diff --git a/README.md b/README.md
index d5c557f..75c934d 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,18 @@
-Experiment with java22 and Rust to monitor exceptions in a JVM
\ No newline at end of file
+Experiment with java22 and Rust to monitor exceptions in a JVM
+
+Running:
+* Update the path to the rust lib (temp fix) in ExceptionLogger for your setup
+* mvn clean install
+* cd rustlib; cargo build
+* create a minimal class in a separate project
+```java
+public class Main {
+    public static void main(String[] args) throws Throwable {
+        throw new Throwable();
+    }
+}
+```
+* run it with (adjust paths): 
+``` bash
+java22 -javaagent:$EXCEPTIONAL_PROJECT/exceptional/agent/target/exceptional-agent-1.0-SNAPSHOT.jar --enable-preview -classpath $YOUR_CLASSPATH Main
+```
diff --git a/agent/pom.xml b/agent/pom.xml
index deb8ba9..2ea49d2 100644
--- a/agent/pom.xml
+++ b/agent/pom.xml
@@ -18,6 +18,15 @@
         <maven.compiler.target>22</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.github.shautvast.exceptional</groupId>
+            <artifactId>exceptional-lib</artifactId>
+            <version>1.0-SNAPSHOT</version>
+        </dependency>
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>
@@ -38,7 +47,9 @@
                             <Premain-Class>com.github.shautvast.exceptional.Agent</Premain-Class>
                             <Can-Retransform-Classes>true</Can-Retransform-Classes>
                             <Can-Redefine-Classes>true</Can-Redefine-Classes>
-                            <Boot-Class-Path>/Users/Shautvast/dev/exceptional/lib/target/exceptional-lib-1.0-SNAPSHOT.jar</Boot-Class-Path>
+                            <Boot-Class-Path>
+                                /Users/Shautvast/dev/exceptional/lib/target/exceptional-lib-1.0-SNAPSHOT.jar
+                            </Boot-Class-Path>
                         </manifestEntries>
                     </archive>
                 </configuration>
diff --git a/agent/src/main/java/com/github/shautvast/exceptional/Agent.java b/agent/src/main/java/com/github/shautvast/exceptional/Agent.java
index 86885fe..e06a45f 100644
--- a/agent/src/main/java/com/github/shautvast/exceptional/Agent.java
+++ b/agent/src/main/java/com/github/shautvast/exceptional/Agent.java
@@ -1,80 +1,80 @@
 package com.github.shautvast.exceptional;
 
-import java.lang.classfile.*;
-import java.lang.classfile.instruction.ReturnInstruction;
+import java.lang.classfile.ClassBuilder;
+import java.lang.classfile.ClassElement;
+import java.lang.classfile.ClassFile;
+import java.lang.classfile.MethodModel;
+import java.lang.classfile.instruction.ThrowInstruction;
 import java.lang.constant.ClassDesc;
 import java.lang.constant.MethodTypeDesc;
-import java.lang.instrument.ClassDefinition;
 import java.lang.instrument.ClassFileTransformer;
 import java.lang.instrument.Instrumentation;
-import java.nio.file.Files;
-import java.nio.file.Path;
+import java.lang.reflect.AccessFlag;
 import java.security.ProtectionDomain;
 
 public class Agent {
 
-    @SuppressWarnings("DataFlowIssue")
+    private static final String EXCEPTIONLOGGER = ExceptionLogger.class.getName();
+
     public static void premain(String agentArgs, Instrumentation instrumentation) throws Exception {
         System.err.println("--->Exceptional agent active");
         // add transformer
         instrumentation.addTransformer(new ClassFileTransformer() {
             @Override
             public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) {
-                return instrumentThrowable(className, classfileBuffer);
+                return instrumentExceptionLoggerAtThrow(className, classfileBuffer);
             }
 
             @Override
             public byte[] transform(Module module, ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) {
-                return instrumentThrowable(className, classfileBuffer);
+                return instrumentExceptionLoggerAtThrow(className, classfileBuffer);
             }
         }, true);
-
-        // we only want to redefine Throwable
-        byte[] bytecode = Files.readAllBytes(
-                Path.of(Agent.class.getResource("/java/lang/Throwable.class").toURI()));
-        instrumentation.redefineClasses(new ClassDefinition(Throwable.class, bytecode));
     }
 
-    private static byte[] instrumentThrowable(String className, byte[] bytecode) {
-        // we only want to instrument Throwable
-        // or rather,,, is this the right way? This way we also intercept new any Exception that is not thrown
-        // But,,, who does that?? (famous last words)
-        if (className.equals("java/lang/Throwable")) {
-            ClassFile classFile = ClassFile.of();
-            ClassModel classModel = classFile.parse(bytecode);
-            return instrumentConstructors(classFile, classModel);
-        } else {
-            return bytecode;
-        }
-    }
-
-    private static byte[] instrumentConstructors(ClassFile classFile, ClassModel classModel) {
+    /*
+     * Every throw opcode will be preceded by a call to our ExceptionLogger
+     */
+    private static byte[] instrumentExceptionLoggerAtThrow(String className, byte[] classfileBuffer) {
+        var classFile = ClassFile.of();
+        var classModel = classFile.parse(classfileBuffer);
         return classFile.build(classModel.thisClass().asSymbol(), classBuilder -> {
             for (ClassElement ce : classModel) {
-                if (ce instanceof MethodModel mm && mm.methodName().toString().equals("<init>")) {
-                    instrumentMethodWithMyExceptionLogger(classBuilder, mm);
-                    continue;
+                // not all methods, TODO include synthetic?
+                if (ce instanceof MethodModel methodModel && !methodModel.flags().has(AccessFlag.ABSTRACT)
+                        && !methodModel.flags().has(AccessFlag.NATIVE)
+                        && !methodModel.flags().has(AccessFlag.BRIDGE)) {
+                    transform(classBuilder, methodModel);
+                } else {
+                    // keep all other class elements
+                    classBuilder.with(ce);
                 }
-                classBuilder.with(ce);
             }
         });
     }
 
-    private static void instrumentMethodWithMyExceptionLogger(ClassBuilder classBuilder, MethodModel methodModel) {
-        methodModel.code().ifPresent(code ->
-                classBuilder.withMethod(methodModel.methodName(), methodModel.methodType(), methodModel.flags().flagsMask(),
-                        methodBuilder ->
-                                methodBuilder.transformCode(code, ((builder, element) -> {
-                                            if (element instanceof ReturnInstruction) {
-                                                builder.aload(0); // load `this` on the stack, ie the Throwable instance
-                                                builder.invokestatic( //  call my code
-                                                        ClassDesc.of("com.github.shautvast.exceptional.ExceptionLogger"), "log",
-                                                        MethodTypeDesc.ofDescriptor("(Ljava/lang/Throwable;)V"));
-                                                builder.return_();
-                                            } else {
-                                                builder.with(element); // leave any other bytecode in place
-                                            }
-                                        })
-                                )));
+    private static void transform(ClassBuilder classBuilder, MethodModel methodModel) {
+        methodModel.code().ifPresent(code -> classBuilder.withMethod(
+                methodModel.methodName(), // copy name, type and modifiers from the original
+                methodModel.methodType(),
+                methodModel.flags().flagsMask(),
+                methodBuilder -> {
+                    // keep the existing annotations (and other method elements) in place
+                    methodModel.forEachElement(methodBuilder::with);
+                    // change the code
+                    methodBuilder.transformCode(code, (builder, element) -> {
+                        // this way of instrumenting may miss the already loaded classes, java.lang.String for example.
+                        // May need to circumvent that
+                        if (element instanceof ThrowInstruction) {
+                            builder.dup(); // on top of the stack is the current exception instance
+                            // duplicate it to make sure the `athrow` op has something to throw
+                            // after the invoke to ExceptionLogger has popped one off
+                            builder.invokestatic( // call my code with the exception as argument
+                                    ClassDesc.of(EXCEPTIONLOGGER), "log",
+                                    MethodTypeDesc.ofDescriptor("(Ljava/lang/Throwable;)V"));
+                        }
+                        builder.with(element); // leave any other element in place
+                    });
+                }));
     }
 }
\ No newline at end of file
diff --git a/lib/dependency-reduced-pom.xml b/lib/dependency-reduced-pom.xml
new file mode 100644
index 0000000..d4cf151
--- /dev/null
+++ b/lib/dependency-reduced-pom.xml
@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <parent>
+    <artifactId>exceptional-parent</artifactId>
+    <groupId>org.github.shautvast.exceptional</groupId>
+    <version>1.0-SNAPSHOT</version>
+  </parent>
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>exceptional-lib</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <build>
+    <plugins>
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <source>22</source>
+          <target>22</target>
+          <compilerArgs>--enable-preview</compilerArgs>
+        </configuration>
+      </plugin>
+      <plugin>
+        <artifactId>maven-shade-plugin</artifactId>
+        <version>3.2.4</version>
+        <executions>
+          <execution>
+            <phase>package</phase>
+            <goals>
+              <goal>shade</goal>
+            </goals>
+            <configuration />
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+  <dependencies>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>RELEASE</version>
+      <scope>test</scope>
+      <exclusions>
+        <exclusion>
+          <artifactId>junit-jupiter-api</artifactId>
+          <groupId>org.junit.jupiter</groupId>
+        </exclusion>
+        <exclusion>
+          <artifactId>junit-jupiter-params</artifactId>
+          <groupId>org.junit.jupiter</groupId>
+        </exclusion>
+        <exclusion>
+          <artifactId>junit-jupiter-engine</artifactId>
+          <groupId>org.junit.jupiter</groupId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+  </dependencies>
+  <properties>
+    <maven.compiler.target>22</maven.compiler.target>
+    <maven.compiler.source>22</maven.compiler.source>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+</project>
diff --git a/lib/pom.xml b/lib/pom.xml
index 31b0304..99ea5bb 100644
--- a/lib/pom.xml
+++ b/lib/pom.xml
@@ -18,6 +18,19 @@
         <maven.compiler.target>22</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
+    <dependencies>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.16.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>RELEASE</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 
     <build>
         <plugins>
@@ -30,8 +43,23 @@
                     <compilerArgs>--enable-preview</compilerArgs>
                 </configuration>
             </plugin>
-
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>3.2.4</version>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 
+
 </project>
\ No newline at end of file
diff --git a/lib/src/main/java/com/github/shautvast/exceptional/ExceptionLogger.java b/lib/src/main/java/com/github/shautvast/exceptional/ExceptionLogger.java
index b8df9ae..303a283 100644
--- a/lib/src/main/java/com/github/shautvast/exceptional/ExceptionLogger.java
+++ b/lib/src/main/java/com/github/shautvast/exceptional/ExceptionLogger.java
@@ -1,11 +1,38 @@
 package com.github.shautvast.exceptional;
 
-import java.util.Arrays;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.lang.foreign.*;
+import java.lang.invoke.MethodHandle;
 
 @SuppressWarnings("unused") // this code is called from the instrumented code
 public class ExceptionLogger {
+    private static final Arena arena = Arena.ofConfined();
+    private static final Linker linker = Linker.nativeLinker();
+    //    //TODO relative path, or configurable
+    private static final SymbolLookup rustlib = SymbolLookup.libraryLookup("/Users/Shautvast/dev/exceptional/rustlib/target/debug/librustlib.dylib", arena);
+    private final static MethodHandle logNative;
+    private final static ObjectMapper objectMapper = new ObjectMapper();
+
+    static {
+        MemorySegment logFunction = rustlib.find("log_java_exception").orElseThrow();
+        logNative = linker.downcallHandle(logFunction, FunctionDescriptor.ofVoid(
+                ValueLayout.ADDRESS
+        ));
+    }
+
+    // how does this behave in a multithreaded context??
+    // probably need a ringbuffer with fixed memory to make this work efficiently
     public static void log(Throwable throwable) {
-        System.out.print("Logging exception:");
-        Arrays.stream(throwable.getStackTrace()).forEach(System.out::println);
+        try {
+            // use json for now because of ease of integration
+            if (throwable != null) {
+                String json = objectMapper.writeValueAsString(throwable);
+                var data = arena.allocateFrom(json); // reuse instead of reallocating?
+                logNative.invoke(data); // invoke the rust function
+            }
+        } catch (Throwable e) {
+            e.printStackTrace(System.err);
+        }
     }
 }
diff --git a/lib/src/test/java/com/github/shautvast/exceptional/ExceptionLoggerTest.java b/lib/src/test/java/com/github/shautvast/exceptional/ExceptionLoggerTest.java
new file mode 100644
index 0000000..8ed57a2
--- /dev/null
+++ b/lib/src/test/java/com/github/shautvast/exceptional/ExceptionLoggerTest.java
@@ -0,0 +1,14 @@
+package com.github.shautvast.exceptional;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ExceptionLoggerTest {
+
+    @Test
+    void test(){
+        ExceptionLogger.log(new Throwable());
+    }
+
+}
\ No newline at end of file
diff --git a/rustlib/Cargo.lock b/rustlib/Cargo.lock
new file mode 100644
index 0000000..6236b71
--- /dev/null
+++ b/rustlib/Cargo.lock
@@ -0,0 +1,96 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "anyhow"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b3d1d046238990b9cf5bcde22a3fb3584ee5cf65fb2765f454ed428c7a0063da"
+
+[[package]]
+name = "itoa"
+version = "1.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e719e8df665df0d1c8fbfd238015744736151d4445ec0836b8e628aae103b77"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fa76aaf39101c457836aec0ce2316dbdc3ab723cdda1c6bd4e6ad4208acaca7"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "rustlib"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "ryu"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f3cb5ba0dc43242ce17de99c180e96db90b235b8a9fdc9543c96d2209116bd9f"
+
+[[package]]
+name = "serde"
+version = "1.0.203"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7253ab4de971e72fb7be983802300c30b5a7f0c2e56fab8abfc6a214307c0094"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.203"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "500cbc0ebeb6f46627f50f3f5811ccf6bf00643be300b4c3eabc0ef55dc5b5ba"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.117"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "455182ea6142b14f93f4bc5320a2b31c1f266b66a4a5c858b013302a5d8cbfc3"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.67"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ff8655ed1d86f3af4ee3fd3263786bc14245ad17c4c7e85ba7187fb3ae028c90"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3354b9ac3fae1ff6755cb6db53683adb661634f67557942dea4facebec0fee4b"
diff --git a/rustlib/Cargo.toml b/rustlib/Cargo.toml
new file mode 100644
index 0000000..f7a7650
--- /dev/null
+++ b/rustlib/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "rustlib"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+bench = false
+
+[dependencies]
+serde_json = { version = "1.0", features = [] }
+serde = { version = "1.0", features = ["derive"] }
+anyhow = "1.0"
\ No newline at end of file
diff --git a/rustlib/src/Throwable.rs b/rustlib/src/Throwable.rs
new file mode 100644
index 0000000..9c1de6e
--- /dev/null
+++ b/rustlib/src/Throwable.rs
@@ -0,0 +1,32 @@
+use serde::Deserialize;
+
+#[derive(Deserialize, Debug)]
+pub struct Throwable {
+    cause: Option<Box<Throwable>>,
+    #[serde(rename (deserialize = "stackTrace"))]
+    stack_trace: Vec<Stacktrace>,
+    message: Option<String>,
+    suppressed: Vec<String>,
+    #[serde(rename (deserialize = "localizedMessage"))]
+    localized_message: Option<String>,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct Stacktrace{
+    #[serde(rename (deserialize = "classLoaderName"))]
+    class_loader_name: Option<String>,
+    #[serde(rename (deserialize = "moduleName"))]
+    module_name: Option<String>,
+    #[serde(rename (deserialize = "moduleVersion"))]
+    module_version: Option<String>,
+    #[serde(rename (deserialize = "methodName"))]
+    method_name: Option<String>,
+    #[serde(rename (deserialize = "fileName"))]
+    file_name: Option<String>,
+    #[serde(rename (deserialize = "lineNumber"))]
+    line_number: Option<u32>,
+    #[serde(rename (deserialize = "className"))]
+    class_name: Option<String>,
+    #[serde(rename (deserialize = "nativeMethod"))]
+    native_method: Option<bool>,
+}
\ No newline at end of file
diff --git a/rustlib/src/lib.rs b/rustlib/src/lib.rs
new file mode 100644
index 0000000..a7f876d
--- /dev/null
+++ b/rustlib/src/lib.rs
@@ -0,0 +1,17 @@
+mod throwable;
+
+use std::ffi::{c_char, CStr};
+
+#[no_mangle]
+pub extern "C" fn log_java_exception(raw_string: *const c_char) {
+    let c_str = unsafe { CStr::from_ptr(raw_string) };
+    let string = c_str.to_str();
+    if let Ok(json) = string {
+        println!("receiving {}", json);
+        let error: throwable::Throwable = serde_json::from_str(json).unwrap();
+        println!("{:?}", error);
+    }
+}
+
+#[cfg(test)]
+mod tests {}