zclaw is a personal AI assistant written in C that runs on ESP32 microcontrollers with an all-in firmware budget of 888 KiB. It supports Telegram chat, GPIO control, cron scheduling, custom tools, and persistent memory.

What hardware does zclaw run on?

ESP32-C3, ESP32-S3, and ESP32-C6. The recommended starter board is the Seeed XIAO ESP32-C3 (~$5).

How much does zclaw cost?

Free and open-source. You need an ESP32 board (~$5-15) and an LLM API key (or local Ollama).

Who competes with zclaw?

MimiClaw (also ESP32, C), PicoClaw (Go, edge hardware), and NullClaw (Zig, smallest x86 footprint).

Executive Summary

zclaw is a personal AI assistant written in pure C that runs on ESP32 microcontrollers with a strict all-in firmware budget of 888 KiB. It brings natural language AI to the cheapest possible hardware — a $5 ESP32 board — with GPIO control, timezone-aware scheduling, persistent memory, and Telegram integration. [1]

AttributeValue
Authortnm
LanguageC
LicenseOpen Source
GitHub Stars1,197
Firmware Size≤ 888 KiB (all-in)

Product Overview

zclaw targets the absolute minimum viable AI assistant: a microcontroller with Wi-Fi, an LLM API key, and natural language control over physical hardware. The 888 KiB budget includes everything — zclaw logic, ESP-IDF/FreeRTOS runtime, Wi-Fi/networking, TLS/crypto, and certificate bundles. [1]

Key Capabilities

CapabilityDescription
Telegram ChatChat via Telegram or hosted web relay
GPIO ControlRead/write with guardrails, bulk gpio_read_all
SchedulingTimezone-aware daily, periodic, and one-shot tasks
Custom ToolsBuilt-in + user-defined tools via natural language
Persistent MemorySurvives reboots, stored in flash
PersonasNeutral, friendly, technical, or witty
Multi-ProviderAnthropic, OpenAI, OpenRouter, Ollama
Encrypted CredentialsSecure flash mode for NVS storage

Hardware

Tested on ESP32-C3, ESP32-S3, and ESP32-C6. Recommended starter: Seeed XIAO ESP32-C3 (~$5). [2]


Strengths

  • Smallest AI assistant — 888 KiB all-in firmware, runs on $5 hardware
  • Physical world control — GPIO read/write enables real IoT automation via natural language
  • No cloud lock-in — Supports Anthropic, OpenAI, OpenRouter, and local Ollama
  • Persistent memory — Context survives reboots, unlike most microcontroller projects
  • One-line install — Bootstrap script handles ESP-IDF setup
  • Active community — 1,197 stars, well-documented with dedicated docs site

Cautions

  • ESP32 only — No x86, ARM server, or general Linux support
  • Requires LLM API — The ESP32 can't run models locally (Ollama needs a separate host)
  • Limited channels — Telegram and web relay only; no Discord, Slack, or WhatsApp
  • C codebase — Higher barrier to contribution than TypeScript/Python alternatives
  • Rate limits — Default 100/hour, 1000/day (configurable at compile time)

Pricing & Licensing

TierPriceIncludes
Open SourceFreeFull firmware, open license

Hardware cost: ~$5-15 for an ESP32 board. Hidden costs: LLM API usage.


Competitive Positioning

CompetitorDifferentiation
MimiClawMimiClaw also targets ESP32 in C but focuses on ESP32-S3 with WebSocket; zclaw has stricter size budget and GPIO focus
PicoClawPicoClaw runs Go on edge Linux; zclaw runs bare-metal C on microcontrollers
NullClawNullClaw is smallest x86 binary (678 KB); zclaw is smallest microcontroller firmware (888 KiB)

Bottom Line

zclaw pushes the personal AI assistant to its absolute minimum: a $5 microcontroller running 888 KiB of firmware that can chat via Telegram, control GPIO pins, schedule tasks, and remember context across reboots. It's the proof that AI assistants don't need gigabytes — or even megabytes.

Recommended for: Hardware hackers, IoT enthusiasts, and anyone who wants an AI assistant on the cheapest possible device.

Not recommended for: Users wanting multi-channel support, rich integrations, or a general-purpose personal agent.


Research by Ry Walker Research • methodology