diff --git a/function-annotations/src/main/java/com/dylibso/chicory/function/annotations/Buffer.java b/function-annotations/src/main/java/com/dylibso/chicory/function/annotations/Buffer.java
new file mode 100644
index 000000000..c7df67ebe
--- /dev/null
+++ b/function-annotations/src/main/java/com/dylibso/chicory/function/annotations/Buffer.java
@@ -0,0 +1,10 @@
+package com.dylibso.chicory.function.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.PARAMETER)
+public @interface Buffer {}
diff --git a/function-annotations/src/main/java/com/dylibso/chicory/function/annotations/CString.java b/function-annotations/src/main/java/com/dylibso/chicory/function/annotations/CString.java
new file mode 100644
index 000000000..f55218d17
--- /dev/null
+++ b/function-annotations/src/main/java/com/dylibso/chicory/function/annotations/CString.java
@@ -0,0 +1,10 @@
+package com.dylibso.chicory.function.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.PARAMETER)
+public @interface CString {}
diff --git a/function-processor/src/main/java/com/dylibso/chicory/function/processor/FunctionProcessor.java b/function-processor/src/main/java/com/dylibso/chicory/function/processor/FunctionProcessor.java
index a6e538558..364ecdf7e 100644
--- a/function-processor/src/main/java/com/dylibso/chicory/function/processor/FunctionProcessor.java
+++ b/function-processor/src/main/java/com/dylibso/chicory/function/processor/FunctionProcessor.java
@@ -6,6 +6,8 @@
 import static javax.tools.Diagnostic.Kind.ERROR;
 import static javax.tools.Diagnostic.Kind.NOTE;
 
+import com.dylibso.chicory.function.annotations.Buffer;
+import com.dylibso.chicory.function.annotations.CString;
 import com.dylibso.chicory.function.annotations.HostModule;
 import com.dylibso.chicory.function.annotations.WasmExport;
 import com.github.javaparser.ast.ArrayCreationLevel;
@@ -137,10 +139,7 @@ private Expression processMethod(
         NodeList<Expression> paramTypes = new NodeList<>();
         NodeList<Expression> arguments = new NodeList<>();
         for (VariableElement parameter : executable.getParameters()) {
-            var argExpr =
-                    new ArrayAccessExpr(
-                            new NameExpr("args"),
-                            new IntegerLiteralExpr(String.valueOf(paramTypes.size())));
+            var argExpr = argExpr(paramTypes.size());
             switch (parameter.asType().toString()) {
                 case "int":
                     paramTypes.add(valueType("I32"));
@@ -158,6 +157,31 @@ private Expression processMethod(
                     paramTypes.add(valueType("F64"));
                     arguments.add(new MethodCallExpr(argExpr, "asDouble"));
                     break;
+                case "java.lang.String":
+                    if (annotatedWith(parameter, Buffer.class)) {
+                        var lenExpr = argExpr(paramTypes.size() + 1);
+                        paramTypes.add(valueType("I32"));
+                        paramTypes.add(valueType("I32"));
+                        arguments.add(
+                                new MethodCallExpr(
+                                        new MethodCallExpr(new NameExpr("instance"), "memory"),
+                                        "readString",
+                                        new NodeList<>(
+                                                new MethodCallExpr(argExpr, "asInt"),
+                                                new MethodCallExpr(lenExpr, "asInt"))));
+                    } else if (annotatedWith(parameter, CString.class)) {
+                        paramTypes.add(valueType("I32"));
+                        paramTypes.add(valueType("I32"));
+                        arguments.add(
+                                new MethodCallExpr(
+                                        new MethodCallExpr(new NameExpr("instance"), "memory"),
+                                        "readCString",
+                                        new NodeList<>(new MethodCallExpr(argExpr, "asInt"))));
+                    } else {
+                        log(ERROR, "Missing annotation for WASM type: java.lang.String", parameter);
+                        throw new AbortProcessingException();
+                    }
+                    break;
                 case "com.dylibso.chicory.runtime.Instance":
                     arguments.add(new NameExpr("instance"));
                     break;
@@ -266,6 +290,10 @@ private static boolean annotatedWith(Element element, Class<? extends Annotation
                 .anyMatch(annotationName::equals);
     }
 
+    private static Expression argExpr(int n) {
+        return new ArrayAccessExpr(new NameExpr("args"), new IntegerLiteralExpr(String.valueOf(n)));
+    }
+
     private static Expression valueType(String type) {
         return new FieldAccessExpr(new NameExpr("ValueType"), type);
     }
diff --git a/function-processor/src/test/java/com/dylibso/chicory/function/processor/FunctionProcessorTest.java b/function-processor/src/test/java/com/dylibso/chicory/function/processor/FunctionProcessorTest.java
index 3cd7614b4..d9fc53155 100644
--- a/function-processor/src/test/java/com/dylibso/chicory/function/processor/FunctionProcessorTest.java
+++ b/function-processor/src/test/java/com/dylibso/chicory/function/processor/FunctionProcessorTest.java
@@ -29,16 +29,30 @@ void generateModules() {
     }
 
     @Test
-    void invalidParameterType() {
+    void invalidParameterTypeUnsupported() {
         Compilation compilation =
                 javac().withProcessors(new FunctionProcessor())
-                        .compile(JavaFileObjects.forResource("InvalidParameter.java"));
+                        .compile(JavaFileObjects.forResource("InvalidParameterUnsupported.java"));
 
         assertThat(compilation).failed();
 
         assertThat(compilation)
-                .hadErrorContaining("Unsupported WASM type: java.lang.String")
-                .inFile(JavaFileObjects.forResource("InvalidParameter.java"))
+                .hadErrorContaining("Unsupported WASM type: java.math.BigDecimal")
+                .inFile(JavaFileObjects.forResource("InvalidParameterUnsupported.java"))
+                .onLineContaining("public long square(BigDecimal x) {");
+    }
+
+    @Test
+    void invalidParameterTypeString() {
+        Compilation compilation =
+                javac().withProcessors(new FunctionProcessor())
+                        .compile(JavaFileObjects.forResource("InvalidParameterString.java"));
+
+        assertThat(compilation).failed();
+
+        assertThat(compilation)
+                .hadErrorContaining("Missing annotation for WASM type: java.lang.String")
+                .inFile(JavaFileObjects.forResource("InvalidParameterString.java"))
                 .onLineContaining("public long concat(int a, String s) {");
     }
 
diff --git a/function-processor/src/test/resources/InvalidParameter.java b/function-processor/src/test/resources/InvalidParameterString.java
similarity index 86%
rename from function-processor/src/test/resources/InvalidParameter.java
rename to function-processor/src/test/resources/InvalidParameterString.java
index 0b2ad0508..e48b9ecaf 100644
--- a/function-processor/src/test/resources/InvalidParameter.java
+++ b/function-processor/src/test/resources/InvalidParameterString.java
@@ -4,7 +4,7 @@
 import com.dylibso.chicory.function.annotations.WasmExport;
 
 @HostModule("bad_param")
-public final class InvalidParameter {
+public final class InvalidParameterString {
 
     @WasmExport
     public long concat(int a, String s) {
diff --git a/function-processor/src/test/resources/InvalidParameterUnsupported.java b/function-processor/src/test/resources/InvalidParameterUnsupported.java
new file mode 100644
index 000000000..2641cc8f4
--- /dev/null
+++ b/function-processor/src/test/resources/InvalidParameterUnsupported.java
@@ -0,0 +1,14 @@
+package chicory.testing;
+
+import com.dylibso.chicory.function.annotations.HostModule;
+import com.dylibso.chicory.function.annotations.WasmExport;
+import java.math.BigDecimal;
+
+@HostModule("bad_param")
+public final class InvalidParameterUnsupported {
+
+    @WasmExport
+    public long square(BigDecimal x) {
+        return x.pow(2);
+    }
+}
diff --git a/function-processor/src/test/resources/Simple.java b/function-processor/src/test/resources/Simple.java
index 40ca63854..e7c677611 100644
--- a/function-processor/src/test/resources/Simple.java
+++ b/function-processor/src/test/resources/Simple.java
@@ -1,17 +1,32 @@
 package chicory.testing;
 
+import com.dylibso.chicory.function.annotations.Buffer;
+import com.dylibso.chicory.function.annotations.CString;
 import com.dylibso.chicory.function.annotations.HostModule;
 import com.dylibso.chicory.function.annotations.WasmExport;
 import com.dylibso.chicory.runtime.HostFunction;
 import com.dylibso.chicory.runtime.Memory;
 import com.dylibso.chicory.wasm.exceptions.ChicoryException;
+import java.security.SecureRandom;
 
 @HostModule("simple")
 public final class Simple {
 
     @WasmExport
-    public void print(Memory memory, int ptr, int len) {
-        System.out.println(memory.readString(ptr, len));
+    public void print(@Buffer String data) {
+        System.out.println(data);
+    }
+
+    @WasmExport
+    public void printx(@CString String data) {
+        System.out.println(data);
+    }
+
+    @WasmExport
+    public void randomGet(Memory memory, int ptr, int len) {
+        byte[] data = new byte[len];
+        new SecureRandom().nextBytes(data);
+        memory.write(ptr, data);
     }
 
     @WasmExport
diff --git a/function-processor/src/test/resources/SimpleGenerated.java b/function-processor/src/test/resources/SimpleGenerated.java
index 47aa27a0f..c80bd824f 100644
--- a/function-processor/src/test/resources/SimpleGenerated.java
+++ b/function-processor/src/test/resources/SimpleGenerated.java
@@ -16,7 +16,8 @@ public static HostFunction[] toHostFunctions(Simple functions) {
         return new HostFunction[] {
             new HostFunction(
                     (Instance instance, Value... args) -> {
-                        functions.print(instance.memory(), args[0].asInt(), args[1].asInt());
+                        functions.print(
+                                instance.memory().readString(args[0].asInt(), args[1].asInt()));
                         return null;
                     },
                     "simple",
@@ -24,6 +25,26 @@ public static HostFunction[] toHostFunctions(Simple functions) {
                     List.of(ValueType.I32, ValueType.I32),
                     List.of()
             ),
+            new HostFunction(
+                    (Instance instance, Value... args) -> {
+                        functions.printx(instance.memory().readCString(args[0].asInt()));
+                        return null;
+                    },
+                    "simple",
+                    "printx",
+                    List.of(ValueType.I32, ValueType.I32),
+                    List.of()
+            ),
+            new HostFunction(
+                    (Instance instance, Value... args) -> {
+                        functions.randomGet(instance.memory(), args[0].asInt(), args[1].asInt());
+                        return null;
+                    },
+                    "simple",
+                    "random_get",
+                    List.of(ValueType.I32, ValueType.I32),
+                    List.of()
+            ),
             new HostFunction(
                     (Instance instance, Value... args) -> {
                         functions.exit();
diff --git a/wasi/src/main/java/com/dylibso/chicory/wasi/WasiPreview1.java b/wasi/src/main/java/com/dylibso/chicory/wasi/WasiPreview1.java
index ddccdad7c..c647e09e3 100644
--- a/wasi/src/main/java/com/dylibso/chicory/wasi/WasiPreview1.java
+++ b/wasi/src/main/java/com/dylibso/chicory/wasi/WasiPreview1.java
@@ -12,6 +12,7 @@
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.stream.Collectors.toList;
 
+import com.dylibso.chicory.function.annotations.Buffer;
 import com.dylibso.chicory.function.annotations.HostModule;
 import com.dylibso.chicory.function.annotations.WasmExport;
 import com.dylibso.chicory.log.Logger;
@@ -691,8 +692,8 @@ public int fdWrite(Memory memory, int fd, int iovs, int iovsLen, int nwrittenPtr
     }
 
     @WasmExport
-    public int pathCreateDirectory(Memory memory, int dirFd, int pathPtr, int pathLen) {
-        logger.infof("path_create_directory: [%s, %s, %s]", dirFd, pathPtr, pathLen);
+    public int pathCreateDirectory(int dirFd, @Buffer String rawPath) {
+        logger.infof("path_create_directory: [%s, \"%s\"]", dirFd, rawPath);
         var descriptor = descriptors.get(dirFd);
         if (descriptor == null) {
             return wasiResult(WasiErrno.EBADF);
@@ -703,7 +704,6 @@ public int pathCreateDirectory(Memory memory, int dirFd, int pathPtr, int pathLe
         }
         Path directory = ((Directory) descriptor).path();
 
-        String rawPath = memory.readString(pathPtr, pathLen);
         Path path = resolvePath(directory, rawPath);
         if (path == null) {
             return wasiResult(WasiErrno.EACCES);
@@ -723,10 +723,8 @@ public int pathCreateDirectory(Memory memory, int dirFd, int pathPtr, int pathLe
 
     @WasmExport
     public int pathFilestatGet(
-            Memory memory, int dirFd, int lookupFlags, int pathPtr, int pathLen, int buf) {
-        logger.infof(
-                "path_filestat_get: [%s, %s, %s, %s, %s]",
-                dirFd, lookupFlags, pathPtr, pathLen, buf);
+            Memory memory, int dirFd, int lookupFlags, @Buffer String rawPath, int buf) {
+        logger.infof("path_filestat_get: [%s, %s, \"%s\", %s]", dirFd, lookupFlags, rawPath, buf);
         var descriptor = descriptors.get(dirFd);
         if (descriptor == null) {
             return wasiResult(WasiErrno.EBADF);
@@ -737,7 +735,6 @@ public int pathFilestatGet(
         }
         Path directory = ((Directory) descriptor).path();
 
-        String rawPath = memory.readString(pathPtr, pathLen);
         Path path = resolvePath(directory, rawPath);
         if (path == null) {
             return wasiResult(WasiErrno.EACCES);
@@ -765,14 +762,13 @@ public int pathFilestatGet(
     public int pathFilestatSetTimes(
             int fd,
             int lookupFlags,
-            int pathPtr,
-            int pathLen,
+            @Buffer String rawPath,
             long accessTime,
             long modifiedTime,
             int fstFlags) {
         logger.infof(
-                "path_filestat_set_times: [%s, %s, %s, %s, %s, %s, %s]",
-                fd, lookupFlags, pathPtr, pathLen, accessTime, modifiedTime, fstFlags);
+                "path_filestat_set_times: [%s, %s, \"%s\", %s, %s, %s]",
+                fd, lookupFlags, rawPath, accessTime, modifiedTime, fstFlags);
         throw new WASMRuntimeException(
                 "We don't yet support this WASI call: path_filestat_set_size");
     }
@@ -781,14 +777,12 @@ public int pathFilestatSetTimes(
     public int pathLink(
             int oldFd,
             int oldFlags,
-            int oldPathPtr,
-            int oldPathLen,
+            @Buffer String rawOldPath,
             int newFd,
-            int newPathPtr,
-            int newPathLen) {
+            @Buffer String rawNewPath) {
         logger.infof(
-                "path_link: [%s, %s, %s, %s, %s, %s, %s]",
-                oldFd, oldFlags, oldPathPtr, oldPathLen, newFd, newPathPtr, newPathLen);
+                "path_link: [%s, %s, \"%s\", %s, \"%s\"]",
+                oldFd, oldFlags, rawOldPath, newFd, rawNewPath);
         throw new WASMRuntimeException("We don't yet support this WASI call: path_link");
     }
 
@@ -797,19 +791,17 @@ public int pathOpen(
             Memory memory,
             int dirFd,
             int lookupFlags,
-            int pathPtr,
-            int pathLen,
+            @Buffer String rawPath,
             int openFlags,
             long rightsBase,
             long rightsInheriting,
             int fdFlags,
             int fdPtr) {
         logger.infof(
-                "path_open: [%s, %s, %s, %s, %s, %s, %s, %s, %s]",
+                "path_open: [%s, %s, \"%s\", %s, %s, %s, %s, %s]",
                 dirFd,
                 lookupFlags,
-                pathPtr,
-                pathLen,
+                rawPath,
                 openFlags,
                 rightsBase,
                 rightsInheriting,
@@ -825,7 +817,6 @@ public int pathOpen(
         }
         Path directory = ((Directory) descriptor).path();
 
-        String rawPath = memory.readString(pathPtr, pathLen);
         Path path = resolvePath(directory, rawPath);
         if (path == null) {
             return wasiResult(WasiErrno.EACCES);
@@ -894,16 +885,15 @@ public int pathOpen(
     }
 
     @WasmExport
-    public int pathReadlink(int dirFd, int pathPtr, int pathLen, int buf, int bufLen, int bufUsed) {
+    public int pathReadlink(int dirFd, @Buffer String rawPath, int buf, int bufLen, int bufUsed) {
         logger.infof(
-                "path_readlink: [%s, %s, %s, %s, %s, %s]",
-                dirFd, pathPtr, pathLen, buf, bufLen, bufUsed);
+                "path_readlink: [%s, \"%s\", %s, %s, %s]", dirFd, rawPath, buf, bufLen, bufUsed);
         throw new WASMRuntimeException("We don't yet support this WASI call: path_readlink");
     }
 
     @WasmExport
-    public int pathRemoveDirectory(Memory memory, int dirFd, int pathPtr, int pathLen) {
-        logger.infof("path_remove_directory: [%s, %s, %s]", dirFd, pathPtr, pathLen);
+    public int pathRemoveDirectory(int dirFd, @Buffer String rawPath) {
+        logger.infof("path_remove_directory: [%s, \"%s\"]", dirFd, rawPath);
         var descriptor = descriptors.get(dirFd);
         if (descriptor == null) {
             return wasiResult(WasiErrno.EBADF);
@@ -914,7 +904,6 @@ public int pathRemoveDirectory(Memory memory, int dirFd, int pathPtr, int pathLe
         }
         Path directory = ((Directory) descriptor).path();
 
-        String rawPath = memory.readString(pathPtr, pathLen);
         Path path = resolvePath(directory, rawPath);
         if (path == null) {
             return wasiResult(WasiErrno.EACCES);
@@ -940,16 +929,8 @@ public int pathRemoveDirectory(Memory memory, int dirFd, int pathPtr, int pathLe
 
     @WasmExport
     public int pathRename(
-            Memory memory,
-            int oldFd,
-            int oldPathPtr,
-            int oldPathLen,
-            int newFd,
-            int newPathPtr,
-            int newPathLen) {
-        logger.infof(
-                "path_rename: [%s, %s, %s, %s, %s, %s]",
-                oldFd, oldPathPtr, oldPathLen, newFd, newPathPtr, newPathLen);
+            int oldFd, @Buffer String oldRawPath, int newFd, @Buffer String newRawPath) {
+        logger.infof("path_rename: [%s, \"%s\", %s, \"%s\"]", oldFd, oldRawPath, newFd, newRawPath);
         var oldDescriptor = descriptors.get(oldFd);
         if (oldDescriptor == null) {
             return wasiResult(WasiErrno.EBADF);
@@ -968,13 +949,11 @@ public int pathRename(
         }
         Path newDirectory = ((Directory) newDescriptor).path();
 
-        String oldRawPath = memory.readString(oldPathPtr, oldPathLen);
         Path oldPath = resolvePath(oldDirectory, oldRawPath);
         if (oldPath == null) {
             return wasiResult(WasiErrno.EACCES);
         }
 
-        String newRawPath = memory.readString(newPathPtr, newPathLen);
         Path newPath = resolvePath(newDirectory, newRawPath);
         if (newPath == null) {
             return wasiResult(WasiErrno.EACCES);
@@ -1007,17 +986,14 @@ public int pathRename(
     }
 
     @WasmExport
-    public int pathSymlink(
-            int oldPathPtr, int oldPathLen, int dirFd, int newPathPtr, int newPathLen) {
-        logger.infof(
-                "path_symlink: [%s, %s, %s, %s, %s]",
-                oldPathPtr, oldPathLen, dirFd, newPathPtr, newPathLen);
+    public int pathSymlink(@Buffer String oldRawPath, int dirFd, @Buffer String newRawPath) {
+        logger.infof("path_symlink: [\"%s\", %s, \"%s\"]", oldRawPath, dirFd, newRawPath);
         throw new WASMRuntimeException("We don't yet support this WASI call: path_symlink");
     }
 
     @WasmExport
-    public int pathUnlinkFile(Memory memory, int dirFd, int pathPtr, int pathLen) {
-        logger.infof("path_unlink_file: [%s, %s, %s]", dirFd, pathPtr, pathLen);
+    public int pathUnlinkFile(int dirFd, @Buffer String rawPath) {
+        logger.infof("path_unlink_file: [%s, \"%s\"]", dirFd, rawPath);
         var descriptor = descriptors.get(dirFd);
         if (descriptor == null) {
             return wasiResult(WasiErrno.EBADF);
@@ -1028,7 +1004,6 @@ public int pathUnlinkFile(Memory memory, int dirFd, int pathPtr, int pathLen) {
         }
         Path directory = ((Directory) descriptor).path();
 
-        String rawPath = memory.readString(pathPtr, pathLen);
         Path path = resolvePath(directory, rawPath);
         if (path == null) {
             return wasiResult(WasiErrno.EACCES);