diff --git a/tomitribe-crest/src/test/java/org/tomitribe/crest/Cli.java b/tomitribe-crest/src/test/java/org/tomitribe/crest/Cli.java
index 8297476..a5f4701 100644
--- a/tomitribe-crest/src/test/java/org/tomitribe/crest/Cli.java
+++ b/tomitribe-crest/src/test/java/org/tomitribe/crest/Cli.java
@@ -28,14 +28,14 @@
 
 public class Cli {
 
-    private final File jar;
+    private final Java java;
 
-    public Cli(final File jar) {
-        this.jar = jar;
+    private Cli(final Java java) {
+        this.java = java;
     }
 
     public Java.Result run(final String... args) throws Exception {
-        return Java.jar(jar, args);
+        return java.run(args);
     }
 
     public static Builder builder() {
@@ -44,6 +44,7 @@ public static Builder builder() {
 
     public static class Builder {
         private final Archive archive = Archive.archive();
+        private final Java.Builder java = Java.builder();
 
         public Builder() {
             final List<Class<?>> required = Arrays.asList(Main.class, Command.class, Converter.class);
@@ -62,6 +63,20 @@ public Builder() {
             manifest(manifest);
         }
 
+        public Java.Builder arg(final String arg) {
+            return java.arg(arg);
+        }
+
+        public Builder env(final String name, final String value) {
+            java.env(name, value);
+            return this;
+        }
+
+        public Builder debug() {
+            java.debug();
+            return this;
+        }
+
         public Builder manifest(final Manifest manifest) {
             archive.add("META-INF/MANIFEST.MF", manifest.write());
             return this;
@@ -113,7 +128,8 @@ public Builder add(final Class<?> clazz) {
         }
 
         public Cli build() {
-            return new Cli(archive.asJar());
+            final File jar = archive.asJar();
+            return new Cli(java.copy().jar(jar).build());
         }
     }
 }
diff --git a/tomitribe-crest/src/test/java/org/tomitribe/crest/CommandNameAndVersionTest.java b/tomitribe-crest/src/test/java/org/tomitribe/crest/CommandNameAndVersionTest.java
index 092d0b2..2077730 100644
--- a/tomitribe-crest/src/test/java/org/tomitribe/crest/CommandNameAndVersionTest.java
+++ b/tomitribe-crest/src/test/java/org/tomitribe/crest/CommandNameAndVersionTest.java
@@ -13,6 +13,7 @@
  */
 package org.tomitribe.crest;
 
+import org.junit.Ignore;
 import org.junit.Test;
 import org.tomitribe.crest.api.Command;
 import org.tomitribe.crest.api.Loader;
@@ -57,14 +58,74 @@ public void manifestImplementationVersion() throws Exception {
      */
     @Test
     public void manifestCommandName() throws Exception {
+        Java.Result result = Cli.builder()
+                .loader(ColorLoader.class)
+                .manifest(Manifest.builder()
+                        .mainClass(Main.class)
+                        .implementationVersion("5.16.1")
+                        .commandName("blue"))
+                .add(ColorCommands.class)
+                .add(ColorLoader.class)
+                .add(SystemPropertiesInLoader.class)
+                .build()
+                .run();
+
+        assertEquals(String.format("Commands: %n" +
+                "                       %n" +
+                "   color               %n" +
+                "   help                %n" +
+                "%n" +
+                "blue 5.16.1%n" +
+                ""), result.getOut());
     }
 
     @Test
     public void manifestCommandVersion() throws Exception {
+        Java.Result result = Cli.builder()
+                .loader(ColorLoader.class)
+                .manifest(Manifest.builder()
+                        .mainClass(Main.class)
+                        .implementationVersion("5.16.1")
+                        .commandName("orange")
+                        .commandVersion("2.4.6")
+                )
+                .add(ColorCommands.class)
+                .add(ColorLoader.class)
+                .add(SystemPropertiesInLoader.class)
+                .build()
+                .run();
+
+        assertEquals(String.format("Commands: %n" +
+                "                       %n" +
+                "   color               %n" +
+                "   help                %n" +
+                "%n" +
+                "orange 2.4.6%n" +
+                ""), result.getOut());
     }
 
     @Test
+    @Ignore
     public void systemPropertyCmd() throws Exception {
+        Java.Result result = Cli.builder()
+                .loader(SystemPropertiesInLoader.class)
+                .manifest(Manifest.builder()
+                        .mainClass(Main.class)
+                )
+                .add(ColorCommands.class)
+                .add(ColorLoader.class)
+                .add(SystemPropertiesInLoader.class)
+                .debug()
+                .build()
+                .run();
+
+        assertEquals(String.format("Commands: %n" +
+                "                       %n" +
+                "   color               %n" +
+                "   help                %n" +
+                "%n" +
+                "green 5.3.1%n" +
+                ""), result.getOut());
     }
 
     @Test
diff --git a/tomitribe-crest/src/test/java/org/tomitribe/crest/Java.java b/tomitribe-crest/src/test/java/org/tomitribe/crest/Java.java
index 51e9adc..a5d5b5d 100644
--- a/tomitribe-crest/src/test/java/org/tomitribe/crest/Java.java
+++ b/tomitribe-crest/src/test/java/org/tomitribe/crest/Java.java
@@ -17,23 +17,48 @@
 package org.tomitribe.crest;
 
 import org.junit.Assert;
+import org.tomitribe.util.Join;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.FutureTask;
+import java.util.stream.Stream;
 
 /**
  * @version $Revision$ $Date$
  */
 public class Java {
 
+    private final List<String> command = new ArrayList<>();
+    private final Map<String, String> environment = new HashMap<>();
+
+    private Java(final List<String> command, final Map<String, String> environment) {
+        this.command.addAll(command);
+        this.environment.putAll(environment);
+    }
+
+    public Result run(final String... args) {
+        final ProcessBuilder java = javaProcess();
+        try {
+            java.environment().putAll(environment);
+            java.command().addAll(command);
+            java.command().addAll(Arrays.asList(args));
+            return new Result(java.start());
+        } catch (final Exception e) {
+            throw new JavaExecutionException(java.command(), e);
+        }
+    }
+
     public static Result jar(final File jar, final String... args) throws IOException, ExecutionException, InterruptedException {
         final ProcessBuilder java = javaProcess();
         java.command().add("-jar");
@@ -48,6 +73,135 @@ public static Result java(final String... args) throws IOException, ExecutionExc
         return new Result(java.start());
     }
 
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+        private final List<String> command = new ArrayList<>();
+        private final Map<String, String> environment = new HashMap<>();
+
+        public Builder env(final String name, final String value) {
+            environment.put(name, value);
+            return this;
+        }
+
+        public Builder jar(final File jar) {
+            command.add("-jar");
+            command.add(jar.getAbsolutePath());
+            return this;
+        }
+
+        public Builder arg(final String arg) {
+            command.add(arg);
+            return this;
+        }
+
+        public Builder classpath(final File... jars) {
+            if (jars == null || jars.length == 0) {
+                throw new IllegalArgumentException("No jars specified");
+            }
+
+            final String classpath = Stream.of(jars)
+                    .map(File::getAbsolutePath)
+                    .reduce((s, s2) -> s + File.pathSeparator + s2)
+                    .get();
+
+            command.add("-classpath");
+            command.add(classpath);
+            return this;
+        }
+
+
+        public Builder debug() {
+            environment.put("JAVA_OPTS", "-Xdebug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005");
+            return this;
+        }
+
+        public Builder enableAssertions() {
+            command.add("-ea");
+            return this;
+        }
+
+        public Builder disableAssertions() {
+            command.add("-da");
+            return this;
+        }
+
+        public Builder ms(final String initial) {
+            command.add("-Xms" + initial);
+            return this;
+        }
+
+        public Builder mx(final String max) {
+            command.add("-Xmx" + max);
+            return this;
+        }
+
+        public Builder client() {
+            command.add("-client");
+            return this;
+        }
+
+        public Builder server() {
+            command.add("-server");
+            return this;
+        }
+
+        // Example of adding a generic method for `-XX` options
+        public Builder xx(final String option, final String value) {
+            command.add("-XX:" + option + "=" + value);
+            return this;
+        }
+
+        public Builder agentlib(final String libName) {
+            command.add("-agentlib:" + libName);
+            return this;
+        }
+
+        public Builder agentlib(final String libName, final String options) {
+            command.add("-agentlib:" + libName + "=" + options);
+            return this;
+        }
+
+
+        public Builder agentpath(final String pathName) {
+            command.add("-agentpath:" + pathName);
+            return this;
+        }
+
+        public Builder agentpath(final String pathName, final String options) {
+            command.add("-agentpath:" + pathName + "=" + options);
+            return this;
+        }
+
+
+        public Builder javaagent(final String libName) {
+            command.add("-javaagent:" + libName);
+            return this;
+        }
+
+        public Builder javaagent(final String jarPath, final String options) {
+            command.add("-javaagent:" + jarPath + "=" + options);
+            return this;
+        }
+
+        public Builder d(final String name, final String value) {
+            command.add("-D:" + name + "=" + value);
+            return this;
+        }
+
+        public Builder copy() {
+            final Builder copy = new Builder();
+            copy.command.addAll(this.command);
+            copy.environment.putAll(this.environment);
+            return copy;
+        }
+
+        public Java build() {
+            return new Java(command, environment);
+        }
+    }
 
     private static ProcessBuilder javaProcess() {
         final File javaHome = new File(System.getenv("JAVA_HOME"));
@@ -146,4 +300,9 @@ public synchronized void run() {
         }
     }
 
+    public static class JavaExecutionException extends RuntimeException {
+        public JavaExecutionException(final List<String> command, final Exception e) {
+            super(String.format("Java command failed:%nargs:%s%nresult:%s", Join.join(" ", command), e));
+        }
+    }
 }