How You Can Use an ESP32 with Hermes Agent

How You Can Use an ESP32 with Hermes Agent

Gemini said

Integrating an ESP32 with Hermes Agent (the local-first, self-improving AI agent ecosystem by Nous Research) allows you to bring physical computing, IoT sensors, and smart-home hardware into your agent’s loop.

Because Hermes Agent is capable of running custom Python code, managing files, and connecting to the Model Context Protocol (MCP), you can integrate an ESP32 using two primary methods:

Method 1: The MCP Server / Custom Skill Approach (Control & Automation)

In this architecture, the ESP32 acts as an IoT peripheral exposing a local API (HTTP REST or MQTT), and Hermes acts as the brain using a custom tool or skill to talk to it.

┌──────────────┐                  ┌──────────────┐                 ┌───────────┐
│ Hermes Agent │ ──(Local API)──> │ Python/MCP   │ ──(Wi-Fi/LAN)─> │   ESP32   │
│ (LLM Brain)  │ <──(JSON/Data)── │ Skill Bridge │ <──(Sensors)─── │ (Hardware)│
└──────────────┘                  └──────────────┘                 └───────────┘

1. Program the ESP32 to Expose an Endpoint

Flash your ESP32 (using Arduino IDE or PlatformIO) to join your local Wi-Fi network and host a simple web server that exposes endpoints to control GPIO pins or read sensors.

C++

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";
WebServer server(80);

void handleToggleLED() {
    digitalWrite(2, !digitalRead(2)); // Toggles onboard LED
    server.send(200, "application/json", "{\"status\":\"success\", \"led\":" + String(digitalRead(2)) + "}");
}

void setup() {
    pinMode(2, OUTPUT);
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) delay(500);
    server.on("/toggle", HTTP_POST, handleToggleLED);
    server.begin();
}

void loop() {
    server.handleClient();
}

2. Create a Hermes Skill or Python Tool

Hermes Agent loves Python scripts. You can prompt Hermes directly to write a script or build a persistent skill to control the device.

XDA Developers

  1. Create a Python script inside your local environment (~/.hermes/scripts/esp32_control.py):
    Python 
    import sys
import requests
ESP32_IP = "http://192.168.1.150"  # Replace with your ESP32's actual IP
def toggle_led():
    try:
        response = requests.post(f"{ESP32_IP}/toggle", timeout=5)
        print(f"ESP32 Response: {response.json()}")
    except Exception as e:
        print(f"Error connecting to ESP32: {e}")
if __name__ == "__main__":
    toggle_led()
  2. In your chat interface with Hermes, tell the agent:

    "I want you to memorize a skill. Whenever I ask you to flip the physical lab light, run the python script at ~/.hermes/scripts/esp32_control.py."

  3. Because Hermes has an agentic learning loop, it will record this to its internal SKILLS.md memory architecture and reuse it autonomously next time you make the request.

Method 2: The Voice Bridge Approach (Hardware Companion)

If you want to use the ESP32 as a physical interface for Hermes Agent—like a smart speaker or desk robot equipped with a microphone and speaker (e.g., ESP32-S3 Box, M5Stack CoreS3)—you can run an open-source bridge layer that links the XiaoZhi protocol to Hermes' Webhook server.

GitHub

Using tools like robot-bridge (designed to map ESP32 smart-audio devices to Hermes), the workflow is configured as follows:

1. Enable Hermes API and Webhooks

Modify your Hermes configuration file (~/.hermes/config.yaml) to allow external connections and enable its webhook platform:

YAML

platforms:
  api_server:
    enabled: true
    host: 127.0.0.1
    port: 8642
  webhook:
    enabled: true
    extra:
      host: 127.0.0.1
      port: 8644

2. How the Interaction Flows

  • ESP32 Side: Flashed with a firmware that records voice commands, encodes the audio to a compressed format like Opus, and streams it over WebSockets.
  • Bridge Layer: A lightweight local Python bridge catches the audio stream, pipes it through local speech-to-text (like faster-whisper), and fires a formatted POST webhook request into Hermes Agent.
  • Hermes Layer: Processes the request utilizing your local LLM (e.g., Qwen3.6 or Gemma via Ollama), generates a response, executes any necessary tools, and pushes text-to-speech audio bytes back through the bridge to play on the ESP32’s speaker.

Best Practices for ESP32 + Hermes Setup

  • Isolate via Tailscale / Local LAN: Do not expose your ESP32 web server or the Hermes API gateway directly to the open internet. Keep them inside a local network or mapped securely using a Tailscale network.
  • Leverage Cron Jobs: Combine Hermes' persistent cron features with your ESP32. You can instruct Hermes: "Every hour, run a Python script to pull the temperature from my ESP32 sensor, analyze the pattern using your local model, and alert me over Telegram if it goes above normal limits."
    XDA Developers

Are you aiming to use the ESP32 primarily to pull sensor data into Hermes, or are you looking to build a dedicated voice-controlled hardware companion?

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