diff --git a/.baseline/checkstyle/checkstyle.xml b/.baseline/checkstyle/checkstyle.xml
index 2f1bfe813..1a086c49c 100644
--- a/.baseline/checkstyle/checkstyle.xml
+++ b/.baseline/checkstyle/checkstyle.xml
@@ -1,15 +1,9 @@
-<?xml version="1.0"?>
-<!DOCTYPE module PUBLIC
-        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
-        "https://checkstyle.org/dtds/configuration_1_3.dtd">
-
-<!--
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><!--
     Palantir Baseline Checkstyle configuration.
     Authors: Robert Fink, Brian Worth, Merrick Zoubeiri, and many other contributors. Based in part on http://checkstyle.sourceforge.net/google_style.html
     Please keep checks alphabetized with one exception: "relaxed" checks are grouped together at the bottom for easier disabling.
     Check-specific comments reference documents internal to Palantir and can be safely ignored or removed.
- -->
-
+ --><!DOCTYPE module PUBLIC "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN" "https://checkstyle.org/dtds/configuration_1_3.dtd">
 <module name="Checker">
     <property name="charset" value="UTF-8"/>
     <property name="severity" value="error"/>
@@ -47,6 +41,10 @@
     <module name="BeforeExecutionExclusionFileFilter">
         <property name="fileNamePattern" value="module\-info\.java$"/>
     </module>
+    <module name="LineLength"> <!-- Java Style Guide: No line-wrapping -->
+        <property name="max" value="120"/>
+        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+    </module>
     <module name="TreeWalker">
         <module name="SuppressionCommentFilter"/> <!-- baseline-gradle: README.md -->
         <module name="SuppressionCommentFilter">
@@ -65,7 +63,9 @@
             <property name="tokens" value="VARIABLE_DEF"/>
             <property name="allowSamelineMultipleAnnotations" value="true"/>
         </module>
-        <module name="AnnotationUseStyle"/> <!-- Java Style Guide: Annotations -->
+        <module name="AnnotationUseStyle"> <!-- Java Style Guide: Annotations -->
+            <property name="trailingArrayComma" value="ignore"/>
+        </module>
         <module name="ArrayTypeStyle"/> <!-- Java Style Guide: No C-style array declarations -->
         <module name="AvoidEscapedUnicodeCharacters"> <!-- Java Style Guide: Non-ASCII characters -->
             <property name="allowEscapesForControlCharacters" value="true"/>
@@ -77,14 +77,7 @@
         </module>
         <module name="AvoidStarImport"/> <!-- Java Style Guide: No wildcard imports -->
         <module name="AvoidStaticImport"> <!-- Java Style Guide: No static imports -->
-            <property name="excludes" value="
-                com.google.common.base.Preconditions.*,
-                com.palantir.logsafe.Preconditions.*,
-                java.util.Collections.*,
-                java.util.stream.Collectors.*,
-                org.apache.commons.lang3.Validate.*,
-                org.assertj.core.api.Assertions.*,
-                org.mockito.Mockito.*"/>
+            <property name="excludes" value="com.google.common.base.Preconditions.*, com.palantir.logsafe.Preconditions.*, java.util.Collections.*, java.util.stream.Collectors.*, org.apache.commons.lang3.Validate.*, org.assertj.core.api.Assertions.*, org.mockito.Mockito.*"/>
         </module>
         <module name="ClassTypeParameterName"> <!-- Java Style Guide: Type variable names -->
             <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
@@ -134,12 +127,12 @@
         <module name="IllegalImport"> <!-- Java Coding Guidelines: Import the canonical package -->
             <property name="id" value="BanShadedClasses"/>
             <property name="illegalPkgs" value=".*\.(repackaged|shaded|thirdparty)"/>
-            <property name="regexp" value="true" />
+            <property name="regexp" value="true"/>
             <message key="import.illegal" value="Must not import repackaged classes."/>
         </module>
         <module name="IllegalImport">
             <property name="illegalPkgs" value="^org\.gradle\.(internal|.*\.internal)"/>
-            <property name="regexp" value="true" />
+            <property name="regexp" value="true"/>
             <message key="import.illegal" value="Do not rely on gradle internal classes as these may change in minor releases - use org.gradle.api versions instead."/>
         </module>
         <module name="IllegalImport">
@@ -192,11 +185,9 @@
             <property name="separated" value="true"/>
             <property name="sortStaticImportsAlphabetically" value="true"/>
         </module>
+        
         <module name="InnerAssignment"/> <!-- Java Coding Guidelines: Inner assignments: Not used -->
-        <module name="LineLength"> <!-- Java Style Guide: No line-wrapping -->
-            <property name="max" value="120"/>
-            <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
-        </module>
+         <!-- Java Style Guide: Nonempty blocks: K & R style -->
         <module name="MemberName"> <!-- Java Style Guide: Non-constant field names -->
             <property name="format" value="^[a-z][a-zA-Z0-9]+$"/>
             <message key="name.invalidPattern" value="Member name ''{0}'' must match pattern ''{1}''."/>
@@ -237,6 +228,7 @@
             <message key="name.invalidPattern" value="Package name ''{0}'' must match pattern ''{1}''."/>
         </module>
         <module name="ParameterAssignment"/> <!-- Java Coding Guidelines: Final variables and parameters -->
+         <!-- Java Style Guide: Horizontal whitespace -->
         <module name="RedundantImport"/> <!-- Java Style Guide: No unused imports -->
         <module name="RedundantModifier"/> <!-- Java Coding Guidelines: Avoid redundant modifiers -->
         <module name="RegexpSinglelineJava"> <!-- Java Coding Guidelines: Use appropriate assertion methods -->
@@ -352,7 +344,7 @@
         </module>
         <module name="RegexpSinglelineJava">
             <property name="format" value="\bCharset.defaultCharset\("/>
-            <property name="message" value="Use explicit charset (e.g. StandardCharsets.UTF-8) instead of default."/>
+            <property name="message" value="Use explicit charset (e.g. StandardCharsets.UTF_8) instead of default."/>
         </module>
         <module name="RegexpSinglelineJava">
             <property name="format" value="\bIOUtils\.toString\("/>
@@ -361,6 +353,7 @@
         <module name="RegexpSinglelineJava">
             <property name="format" value="\/\/TODO|\/\/ TODO(?!\([^()\s]+\): )"/>
             <property name="message" value="TODO format: // TODO(#issue): explanation"/>
+            <property name="ignoreCase" value="true"/>
         </module>
         <module name="RegexpSinglelineJava">
             <property name="format" value="(void setUp\(\))|(void setup\(\))|(void setupStatic\(\))|(void setUpStatic\(\))|(void beforeTest\(\))|(void teardown\(\))|(void tearDown\(\))|(void beforeStatic\(\))|(void afterStatic\(\))"/>
@@ -368,11 +361,11 @@
         </module>
         <module name="RightCurly"> <!-- Java Style Guide: Nonempty blocks: K & R style -->
             <property name="option" value="same"/>
-            <property name="tokens" value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_DO"/>
+            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_DO"/>
         </module>
         <module name="RightCurly"> <!-- Java Style Guide: Nonempty blocks: K & R style -->
             <property name="option" value="alone"/>
-            <property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT, INSTANCE_INIT"/>
+            <property name="tokens" value="LITERAL_FOR, LITERAL_WHILE, STATIC_INIT, INSTANCE_INIT"/>
         </module>
         <module name="SeparatorWrap"> <!-- Java Style Guide: Where to break -->
             <property name="tokens" value="DOT"/>
@@ -390,7 +383,7 @@
         <module name="SuppressWarnings">
             <property name="format" value="serial"/>
         </module>
-        <module name="SuppressWarningsHolder" />  <!-- Required for SuppressWarningsFilter -->
+        <module name="SuppressWarningsHolder"/>  <!-- Required for SuppressWarningsFilter -->
         <module name="TypeName"> <!-- Java Style Guide: Class names -->
             <message key="name.invalidPattern" value="Type name ''{0}'' must match pattern ''{1}''."/>
         </module>
@@ -401,16 +394,7 @@
         <module name="UpperEll"/> <!-- Java Style Guide: Numeric Literals -->
         <module name="VisibilityModifier"/> <!-- Java Coding Guidelines: Minimize mutability -->
         <module name="WhitespaceAfter"/> <!-- Java Style Guide: Horizontal whitespace -->
-        <module name="WhitespaceAround"> <!-- Java Style Guide: Horizontal whitespace -->
-            <property name="allowEmptyConstructors" value="true"/>
-            <property name="allowEmptyMethods" value="true"/>
-            <property name="allowEmptyTypes" value="true"/>
-            <property name="allowEmptyLoops" value="true"/>
-            <property name="allowEmptyLambdas" value="true"/>
-            <property name="ignoreEnhancedForColon" value="false"/>
-            <message key="ws.notFollowed" value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
-            <message key="ws.notPreceded" value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
-        </module>
+        
 
         <!-- Stricter checks begin: delete some or all of the following for faster prototyping, but please restore before pushing to production. -->
 
@@ -423,13 +407,10 @@
             <property name="ignoredAnnotations" value="ParameterizedTest, Test, Before, BeforeEach, After, AfterEach, BeforeClass, BeforeAll, AfterClass, AfterAll"/>
         </module>
         <module name="JavadocMethod"> <!-- Java Style Guide: Where Javadoc is used -->
-            <property name="scope" value="public"/>
+            <property name="accessModifiers" value="public"/>
             <property name="allowMissingParamTags" value="true"/>
-            <property name="allowMissingThrowsTags" value="true"/>
             <property name="allowMissingReturnTag" value="true"/>
-            <property name="minLineCount" value="99999999"/>
             <property name="allowedAnnotations" value="Override, Test"/>
-            <property name="allowThrowsTagsForSubclasses" value="true"/>
         </module>
         <module name="JavadocStyle"/> <!-- Java Style Guide: Javadoc -->
         <module name="JavadocTagContinuationIndentation"> <!-- Java Style Guide: At-clauses -->
@@ -462,4 +443,4 @@
 
         <!-- Stricter checks end -->
     </module>
-</module>
+</module>
\ No newline at end of file
diff --git a/.baseline/idea/intellij-java-palantir-style.xml b/.baseline/idea/intellij-java-palantir-style.xml
index 945d8bad0..f41e2b8aa 100644
--- a/.baseline/idea/intellij-java-palantir-style.xml
+++ b/.baseline/idea/intellij-java-palantir-style.xml
@@ -44,6 +44,18 @@
               <package name="" withSubpackages="true" static="false" />
             </value>
           </option>
+          <DO_NOT_IMPORT_INNER>
+            <CLASS name="Builder" />
+            <CLASS name="Callback" />
+            <CLASS name="Class" />
+            <CLASS name="Entry" />
+            <CLASS name="Enum" />
+            <CLASS name="Factory" />
+            <CLASS name="Type" />
+            <CLASS name="Key" />
+            <CLASS name="Id" />
+            <CLASS name="Provider" />
+          </DO_NOT_IMPORT_INNER>
         </GroovyCodeStyleSettings>
         <option name="JD_ALIGN_EXCEPTION_COMMENTS" value="false" />
         <option name="JD_ALIGN_PARAM_COMMENTS" value="false" />
diff --git a/build.gradle b/build.gradle
index 01ad0d6c1..ae0f97757 100644
--- a/build.gradle
+++ b/build.gradle
@@ -25,7 +25,7 @@ buildscript {
         classpath 'com.palantir.gradle.externalpublish:gradle-external-publish-plugin:1.4.0'
         classpath 'com.palantir.javaformat:gradle-palantir-java-format:1.0.1'
         classpath 'com.palantir.gradle.consistentversions:gradle-consistent-versions:1.17.2'
-        classpath 'com.palantir.baseline:gradle-baseline-java:3.14.1'
+        classpath 'com.palantir.baseline:gradle-baseline-java:4.56.0'
         classpath 'com.palantir.gradle.conjure:gradle-conjure:4.18.0'
         classpath 'com.palantir.gradle.gitversion:gradle-git-version:0.12.2'
         classpath 'gradle.plugin.org.inferred:gradle-processors:3.6.0'
diff --git a/conjure-python-core/src/main/java/com/palantir/conjure/python/ConjurePythonGenerator.java b/conjure-python-core/src/main/java/com/palantir/conjure/python/ConjurePythonGenerator.java
index 4e3d84d10..ed839e0de 100644
--- a/conjure-python-core/src/main/java/com/palantir/conjure/python/ConjurePythonGenerator.java
+++ b/conjure-python-core/src/main/java/com/palantir/conjure/python/ConjurePythonGenerator.java
@@ -160,7 +160,7 @@ private PythonFile getImplPythonFile(
 
         PythonPackage rootPackage = PythonPackage.of(implPackageNameProcessor.process(""));
         List<PythonFile> pythonFiles = KeyedStream.stream(snippetsByPackage)
-                .map((pythonPackage, pythonSnippets) -> PythonFile.builder()
+                .map((_pythonPackage, pythonSnippets) -> PythonFile.builder()
                         .pythonPackage(rootPackage)
                         .fileName(IMPL_PY)
                         .contents(pythonSnippets)
@@ -239,7 +239,7 @@ private PythonFile getRootInit(Set<PythonPackage> packageNames, PythonPackage ro
                         .text(String.format("__conjure_generator_version__ = \"%s\"", config.generatorVersion()))
                         .build());
         config.packageVersion()
-                .ifPresent(version -> builder.addContents(PythonLine.builder()
+                .ifPresent(_version -> builder.addContents(PythonLine.builder()
                         .pythonPackage(rootPackage)
                         .text(String.format(
                                 "__version__ = \"%s\"", config.packageVersion().get()))
diff --git a/conjure-python-core/src/main/java/com/palantir/conjure/python/PythonAliasTopologicalSorter.java b/conjure-python-core/src/main/java/com/palantir/conjure/python/PythonAliasTopologicalSorter.java
index eb5c67628..ce42c97d9 100644
--- a/conjure-python-core/src/main/java/com/palantir/conjure/python/PythonAliasTopologicalSorter.java
+++ b/conjure-python-core/src/main/java/com/palantir/conjure/python/PythonAliasTopologicalSorter.java
@@ -57,7 +57,7 @@ public static List<AliasSnippet> getSortedSnippets(List<AliasSnippet> snippets)
                 .collect(Collectors.toSet());
         Map<AliasSnippet, Integer> nonRootsToInDegree = mutableGraph.nodes().stream()
                 .filter(node -> mutableGraph.inDegree(node) > 0)
-                .collect(Collectors.toMap(node -> node, mutableGraph::inDegree, (a, b) -> a));
+                .collect(Collectors.toMap(node -> node, mutableGraph::inDegree, (a, _b) -> a));
 
         // Kahn's Algorithm https://en.wikipedia.org/wiki/Topological_sorting#Kahn's_algorithm
         while (!roots.isEmpty()) {
diff --git a/conjure-python-core/src/main/java/com/palantir/conjure/python/client/ClientGenerator.java b/conjure-python-core/src/main/java/com/palantir/conjure/python/client/ClientGenerator.java
index 5280d6158..773168fc5 100644
--- a/conjure-python-core/src/main/java/com/palantir/conjure/python/client/ClientGenerator.java
+++ b/conjure-python-core/src/main/java/com/palantir/conjure/python/client/ClientGenerator.java
@@ -104,7 +104,7 @@ private PythonEndpointDefinition generateEndpoint(
                         .myPyType(argEntry.getType().accept(myPyTypeNameVisitor))
                         .isOptional(dealiasingTypeVisitor
                                 .dealias(argEntry.getType())
-                                .fold(typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
+                                .fold(_typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
                         .build())
                 .collect(Collectors.toList());
 
@@ -128,7 +128,7 @@ private PythonEndpointDefinition generateEndpoint(
                         .getReturns()
                         .map(rt -> dealiasingTypeVisitor
                                 .dealias(rt)
-                                .fold(typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
+                                .fold(_typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
                         .orElse(false))
                 .build();
     }
diff --git a/conjure-python-core/src/main/java/com/palantir/conjure/python/types/PythonTypeGenerator.java b/conjure-python-core/src/main/java/com/palantir/conjure/python/types/PythonTypeGenerator.java
index ad5eeb28d..f1e29d9cf 100644
--- a/conjure-python-core/src/main/java/com/palantir/conjure/python/types/PythonTypeGenerator.java
+++ b/conjure-python-core/src/main/java/com/palantir/conjure/python/types/PythonTypeGenerator.java
@@ -112,7 +112,7 @@ private BeanSnippet generateBean(ObjectDefinition typeDef) {
                         .myPyType(entry.getType().accept(myPyTypeNameVisitor))
                         .isOptional(dealiasingTypeVisitor
                                 .dealias(entry.getType())
-                                .fold(typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
+                                .fold(_typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
                         .build())
                 .collect(Collectors.toList());
 
@@ -166,7 +166,7 @@ private UnionSnippet generateUnion(UnionDefinition typeDef) {
                             .pythonType(conjureType.accept(pythonTypeNameVisitor))
                             .isOptional(dealiasingTypeVisitor
                                     .dealias(unionMember.getType())
-                                    .fold(typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
+                                    .fold(_typeDefinition -> false, type -> type.accept(TypeVisitor.IS_OPTIONAL)))
                             .build();
                 })
                 .collect(Collectors.toList());