ESPHome Web Server API List Components

An ESPHome external component that adds the missing /components HTTP endpoint to your device's web server, providing a JSON API to list all components and their metadata.

Overview

This component extends the built-in ESPHome web server by adding a new endpoint at /components that returns a JSON response containing information about all components configured on your device. This is particularly useful for:

• Building custom dashboards or integrations
• Debugging entity configurations
• Discovering available components programmatically
• Creating dynamic UI applications that need to know about device capabilities

Features

• 🌐 Adds /components GET endpoint to existing ESPHome web server
• 📊 Returns comprehensive entity metadata (key, object_id, name, type)
• 🔧 Supports all major ESPHome entity types
• ⚡ ESP-IDF compatible
• 📱 JSON response format for easy integration
• 🛡️ Leverages existing web server security and configuration

Supported Entity Types

• sensor - Sensors that provide numeric values
• binary_sensor - On/off sensors
• switch - Controllable switches
• number - Numeric input controls
• light - Lighting controls
• climate - Climate control (heating/cooling)
• text_sensor - Text-based sensors
• fan - Fan controls
• cover - Covers/blinds/shutters
• select - Selection controls
• unknown - Fallback for unrecognized types

Installation

Add this component to your ESPHome configuration as an external component:

external_components:
  - source:
      type: git
      url: https://github.com/andrewbackway/esphome-webserver-listcomponents
      components: ["webserver_listcomponents"]

# Enable the built-in web server (required)
web_server:
  port: 80

# Enable the list components component
webserver_listcomponents:

Prerequisites

• ESPHome with web server component enabled
• ESP32 or ESP8266 device
• Network connectivity (Wi-Fi configured)

API Documentation

GET /components

Returns a JSON object containing an array of all components configured on the device.

Request:

GET /components HTTP/1.1
Host: your-device-ip

Response:

{
  "components": [
    {
      "key": "sensor-temperature-123456",
      "object_id": "temperature", 
      "name": "Living Room Temperature",
      "type": "sensor"
    },
    {
      "key": "switch-relay-789012",
      "object_id": "relay",
      "name": "Main Relay",
      "type": "switch"
    },
    {
      "key": "binary_sensor-motion-345678",
      "object_id": "motion",
      "name": "Motion Detector",
      "type": "binary_sensor"
    }
  ]
}

Response Fields:

• key - Unique identifier for the entity
• object_id - The entity's object ID as defined in configuration
• name - Human-readable display name
• type - Entity type (sensor, switch, etc.)

Status Codes:

• 200 - Success
• 404 - Endpoint not found (component not configured or web server disabled)
• 500 - Internal server error

Example Usage

Python Integration

import requests
import json

# Get components from your ESPHome device
response = requests.get('http://192.168.1.100/components')
data = response.json()

for entity in data['components']:
    print(f"Found {entity['type']}: {entity['name']} ({entity['object_id']})")

JavaScript/Fetch

fetch('http://192.168.1.100/components')
  .then(response => response.json())
  .then(data => {
    data.components.forEach(entity => {
      console.log(`${entity.type}: ${entity.name}`);
    });
  });

cURL

curl http://192.168.1.100/components | jq '.components[] | {name, type}'

Complete Configuration Example

# ESPHome configuration example
esphome:
  name: my-device
  platform: ESP32
  board: esp32dev

wifi:
  ssid: "Your-WiFi"
  password: "your-password"

# Enable logging
logger:

# Enable Home Assistant API
api:

# Enable OTA updates
ota:

# Enable web server
web_server:
  port: 80
  auth:
    username: admin
    password: password

# Add the list components component
external_components:
  - source:
      type: git
      url: https://github.com/andrewbackway/esphome-webserver-listcomponents
      components: ["webserver_listcomponents"]

webserver_listcomponents:

# Example components that will appear in /components
sensor:
  - platform: dht
    pin: GPIO4
    temperature:
      name: "Temperature"
    humidity:
      name: "Humidity"

switch:
  - platform: gpio
    pin: GPIO2
    name: "LED"

binary_sensor:
  - platform: gpio
    pin: GPIO0
    name: "Button"

Technical Details

Implementation Notes

• ESP-IDF Compatible: Designed specifically to work with ESP-IDF framework
• Memory Efficient: Uses a 4KB JSON buffer optimized for typical entity counts
• Thread Safe: Integrates safely with ESPHome's component lifecycle
• Setup Priority: Runs after Wi-Fi to ensure web server availability

Dependencies

This component relies on:

• esphome/components/web_server - For the HTTP server infrastructure
• AsyncWebServer - For HTTP request handling
• ArduinoJson - For JSON serialization

Logging

The component logs to the WebServerListComponents tag with different levels:

• ESP_LOGD - Debug information about setup and responses
• ESP_LOGI - Information about successful route registration
• ESP_LOGE - Errors during setup or operation

Troubleshooting

Common Issues

"Built-in web_server not found"

• Ensure web_server: is configured in your YAML
• Verify the web server component is loading successfully

404 on /components endpoint

• Check that webserver-listcomponents: is included in your configuration
• Verify the external component was loaded successfully
• Check device logs for setup errors

Empty components array

• This is normal if no components are configured on the device
• Add some sensors, switches, or other components to see results

Debug Logging

Enable debug logging to see detailed component operation:

logger:
  level: DEBUG
  logs:
    :WebServerListComponents DEBUG

Contributing

Issues and pull requests are welcome! Please feel free to contribute improvements, bug fixes, or additional features.

License

This project follows the same license terms as ESPHome.