Iteration Layer

Image Generation

Generate composited images from layer definitions with a single API call. Define a canvas, add layers — solid colors, gradients, text, images, QR codes, barcodes, layouts — and receive the rendered image as base64-encoded JSON in the response.

Key Features

  • Layer Types — Solid colors (with optional angled edges and border radius), gradients (linear and radial, with border radius), text (with markdown bold/italic), images (with optional background removal and border radius), QR codes, barcodes, and layouts (horizontal/vertical flow with gap, alignment, padding, and nested children).
  • Layer Compositing — Layers are rendered in index order and composited onto a transparent canvas with per-layer opacity and rotation.
  • Text Rendering — Render text with custom fonts, alignment, and markdown formatting (**bold** and *italic*). Supports line wrapping, vertical alignment, and automatic font size scaling.
  • Bundled Google Fonts — The top Google Fonts are bundled and available by default, including Inter, Roboto, OpenSans, Montserrat, Poppins, Lato, and many more. No font upload required for most text rendering needs.
  • Custom Fonts — Upload additional fonts as base64 (TTF, OTF, WOFF, WOFF2) for text rendering.
  • QR Codes — Generate QR codes with custom foreground and background colors.
  • Barcodes — Generate barcodes in multiple formats: Code 128, EAN-13, EAN-8, Code 39, ITF, and Codabar.
  • Background Removal — Automatically remove backgrounds from images using AI-powered detection.
  • Output Formats — PNG, JPEG, WebP, TIFF, GIF, or AVIF.

Overview

The Image Generation API composites multiple layers onto a canvas to produce a single output image. You define the canvas dimensions, optionally provide custom fonts, and specify an ordered list of layers. Each layer is rendered and composited by index order.

Endpoint: POST /image-generation/v1/generate

Output formats: PNG (default), JPEG, WebP, TIFF, GIF, AVIF

Request Format

Request
curl -X POST https://api.iterationlayer.com/image-generation/v1/generate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "dimensions": {
      "width": 800,
      "height": 600
    },
    "layers": [
      {
        "index": 0,
        "type": "solid-color",
        "hex_color": "#FFFFFF"
      },
      {
        "index": 1,
        "type": "text",
        "text": "Hello World",
        "font_name": "Roboto",
        "font_size_in_px": 48,
        "text_color": "#000000",
        "position": {
          "x": 50.0,
          "y": 50.0
        },
        "dimensions": {
          "width": 700,
          "height": 100
        }
      }
    ],
    "output_format": "png"
  }'
Response
{
  "success": true,
  "data": {
    "buffer": "iVBORw0KGgoAAAANSUhEUgAA...",
    "mime_type": "image/png"
  }
}
Request
import { IterationLayer } from "iterationlayer";
const client = new IterationLayer({
  apiKey: "YOUR_API_KEY",
});

const result = await client.generateImage({
  dimensions: {
    width: 800,
    height: 600,
  },
  layers: [
    {
      index: 0,
      type: "solid-color",
      hex_color: "#FFFFFF",
    },
    {
      index: 1,
      type: "text",
      text: "Hello World",
      font_name: "Roboto",
      font_size_in_px: 48,
      text_color: "#000000",
      position: {
        x: 50,
        y: 50,
      },
      dimensions: {
        width: 700,
        height: 100,
      },
    },
  ],
  output_format: "png",
});
Response
{
  "success": true,
  "data": {
    "buffer": "iVBORw0KGgoAAAANSUhEUgAA...",
    "mime_type": "image/png"
  }
}
Request
from iterationlayer import IterationLayer
client = IterationLayer(api_key="YOUR_API_KEY")

result = client.generate_image(
    dimensions={
        "width": 800,
        "height": 600,
    },
    layers=[
        {
            "index": 0,
            "type": "solid-color",
            "hex_color": "#FFFFFF",
        },
        {
            "index": 1,
            "type": "text",
            "text": "Hello World",
            "font_name": "Roboto",
            "font_size_in_px": 48,
            "text_color": "#000000",
            "position": {
                "x": 50,
                "y": 50,
            },
            "dimensions": {
                "width": 700,
                "height": 100,
            },
        },
    ],
    output_format="png",
)
Response
{
  "success": true,
  "data": {
    "buffer": "iVBORw0KGgoAAAANSUhEUgAA...",
    "mime_type": "image/png"
  }
}
Request
import il "github.com/iterationlayer/sdk-go"
client := il.NewClient("YOUR_API_KEY")

result, err := client.GenerateImage(il.GenerateImageRequest{
    Dimensions: il.Dimensions{
        Width:  800,
        Height: 600,
    },
    OutputFormat: "png",
    Layers: []il.Layer{
        il.NewSolidColorBackgroundLayer(0, "#FFFFFF"),
        il.NewTextLayer(1, "Hello World", "Roboto", 48, "#000000",
            il.Position{
                X: 50,
                Y: 50,
            },
            il.Dimensions{
                Width:  700,
                Height: 100,
            }),
    },
})
Response
{
  "success": true,
  "data": {
    "buffer": "iVBORw0KGgoAAAANSUhEUgAA...",
    "mime_type": "image/png"
  }
}

Top-Level Fields

Field Type Required Description
dimensions object Yes Canvas size with width (integer, > 0) and height (integer, > 0)
layers array Yes Ordered list of layer definitions (at least one)
output_format string No One of: png (default), jpeg, webp, tiff, gif, avif
fonts array No Custom font definitions for text layers
webhook_url string No HTTPS URL to receive results asynchronously. If provided, returns 201 immediately. See Webhooks.

Async Mode

Add a webhook_url parameter to process the request in the background. The API returns 201 Accepted immediately and delivers the result to your webhook URL when processing completes. See Webhooks for payload format and retry behavior.

Font Definition

The top Google Fonts are bundled and available by default. Text layers can reference any bundled font by name without providing font definitions. If a text layer references a font name that isn’t found, it falls back to Inter Regular.

Bundled fonts:

  • AlfaSlabOne
  • AnekTelugu
  • Anton
  • Archivo
  • ArchivoBlack
  • Arimo
  • Assistant
  • Barlow
  • BarlowCondensed
  • BebasNeue
  • Bitter
  • BricolageGrotesque
  • Bungee
  • Cabin
  • Cairo
  • Caveat
  • ChangaOne
  • CommitMono
  • CormorantGaramond
  • CrimsonText
  • DancingScript
  • DMSans
  • Dosis
  • EBGaramond
  • Exo2
  • Figtree
  • FiraSans
  • FjallaOne
  • GravitasOne
  • Heebo
  • Hind
  • HindSiliguri
  • IBMPlexSans
  • Inconsolata
  • Inter
  • InterTight
  • JosefinSans
  • Jost
  • Kanit
  • Karla
  • Lato
  • Lexend
  • LibreBaskerville
  • LibreFranklin
  • Lobster
  • Lora
  • Manrope
  • Merriweather
  • Montserrat
  • MPLUSRounded1c
  • Mukta
  • Mulish
  • NanumGothic
  • NotoSans
  • NotoSansArabic
  • NotoSansJP
  • NotoSansKR
  • NotoSansSC
  • NotoSansTC
  • NotoSansTelugu
  • NotoSerif
  • NotoSerifJP
  • Nunito
  • NunitoSans
  • OpenSans
  • Oswald
  • Outfit
  • Overpass
  • Oxygen
  • Pacifico
  • PlayfairDisplay
  • PlusJakartaSans
  • Poppins
  • Prompt
  • PTSans
  • PTSerif
  • PublicSans
  • Quicksand
  • Raleway
  • Ramabhadra
  • RedHatDisplay
  • Roboto
  • RobotoCondensed
  • RobotoFlex
  • RobotoMono
  • RobotoSlab
  • Rubik
  • Saira
  • SchibstedGrotesk
  • ShareTech
  • Slabo27px
  • SmoochSans
  • Sora
  • SourceCodePro
  • SourceSans3
  • SpaceGrotesk
  • TitilliumWeb
  • Ubuntu
  • WorkSans

To use additional fonts beyond the bundled set, provide them as base64-encoded font files. Fonts are matched by name, weight, and style.

Field Type Required Description
name string Yes Font family name (referenced by text layers)
weight string Yes Font weight: thin, extralight, light, regular, medium, semibold, bold, extrabold, black
style string Yes One of: normal, italic
buffer string Yes Base64-encoded font file (TTF, OTF, WOFF, or WOFF2)

Shared Layer Fields

All layer types share these base fields:

Field Type Required Description
index integer Yes Render order (>= 0). Lower indices are rendered first (behind).
type string Yes Layer type identifier
opacity integer No Opacity percentage (0–100, default: 100)

Layers that support positioning also include:

Field Type Required Description
position object Yes x (float, >= 0) and y (float, >= 0) offset from top-left
dimensions object Yes width (integer, > 0) and height (integer, > 0) of the layer
rotation_in_degrees float No Rotation angle in degrees

Layer Types

solid-color

A solid color fill. When position and dimensions are omitted, fills the entire canvas. Supports rounded corners and angled edges.

Field Type Required Description
hex_color string Yes Fill color (e.g., #FF5500)
position object No Position on canvas (defaults to full canvas)
dimensions object No Layer size (defaults to canvas size)
rotation_in_degrees float No Rotation angle
border_radius integer No Uniform corner radius in pixels
border_top_left_radius integer No Top-left corner radius
border_top_right_radius integer No Top-right corner radius
border_bottom_left_radius integer No Bottom-left corner radius
border_bottom_right_radius integer No Bottom-right corner radius
angled_edges array No Angled edge definitions

Set either border_radius for uniform corners or individual per-corner fields — not both.

{
  "index": 0,
  "type": "solid-color",
  "hex_color": "#FFFFFF"
}

Positioned with rounded corners:

{
  "index": 1,
  "type": "solid-color",
  "hex_color": "#3366FF",
  "position": {
    "x": 50.0,
    "y": 100.0
  },
  "dimensions": {
    "width": 300,
    "height": 200
  },
  "border_radius": 24
}

Angled Edges

Each angled edge definition cuts one side of the layer at an angle:

Field Type Required Description
edge string Yes One of: left, right, top, bottom
angle_in_degrees float Yes Angle between -45.0 and 45.0 degrees
{
  "index": 1,
  "type": "solid-color",
  "hex_color": "#3366FF",
  "position": {
    "x": 50.0,
    "y": 100.0
  },
  "dimensions": {
    "width": 300,
    "height": 200
  },
  "angled_edges": [
    {
      "edge": "right",
      "angle_in_degrees": 15.0
    }
  ]
}

gradient

A positioned gradient fill. Supports linear and radial gradients with configurable color stops and rounded corners.

Field Type Required Description
gradient_type string Yes One of: linear, radial
colors array Yes List of color stops (see below)
position object Yes Position on canvas
dimensions object Yes Gradient size
angle_in_degrees float No Angle for linear gradients (default: 0, left-to-right)
rotation_in_degrees float No Rotation angle
border_radius integer No Uniform corner radius in pixels
border_top_left_radius integer No Top-left corner radius
border_top_right_radius integer No Top-right corner radius
border_bottom_left_radius integer No Bottom-left corner radius
border_bottom_right_radius integer No Bottom-right corner radius

Color Stop

Field Type Required Description
hex_color string Yes Stop color (e.g., #FF0000)
position float Yes Stop position as percentage (0.0–100.0)
{
  "index": 1,
  "type": "gradient",
  "gradient_type": "linear",
  "angle_in_degrees": 90.0,
  "colors": [
    {
      "hex_color": "#FF0000",
      "position": 0.0
    },
    {
      "hex_color": "#0000FF",
      "position": 100.0
    }
  ],
  "position": {
    "x": 0.0,
    "y": 0.0
  },
  "dimensions": {
    "width": 800,
    "height": 600
  }
}

text

Render text with custom fonts, alignment, and optional markdown formatting. Supports **bold** and *italic* syntax. When should_auto_scale is true, the font size is automatically scaled down from font_size_in_px until the text fits within the layer dimensions.

Field Type Required Description
text string Yes Text content (supports **bold** and *italic* markdown)
font_name string Yes Font family name (any bundled font or a custom font definition)
font_size_in_px integer Yes Font size in pixels (> 0)
text_color string Yes Text color as hex (e.g., #000000)
position object Yes Position on canvas
dimensions object Yes Text bounding box
font_weight string No Font weight: thin, extralight, light, regular (default), medium, semibold, bold, extrabold, black
font_style string No One of: normal, italic
text_align string No One of: left, center, right
vertical_align string No One of: top, center, bottom
is_splitting_lines boolean No Enable line wrapping (default: true)
paragraph_spacing_in_px integer No Extra spacing between paragraphs
should_auto_scale boolean No Automatically scale font size down to fit the layer dimensions (default: false)
rotation_in_degrees float No Rotation angle
{
  "index": 2,
  "type": "text",
  "text": "**Important:** This is *formatted* text.",
  "font_name": "Inter",
  "font_size_in_px": 24,
  "text_color": "#333333",
  "text_align": "center",
  "vertical_align": "center",
  "position": {
    "x": 100.0,
    "y": 200.0
  },
  "dimensions": {
    "width": 600,
    "height": 150
  }
}

image

An image layer. Provide the image as base64-encoded data or a URL. When position and dimensions are omitted, the image fills the entire canvas (cover-fit).

Field Type Required Description
file object Yes Image source (see below)
position object No Position on canvas (defaults to full canvas)
dimensions object No Target dimensions (defaults to canvas size)
rotation_in_degrees float No Rotation angle
should_use_smart_cropping boolean No Use AI smart crop for resizing (default: false)
should_remove_background boolean No Remove the image background using AI (default: false)
border_radius integer No Uniform corner radius in pixels
border_top_left_radius integer No Top-left corner radius
border_top_right_radius integer No Top-right corner radius
border_bottom_left_radius integer No Bottom-left corner radius
border_bottom_right_radius integer No Bottom-right corner radius

The file object supports two formats:

Field Type Description
type string "base64" or "url"
name string Filename (e.g., "photo.png")
base64 string Base64-encoded image data (when type is "base64")
url string Image URL (when type is "url")

When should_use_smart_cropping is true, the image is cropped around detected faces, people, or objects using AI detection. When false, a standard cover-fit resize is used.

When should_remove_background is true, the image background is automatically removed using AI-powered segmentation before compositing. This is useful for placing product photos or portraits onto custom backgrounds.

Positioned with rounded corners:

{
  "index": 1,
  "type": "image",
  "file": {
    "type": "base64",
    "name": "photo.png",
    "base64": "<base64-data>"
  },
  "position": {
    "x": 50.0,
    "y": 50.0
  },
  "dimensions": {
    "width": 200,
    "height": 200
  },
  "border_radius": 16,
  "should_use_smart_cropping": true
}

Full-canvas overlay:

{
  "index": 3,
  "type": "image",
  "file": {
    "type": "base64",
    "name": "overlay.png",
    "base64": "<base64-data>"
  },
  "opacity": 50
}

qr-code

Generate a QR code with custom colors.

Field Type Required Description
value string Yes Data to encode in the QR code
position object Yes Position on canvas
dimensions object Yes QR code size
foreground_hex_color string Yes Foreground (module) color
background_hex_color string Yes Background color
rotation_in_degrees float No Rotation angle
{
  "index": 2,
  "type": "qr-code",
  "value": "https://example.com",
  "position": {
    "x": 600.0,
    "y": 400.0
  },
  "dimensions": {
    "width": 150,
    "height": 150
  },
  "foreground_hex_color": "#000000",
  "background_hex_color": "#FFFFFF"
}

barcode

Generate a barcode in one of the supported formats.

Field Type Required Description
value string Yes Data to encode
format string Yes One of: code128, ean13, ean8, code39, itf, codabar
position object Yes Position on canvas
dimensions object Yes Barcode size
foreground_hex_color string Yes Bar color
background_hex_color string Yes Background color
rotation_in_degrees float No Rotation angle

Format notes:

  • ean13 — Requires exactly 12 or 13 digits
  • ean8 — Requires exactly 7 or 8 digits
  • itf — Requires an even number of digits
  • codabar — Must start and end with A, B, C, or D
  • code128 — Supports alphanumeric characters
  • code39 — Supports uppercase letters, digits, and special characters
{
  "index": 3,
  "type": "barcode",
  "value": "ABC123456",
  "format": "code128",
  "position": {
    "x": 100.0,
    "y": 450.0
  },
  "dimensions": {
    "width": 300,
    "height": 80
  },
  "foreground_hex_color": "#000000",
  "background_hex_color": "#FFFFFF"
}

layout

A flow layout that arranges child layers horizontally or vertically. Supports gap spacing, cross-axis alignment, background color with padding and border radius, and optional fixed dimensions. Layout layers can be nested — child layers can include other layouts.

Field Type Required Description
direction string No "horizontal" (default) or "vertical"
gap integer No Spacing between children in pixels (default: 0)
horizontal_alignment string No Horizontal alignment: "start" (default), "center", "end"
vertical_alignment string No Vertical alignment: "start" (default), "center", "end"
layers array Yes Child layer definitions (any layer type, including layout)
position object No Position on canvas
dimensions object No Fixed width and height (clips if content is larger, pads with transparency if smaller)
background_color string No Background color as hex (e.g., #336699)
background_layers array No Array of layer definitions rendered behind content (overrides background_color)
padding integer No Uniform inner padding in pixels
padding_top integer No Top padding
padding_right integer No Right padding
padding_bottom integer No Bottom padding
padding_left integer No Left padding
border_radius integer No Uniform corner radius in pixels
border_top_left_radius integer No Top-left corner radius
border_top_right_radius integer No Top-right corner radius
border_bottom_left_radius integer No Bottom-left corner radius
border_bottom_right_radius integer No Bottom-right corner radius

Set either padding for uniform padding or individual per-side fields — not both. Same for border_radius vs per-corner fields.

When dimensions is omitted, the layout auto-sizes to fit its content. Text layers with "auto" width inside a layout will shrink-wrap to their text content.

Horizontal pill with icon and text:

{
  "index": 1,
  "type": "layout",
  "direction": "horizontal",
  "gap": 8,
  "vertical_alignment": "center",
  "background_color": "#0284c7",
  "padding": 12,
  "border_radius": 20,
  "position": {
    "x": 20.0,
    "y": 50.0
  },
  "layers": [
    {
      "type": "image",
      "file": {
        "type": "base64",
        "name": "icon.svg",
        "base64": "<base64-svg>"
      },
      "dimensions": {
        "width": 20,
        "height": 20
      }
    },
    {
      "type": "text",
      "text": "Click here",
      "font_name": "Inter",
      "font_size_in_px": 16,
      "text_color": "#FFFFFF",
      "dimensions": {
        "width": "auto",
        "height": 24
      }
    }
  ]
}

Vertical card with fixed dimensions:

{
  "index": 2,
  "type": "layout",
  "direction": "vertical",
  "gap": 12,
  "background_color": "#FFFFFF",
  "padding": 24,
  "border_radius": 16,
  "dimensions": {
    "width": 300,
    "height": 200
  },
  "position": {
    "x": 50.0,
    "y": 100.0
  },
  "layers": [
    {
      "type": "text",
      "text": "Card Title",
      "font_name": "Inter",
      "font_size_in_px": 24,
      "font_weight": "bold",
      "text_color": "#1e293b",
      "dimensions": {
        "width": 252,
        "height": 32
      }
    },
    {
      "type": "text",
      "text": "Card description text goes here.",
      "font_name": "Inter",
      "font_size_in_px": 14,
      "text_color": "#64748b",
      "dimensions": {
        "width": 252,
        "height": 60
      }
    }
  ]
}

Recipes

For complete, runnable examples see the Recipes page.

  • Generate Social Card – Create an Open Graph social sharing card with dynamic title, description, and branding.
  • Generate Certificate Image – Generate a certificate image with recipient name, course title, and completion date for digital sharing.
  • Generate YouTube Thumbnail – Generate a YouTube thumbnail with bold title text, gradient background, and a static image cutout.
  • Generate Product Listing Image – Generate a product listing image with photo, price badge, and promotional text overlay.
  • Generate Event Ticket – Generate a scannable event ticket image with QR code, event details, and branding.
  • Generate Product Slide – Generate a branded product slide with headline, feature pills, and CTA using layout layers.

Error Responses

Status Description
400 Invalid request (missing dimensions, missing layers, invalid hex color, unsupported barcode format)
401 Missing or invalid API key
422 Processing error (font loading failure, image compositing error, barcode encoding error)
429 Rate limit exceeded