Timeline Template

A real-time sparkline chart for tracking values over time. Each push sends a data point; the server accumulates history and delivers the sparkline data to iOS via push notifications.

Fields

Field	Type	Description
`template`	string	Required. Must be `"timeline"`
`value`	object	The data point(s) for this push. Required. A labeled map (e.g. `{\"CPU\": 72.5}` or `{\"CPU\": 72.5, \"GPU\": 45.2}`). Max 4 series, 32-char keys
`unit`	string	Unit suffix on value display (e.g. "°C", "%"). Max 32 characters. Used as fallback when `units` is set
`units`	object	Per-series unit overrides. Keys must match `value` keys; missing keys fall back to `unit`. Max 32-char values
`scale`	string	Y-axis scaling: `"linear"` (default) or `"logarithmic"`
`decimals`	integer	Decimal places for display. `null` = auto-detect. Range 0–10
`smoothing`	boolean	Curve interpolation between points. Default: `false` (straight segments)
`thresholds`	array	Up to 5 horizontal reference lines. Each has `value` (required), `color`, and `label` (max 12 chars)
`state`	string	Status text (e.g. "Heating", "Monitoring")
`icon`	string	SF Symbol name (e.g. `"chart.xyaxis.line"`) or MDI icon with `mdi:` prefix
`accent_color`	string	Named color or hex. Default: `teal`

ℹ Info

The server accumulates history automatically — each push appends a timestamped data point. The history field in the response is read-only (client-supplied history is ignored). Up to 300 points per series are stored; APNs payloads are dynamically downsampled via LTTB to fit 4KB while preserving peaks and visual shape.

Example: Single Value

Server temperature monitoring

{
  "state": "ONGOING",
  "content": {
    "template": "timeline",
    "value": {"Temperature": 13.7},
    "unit": "°C",
    "state": "Heating",
    "icon": "thermometer.medium",
    "accent_color": "orange",
    "smoothing": true
  }
}

Example: Multi-Value with Thresholds

System health with mixed units

{
  "state": "ONGOING",
  "content": {
    "template": "timeline",
    "value": {
      "CPU": 72.5,
      "GPU": 45.2,
      "Fan": 60.0,
      "SSD": 38.1
    },
    "unit": "%",
    "units": { "GPU": "°C", "SSD": "°C" },
    "state": "Monitoring",
    "thresholds": [
      { "value": 80, "color": "red", "label": "Critical" },
      { "value": 60, "color": "orange" }
    ]
  }
}

Typical Flow

Start tracking (ENDED -> ONGOING): Set initial value, unit, and display options (scale, smoothing, thresholds)
Send data points (ONGOING -> ONGOING): Push updated values — the sparkline grows with each push
Stop tracking (ONGOING -> ENDED): Final value displayed, sparkline frozen

💡 Tip

Value-only updates are delivered at low priority to conserve the iOS push budget. Changing scale, smoothing, decimals, unit, or units triggers high-priority delivery.

Use Cases

Server monitoring — CPU temperature, memory usage, network throughput over time
Smart home — room temperature trends, humidity tracking, energy consumption
3D printing — hotend/bed temperature curves during a print
CI/CD — build time trends, test suite duration over consecutive runs
IoT — sensor readings over time with threshold alerts