diff --git a/Gemfile b/Gemfile
index fa6f2c7..e1670d0 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,6 +5,7 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in scheemer.gemspec
 gemspec
 
+gem "pry-nav"
 gem "rake", "~> 13.0"
 gem "rspec", "~> 3.0"
 gem "rubocop", "~> 1.21"
diff --git a/Gemfile.lock b/Gemfile.lock
index d3112e7..fa324ed 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,12 +2,22 @@ PATH
   remote: .
   specs:
     scheemer (3.0.0)
+      activesupport
       dry-schema (~> 1.13)
+      json-schema (~> 4.0)
 
 GEM
   remote: https://rubygems.org/
   specs:
+    activesupport (7.0.4.3)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 1.6, < 2)
+      minitest (>= 5.1)
+      tzinfo (~> 2.0)
+    addressable (2.8.4)
+      public_suffix (>= 2.0.2, < 6.0)
     ast (2.4.2)
+    coderay (1.1.3)
     concurrent-ruby (1.2.2)
     diff-lcs (1.5.0)
     dry-configurable (1.0.1)
@@ -36,10 +46,22 @@ GEM
       dry-inflector (~> 1.0)
       dry-logic (~> 1.4)
       zeitwerk (~> 2.6)
+    i18n (1.13.0)
+      concurrent-ruby (~> 1.0)
     json (2.6.3)
+    json-schema (4.0.0)
+      addressable (>= 2.8)
+    method_source (1.0.0)
+    minitest (5.18.0)
     parallel (1.23.0)
     parser (3.2.2.1)
       ast (~> 2.4.1)
+    pry (0.14.2)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
+    pry-nav (1.0.0)
+      pry (>= 0.9.10, < 0.15)
+    public_suffix (5.0.1)
     rainbow (3.1.1)
     rake (13.0.6)
     regexp_parser (2.8.0)
@@ -72,6 +94,8 @@ GEM
     rubocop-rspec (2.12.1)
       rubocop (~> 1.31)
     ruby-progressbar (1.13.0)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
     unicode-display_width (2.4.2)
     zeitwerk (2.6.8)
 
@@ -79,6 +103,7 @@ PLATFORMS
   x86_64-linux-musl
 
 DEPENDENCIES
+  pry-nav
   rake (~> 13.0)
   rspec (~> 3.0)
   rubocop (~> 1.21)
diff --git a/lib/scheemer/params.rb b/lib/scheemer/params.rb
index d548602..cf3e327 100644
--- a/lib/scheemer/params.rb
+++ b/lib/scheemer/params.rb
@@ -3,6 +3,7 @@
 require_relative "./fallbacker"
 
 require_relative "./extensions/string"
+require "active_support/core_ext/hash"
 
 module Scheemer
   # This handles the conversion from the HTTP linguo (camelCase)
@@ -28,7 +29,10 @@ def params_fallbacks
 
     module InstanceMethods
       def initialize(params, data = {})
-        @params = Fallbacker.apply(params, self.class.params_fallbacks)
+        @params = Fallbacker.apply(
+          params.to_h.deep_symbolize_keys,
+          self.class.params_fallbacks
+        )
 
         validate!(data.to_h) if respond_to?(:validate!)
       end
diff --git a/lib/scheemer/schema.rb b/lib/scheemer/schema.rb
index 2cf2f91..6a2108a 100644
--- a/lib/scheemer/schema.rb
+++ b/lib/scheemer/schema.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "dry-schema"
+require "json-schema"
 
 Dry::Schema.load_extensions(:hints, :json_schema)
 
@@ -40,6 +41,8 @@ def check_schema_exists!
 
     def initialize(&)
       @definitions = ::Dry::Schema.Params do
+        config.validate_keys = false
+
         instance_eval(&)
       end
     end
@@ -49,15 +52,16 @@ def validate(params)
     end
 
     def validate!(params)
-      validate(params).tap do |result|
-        next if result.success?
+      valid_as_json = JSON::Validator.validate(json_schema, params)
+      valid_as_dry = validate(params)
 
-        raise InvalidSchemaError, result.messages.to_h
-      end
+      return params if valid_as_json && valid_as_dry.success?
+
+      raise InvalidSchemaError, valid_as_dry.messages.to_h
     end
 
     def json_schema
-      @definitions.json_schema
+      @definitions.json_schema(loose: true)
     end
   end
 end
diff --git a/scheemer.gemspec b/scheemer.gemspec
index eceae48..e90c088 100644
--- a/scheemer.gemspec
+++ b/scheemer.gemspec
@@ -32,6 +32,8 @@ Gem::Specification.new do |spec|
 
   # Uncomment to register a new dependency of your gem
   spec.add_dependency "dry-schema", "~> 1.13"
+  spec.add_dependency "json-schema", "~> 4.0"
+  spec.add_dependency "activesupport"
 
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html
diff --git a/spec/scheemer/params_spec.rb b/spec/scheemer/params_spec.rb
index cced0ea..64a413f 100644
--- a/spec/scheemer/params_spec.rb
+++ b/spec/scheemer/params_spec.rb
@@ -11,20 +11,34 @@
         end
       end
 
-      subject(:record) { klass.new({ someValue: "testing" }) }
+      context "when keys are symbols" do
+        subject(:record) { klass.new({ someValue: "testing" }) }
+
+        it "allows access to fields using underscored accessors" do
+          expect(record.some_value).to eql("testing")
+        end
 
-      it "allows access to fields using underscored accessors" do
-        expect(record.some_value).to eql("testing")
+        it "allows access to fields using camelcase accessors" do
+          expect(record.someValue).to eql("testing")
+        end
       end
 
-      it "allows access to fields using camelcase accessors" do
-        expect(record.someValue).to eql("testing")
+      context "when keys are strings" do
+        subject(:record) { klass.new({ "someValue" => "testing" }) }
+
+        it "allows access to fields using underscored accessors" do
+          expect(record.some_value).to eql("testing")
+        end
+
+        it "allows access to fields using camelcase accessors" do
+          expect(record.someValue).to eql("testing")
+        end
       end
     end
   end
 
   describe ".on_missing" do
-    context "with a single level key" do
+    context "with a shallow key" do
       let(:klass) do
         Class.new do
           extend Scheemer::Params::DSL
@@ -35,7 +49,7 @@
 
       subject(:record) { klass.new({ someValue: "testing" }) }
 
-      it "allows access to fields using underscored accessors" do
+      it "fills in the missing missing" do
         expect(record.content).to eql({ fall: "back" })
         expect(record.someValue).to eql("testing")
       end
diff --git a/spec/scheemer/schema_spec.rb b/spec/scheemer/schema_spec.rb
index 86021a7..3c9ae15 100644
--- a/spec/scheemer/schema_spec.rb
+++ b/spec/scheemer/schema_spec.rb
@@ -6,7 +6,7 @@
   describe ".validate!" do
     subject(:schema) do
       described_class.new do
-        required(:test)
+        required(:test).filled(:string)
       end
     end
 
@@ -24,4 +24,30 @@
       end
     end
   end
+
+  describe "#json_schema" do
+    context "when a key is using unsupported `format?`" do
+      subject(:schema) do
+        described_class.new do
+          required(:test).filled(:str?, format?: /asd/)
+        end
+      end
+
+      it "generates the schema without it" do
+        expect(schema.json_schema).to eql(
+          {
+            "$schema": "http://json-schema.org/draft-06/schema#",
+            properties: {
+              test: {
+                minLength: 1,
+                type: "string",
+              },
+            },
+            required: ["test"],
+            type: "object",
+          }
+        )
+      end
+    end
+  end
 end
diff --git a/spec/scheemer_spec.rb b/spec/scheemer_spec.rb
index ec30500..145d447 100644
--- a/spec/scheemer_spec.rb
+++ b/spec/scheemer_spec.rb
@@ -21,7 +21,9 @@
         end
       end
 
-      subject(:record) { klass.new({ root: { someValue: "testing" } }) }
+      subject(:record) do
+        klass.new({ root: { someValue: "testing" } })
+      end
 
       it "allows access to fields using underscored accessors" do
         expect(record.some_value).to eql("testing")
@@ -58,5 +60,41 @@
 
       it { expect { klass.new({}) }.to raise_error(NotImplementedError) }
     end
+
+    context "when the extra fields are specified" do
+      let(:klass) do
+        Class.new do
+          extend Scheemer::DSL
+
+          schema do
+            required(:item).hash do
+              required(:content).hash do
+                required(:name).filled(:string)
+                optional(:address).filled(:string)
+              end
+            end
+          end
+        end
+      end
+      let(:data) do
+        {
+          item: {
+            content: {
+              name: "John",
+              age: "9999",
+              address: "John's Street 69"
+            }
+          }
+        }
+      end
+
+      subject(:record) { klass.new(data) } 
+
+      it "it allows all fields through" do
+        expect(record.content.dig(:name)).to eql "John"
+        expect(record.content.dig(:age)).to eql "9999"
+        expect(record.content.dig(:address)).to eql "John's Street 69"
+      end
+    end
   end
 end