diff --git a/src/lib/error.hpp b/src/lib/error.hpp
index 207b0ee..697c9b4 100644
--- a/src/lib/error.hpp
+++ b/src/lib/error.hpp
@@ -17,6 +17,11 @@
 
 #include <cstdint>
 
+
+//TODO: needed macros:
+// TRY: takes a variable, a function call, and the ErrorOr return type of the calling function - intended to automatically unwrap the ErrorOr data type or propagate the error upwards
+// RAISE: takes an error code and optionally a message to produce something like `return ErrorOr<T>(true, errorCode, file, lineNumber, message)`
+
 template <typename T>
 struct ErrorOr {
     bool isError;
@@ -100,6 +105,9 @@ namespace ErrorCodes {
     // when too much data is available
     const uint8_t OVERFLOW = 13;
 
+    const uint8_t COMPRESSION = 14;
+    const uint8_t DECOMPRESSION = 15;
+
     const uint8_t UNIMPLEMENTED = 254;
 
     const uint8_t UNKNOWN = 255;
diff --git a/src/lib/zlibutil.cpp b/src/lib/zlibutil.cpp
index d9f1a85..e872cad 100644
--- a/src/lib/zlibutil.cpp
+++ b/src/lib/zlibutil.cpp
@@ -16,92 +16,101 @@
 // version 3 along with this program.
 // If not, see https://www.gnu.org/licenses/agpl-3.0.en.html
 
-#include "../lib/zlibutil.hpp" 
+// includes vector and error.hpp
+#include "zlibutil.hpp"
 
-#include <bitset>
-#include <iomanip>
-#include <iostream>
-#include <vector>
-#include <tinyutf8/tinyutf8.h>
 #include <zlib/zlib.h>
 #include <cstring>
 
-#include "../lib/cli.hpp"
-#include "../lib/file.hpp"
-
 #define EXIT_SUCCESS 0
 #define EXIT_RUNTIME 1
 #define EXIT_USAGE   2
 
-#include <iostream>
-#include <fstream>
-#include <vector>
-#include <zlib.h>
-
 #define CHUNK_SIZE 16384 // Chunk size
 
+namespace zlib {
 
-std::vector<char> compressData(const char* data, int size) {
-    z_stream zs;
-    memset(&zs, 0, sizeof(zs));
+    ErrorOr<std::vector<uint8_t>> compressData(std::vector<uint8_t> data) {
+        // I, too, love the fact that raw bytes are signed and therefore can have negative values. -_-
+        std::vector<int8_t> signedData = std::vector<int8_t>(data.begin(), data.end());
 
-    if (deflateInit(&zs, Z_DEFAULT_COMPRESSION) != Z_OK)
-        throw(std::runtime_error("deflateInit failed while compressing."));
+        z_stream zs;
+        memset(&zs, 0, sizeof(zs));
 
-    zs.next_in = reinterpret_cast<Bytef*>(const_cast<char*>(data));
-    zs.avail_in = size;
+        if (deflateInit(&zs, Z_DEFAULT_COMPRESSION) != Z_OK) {
+            return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::COMPRESSION);
+            //TODO: include error message once implemented
+            //throw(std::runtime_error("deflateInit failed while compressing."));
+        }
 
-    int ret;
-    char outbuffer[CHUNK_SIZE];
-    std::vector<char> compressedData;
+        zs.next_in = reinterpret_cast<Bytef*>(reinterpret_cast<char*>(signedData.data()));
+        zs.avail_in = signedData.size();
 
-    do {
-        zs.next_out = reinterpret_cast<Bytef*>(outbuffer);
-        zs.avail_out = CHUNK_SIZE;
+        int ret;
+        char outbuffer[CHUNK_SIZE];
+        std::vector<char> compressedData;
 
-        ret = deflate(&zs, Z_FINISH);
+        do {
+            zs.next_out = reinterpret_cast<Bytef*>(outbuffer);
+            zs.avail_out = CHUNK_SIZE;
 
-        if (compressedData.size() < zs.total_out)
-            compressedData.insert(compressedData.end(), outbuffer, outbuffer + CHUNK_SIZE - zs.avail_out);
-    } while (ret == Z_OK);
+            ret = deflate(&zs, Z_FINISH);
 
-    deflateEnd(&zs);
+            if (compressedData.size() < zs.total_out)
+                compressedData.insert(compressedData.end(), outbuffer, outbuffer + CHUNK_SIZE - zs.avail_out);
+        } while (ret == Z_OK);
 
-    if (ret != Z_STREAM_END)
-        throw(std::runtime_error("Error while compressing: " + std::to_string(ret)));
+        deflateEnd(&zs);
+
+        if (ret != Z_STREAM_END) {
+            return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::COMPRESSION);
+            //TODO: include error message once implemented
+            //throw(std::runtime_error("Error while compressing: " + std::to_string(ret)));
+        }
+
+        return ErrorOr<std::vector<uint8_t>>(std::vector<uint8_t>(compressedData.begin(), compressedData.end()));
+    }
+
+
+    ErrorOr<std::vector<uint8_t>> decompressData(std::vector<uint8_t> data) {
+        // I, too, love the fact that raw bytes are signed and therefore can have negative values. -_-
+        std::vector<int8_t> signedData = std::vector<int8_t>(data.begin(), data.end());
+
+        z_stream zs;
+        memset(&zs, 0, sizeof(zs));
+
+        if (inflateInit(&zs) != Z_OK) {
+            return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::DECOMPRESSION);
+            //TODO: include error message once implemented
+            //throw(std::runtime_error("inflateInit failed while decompressing."));
+        }
+
+        zs.next_in = reinterpret_cast<Bytef*>(reinterpret_cast<char*>(signedData.data()));
+        zs.avail_in = signedData.size();
+
+        int ret;
+        char outbuffer[CHUNK_SIZE];
+        std::vector<char> decompressedData;
+
+        do {
+            zs.next_out = reinterpret_cast<Bytef*>(outbuffer);
+            zs.avail_out = CHUNK_SIZE;
+
+            ret = inflate(&zs, 0);
+
+            if (decompressedData.size() < zs.total_out)
+                decompressedData.insert(decompressedData.end(), outbuffer, outbuffer + CHUNK_SIZE - zs.avail_out);
+        } while (ret == Z_OK);
+
+        inflateEnd(&zs);
+
+        if (ret != Z_STREAM_END) {
+            return ErrorOr<std::vector<uint8_t>>(true, ErrorCodes::DECOMPRESSION);
+            //TODO: include error message once implemented
+            //throw(std::runtime_error("Error while decompressing: " + std::to_string(ret)));
+        }
+
+        return ErrorOr<std::vector<uint8_t>>(std::vector<uint8_t>(decompressedData.begin(), decompressedData.end()));
+    }
 
-    return compressedData;
-}
-
-
-std::vector<char> decompressData(const char* data, int size) {
-    z_stream zs;
-    memset(&zs, 0, sizeof(zs));
-
-    if (inflateInit(&zs) != Z_OK)
-        throw(std::runtime_error("inflateInit failed while decompressing."));
-
-    zs.next_in = reinterpret_cast<Bytef*>(const_cast<char*>(data));
-    zs.avail_in = size;
-
-    int ret;
-    char outbuffer[CHUNK_SIZE];
-    std::vector<char> decompressedData;
-
-    do {
-        zs.next_out = reinterpret_cast<Bytef*>(outbuffer);
-        zs.avail_out = CHUNK_SIZE;
-
-        ret = inflate(&zs, 0);
-
-        if (decompressedData.size() < zs.total_out)
-            decompressedData.insert(decompressedData.end(), outbuffer, outbuffer + CHUNK_SIZE - zs.avail_out);
-    } while (ret == Z_OK);
-
-    inflateEnd(&zs);
-
-    if (ret != Z_STREAM_END)
-        throw(std::runtime_error("Error while decompressing: " + std::to_string(ret)));
-
-    return decompressedData;
 }
diff --git a/src/lib/zlibutil.hpp b/src/lib/zlibutil.hpp
index 3be3de2..861aeb8 100644
--- a/src/lib/zlibutil.hpp
+++ b/src/lib/zlibutil.hpp
@@ -16,12 +16,12 @@
 // version 3 along with this program.
 // If not, see https://www.gnu.org/licenses/agpl-3.0.en.html
 
+#pragma once
+
 #include <vector>
+#include "error.hpp"
 
-#ifndef ZLIBUTIL_H
-#define ZLIBUTIL_H
-
-std::vector<char> compressData(const char* data, int size);
-std::vector<char> decompressData(const char* data, int size);
-
-#endif // ZLIBUTIL_H
+namespace zlib {
+    ErrorOr<std::vector<uint8_t>> compressData(std::vector<uint8_t> data);
+    ErrorOr<std::vector<uint8_t>> decompressData(std::vector<uint8_t> data);
+}