diff --git a/src/main/kotlin/net/revanced/patcher/Patcher.kt b/src/main/kotlin/net/revanced/patcher/Patcher.kt
index 6a9acfe..56081ce 100644
--- a/src/main/kotlin/net/revanced/patcher/Patcher.kt
+++ b/src/main/kotlin/net/revanced/patcher/Patcher.kt
@@ -2,36 +2,47 @@ package net.revanced.patcher
 
 import net.revanced.patcher.patch.Patch
 import net.revanced.patcher.signature.Signature
-import net.revanced.patcher.store.MethodStore
+import net.revanced.patcher.store.ASMStore
 import net.revanced.patcher.store.PatchStore
+import net.revanced.patcher.util.Jar2ASM
 import java.io.InputStream
 import java.lang.IllegalStateException
 
+/**
+ * The patcher. (docs WIP)
+ *
+ * @param input the input stream to read from, must be a JAR file (for now)
+ */
 class Patcher(
-    private val input: InputStream,
+    input: InputStream,
     private val signatures: Array<Signature>,
     patches: Array<Patch>,
 ) {
     private val patchStore = PatchStore()
-    private val methodStore = MethodStore()
+    private val asmStore = ASMStore()
 
     private val scanned = false
 
     init {
         patchStore.addPatches(*patches)
+        loadJar(input)
     }
 
     fun scan() {
-        // methodStore.methods = PatternScanner(signatures).resolve()
+        val methods = PatternScanner(signatures).resolve()
     }
 
     fun patch(): String? {
         if (!scanned) throw IllegalStateException("Pattern scanner not yet ran")
-        for (patch in patchStore.patches) {
+        for ((_, patch) in patchStore.patches) {
             val result = patch.execute()
             if (result.isSuccess()) continue
             return result.error()!!.errorMessage()
         }
         return null
     }
+
+    private fun loadJar(input: InputStream) {
+        asmStore.classes.putAll(Jar2ASM.jar2asm(input))
+    }
 }
\ No newline at end of file
diff --git a/src/main/kotlin/net/revanced/patcher/PatternScanner.kt b/src/main/kotlin/net/revanced/patcher/PatternScanner.kt
index 1d96b2f..a58b4b9 100644
--- a/src/main/kotlin/net/revanced/patcher/PatternScanner.kt
+++ b/src/main/kotlin/net/revanced/patcher/PatternScanner.kt
@@ -6,5 +6,4 @@ class PatternScanner(signatures: Array<Signature>) {
     fun resolve() {
         TODO("Not yet implemented")
     }
-
 }
diff --git a/src/main/kotlin/net/revanced/patcher/store/MethodStore.kt b/src/main/kotlin/net/revanced/patcher/store/ASMStore.kt
similarity index 54%
rename from src/main/kotlin/net/revanced/patcher/store/MethodStore.kt
rename to src/main/kotlin/net/revanced/patcher/store/ASMStore.kt
index a1a0df5..c54e769 100644
--- a/src/main/kotlin/net/revanced/patcher/store/MethodStore.kt
+++ b/src/main/kotlin/net/revanced/patcher/store/ASMStore.kt
@@ -1,7 +1,9 @@
 package net.revanced.patcher.store
 
+import org.objectweb.asm.tree.ClassNode
 import org.objectweb.asm.tree.MethodNode
 
-class MethodStore {
+class ASMStore {
+    val classes: MutableMap<String, ClassNode> = mutableMapOf()
     val methods: MutableMap<String, MethodNode> = mutableMapOf()
 }
\ No newline at end of file
diff --git a/src/main/kotlin/net/revanced/patcher/util/Jar2ASM.kt b/src/main/kotlin/net/revanced/patcher/util/Jar2ASM.kt
new file mode 100644
index 0000000..c39b76e
--- /dev/null
+++ b/src/main/kotlin/net/revanced/patcher/util/Jar2ASM.kt
@@ -0,0 +1,18 @@
+package net.revanced.patcher.util
+
+import org.objectweb.asm.tree.ClassNode
+import java.io.InputStream
+import java.util.jar.JarInputStream
+
+object Jar2ASM {
+    fun jar2asm(input: InputStream): Map<String, ClassNode> {
+        return buildMap {
+            val jar = JarInputStream(input)
+            var e = jar.nextJarEntry
+            while (e != null) {
+                TODO("Read jar file ...")
+                e = jar.nextJarEntry
+            }
+        }
+    }
+}
\ No newline at end of file