The ImageKit Ruby library provides convenient access to the ImageKit REST API from any Ruby 3.2.0+ application. The library supports building and transforming URLs, generating signed URLs for secure content delivery, and handling file uploads. It ships with comprehensive types & docstrings in Yard, RBS, and RBI – see below for usage with Sorbet. The standard library's net/http is used as the HTTP transport, with connection pooling via the connection_pool gem.
The official ImageKit Ruby documentation provides complete integration guides and examples.
If you're using Ruby on Rails, the ImageKit Rails gem builds on top of this SDK to provide Rails-specific integrations including Active Storage and view helpers.
- Documentation
- Installation
- Usage
- URL Generation
- Helper Methods
- Handling errors
- Advanced concepts
- Sorbet
- Versioning
- Requirements
- Contributing
To use this gem, install via Bundler by adding the following to your application's Gemfile:
gem "imagekitio", "~> 4.0.0"require "imagekitio"
image_kit = Imagekitio::Client.new(
private_key: ENV["IMAGEKIT_PRIVATE_KEY"], # This is the default and can be omitted
)
response = image_kit.files.upload(
file: Pathname("/path/to/file"),
file_name: "file-name.jpg"
)
puts(response.file_id)Request parameters that correspond to file uploads can be passed as raw contents, a Pathname instance, or an IO stream.
require "pathname"
# Use `Pathname` to stream from disk (memory efficient, supports retries):
response = image_kit.files.upload(file: Pathname("/path/to/file"))
# Or pass file contents directly
response = image_kit.files.upload(file: File.read("/path/to/file"))
# Or, to control the filename and/or content type:
file = Imagekitio::FilePart.new(File.read("/path/to/file"), filename: "/path/to/file", content_type: "…")
response = image_kit.files.upload(file: file)
puts(response.file_id)Note that you can also pass a raw IO descriptor, but this disables retries, as the library can't be sure if the descriptor is a file or pipe (which cannot be rewound).
The ImageKit SDK provides a powerful helper.build_url() method for generating optimized image and video URLs with transformations. Here are examples ranging from simple URLs to complex transformations with overlays and signed URLs.
Generate a simple URL without any transformations:
require "imagekitio"
image_kit = Imagekitio::Client.new(
private_key: ENV["IMAGEKIT_PRIVATE_KEY"]
)
# Basic URL without transformations
url = image_kit.helper.build_url({
src: "/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id"
})
puts url
# Output: https://ik.imagekit.io/your_imagekit_id/default-image.jpgYou can also use absolute URLs:
url = image_kit.helper.build_url({
src: "https://ik.imagekit.io/your_imagekit_id/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id"
})Apply common transformations like resizing, cropping, and format conversion:
# URL with basic transformations
url = image_kit.helper.build_url({
src: "/path/to/image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 400,
height: 300,
crop: :maintain_ratio,
quality: 80,
format_: :webp
}
]
})
# Output: https://ik.imagekit.io/your_imagekit_id/path/to/image.jpg?tr=w-400,h-300,c-maintain_ratio,q-80,f-webpMore transformation examples:
# Image resizing and cropping
url = image_kit.helper.build_url({
src: "/product.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 800,
height: 600,
crop: :at_max,
focus: "auto"
}
]
})
# Image effects
url = image_kit.helper.build_url({
src: "/photo.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
blur: 10,
grayscale: true,
radius: 20
}
]
})
# Format and quality optimization
url = image_kit.helper.build_url({
src: "/image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
format_: :auto,
quality: 85,
progressive: true
}
]
})Add image overlays to your base image:
# URL with image overlay
url = image_kit.helper.build_url({
src: "/path/to/base-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 500,
height: 400,
overlay: {
type: :image,
input: "/path/to/overlay-logo.png",
position: {
x: 10,
y_: 10
},
transformation: [
{
width: 100,
height: 50
}
]
}
}
]
})
# Output: URL with image overlay positioned at x:10, y:10Add customized text overlays:
# URL with text overlay
url = image_kit.helper.build_url({
src: "/path/to/base-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 600,
height: 400,
overlay: {
type: :text,
text: "Sample Text Overlay",
position: {
x: 50,
y_: 50,
focus: :center
},
transformation: [
{
font_size: 40,
font_family: "Arial",
font_color: "FFFFFF",
typography: "b" # bold
}
]
}
}
]
})
# Output: URL with bold white Arial text overlay at center positionYou can combine multiple overlays for complex compositions:
# URL with multiple overlays (text + image)
url = image_kit.helper.build_url({
src: "/path/to/base-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 800,
height: 600,
overlay: {
type: :text,
text: "Header Text",
position: { x: 20, y_: 20 },
transformation: [{ font_size: 30, font_color: "000000" }]
}
},
{
overlay: {
type: :image,
input: "/watermark.png",
position: { focus: :bottom_right },
transformation: [{ width: 100, opacity: 70 }]
}
}
]
})
# Output: URL with text overlay at top-left and semi-transparent watermark at bottom-rightGenerate signed URLs that expire after a specified time for secure content delivery:
# Generate a signed URL that expires in 1 hour (3600 seconds)
url = image_kit.helper.build_url({
src: "/private/secure-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 400,
height: 300,
quality: 90
}
],
signed: true,
expires_in: 3600 # URL expires in 1 hour
})
# Output: URL with signature parameters (?ik-t=timestamp&ik-s=signature)
# Generate a signed URL that doesn't expire
url = image_kit.helper.build_url({
src: "/private/secure-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
signed: true
# No expires_in means the URL won't expire
})
# Output: URL with signature parameter (?ik-s=signature)Apply multiple transformation steps by passing multiple transformation objects. Each transformation is applied sequentially:
# First resize, then apply effects
url = image_kit.helper.build_url({
src: "/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 400,
height: 300
},
{
rotation: 90,
blur: 5
}
]
})
# Output: https://ik.imagekit.io/your_imagekit_id/default-image.jpg?tr=w-400,h-300:rt-90,bl-5ImageKit frequently adds new transformation parameters that might not yet be documented in the SDK. You can use the raw parameter to access these features or create custom transformation strings:
# Using raw parameter for custom transformations
url = image_kit.helper.build_url({
src: "/path/to/image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation: [
{
width: 400,
height: 300,
raw: "something-new"
}
]
})
# Output: https://ik.imagekit.io/your_imagekit_id/path/to/image.jpg?tr=w-400,h-300,something-newYou can control where transformations appear in the URL:
# Add transformations to the URL path instead of query parameters
url = image_kit.helper.build_url({
src: "/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
transformation_position: :path,
transformation: [
{
width: 400,
height: 300
}
]
})
# Output: https://ik.imagekit.io/your_imagekit_id/tr:w-400,h-300/default-image.jpgAdd custom query parameters:
url = image_kit.helper.build_url({
src: "/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
query_parameters: {
version: "1",
cache: "max"
}
})The SDK provides several helper methods for common ImageKit operations.
Generate authentication parameters for secure client-side file uploads. These parameters allow you to securely upload files directly from the browser without exposing your private API key:
require "imagekitio"
image_kit = Imagekitio::Client.new(
private_key: ENV["IMAGEKIT_PRIVATE_KEY"]
)
# Generate authentication parameters with default expiry (30 minutes)
auth_params = image_kit.helper.get_authentication_parameters
puts auth_params
# Output: { token: "unique-token", expire: 1234567890, signature: "signature-hash" }Customize the token and expiration:
# Custom token and expiry (1 hour from now)
auth_params = image_kit.helper.get_authentication_parameters(
token: "my-custom-token",
expire: Time.now.to_i + 3600
)
# Output: { token: "my-custom-token", expire: 1234567890, signature: "generated-signature" }These authentication parameters can be used in client-side upload forms to securely upload files without exposing your private API key.
Generate responsive image attributes for HTML <img> tags. This creates optimized srcset and sizes attributes for responsive images:
# Width-based responsive images (generates w descriptors)
attrs = image_kit.helper.get_responsive_image_attributes({
src: "/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
sizes: "(min-width: 768px) 50vw, 100vw",
transformation: [
{
quality: 80,
format_: :auto
}
]
})
puts attrs.src
# Largest candidate URL
puts attrs.src_set
# URL1 640w, URL2 750w, URL3 1080w, ...
puts attrs.sizes
# (min-width: 768px) 50vw, 100vwDPR-based responsive images (generates x descriptors):
# When width is provided without sizes, generates 1x and 2x variants
attrs = image_kit.helper.get_responsive_image_attributes({
src: "/profile.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
width: 400,
transformation: [
{
quality: 85
}
]
})
puts attrs.src_set
# URL1 1x, URL2 2x
puts attrs.width
# 400Custom breakpoints for device widths:
attrs = image_kit.helper.get_responsive_image_attributes({
src: "/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
sizes: "100vw",
device_breakpoints: [320, 640, 1024, 1920],
image_breakpoints: [16, 32, 64],
transformation: [
{
crop: :at_max
}
]
})The returned attributes can be directly used in your HTML:
<img
src="<%= attrs.src %>"
srcset="<%= attrs.src_set %>"
sizes="<%= attrs.sizes %>"
alt="Responsive image"
/>Generate signed responsive image URLs:
# Generate signed responsive image URLs
attrs = image_kit.helper.get_responsive_image_attributes({
src: "/default-image.jpg",
url_endpoint: "https://ik.imagekit.io/your_imagekit_id",
sizes: "100vw",
signed: true,
expires_in: 3600,
transformation: [
{
quality: 80
}
]
})When the library is unable to connect to the API, or if the API returns a non-success status code (i.e., 4xx or 5xx response), a subclass of Imagekitio::Errors::APIError will be thrown:
begin
file = image_kit.files.upload(
file: File.read("/path/to/file.jpg"),
file_name: "file-name.jpg"
)
rescue Imagekitio::Errors::APIConnectionError => e
puts("The server could not be reached")
puts(e.cause) # an underlying Exception, likely raised within `net/http`
rescue Imagekitio::Errors::RateLimitError => e
puts("A 429 status code was received; we should back off a bit.")
rescue Imagekitio::Errors::APIStatusError => e
puts("Another non-200-range status code was received")
puts(e.status)
endError codes are as follows:
| Cause | Error Type |
|---|---|
| HTTP 400 | BadRequestError |
| HTTP 401 | AuthenticationError |
| HTTP 403 | PermissionDeniedError |
| HTTP 404 | NotFoundError |
| HTTP 409 | ConflictError |
| HTTP 422 | UnprocessableEntityError |
| HTTP 429 | RateLimitError |
| HTTP >= 500 | InternalServerError |
| Other HTTP error | APIStatusError |
| Timeout | APITimeoutError |
| Network error | APIConnectionError |
Certain errors will be automatically retried 2 times by default, with a short exponential backoff.
Connection errors (for example, due to a network connectivity problem), 408 Request Timeout, 409 Conflict, 429 Rate Limit, >=500 Internal errors, and timeouts will all be retried by default.
You can use the max_retries option to configure or disable this:
# Configure the default for all requests:
image_kit = Imagekitio::Client.new(
max_retries: 0 # default is 2
)
# Or, configure per-request:
image_kit.files.upload(
file: File.read("/path/to/file.jpg"),
file_name: "file-name.jpg",
request_options: {max_retries: 5}
)By default, requests will time out after 60 seconds. You can use the timeout option to configure or disable this:
# Configure the default for all requests:
image_kit = Imagekitio::Client.new(
timeout: nil # default is 60
)
# Or, configure per-request:
image_kit.files.upload(
file: File.read("/path/to/file.jpg"),
file_name: "file-name.jpg",
request_options: {timeout: 5}
)On timeout, Imagekitio::Errors::APITimeoutError is raised.
Note that requests that time out are retried by default.
All parameter and response objects inherit from Imagekitio::Internal::Type::BaseModel, which provides several conveniences, including:
-
All fields, including unknown ones, are accessible with
obj[:prop]syntax, and can be destructured withobj => {prop: prop}or pattern-matching syntax. -
Structural equivalence for equality; if two API calls return the same values, comparing the responses with == will return true.
-
Both instances and the classes themselves can be pretty-printed.
-
Helpers such as
#to_h,#deep_to_h,#to_json, and#to_yaml.
You can send undocumented parameters to any endpoint, and read undocumented response properties, like so:
Note: the extra_ parameters of the same name overrides the documented parameters.
response =
image_kit.files.upload(
file: File.read("/path/to/file.jpg"),
file_name: "file-name.jpg",
request_options: {
extra_query: {my_query_parameter: value},
extra_body: {my_body_parameter: value},
extra_headers: {"my-header": value}
}
)
puts(response[:my_undocumented_property])If you want to explicitly send an extra param, you can do so with the extra_query, extra_body, and extra_headers under the request_options: parameter when making a request, as seen in the examples above.
To make requests to undocumented endpoints while retaining the benefit of auth, retries, and so on, you can make requests using client.request, like so:
response = client.request(
method: :post,
path: '/undocumented/endpoint',
query: {"dog": "woof"},
headers: {"useful-header": "interesting-value"},
body: {"hello": "world"}
)The Imagekitio::Client instances are threadsafe, but are only are fork-safe when there are no in-flight HTTP requests.
Each instance of Imagekitio::Client has its own HTTP connection pool with a default size of 99. As such, we recommend instantiating the client once per application in most settings.
When all available connections from the pool are checked out, requests wait for a new connection to become available, with queue time counting towards the request timeout.
Unless otherwise specified, other classes in the SDK do not have locks protecting their underlying data structure.
This library provides comprehensive RBI definitions, and has no dependency on sorbet-runtime.
You can provide typesafe request parameters like so:
image_kit.files.upload(
file: File.read("/path/to/file.jpg"),
file_name: "file-name.jpg"
)Or, equivalently:
# Hashes work, but are not typesafe:
image_kit.files.upload(
file: File.read("/path/to/file.jpg"),
file_name: "file-name.jpg"
)
# You can also splat a full Params class:
params = Imagekitio::FileUploadParams.new(
file: File.read("/path/to/file.jpg"),
file_name: "file-name.jpg"
)
image_kit.files.upload(**params)Since this library does not depend on sorbet-runtime, it cannot provide T::Enum instances. Instead, we provide "tagged symbols" instead, which is always a primitive at runtime:
# :all
puts(Imagekitio::AssetListParams::FileType::ALL)
# Revealed type: `T.all(Imagekitio::AssetListParams::FileType, Symbol)`
T.reveal_type(Imagekitio::AssetListParams::FileType::ALL)Enum parameters have a "relaxed" type, so you can either pass in enum constants or their literal value:
# Using the enum constants preserves the tagged type information:
image_kit.assets.list(
file_type: Imagekitio::AssetListParams::FileType::ALL,
# …
)
# Literal values are also permissible:
image_kit.assets.list(
file_type: :all,
# …
)This package follows SemVer conventions. As the library is in initial development and has a major version of 0, APIs may change at any time.
This package considers improvements to the (non-runtime) *.rbi and *.rbs type definitions to be non-breaking changes.
Ruby 3.2.0 or higher.