▣ IMAGE PROCESSING · SMART GENERATION

Generate HeatMap Chart API

Hosted on ApyHub

What it does

The Calendar Heatmap API turns dated numeric data into a calendar heatmap chart. Send a title and a data array of { date, value } points, and get back an SVG chart image, either as a file from /download or as a pre-signed URL in the data field from /link.

Each point needs a date in YYYY-MM-DD format and a numeric value. Values map to a color scale you can set in options with color_low, color_med_low, color_med, color_high, and color_empty, each a 6-character hex code without the #. Pre-signed links expire after 15 minutes, so download or store the image if you need it longer.

Use the calendar heatmap API to build a GitHub-style contribution graph, show daily sign-ins, orders, or support tickets in a weekly report, or add an activity heatmap to an email digest or customer dashboard. It works as a server-side heatmap generator for any metric you count per day. It draws date-based calendar heatmaps; matrix and map-style heatmaps sit outside its scope.

Convert the chart with the SVG to PNG API when an email client or document tool needs a raster image, then bundle it into a report with the Image to PDF API. For category totals in the same report, use the Bar Graph API. AI agents can generate these heatmaps through ApyHub MCP.

▣ ENDPOINT 01 / 02

POST

Generate calendar heatmap chart image

https://api.eu.apyhub.com/apyhub/generate-simple-heatmap-chart/download

QUICKSTART

GUIDE

Quickstart

Generate and download a simple heatmap chart image from a small date/value dataset.

curl -X POST "https://api.eu.apyhub.com/apyhub/generate-simple-heatmap-chart/download?output=daily-user-activity-heatmap-chart" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "title": "Daily User Activity",
    "data": [
      { "date": "2026-06-01", "value": 3 },
      { "date": "2026-06-02", "value": 7 },
      { "date": "2026-06-03", "value": 12 }
    ]
  }'

What you'll get back

Returns a binary file response which you can save directly to disk.

TRY ITLIVE · 60 ATOMS

API key

Loading your default key…

The full key is used to call the gateway and stays in this tab — never sent to orbit or saved.

About this endpoint

What it does

Generates a calendar heatmap chart image from the supplied data and title, then returns the generated image as a binary response.

Request Body

Parameter	Type	Description
data	Object Array	Array of `{ date, value }` objects used to build the chart. Each item must include the date and numeric value.
data[].date	String	Date in `YYYY-MM-DD` format.
data[].value	Number	Value for the given date.
title	String	Chart title. Must be at least 1 character long.
options	Object	Optional chart color settings. See schema for nested fields.
options.color_low	String	6-character hex color without the leading `#` symbol.
options.color_med	String	6-character hex color without the leading `#` symbol.
options.color_high	String	6-character hex color without the leading `#` symbol.
options.color_empty	String	6-character hex color without the leading `#` symbol.
options.color_med_low	String	6-character hex color without the leading `#` symbol.

Response

Returns a binary response containing the generated chart image.

▣ ENDPOINT 02 / 02

POST

Generate calendar heatmap chart link

https://api.eu.apyhub.com/apyhub/generate-simple-heatmap-chart/link

QUICKSTART

GUIDE

Quickstart

Generate a simple heatmap chart from a title and date/value data points.

curl -X POST "https://api.eu.apyhub.com/apyhub/generate-simple-heatmap-chart/link?output=daily-user-activity-heatmap-chart" \
  -H "apy-token: $APY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"title":"Daily User Activity","data":[{"date":"2026-06-01","value":3},{"date":"2026-06-02","value":7},{"date":"2026-06-03","value":12}]}'

What you'll get back

Returns a JSON object with a data string field containing a pre-signed URI for the generated chart image.

{
  "data": "https://apyhub-outgoing.s3.eu-west-1.amazonaws.com/mono-go/chart_generator/general/chart_generator_2026-08-07_a84eb504.svg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIARJOHWS6LWTUUGYPI%2F20260807%2Feu-west-1%2Fs3%2Faws4_request&X-Amz-Date=20260807T131605Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&response-content-disposition=inline&response-content-type=image%2Fsvg%2Bxml&X-Amz-Signature=ab454ac962c26ecaebaffca14110374ee658808bcd7de47371ed84aa374ca70b"
}

TRY ITLIVE · 60 ATOMS

API key

Loading your default key…

The full key is used to call the gateway and stays in this tab — never sent to orbit or saved.

About this endpoint

What it does

Generates a calendar heatmap chart link from the provided title, dated data points, and optional color settings. The response returns a JSON object containing a pre-signed URL for the generated chart image.

Request Body

Parameter	Type	Description
title	String	Chart title.
data	Object Array	Array of data points for the heatmap. Each item must include `date` and `value`.
data[].date	String	Date in `YYYY-MM-DD` format.
data[].value	Number	Numeric value for the corresponding date.
options	Object	Optional color configuration. See the schema for nested fields.
options.color_low	String	6-character hex color without the leading `#` symbol. Pattern: `^[A-Fa-f0-9]{6}$`.
options.color_med	String	6-character hex color without the leading `#` symbol. Pattern: `^[A-Fa-f0-9]{6}$`.
options.color_high	String	6-character hex color without the leading `#` symbol. Pattern: `^[A-Fa-f0-9]{6}$`.
options.color_empty	String	6-character hex color without the leading `#` symbol. Pattern: `^[A-Fa-f0-9]{6}$`.
options.color_med_low	String	6-character hex color without the leading `#` symbol. Pattern: `^[A-Fa-f0-9]{6}$`.

Response

Returns a JSON object with a data string field formatted as a URI. This data field contains the pre-signed URL for the generated chart image.

Parameter	Type	Description
data	String	Pre-signed URL for the generated chart image.

▣ COMMON ERRORS

Errors any endpoint can return

400bad_request

Required parameter missing or malformed body.

401unauthorized

API key missing, revoked, or not authorized for this service.

429rate_limited

Your plan's per-second rate exceeded. Retry with exponential backoff.

503upstream_busy

Backend temporarily unavailable. Try again in a few seconds.

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