Data Fetcher

The Data Fetcher lets SVITRIX automatically pull data from external HTTP/HTTPS APIs and display the results on the LED matrix — no smart home system required.

How It Works

You configure one or more data sources, each pointing to an external API
SVITRIX periodically fetches each source and extracts a value from the JSON response
The extracted value is formatted and displayed as a custom app in the app loop

Web Interface

Navigate to http://[IP]/datafetcher in your browser to manage data sources through a visual interface. You can add, edit, and remove sources without writing any API calls.

Configuration

Each data source has the following settings:

Setting	Description
Name	Unique identifier — becomes the app name shown in the loop
URL	Full HTTP or HTTPS URL of the API endpoint
JSON Path	Dot-notation path to the value in the response (e.g., `bitcoin.usd` or `data.0.price`)
Display Format	Optional printf-style format for a single value (e.g., `$%.0f` for "$67432", `%.1f°C` for "23.5°C"). Allowed specifiers: `%d %i %u %o %x %X %f %g %e %E %s` with optional width and precision (1–2 digits each). Use `%%` for a literal `%` (e.g., `%d%%` → "85%").
Icon	Optional icon name from the ICONS folder
Color	Optional text color as hex `#RRGGBB`
Interval	Polling interval in seconds (minimum 60, default 900)
Duration	Display duration in seconds (0 = use global timePerApp setting)
Enabled	When disabled, the source is saved but not displayed in rotation

JSON Path

The JSON Path indicates where to find the value you want to extract from the API response. Use dot notation to navigate through the structure.

How to find the path

Open the API URL in your browser
Observe the JSON structure
Write the path using dots to separate levels

Path examples

If the API returns:

json

{
  "rates": {
    "MXN": 17.45,
    "EUR": 0.92
  }
}

→ Path: rates.MXN → Result: 17.45

For arrays, use the numeric index:

json

{
  "data": [
    { "price": 67000 },
    { "price": 3400 }
  ]
}

→ Path: data.0.price → Result: 67000 (first element)

Display Format

The Display Format uses printf syntax to style the extracted value.

Quick reference

Format	Example output	Description
`$%.2f`	$17.45	Currency with 2 decimals
`$%.0f`	$67432	Currency without decimals
`%.1f°C`	23.5°C	One decimal with unit
`%d%%`	85%	Integer with % symbol
`%s`	text	Unmodified text
(empty)	17.45	Raw value

Allowed specifiers

Numbers: %d %i (integers), %f %g %e (decimals)
Text: %s (string)
Literal %: %% (displays a single %)

Optional modifiers

Minimum width: %8d → " 42" (8 characters)
Decimal precision: %.2f → "3.14" (2 decimals)
Combined: %8.2f → " 3.14"

Icon

The Icon field accepts:

File name: name of an icon in the /ICONS/ folder (without extension)
LaMetric number: numeric ID from LaMetric Icon Gallery — the system looks for [number].gif in /ICONS/

Examples: bitcoin, 16437, weather

Tip: Download icons from the Icons section in the web interface before using them.

Examples

Bitcoin Price

Name: btc
URL: https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies=usd
JSON Path: bitcoin.usd
Format: $%.0f
Color: #F7931A
Interval: 300

USD/MXN Exchange Rate

Name: USDMXN
URL: https://open.er-api.com/v6/latest/USD
JSON Path: rates.MXN
Format: $%.2f
Color: #00AA00
Interval: 3600

Ethereum Price

Name: eth
URL: https://api.coingecko.com/api/v3/simple/price?ids=ethereum&vs_currencies=usd
JSON Path: ethereum.usd
Format: $%.0f
Color: #627EEA
Interval: 300

GitHub Stars for a Repository

Name: stars
URL: https://api.github.com/repos/USER/REPO
JSON Path: stargazers_count
Format: %d ★
Color: #FFD700
Interval: 3600

Your Public IP

Name: myip
URL: https://api.ipify.org?format=json
JSON Path: ip
Format: %s
Interval: 86400

Public API Sources

These collections contain hundreds of free APIs compatible with SVITRIX:

Resource	URL	Description
Public APIs	https://github.com/public-apis/public-apis	1400+ APIs in 50 categories, filterable by auth
API List	https://apilist.fun	Search by topic and popularity
Free APIs	https://free-apis.github.io	Curated list of free APIs
No Auth APIs	https://mixedanalytics.com/blog/list-actually-free-open-no-auth-needed-apis/	APIs without authentication
RapidAPI Free	https://rapidapi.com/collection/list-of-free-apis	With examples and documentation

Compatibility Requirements

For an API to work with SVITRIX:

✅ No authentication or API key in the URL (no custom headers)
✅ JSON response under 4 KB
✅ Extractable value with dot notation (data.value, items.0.price)
✅ Public endpoint accessible from your network

Ideas by Category

Category	Suggested APIs
Finance	CoinGecko, ExchangeRate-API, Alpha Vantage
Weather	Open-Meteo, WeatherAPI (already integrated)
Monitoring	UptimeRobot, Pi-hole, Home Assistant
Development	GitHub API, GitLab API
Entertainment	Spotify (with token), Twitch
Utilities	ipify, WorldTimeAPI

Enable / Disable Sources

You can temporarily disable a source without deleting it:

In the web interface, each source has an Enable/Disable button
Disabled sources remain saved but are not fetched or displayed
When re-enabling a source, it fetches immediately and returns to rotation
Useful for pausing sources during API maintenance or to reduce traffic

Limitations

Maximum 8 data sources simultaneously
API response must be under 4 KB
Only public APIs are supported (no custom authentication headers)
Minimum polling interval is 60 seconds
HTTPS is supported but without certificate validation

API

Data sources can also be managed via the HTTP API.

Data Fetcher ​

How It Works ​

Web Interface ​

Configuration ​

JSON Path ​

How to find the path ​

Path examples ​

Display Format ​

Quick reference ​

Allowed specifiers ​

Optional modifiers ​

Icon ​

Examples ​

Bitcoin Price ​

USD/MXN Exchange Rate ​

Ethereum Price ​

GitHub Stars for a Repository ​

Your Public IP ​

Public API Sources ​

Compatibility Requirements ​

Ideas by Category ​

Enable / Disable Sources ​

Limitations ​

API ​