diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index bd7f384..29102ae 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "4.2.0"
+  ".": "4.3.0"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index dbc39e1..7401c19 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 47
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/imagekit-inc%2Fimagekit-13fc3d7cafdea492f62eef7c1d63424d6d9d8adbff74b9f6ca6fd3fc12a36840.yml
-openapi_spec_hash: a1fe6fa48207791657a1ea2d60a6dfcc
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/imagekit-inc%2Fimagekit-e5b5a158784fff63311ceef956e8d5ce9e87c6b557d23ab737270040eb39adcd.yml
+openapi_spec_hash: b0293985a8806f367319af573d1b418c
 config_hash: 47cb702ee2cb52c58d803ae39ade9b44
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b37e93d..ef50677 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,28 @@
 # Changelog
 
+## 4.3.0 (2026-02-27)
+
+Full Changelog: [v4.2.0...v4.3.0](https://github.com/imagekit-developer/imagekit-ruby/compare/v4.2.0...v4.3.0)
+
+### Features
+
+* **api:** dpr type update ([650aa0f](https://github.com/imagekit-developer/imagekit-ruby/commit/650aa0f905b4a586c036ae2f019bd7cfb7775d40))
+
+
+### Bug Fixes
+
+* **client:** always add content-length to post body, even when empty ([e156b70](https://github.com/imagekit-developer/imagekit-ruby/commit/e156b70c82c9b38de49307218fb3f687f651aa5b))
+* **client:** loosen json header parsing ([9fc1fc6](https://github.com/imagekit-developer/imagekit-ruby/commit/9fc1fc60c60173f92f1f99fabe38f9ec826d940d))
+* **client:** serialize query parameters properly ([bbfc6e0](https://github.com/imagekit-developer/imagekit-ruby/commit/bbfc6e0d80da5661600a888e8c915d336919fe36))
+* properly mock time in ruby ci tests ([8f0a0a9](https://github.com/imagekit-developer/imagekit-ruby/commit/8f0a0a93ebc66d8d56d5e47950607f8d67f37514))
+
+
+### Chores
+
+* **docs:** remove www prefix ([a4b9610](https://github.com/imagekit-developer/imagekit-ruby/commit/a4b961058ac8967dcfef109421dbca9ee3eedf0b))
+* **internal:** remove mock server code ([c8aa3b8](https://github.com/imagekit-developer/imagekit-ruby/commit/c8aa3b8c2320102d8e29941f78f1f1ade06cab00))
+* update mock server docs ([1e5ed9e](https://github.com/imagekit-developer/imagekit-ruby/commit/1e5ed9ea31388b76995c292fc22f9ed773ad6f40))
+
 ## 4.2.0 (2026-02-02)
 
 Full Changelog: [v4.1.2...v4.2.0](https://github.com/imagekit-developer/imagekit-ruby/compare/v4.1.2...v4.2.0)
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a225d78..021d116 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -43,13 +43,13 @@ If you’d like to use the repository from source, you can either install from g
 To install via git in your `Gemfile`:
 
 ```ruby
-gem "imagekitio", git: "https://www.github.com/imagekit-developer/imagekit-ruby"
+gem "imagekitio", git: "https://github.com/imagekit-developer/imagekit-ruby"
 ```
 
 Alternatively, reference local copy of the repo:
 
 ```bash
-$ git clone -- 'https://www.github.com/imagekit-developer/imagekit-ruby' '<path-to-repo>'
+$ git clone -- 'https://github.com/imagekit-developer/imagekit-ruby' '<path-to-repo>'
 ```
 
 ```ruby
@@ -66,12 +66,6 @@ $ bundle exec rake
 
 ## Running tests
 
-Most tests require you to [set up a mock server](https://github.com/stoplightio/prism) against the OpenAPI spec to run the tests.
-
-```bash
-$ npx prism mock path/to/your/openapi.yml
-```
-
 ```bash
 $ bundle exec rake test
 ```
diff --git a/Gemfile.lock b/Gemfile.lock
index f0715a9..7d5f9a1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,7 +11,7 @@ GIT
 PATH
   remote: .
   specs:
-    imagekitio (4.2.0)
+    imagekitio (4.3.0)
       cgi
       connection_pool
 
diff --git a/README.md b/README.md
index 390b3d7..eb891d0 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ To use this gem, install via Bundler by adding the following to your application
 <!-- x-release-please-start-version -->
 
 ```ruby
-gem "imagekitio", "~> 4.2.0"
+gem "imagekitio", "~> 4.3.0"
 ```
 
 <!-- x-release-please-end -->
diff --git a/lib/imagekitio/internal/transport/pooled_net_requester.rb b/lib/imagekitio/internal/transport/pooled_net_requester.rb
index fa32384..dfed0d7 100644
--- a/lib/imagekitio/internal/transport/pooled_net_requester.rb
+++ b/lib/imagekitio/internal/transport/pooled_net_requester.rb
@@ -75,7 +75,7 @@ def build_request(request, &blk)
 
             case body
             in nil
-              nil
+              req["content-length"] ||= 0 unless req["transfer-encoding"]
             in String
               req["content-length"] ||= body.bytesize.to_s unless req["transfer-encoding"]
               req.body_stream = Imagekitio::Internal::Util::ReadIOAdapter.new(body, &blk)
diff --git a/lib/imagekitio/internal/util.rb b/lib/imagekitio/internal/util.rb
index 1dd7d34..c6ffdf2 100644
--- a/lib/imagekitio/internal/util.rb
+++ b/lib/imagekitio/internal/util.rb
@@ -485,11 +485,42 @@ def writable_enum(&blk)
       end
 
       # @type [Regexp]
-      JSON_CONTENT = %r{^application/(?:vnd(?:\.[^.]+)*\+)?json(?!l)}
+      JSON_CONTENT = %r{^application/(?:[a-zA-Z0-9.-]+\+)?json(?!l)}
       # @type [Regexp]
       JSONL_CONTENT = %r{^application/(:?x-(?:n|l)djson)|(:?(?:x-)?jsonl)}
 
       class << self
+        # @api private
+        #
+        # @param query [Hash{Symbol=>Object}]
+        #
+        # @return [Hash{Symbol=>Object}]
+        def encode_query_params(query)
+          out = {}
+          query.each { write_query_param_element!(out, _1, _2) }
+          out
+        end
+
+        # @api private
+        #
+        # @param collection [Hash{Symbol=>Object}]
+        # @param key [String]
+        # @param element [Object]
+        #
+        # @return [nil]
+        private def write_query_param_element!(collection, key, element)
+          case element
+          in Hash
+            element.each do |name, value|
+              write_query_param_element!(collection, "#{key}[#{name}]", value)
+            end
+          in Array
+            collection[key] = element.map(&:to_s).join(",")
+          else
+            collection[key] = element.to_s
+          end
+        end
+
         # @api private
         #
         # @param y [Enumerator::Yielder]
diff --git a/lib/imagekitio/models/transformation.rb b/lib/imagekitio/models/transformation.rb
index 160d809..63e6b76 100644
--- a/lib/imagekitio/models/transformation.rb
+++ b/lib/imagekitio/models/transformation.rb
@@ -209,8 +209,8 @@ class Transformation < Imagekitio::Internal::Type::BaseModel
       #     [Arithmetic expressions](https://imagekit.io/docs/arithmetic-expressions-in-transformations).
       #   - See [DPR](https://imagekit.io/docs/image-resize-and-crop#dpr---dpr).
       #
-      #   @return [Float, nil]
-      optional :dpr, Float
+      #   @return [Float, String, nil]
+      optional :dpr, union: -> { Imagekitio::Transformation::Dpr }
 
       # @!attribute duration
       #   Specifies the duration (in seconds) for trimming videos, e.g., `5` or `10.5`.
@@ -549,7 +549,7 @@ class Transformation < Imagekitio::Internal::Type::BaseModel
       #
       #   @param distort [String] Distorts the shape of an image. Supports two modes:
       #
-      #   @param dpr [Float] Accepts values between 0.1 and 5, or `auto` for automatic device pixel ratio (DP
+      #   @param dpr [Float, String] Accepts values between 0.1 and 5, or `auto` for automatic device pixel ratio (DP
       #
       #   @param duration [Float, String] Specifies the duration (in seconds) for trimming videos, e.g., `5` or `10.5`.
       #
@@ -785,6 +785,25 @@ module CropMode
         #   @return [Array<Symbol>]
       end
 
+      # Accepts values between 0.1 and 5, or `auto` for automatic device pixel ratio
+      # (DPR) calculation. Also accepts arithmetic expressions.
+      #
+      # - Learn about
+      #   [Arithmetic expressions](https://imagekit.io/docs/arithmetic-expressions-in-transformations).
+      # - See [DPR](https://imagekit.io/docs/image-resize-and-crop#dpr---dpr).
+      #
+      # @see Imagekitio::Models::Transformation#dpr
+      module Dpr
+        extend Imagekitio::Internal::Type::Union
+
+        variant Float
+
+        variant String
+
+        # @!method self.variants
+        #   @return [Array(Float, String)]
+      end
+
       # Specifies the duration (in seconds) for trimming videos, e.g., `5` or `10.5`.
       # Typically used with startOffset to indicate the length from the start offset.
       # Arithmetic expressions are supported. See
diff --git a/lib/imagekitio/resources/accounts/usage.rb b/lib/imagekitio/resources/accounts/usage.rb
index adcdbc9..bbb3fc3 100644
--- a/lib/imagekitio/resources/accounts/usage.rb
+++ b/lib/imagekitio/resources/accounts/usage.rb
@@ -25,10 +25,11 @@ class Usage
         # @see Imagekitio::Models::Accounts::UsageGetParams
         def get(params)
           parsed, options = Imagekitio::Accounts::UsageGetParams.dump_request(params)
+          query = Imagekitio::Internal::Util.encode_query_params(parsed)
           @client.request(
             method: :get,
             path: "v1/accounts/usage",
-            query: parsed.transform_keys(end_date: "endDate", start_date: "startDate"),
+            query: query.transform_keys(end_date: "endDate", start_date: "startDate"),
             model: Imagekitio::Models::Accounts::UsageGetResponse,
             options: options
           )
diff --git a/lib/imagekitio/resources/assets.rb b/lib/imagekitio/resources/assets.rb
index f9d64ff..bcc98aa 100644
--- a/lib/imagekitio/resources/assets.rb
+++ b/lib/imagekitio/resources/assets.rb
@@ -34,10 +34,11 @@ class Assets
       # @see Imagekitio::Models::AssetListParams
       def list(params = {})
         parsed, options = Imagekitio::AssetListParams.dump_request(params)
+        query = Imagekitio::Internal::Util.encode_query_params(parsed)
         @client.request(
           method: :get,
           path: "v1/files",
-          query: parsed.transform_keys(file_type: "fileType", search_query: "searchQuery"),
+          query: query.transform_keys(file_type: "fileType", search_query: "searchQuery"),
           model: Imagekitio::Internal::Type::ArrayOf[union: Imagekitio::Models::AssetListResponseItem],
           options: options
         )
diff --git a/lib/imagekitio/resources/beta/v2/files.rb b/lib/imagekitio/resources/beta/v2/files.rb
index 678ca31..78b2061 100644
--- a/lib/imagekitio/resources/beta/v2/files.rb
+++ b/lib/imagekitio/resources/beta/v2/files.rb
@@ -19,10 +19,11 @@ class Files
           # about how to implement secure client-side file upload.
           #
           # **File size limit** \
-          # On the free plan, the maximum upload file sizes are 20MB for images, audio, and raw
-          # files, and 100MB for videos. On the paid plan, these limits increase to 40MB for
-          # images, audio, and raw files, and 2GB for videos. These limits can be further increased
-          # with higher-tier plans.
+          # On the free plan, the maximum upload file sizes are 25MB for images, audio, and raw
+          # files, and 100MB for videos. On the Lite paid plan, these limits increase to 40MB
+          # for images, audio, and raw files and 300MB for videos, whereas on the Pro paid plan,
+          # these limits increase to 50MB for images, audio, and raw files and 2GB for videos.
+          # These limits can be further increased with enterprise plans.
           #
           # **Version limit** \
           # A file can have a maximum of 100 versions.
diff --git a/lib/imagekitio/resources/custom_metadata_fields.rb b/lib/imagekitio/resources/custom_metadata_fields.rb
index 7a81171..73971d2 100644
--- a/lib/imagekitio/resources/custom_metadata_fields.rb
+++ b/lib/imagekitio/resources/custom_metadata_fields.rb
@@ -89,10 +89,11 @@ def update(id, params = {})
       # @see Imagekitio::Models::CustomMetadataFieldListParams
       def list(params = {})
         parsed, options = Imagekitio::CustomMetadataFieldListParams.dump_request(params)
+        query = Imagekitio::Internal::Util.encode_query_params(parsed)
         @client.request(
           method: :get,
           path: "v1/customMetadataFields",
-          query: parsed.transform_keys(folder_path: "folderPath", include_deleted: "includeDeleted"),
+          query: query.transform_keys(folder_path: "folderPath", include_deleted: "includeDeleted"),
           model: Imagekitio::Internal::Type::ArrayOf[Imagekitio::CustomMetadataField],
           options: options
         )
diff --git a/lib/imagekitio/resources/files.rb b/lib/imagekitio/resources/files.rb
index 7e961f4..31b8d2d 100644
--- a/lib/imagekitio/resources/files.rb
+++ b/lib/imagekitio/resources/files.rb
@@ -207,10 +207,11 @@ def rename(params)
       # by verifying the entire payload using JWT.
       #
       # **File size limit** \
-      # On the free plan, the maximum upload file sizes are 20MB for images, audio, and raw
-      # files and 100MB for videos. On the paid plan, these limits increase to 40MB for images,
-      # audio, and raw files and 2GB for videos. These limits can be further increased with
-      # higher-tier plans.
+      # On the free plan, the maximum upload file sizes are 25MB for images, audio, and raw
+      # files and 100MB for videos. On the Lite paid plan, these limits increase to 40MB
+      # for images, audio, and raw files and 300MB for videos, whereas on the Pro paid plan,
+      # these limits increase to 50MB for images, audio, and raw files and 2GB for videos.
+      # These limits can be further increased with enterprise plans.
       #
       # **Version limit** \
       # A file can have a maximum of 100 versions.
diff --git a/lib/imagekitio/resources/files/metadata.rb b/lib/imagekitio/resources/files/metadata.rb
index f732ab3..dadbea2 100644
--- a/lib/imagekitio/resources/files/metadata.rb
+++ b/lib/imagekitio/resources/files/metadata.rb
@@ -48,10 +48,11 @@ def get(file_id, params = {})
         # @see Imagekitio::Models::Files::MetadataGetFromURLParams
         def get_from_url(params)
           parsed, options = Imagekitio::Files::MetadataGetFromURLParams.dump_request(params)
+          query = Imagekitio::Internal::Util.encode_query_params(parsed)
           @client.request(
             method: :get,
             path: "v1/metadata",
-            query: parsed,
+            query: query,
             model: Imagekitio::Metadata,
             options: options
           )
diff --git a/lib/imagekitio/version.rb b/lib/imagekitio/version.rb
index abbbfc1..5d680d0 100644
--- a/lib/imagekitio/version.rb
+++ b/lib/imagekitio/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Imagekitio
-  VERSION = "4.2.0"
+  VERSION = "4.3.0"
 end
diff --git a/rbi/imagekitio/internal/util.rbi b/rbi/imagekitio/internal/util.rbi
index 9fbebf9..f4aceb3 100644
--- a/rbi/imagekitio/internal/util.rbi
+++ b/rbi/imagekitio/internal/util.rbi
@@ -296,11 +296,31 @@ module Imagekitio
       end
 
       JSON_CONTENT =
-        T.let(%r{^application/(?:vnd(?:\.[^.]+)*\+)?json(?!l)}, Regexp)
+        T.let(%r{^application/(?:[a-zA-Z0-9.-]+\+)?json(?!l)}, Regexp)
       JSONL_CONTENT =
         T.let(%r{^application/(:?x-(?:n|l)djson)|(:?(?:x-)?jsonl)}, Regexp)
 
       class << self
+        # @api private
+        sig do
+          params(query: Imagekitio::Internal::AnyHash).returns(
+            Imagekitio::Internal::AnyHash
+          )
+        end
+        def encode_query_params(query)
+        end
+
+        # @api private
+        sig do
+          params(
+            collection: Imagekitio::Internal::AnyHash,
+            key: String,
+            element: T.anything
+          ).void
+        end
+        private def write_query_param_element!(collection, key, element)
+        end
+
         # @api private
         sig do
           params(
diff --git a/rbi/imagekitio/models/transformation.rbi b/rbi/imagekitio/models/transformation.rbi
index 607451a..18d01f0 100644
--- a/rbi/imagekitio/models/transformation.rbi
+++ b/rbi/imagekitio/models/transformation.rbi
@@ -283,10 +283,10 @@ module Imagekitio
       # - Learn about
       #   [Arithmetic expressions](https://imagekit.io/docs/arithmetic-expressions-in-transformations).
       # - See [DPR](https://imagekit.io/docs/image-resize-and-crop#dpr---dpr).
-      sig { returns(T.nilable(Float)) }
+      sig { returns(T.nilable(Imagekitio::Transformation::Dpr::Variants)) }
       attr_reader :dpr
 
-      sig { params(dpr: Float).void }
+      sig { params(dpr: Imagekitio::Transformation::Dpr::Variants).void }
       attr_writer :dpr
 
       # Specifies the duration (in seconds) for trimming videos, e.g., `5` or `10.5`.
@@ -672,7 +672,7 @@ module Imagekitio
           crop_mode: Imagekitio::Transformation::CropMode::OrSymbol,
           default_image: String,
           distort: String,
-          dpr: Float,
+          dpr: Imagekitio::Transformation::Dpr::Variants,
           duration: Imagekitio::Transformation::Duration::Variants,
           end_offset: Imagekitio::Transformation::EndOffset::Variants,
           flip: Imagekitio::Transformation::Flip::OrSymbol,
@@ -1006,7 +1006,7 @@ module Imagekitio
             crop_mode: Imagekitio::Transformation::CropMode::OrSymbol,
             default_image: String,
             distort: String,
-            dpr: Float,
+            dpr: Imagekitio::Transformation::Dpr::Variants,
             duration: Imagekitio::Transformation::Duration::Variants,
             end_offset: Imagekitio::Transformation::EndOffset::Variants,
             flip: Imagekitio::Transformation::Flip::OrSymbol,
@@ -1323,6 +1323,24 @@ module Imagekitio
         end
       end
 
+      # Accepts values between 0.1 and 5, or `auto` for automatic device pixel ratio
+      # (DPR) calculation. Also accepts arithmetic expressions.
+      #
+      # - Learn about
+      #   [Arithmetic expressions](https://imagekit.io/docs/arithmetic-expressions-in-transformations).
+      # - See [DPR](https://imagekit.io/docs/image-resize-and-crop#dpr---dpr).
+      module Dpr
+        extend Imagekitio::Internal::Type::Union
+
+        Variants = T.type_alias { T.any(Float, String) }
+
+        sig do
+          override.returns(T::Array[Imagekitio::Transformation::Dpr::Variants])
+        end
+        def self.variants
+        end
+      end
+
       # Specifies the duration (in seconds) for trimming videos, e.g., `5` or `10.5`.
       # Typically used with startOffset to indicate the length from the start offset.
       # Arithmetic expressions are supported. See
diff --git a/rbi/imagekitio/resources/beta/v2/files.rbi b/rbi/imagekitio/resources/beta/v2/files.rbi
index 1a8bba3..6ec4fd2 100644
--- a/rbi/imagekitio/resources/beta/v2/files.rbi
+++ b/rbi/imagekitio/resources/beta/v2/files.rbi
@@ -16,10 +16,11 @@ module Imagekitio
           # about how to implement secure client-side file upload.
           #
           # **File size limit** \
-          # On the free plan, the maximum upload file sizes are 20MB for images, audio, and raw
-          # files, and 100MB for videos. On the paid plan, these limits increase to 40MB for
-          # images, audio, and raw files, and 2GB for videos. These limits can be further increased
-          # with higher-tier plans.
+          # On the free plan, the maximum upload file sizes are 25MB for images, audio, and raw
+          # files, and 100MB for videos. On the Lite paid plan, these limits increase to 40MB
+          # for images, audio, and raw files and 300MB for videos, whereas on the Pro paid plan,
+          # these limits increase to 50MB for images, audio, and raw files and 2GB for videos.
+          # These limits can be further increased with enterprise plans.
           #
           # **Version limit** \
           # A file can have a maximum of 100 versions.
diff --git a/rbi/imagekitio/resources/files.rbi b/rbi/imagekitio/resources/files.rbi
index d8a7ec4..85d1eee 100644
--- a/rbi/imagekitio/resources/files.rbi
+++ b/rbi/imagekitio/resources/files.rbi
@@ -168,10 +168,11 @@ module Imagekitio
       # by verifying the entire payload using JWT.
       #
       # **File size limit** \
-      # On the free plan, the maximum upload file sizes are 20MB for images, audio, and raw
-      # files and 100MB for videos. On the paid plan, these limits increase to 40MB for images,
-      # audio, and raw files and 2GB for videos. These limits can be further increased with
-      # higher-tier plans.
+      # On the free plan, the maximum upload file sizes are 25MB for images, audio, and raw
+      # files and 100MB for videos. On the Lite paid plan, these limits increase to 40MB
+      # for images, audio, and raw files and 300MB for videos, whereas on the Pro paid plan,
+      # these limits increase to 50MB for images, audio, and raw files and 2GB for videos.
+      # These limits can be further increased with enterprise plans.
       #
       # **Version limit** \
       # A file can have a maximum of 100 versions.
diff --git a/scripts/mock b/scripts/mock
deleted file mode 100755
index 0b28f6e..0000000
--- a/scripts/mock
+++ /dev/null
@@ -1,41 +0,0 @@
-#!/usr/bin/env bash
-
-set -e
-
-cd "$(dirname "$0")/.."
-
-if [[ -n "$1" && "$1" != '--'* ]]; then
-  URL="$1"
-  shift
-else
-  URL="$(grep 'openapi_spec_url' .stats.yml | cut -d' ' -f2)"
-fi
-
-# Check if the URL is empty
-if [ -z "$URL" ]; then
-  echo "Error: No OpenAPI spec path/url provided or found in .stats.yml"
-  exit 1
-fi
-
-echo "==> Starting mock server with URL ${URL}"
-
-# Run prism mock on the given spec
-if [ "$1" == "--daemon" ]; then
-  npm exec --package=@stainless-api/prism-cli@5.15.0 -- prism mock "$URL" &> .prism.log &
-
-  # Wait for server to come online
-  echo -n "Waiting for server"
-  while ! grep -q "✖  fatal\|Prism is listening" ".prism.log" ; do
-    echo -n "."
-    sleep 0.1
-  done
-
-  if grep -q "✖  fatal" ".prism.log"; then
-    cat .prism.log
-    exit 1
-  fi
-
-  echo
-else
-  npm exec --package=@stainless-api/prism-cli@5.15.0 -- prism mock "$URL"
-fi
diff --git a/scripts/test b/scripts/test
index e0dc137..df8caf9 100755
--- a/scripts/test
+++ b/scripts/test
@@ -4,53 +4,7 @@ set -e
 
 cd -- "$(dirname -- "$0")/.."
 
-RED='\033[0;31m'
-GREEN='\033[0;32m'
-YELLOW='\033[0;33m'
-NC='\033[0m' # No Color
 
-function prism_is_running() {
-  curl --silent "http://localhost:4010" >/dev/null 2>&1
-}
-
-kill_server_on_port() {
-  pids=$(lsof -t -i tcp:"$1" || echo "")
-  if [ "$pids" != "" ]; then
-    kill "$pids"
-    echo "Stopped $pids."
-  fi
-}
-
-function is_overriding_api_base_url() {
-  [ -n "$TEST_API_BASE_URL" ]
-}
-
-if ! is_overriding_api_base_url && ! prism_is_running ; then
-  # When we exit this script, make sure to kill the background mock server process
-  trap 'kill_server_on_port 4010' EXIT
-
-  # Start the dev server
-  ./scripts/mock --daemon
-fi
-
-if is_overriding_api_base_url ; then
-  echo -e "${GREEN}✔ Running tests against ${TEST_API_BASE_URL}${NC}"
-  echo
-elif ! prism_is_running ; then
-  echo -e "${RED}ERROR:${NC} The test suite will not run without a mock Prism server"
-  echo -e "running against your OpenAPI spec."
-  echo
-  echo -e "To run the server, pass in the path or url of your OpenAPI"
-  echo -e "spec to the prism command:"
-  echo
-  echo -e "  \$ ${YELLOW}npm exec --package=@stainless-api/prism-cli@5.15.0 -- prism mock path/to/your.openapi.yml${NC}"
-  echo
-
-  exit 1
-else
-  echo -e "${GREEN}✔ Mock prism server is running with your OpenAPI spec${NC}"
-  echo
-fi
 
 echo "==> Running tests"
 bundle exec rake test "$@"
diff --git a/sig/imagekitio/internal/util.rbs b/sig/imagekitio/internal/util.rbs
index 73bf10f..62eba05 100644
--- a/sig/imagekitio/internal/util.rbs
+++ b/sig/imagekitio/internal/util.rbs
@@ -106,6 +106,16 @@ module Imagekitio
       JSON_CONTENT: Regexp
       JSONL_CONTENT: Regexp
 
+      def encode_query_params: (
+        ::Hash[Symbol, top] query
+      ) -> ::Hash[Symbol, top]
+
+      private def write_query_param_element!: (
+        ::Hash[Symbol, top] collection,
+        String key,
+        top element
+      ) -> nil
+
       def self?.write_multipart_content: (
         Enumerator::Yielder y,
         val: top,
diff --git a/sig/imagekitio/models/transformation.rbs b/sig/imagekitio/models/transformation.rbs
index 80be008..ab5fdb4 100644
--- a/sig/imagekitio/models/transformation.rbs
+++ b/sig/imagekitio/models/transformation.rbs
@@ -22,7 +22,7 @@ module Imagekitio
         crop_mode: Imagekitio::Models::Transformation::crop_mode,
         default_image: String,
         distort: String,
-        dpr: Float,
+        dpr: Imagekitio::Models::Transformation::dpr,
         duration: Imagekitio::Models::Transformation::duration,
         end_offset: Imagekitio::Models::Transformation::end_offset,
         flip: Imagekitio::Models::Transformation::flip,
@@ -161,9 +161,11 @@ module Imagekitio
 
       def distort=: (String) -> String
 
-      attr_reader dpr: Float?
+      attr_reader dpr: Imagekitio::Models::Transformation::dpr?
 
-      def dpr=: (Float) -> Float
+      def dpr=: (
+        Imagekitio::Models::Transformation::dpr
+      ) -> Imagekitio::Models::Transformation::dpr
 
       attr_reader duration: Imagekitio::Models::Transformation::duration?
 
@@ -362,7 +364,7 @@ module Imagekitio
         ?crop_mode: Imagekitio::Models::Transformation::crop_mode,
         ?default_image: String,
         ?distort: String,
-        ?dpr: Float,
+        ?dpr: Imagekitio::Models::Transformation::dpr,
         ?duration: Imagekitio::Models::Transformation::duration,
         ?end_offset: Imagekitio::Models::Transformation::end_offset,
         ?flip: Imagekitio::Models::Transformation::flip,
@@ -419,7 +421,7 @@ module Imagekitio
         crop_mode: Imagekitio::Models::Transformation::crop_mode,
         default_image: String,
         distort: String,
-        dpr: Float,
+        dpr: Imagekitio::Models::Transformation::dpr,
         duration: Imagekitio::Models::Transformation::duration,
         end_offset: Imagekitio::Models::Transformation::end_offset,
         flip: Imagekitio::Models::Transformation::flip,
@@ -570,6 +572,14 @@ module Imagekitio
         def self?.values: -> ::Array[Imagekitio::Models::Transformation::crop_mode]
       end
 
+      type dpr = Float | String
+
+      module Dpr
+        extend Imagekitio::Internal::Type::Union
+
+        def self?.variants: -> ::Array[Imagekitio::Models::Transformation::dpr]
+      end
+
       type duration = Float | String
 
       module Duration
diff --git a/test/imagekitio/client_test.rb b/test/imagekitio/client_test.rb
index c58cec4..ac64c1d 100644
--- a/test/imagekitio/client_test.rb
+++ b/test/imagekitio/client_test.rb
@@ -136,9 +136,11 @@ def test_client_retry_after_seconds
   end
 
   def test_client_retry_after_date
+    time_now = Time.now
+
     stub_request(:post, "http://localhost/api/v1/files/upload").to_return_json(
       status: 500,
-      headers: {"retry-after" => (Time.now + 10).httpdate},
+      headers: {"retry-after" => (time_now + 10).httpdate},
       body: {}
     )
 
@@ -150,11 +152,11 @@ def test_client_retry_after_date
         max_retries: 1
       )
 
+    Thread.current.thread_variable_set(:time_now, time_now)
     assert_raises(Imagekitio::Errors::InternalServerError) do
-      Thread.current.thread_variable_set(:time_now, Time.now)
       image_kit.files.upload(file: Pathname(__FILE__), file_name: "fileName")
-      Thread.current.thread_variable_set(:time_now, nil)
     end
+    Thread.current.thread_variable_set(:time_now, nil)
 
     assert_requested(:any, /./, times: 2)
     assert_in_delta(10, Thread.current.thread_variable_get(:mock_sleep).last, 1.0)
diff --git a/test/imagekitio/internal/util_test.rb b/test/imagekitio/internal/util_test.rb
index 976d5b0..1b29975 100644
--- a/test/imagekitio/internal/util_test.rb
+++ b/test/imagekitio/internal/util_test.rb
@@ -171,6 +171,8 @@ def test_json_content
     cases = {
       "application/json" => true,
       "application/jsonl" => false,
+      "application/arbitrary+json" => true,
+      "application/ARBITRARY+json" => true,
       "application/vnd.github.v3+json" => true,
       "application/vnd.api+json" => true
     }
diff --git a/test/imagekitio/resources/accounts/origins_test.rb b/test/imagekitio/resources/accounts/origins_test.rb
index 49f7a48..78285d1 100644
--- a/test/imagekitio/resources/accounts/origins_test.rb
+++ b/test/imagekitio/resources/accounts/origins_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Accounts::OriginsTest < Imagekitio::Test::ResourceTest
   def test_create_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.accounts.origins.create(
@@ -114,7 +114,7 @@ def test_create_required_params
   end
 
   def test_update_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.accounts.origins.update(
@@ -225,7 +225,7 @@ def test_update_required_params
   end
 
   def test_list
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.origins.list
 
@@ -235,7 +235,7 @@ def test_list
   end
 
   def test_delete
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.origins.delete("id")
 
@@ -245,7 +245,7 @@ def test_delete
   end
 
   def test_get
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.origins.get("id")
 
diff --git a/test/imagekitio/resources/accounts/url_endpoints_test.rb b/test/imagekitio/resources/accounts/url_endpoints_test.rb
index fa91264..966e30b 100644
--- a/test/imagekitio/resources/accounts/url_endpoints_test.rb
+++ b/test/imagekitio/resources/accounts/url_endpoints_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Accounts::URLEndpointsTest < Imagekitio::Test::ResourceTest
   def test_create_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.url_endpoints.create(description: "My custom URL endpoint")
 
@@ -24,7 +24,7 @@ def test_create_required_params
   end
 
   def test_update_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.url_endpoints.update("id", description: "My custom URL endpoint")
 
@@ -44,7 +44,7 @@ def test_update_required_params
   end
 
   def test_list
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.url_endpoints.list
 
@@ -54,7 +54,7 @@ def test_list
   end
 
   def test_delete
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.url_endpoints.delete("id")
 
@@ -64,7 +64,7 @@ def test_delete
   end
 
   def test_get
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.url_endpoints.get("id")
 
diff --git a/test/imagekitio/resources/accounts/usage_test.rb b/test/imagekitio/resources/accounts/usage_test.rb
index f928f45..64346dd 100644
--- a/test/imagekitio/resources/accounts/usage_test.rb
+++ b/test/imagekitio/resources/accounts/usage_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Accounts::UsageTest < Imagekitio::Test::ResourceTest
   def test_get_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.accounts.usage.get(end_date: "2019-12-27", start_date: "2019-12-27")
 
diff --git a/test/imagekitio/resources/assets_test.rb b/test/imagekitio/resources/assets_test.rb
index f4b2148..882e51f 100644
--- a/test/imagekitio/resources/assets_test.rb
+++ b/test/imagekitio/resources/assets_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::AssetsTest < Imagekitio::Test::ResourceTest
   def test_list
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.assets.list
 
diff --git a/test/imagekitio/resources/beta/v2/files_test.rb b/test/imagekitio/resources/beta/v2/files_test.rb
index 640bff4..c2f5728 100644
--- a/test/imagekitio/resources/beta/v2/files_test.rb
+++ b/test/imagekitio/resources/beta/v2/files_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Beta::V2::FilesTest < Imagekitio::Test::ResourceTest
   def test_upload_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.beta.v2.files.upload(file: Pathname(__FILE__), file_name: "fileName")
 
diff --git a/test/imagekitio/resources/cache/invalidation_test.rb b/test/imagekitio/resources/cache/invalidation_test.rb
index 2d29a04..dec4bfc 100644
--- a/test/imagekitio/resources/cache/invalidation_test.rb
+++ b/test/imagekitio/resources/cache/invalidation_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Cache::InvalidationTest < Imagekitio::Test::ResourceTest
   def test_create_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.cache.invalidation.create(url: "https://ik.imagekit.io/your_imagekit_id/default-image.jpg")
@@ -21,7 +21,7 @@ def test_create_required_params
   end
 
   def test_get
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.cache.invalidation.get("requestId")
 
diff --git a/test/imagekitio/resources/custom_metadata_fields_test.rb b/test/imagekitio/resources/custom_metadata_fields_test.rb
index fcddba8..1d455ad 100644
--- a/test/imagekitio/resources/custom_metadata_fields_test.rb
+++ b/test/imagekitio/resources/custom_metadata_fields_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::CustomMetadataFieldsTest < Imagekitio::Test::ResourceTest
   def test_create_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.custom_metadata_fields.create(label: "price", name: "price", schema: {type: :Number})
@@ -24,7 +24,7 @@ def test_create_required_params
   end
 
   def test_update
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.custom_metadata_fields.update("id")
 
@@ -43,7 +43,7 @@ def test_update
   end
 
   def test_list
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.custom_metadata_fields.list
 
@@ -53,7 +53,7 @@ def test_list
   end
 
   def test_delete
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.custom_metadata_fields.delete("id")
 
diff --git a/test/imagekitio/resources/files/bulk_test.rb b/test/imagekitio/resources/files/bulk_test.rb
index 56991d8..6699988 100644
--- a/test/imagekitio/resources/files/bulk_test.rb
+++ b/test/imagekitio/resources/files/bulk_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Files::BulkTest < Imagekitio::Test::ResourceTest
   def test_delete_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.files.bulk.delete(file_ids: %w[598821f949c0a938d57563bd 598821f949c0a938d57563be])
@@ -21,7 +21,7 @@ def test_delete_required_params
   end
 
   def test_add_tags_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.files.bulk.add_tags(
@@ -41,7 +41,7 @@ def test_add_tags_required_params
   end
 
   def test_remove_ai_tags_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.files.bulk.remove_ai_tags(
@@ -61,7 +61,7 @@ def test_remove_ai_tags_required_params
   end
 
   def test_remove_tags_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.files.bulk.remove_tags(
diff --git a/test/imagekitio/resources/files/metadata_test.rb b/test/imagekitio/resources/files/metadata_test.rb
index ce2626c..2c48eb2 100644
--- a/test/imagekitio/resources/files/metadata_test.rb
+++ b/test/imagekitio/resources/files/metadata_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Files::MetadataTest < Imagekitio::Test::ResourceTest
   def test_get
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.metadata.get("fileId")
 
@@ -33,7 +33,7 @@ def test_get
   end
 
   def test_get_from_url_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.metadata.get_from_url(url: "https://example.com")
 
diff --git a/test/imagekitio/resources/files/versions_test.rb b/test/imagekitio/resources/files/versions_test.rb
index b1d3dc4..3abf45a 100644
--- a/test/imagekitio/resources/files/versions_test.rb
+++ b/test/imagekitio/resources/files/versions_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Files::VersionsTest < Imagekitio::Test::ResourceTest
   def test_list
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.versions.list("fileId")
 
@@ -14,7 +14,7 @@ def test_list
   end
 
   def test_delete_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.versions.delete("versionId", file_id: "fileId")
 
@@ -30,7 +30,7 @@ def test_delete_required_params
   end
 
   def test_get_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.versions.get("versionId", file_id: "fileId")
 
@@ -73,7 +73,7 @@ def test_get_required_params
   end
 
   def test_restore_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.versions.restore("versionId", file_id: "fileId")
 
diff --git a/test/imagekitio/resources/files_test.rb b/test/imagekitio/resources/files_test.rb
index 314183f..aedd4b4 100644
--- a/test/imagekitio/resources/files_test.rb
+++ b/test/imagekitio/resources/files_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::FilesTest < Imagekitio::Test::ResourceTest
   def test_update
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.update("fileId")
 
@@ -14,7 +14,7 @@ def test_update
   end
 
   def test_delete
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.delete("fileId")
 
@@ -24,7 +24,7 @@ def test_delete
   end
 
   def test_copy_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.files.copy(destination_path: "/folder/to/copy/into/", source_file_path: "/path/to/file.jpg")
@@ -41,7 +41,7 @@ def test_copy_required_params
   end
 
   def test_get
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.get("fileId")
 
@@ -84,7 +84,7 @@ def test_get
   end
 
   def test_move_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.files.move(destination_path: "/folder/to/move/into/", source_file_path: "/path/to/file.jpg")
@@ -101,7 +101,7 @@ def test_move_required_params
   end
 
   def test_rename_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.rename(file_path: "/path/to/file.jpg", new_file_name: "newFileName.jpg")
 
@@ -117,7 +117,7 @@ def test_rename_required_params
   end
 
   def test_upload_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.files.upload(file: Pathname(__FILE__), file_name: "fileName")
 
diff --git a/test/imagekitio/resources/folders/job_test.rb b/test/imagekitio/resources/folders/job_test.rb
index 810a3c2..02f4606 100644
--- a/test/imagekitio/resources/folders/job_test.rb
+++ b/test/imagekitio/resources/folders/job_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::Folders::JobTest < Imagekitio::Test::ResourceTest
   def test_get
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.folders.job.get("jobId")
 
diff --git a/test/imagekitio/resources/folders_test.rb b/test/imagekitio/resources/folders_test.rb
index eb4097a..ec2ee28 100644
--- a/test/imagekitio/resources/folders_test.rb
+++ b/test/imagekitio/resources/folders_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::FoldersTest < Imagekitio::Test::ResourceTest
   def test_create_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.folders.create(folder_name: "summer", parent_folder_path: "/product/images/")
 
@@ -20,7 +20,7 @@ def test_create_required_params
   end
 
   def test_delete_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.folders.delete(folder_path: "/folder/to/delete/")
 
@@ -36,7 +36,7 @@ def test_delete_required_params
   end
 
   def test_copy_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.folders.copy(
@@ -56,7 +56,7 @@ def test_copy_required_params
   end
 
   def test_move_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.folders.move(
@@ -76,7 +76,7 @@ def test_move_required_params
   end
 
   def test_rename_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.folders.rename(folder_path: "/path/of/folder", new_folder_name: "new-folder-name")
 
diff --git a/test/imagekitio/resources/saved_extensions_test.rb b/test/imagekitio/resources/saved_extensions_test.rb
index 9ce1a47..9102206 100644
--- a/test/imagekitio/resources/saved_extensions_test.rb
+++ b/test/imagekitio/resources/saved_extensions_test.rb
@@ -4,7 +4,7 @@
 
 class Imagekitio::Test::Resources::SavedExtensionsTest < Imagekitio::Test::ResourceTest
   def test_create_required_params
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response =
       @image_kit.saved_extensions.create(
@@ -30,7 +30,7 @@ def test_create_required_params
   end
 
   def test_update
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.saved_extensions.update("id")
 
@@ -51,7 +51,7 @@ def test_update
   end
 
   def test_list
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.saved_extensions.list
 
@@ -61,7 +61,7 @@ def test_list
   end
 
   def test_delete
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.saved_extensions.delete("id")
 
@@ -71,7 +71,7 @@ def test_delete
   end
 
   def test_get
-    skip("Prism tests are disabled")
+    skip("Mock server tests are disabled")
 
     response = @image_kit.saved_extensions.get("id")