diff --git a/api/openapi.yaml b/api/openapi.yaml
index 76fc716..076dddc 100644
--- a/api/openapi.yaml
+++ b/api/openapi.yaml
@@ -1120,6 +1120,8 @@ components:
     Project:
       example:
         '@type': Project
+        defaultBranch:
+          id: 046b6c7f-0b8a-43b9-b35d-6489e6daee91
         name: name
         description: description
         id: 046b6c7f-0b8a-43b9-b35d-6489e6daee91
@@ -1128,6 +1130,8 @@ components:
           enum:
           - Project
           type: string
+        defaultBranch:
+          $ref: '#/components/schemas/Project_defaultBranch'
         description:
           type: string
         id:
@@ -1390,6 +1394,14 @@ components:
         error:
           type: string
       type: object
+    Project_defaultBranch:
+      description: Branch
+      example:
+        id: 046b6c7f-0b8a-43b9-b35d-6489e6daee91
+      properties:
+        id:
+          format: uuid
+          type: string
     Branch_head:
       description: Commit
       example:
diff --git a/build.gradle b/build.gradle
index eeb2d59..1f394f0 100644
--- a/build.gradle
+++ b/build.gradle
@@ -3,7 +3,7 @@ apply plugin: 'eclipse'
 apply plugin: 'java'
 
 group = 'org.omg.sysml'
-version = '2021-04'
+version = '2021-05'
 
 buildscript {
     repositories {
diff --git a/build.sbt b/build.sbt
index 1c260a9..72e6f73 100644
--- a/build.sbt
+++ b/build.sbt
@@ -2,7 +2,7 @@ lazy val root = (project in file(".")).
   settings(
     organization := "org.omg.sysml",
     name := "sysml-v2-api-client",
-    version := "2021-04",
+    version := "2021-05",
     scalaVersion := "2.11.4",
     scalacOptions ++= Seq("-feature"),
     javacOptions in compile ++= Seq("-Xlint:deprecation"),
diff --git a/docs/Project.md b/docs/Project.md
index 112d1f9..0311d45 100644
--- a/docs/Project.md
+++ b/docs/Project.md
@@ -7,6 +7,7 @@
 Name | Type | Description | Notes
 ------------ | ------------- | ------------- | -------------
 **atType** | [**AtTypeEnum**](#AtTypeEnum) |  |  [optional]
+**defaultBranch** | [**ProjectDefaultBranch**](ProjectDefaultBranch.md) |  |  [optional]
 **description** | **String** |  |  [optional]
 **id** | [**UUID**](UUID.md) |  |  [optional]
 **name** | **String** |  |  [optional]
diff --git a/docs/ProjectDefaultBranch.md b/docs/ProjectDefaultBranch.md
new file mode 100644
index 0000000..4bb7931
--- /dev/null
+++ b/docs/ProjectDefaultBranch.md
@@ -0,0 +1,13 @@
+
+
+# ProjectDefaultBranch
+
+Branch
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**id** | [**UUID**](UUID.md) |  |  [optional]
+
+
+
diff --git a/pom.xml b/pom.xml
index 73bc756..3e1abbe 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
     <artifactId>sysml-v2-api-client</artifactId>
     <packaging>jar</packaging>
     <name>sysml-v2-api-client</name>
-    <version>2021-04</version>
+    <version>2021-05</version>
     <url>https://github.com/openapitools/openapi-generator</url>
     <description>OpenAPI Java</description>
     <scm>
diff --git a/src/main/java/org/omg/sysml/ApiClient.java b/src/main/java/org/omg/sysml/ApiClient.java
index ec6014e..9e9e2d4 100644
--- a/src/main/java/org/omg/sysml/ApiClient.java
+++ b/src/main/java/org/omg/sysml/ApiClient.java
@@ -108,7 +108,7 @@ private void init() {
         json = new JSON();
 
         // Set default User-Agent.
-        setUserAgent("OpenAPI-Generator/2021-04/java");
+        setUserAgent("OpenAPI-Generator/2021-05/java");
 
         authentications = new HashMap<String, Authentication>();
     }
diff --git a/src/main/java/org/omg/sysml/model/Project.java b/src/main/java/org/omg/sysml/model/Project.java
index 164b209..2533768 100644
--- a/src/main/java/org/omg/sysml/model/Project.java
+++ b/src/main/java/org/omg/sysml/model/Project.java
@@ -24,6 +24,7 @@
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.UUID;
+import org.omg.sysml.model.ProjectDefaultBranch;
 
 /**
  * Project
@@ -79,6 +80,10 @@ public AtTypeEnum read(final JsonReader jsonReader) throws IOException {
   @SerializedName(SERIALIZED_NAME_AT_TYPE)
   private AtTypeEnum atType;
 
+  public static final String SERIALIZED_NAME_DEFAULT_BRANCH = "defaultBranch";
+  @SerializedName(SERIALIZED_NAME_DEFAULT_BRANCH)
+  private ProjectDefaultBranch defaultBranch;
+
   public static final String SERIALIZED_NAME_DESCRIPTION = "description";
   @SerializedName(SERIALIZED_NAME_DESCRIPTION)
   private String description;
@@ -115,6 +120,29 @@ public void setAtType(AtTypeEnum atType) {
   }
 
 
+  public Project defaultBranch(ProjectDefaultBranch defaultBranch) {
+    
+    this.defaultBranch = defaultBranch;
+    return this;
+  }
+
+   /**
+   * Get defaultBranch
+   * @return defaultBranch
+  **/
+  @javax.annotation.Nullable
+  @ApiModelProperty(value = "")
+
+  public ProjectDefaultBranch getDefaultBranch() {
+    return defaultBranch;
+  }
+
+
+  public void setDefaultBranch(ProjectDefaultBranch defaultBranch) {
+    this.defaultBranch = defaultBranch;
+  }
+
+
   public Project description(String description) {
     
     this.description = description;
@@ -194,6 +222,7 @@ public boolean equals(java.lang.Object o) {
     }
     Project project = (Project) o;
     return Objects.equals(this.atType, project.atType) &&
+        Objects.equals(this.defaultBranch, project.defaultBranch) &&
         Objects.equals(this.description, project.description) &&
         Objects.equals(this.id, project.id) &&
         Objects.equals(this.name, project.name);
@@ -201,7 +230,7 @@ public boolean equals(java.lang.Object o) {
 
   @Override
   public int hashCode() {
-    return Objects.hash(atType, description, id, name);
+    return Objects.hash(atType, defaultBranch, description, id, name);
   }
 
 
@@ -210,6 +239,7 @@ public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Project {\n");
     sb.append("    atType: ").append(toIndentedString(atType)).append("\n");
+    sb.append("    defaultBranch: ").append(toIndentedString(defaultBranch)).append("\n");
     sb.append("    description: ").append(toIndentedString(description)).append("\n");
     sb.append("    id: ").append(toIndentedString(id)).append("\n");
     sb.append("    name: ").append(toIndentedString(name)).append("\n");
diff --git a/src/main/java/org/omg/sysml/model/ProjectDefaultBranch.java b/src/main/java/org/omg/sysml/model/ProjectDefaultBranch.java
new file mode 100644
index 0000000..f7d0cf9
--- /dev/null
+++ b/src/main/java/org/omg/sysml/model/ProjectDefaultBranch.java
@@ -0,0 +1,101 @@
+/*
+ * SysML v2 API and Services
+ * REST/HTTP binding (PSM) for the SysML v2 standard API.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.omg.sysml.model;
+
+import java.util.Objects;
+import java.util.Arrays;
+import com.google.gson.TypeAdapter;
+import com.google.gson.annotations.JsonAdapter;
+import com.google.gson.annotations.SerializedName;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import io.swagger.annotations.ApiModel;
+import io.swagger.annotations.ApiModelProperty;
+import java.io.IOException;
+import java.util.UUID;
+
+/**
+ * Branch
+ */
+@ApiModel(description = "Branch")
+
+public class ProjectDefaultBranch {
+  public static final String SERIALIZED_NAME_ID = "id";
+  @SerializedName(SERIALIZED_NAME_ID)
+  private UUID id;
+
+
+  public ProjectDefaultBranch id(UUID id) {
+    
+    this.id = id;
+    return this;
+  }
+
+   /**
+   * Get id
+   * @return id
+  **/
+  @javax.annotation.Nullable
+  @ApiModelProperty(value = "")
+
+  public UUID getId() {
+    return id;
+  }
+
+
+  public void setId(UUID id) {
+    this.id = id;
+  }
+
+
+  @Override
+  public boolean equals(java.lang.Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    ProjectDefaultBranch projectDefaultBranch = (ProjectDefaultBranch) o;
+    return Objects.equals(this.id, projectDefaultBranch.id);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(id);
+  }
+
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+    sb.append("class ProjectDefaultBranch {\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("}");
+    return sb.toString();
+  }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(java.lang.Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+
+}
+
diff --git a/src/test/java/org/omg/sysml/model/ProjectDefaultBranchTest.java b/src/test/java/org/omg/sysml/model/ProjectDefaultBranchTest.java
new file mode 100644
index 0000000..a56eb8c
--- /dev/null
+++ b/src/test/java/org/omg/sysml/model/ProjectDefaultBranchTest.java
@@ -0,0 +1,52 @@
+/*
+ * SysML v2 API and Services
+ * REST/HTTP binding (PSM) for the SysML v2 standard API.
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+
+package org.omg.sysml.model;
+
+import com.google.gson.TypeAdapter;
+import com.google.gson.annotations.JsonAdapter;
+import com.google.gson.annotations.SerializedName;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import io.swagger.annotations.ApiModel;
+import io.swagger.annotations.ApiModelProperty;
+import java.io.IOException;
+import java.util.UUID;
+import org.junit.Assert;
+import org.junit.Ignore;
+import org.junit.Test;
+
+
+/**
+ * Model tests for ProjectDefaultBranch
+ */
+public class ProjectDefaultBranchTest {
+    private final ProjectDefaultBranch model = new ProjectDefaultBranch();
+
+    /**
+     * Model tests for ProjectDefaultBranch
+     */
+    @Test
+    public void testProjectDefaultBranch() {
+        // TODO: test ProjectDefaultBranch
+    }
+
+    /**
+     * Test the property 'id'
+     */
+    @Test
+    public void idTest() {
+        // TODO: test id
+    }
+
+}
diff --git a/src/test/java/org/omg/sysml/model/ProjectTest.java b/src/test/java/org/omg/sysml/model/ProjectTest.java
index 196cd99..011ab2f 100644
--- a/src/test/java/org/omg/sysml/model/ProjectTest.java
+++ b/src/test/java/org/omg/sysml/model/ProjectTest.java
@@ -22,6 +22,7 @@
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.UUID;
+import org.omg.sysml.model.ProjectDefaultBranch;
 import org.junit.Assert;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -49,6 +50,14 @@ public void atTypeTest() {
         // TODO: test atType
     }
 
+    /**
+     * Test the property 'defaultBranch'
+     */
+    @Test
+    public void defaultBranchTest() {
+        // TODO: test defaultBranch
+    }
+
     /**
      * Test the property 'description'
      */
diff --git a/test-sysml-v2-api-java-client.jsh b/test-sysml-v2-api-java-client.jsh
deleted file mode 100755
index 91ef2eb..0000000
--- a/test-sysml-v2-api-java-client.jsh
+++ /dev/null
@@ -1,52 +0,0 @@
-//usr/bin/env jshell --show-version "$0" "$@"; exit $?
-/env -class-path ~/SysML-v2-API-Java-Client/build/libs/sysml-v2-api-client-2020-05-rc1-all.jar
-
-import java.util.Arrays;
-import java.util.UUID;
-
-import org.omg.sysml.ApiClient;
-import org.omg.sysml.api.*;
-import org.omg.sysml.model.*;
-
-var apiClient = new ApiClient();
-apiClient.setBasePath("http://localhost:9000");
-
-var project = new Project();
-project.setName("MyProject");
-
-var projectApi = new ProjectApi(apiClient);
-var projectResponse = projectApi.postProject(project);
-System.out.println("--- Project ---");
-System.out.println(projectResponse);
-
-var firstBlock = new Element();
-firstBlock.put("@type", "Block");
-// Fluent API getters/setters also supported
-var firstIdentity = new ElementIdentity().id(UUID.fromString("b92bb8e8-740b-4eee-b621-91a82be67d6a"));
-var firstElementVersion = new ElementVersion().data(firstBlock).identity(firstIdentity);
-var secondBlock = new Element();
-secondBlock.put("@type", "Block");
-var secondIdentity = new ElementIdentity().id(UUID.fromString("a429229d-333a-4f2d-89b4-82354d29109d"));
-var secondElementVersion = new ElementVersion().data(secondBlock).identity(secondIdentity);
-var firstCommit = new Commit().changes(Arrays.asList(firstElementVersion, secondElementVersion));
-
-var commitApi = new CommitApi(apiClient);
-var firstCommitResponse = commitApi.postCommitByProject(projectResponse.getId(), firstCommit);
-System.out.println("--- First Commit ---");
-System.out.println(firstCommitResponse);
-
-var generalization = new Element();
-generalization.put("@type", "Generalization");
-var firstBlockIdentified = new Identified().atId(UUID.fromString("b92bb8e8-740b-4eee-b621-91a82be67d6a"));
-generalization.put("source", Arrays.asList(firstBlockIdentified));
-var secondBlockIdentified = new Identified().atId(UUID.fromString("a429229d-333a-4f2d-89b4-82354d29109d"));
-generalization.put("target", Arrays.asList(secondBlockIdentified));
-// Note that no ElementIdentity is provided. Server will generate one when not provided.
-var generalizationElementVersion = new ElementVersion().data(generalization);
-var firstCommitRecord = new Record().id(firstCommitResponse.getId());
-var secondCommit = new Commit().previousCommit(firstCommitRecord).changes(Arrays.asList(generalizationElementVersion));
-var secondCommitResponse = commitApi.postCommitByProject(projectResponse.getId(), secondCommit);
-System.out.println("--- Second Commit ---");
-System.out.println(secondCommitResponse);
-
-/exit