diff --git a/src/main/kotlin/net/revanced/patcher/Patcher.kt b/src/main/kotlin/net/revanced/patcher/Patcher.kt
index c4a8579..e823b6e 100644
--- a/src/main/kotlin/net/revanced/patcher/Patcher.kt
+++ b/src/main/kotlin/net/revanced/patcher/Patcher.kt
@@ -1,25 +1,26 @@
 package net.revanced.patcher
 
-import net.revanced.patcher.sigscan.Sig
-import net.revanced.patcher.sigscan.SigScanner
-import org.jf.dexlib2.Opcode
+import net.revanced.patcher.version.YTVersion
+import org.jf.dexlib2.DexFileFactory
 import java.io.File
-import java.lang.reflect.Modifier
 
-class Patcher {
-    companion object {
-        /**
-         * Invokes the patcher on the given input file.
-         *
-         * @param input the input file
-         * @param output the output file
-         */
-        fun invoke(input: File, output: File) {
-            SigScanner(Sig(
-                arrayOf(Opcode.ADD_INT),
-                Modifier.PUBLIC or Modifier.STATIC,
-                String.Companion::class
-            )).scan(emptyArray())
-        }
+/**
+ * Creates a patcher.
+ *
+ * @param input the input dex file
+ * @param output the output dex file
+ * @param version the YT version of this dex file
+ */
+class Patcher(private val input: File, private val output: File, private val version: YTVersion) {
+    // setting opcodes to null causes it to autodetect, perfect!
+    private val dexFile = DexFileFactory.loadDexFile(input, null)
+
+    /**
+     * Runs the patcher.
+     */
+    fun run() {
+
     }
 }
+
+
diff --git a/src/main/kotlin/net/revanced/patcher/signatures/ElementType.kt b/src/main/kotlin/net/revanced/patcher/signatures/ElementType.kt
new file mode 100644
index 0000000..27fa9d3
--- /dev/null
+++ b/src/main/kotlin/net/revanced/patcher/signatures/ElementType.kt
@@ -0,0 +1,15 @@
+package net.revanced.patcher.signatures
+
+class ElementType private constructor() {
+    companion object {
+        const val Void = "()V"
+        const val Boolean = "()Z"
+        const val Byte = "()B"
+        const val Char = "()C"
+        const val Short = "()S"
+        const val Int = "()I"
+        const val Long = "()J"
+        const val Float = "()F"
+        const val Double = "()D"
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/net/revanced/patcher/sigscan/Sig.kt b/src/main/kotlin/net/revanced/patcher/signatures/Signature.kt
similarity index 57%
rename from src/main/kotlin/net/revanced/patcher/sigscan/Sig.kt
rename to src/main/kotlin/net/revanced/patcher/signatures/Signature.kt
index 3d570e8..603093e 100644
--- a/src/main/kotlin/net/revanced/patcher/sigscan/Sig.kt
+++ b/src/main/kotlin/net/revanced/patcher/signatures/Signature.kt
@@ -1,18 +1,32 @@
-package net.revanced.patcher.sigscan
+package net.revanced.patcher.signatures
 
 import org.jf.dexlib2.Opcode
-import kotlin.reflect.KClass
 
-data class Sig(
+/**
+ * An ASM signature.
+ *
+ * ```
+ * Signature(
+ *    arrayOf(Opcode.ADD_INT),
+ *    Modifier.PUBLIC or Modifier.STATIC,
+ *    "Ljava/lang/String;"
+ * )
+ * ```
+ *
+ * @param opcodes the opcode signature
+ * @param attributes the modifiers of the method you are searching for
+ * @param returnType the return type of the method as string, see: https://stackoverflow.com/a/9909370
+ */
+data class Signature(
     val opcodes: Array<Opcode>,
     val attributes: Int,
-    val returnType: KClass<*>
+    val returnType: String
 ) {
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (javaClass != other?.javaClass) return false
 
-        other as Sig
+        other as Signature
 
         if (!opcodes.contentEquals(other.opcodes)) return false
         if (attributes != other.attributes) return false
diff --git a/src/main/kotlin/net/revanced/patcher/signatures/SignatureSupplier.kt b/src/main/kotlin/net/revanced/patcher/signatures/SignatureSupplier.kt
new file mode 100644
index 0000000..f42db46
--- /dev/null
+++ b/src/main/kotlin/net/revanced/patcher/signatures/SignatureSupplier.kt
@@ -0,0 +1,5 @@
+package net.revanced.patcher.signatures
+
+interface SignatureSupplier {
+    fun signatures(): Array<Signature>
+}
\ No newline at end of file
diff --git a/src/main/kotlin/net/revanced/patcher/signatures/v17_03_38/Sigs.kt b/src/main/kotlin/net/revanced/patcher/signatures/v17_03_38/Sigs.kt
new file mode 100644
index 0000000..f39caf4
--- /dev/null
+++ b/src/main/kotlin/net/revanced/patcher/signatures/v17_03_38/Sigs.kt
@@ -0,0 +1,34 @@
+package net.revanced.patcher.signatures.v17_03_38
+
+import net.revanced.patcher.signatures.SignatureSupplier
+import net.revanced.patcher.signatures.ElementType
+import net.revanced.patcher.signatures.Signature
+import java.lang.reflect.Modifier
+
+import org.jf.dexlib2.Opcode.*
+
+class Sigs: SignatureSupplier {
+    override fun signatures(): Array<Signature> {
+        return arrayOf(
+            // public static aT(Landroid/content/Context;I)Z
+            Signature(
+                arrayOf(
+                    IF_LT,   // if-lt p0, p1, :cond_1
+                    CONST_4, // const/4 p0, 0x1
+                    // TODO(Inject):
+                    // invoke-static {p0}, Lfi/razerman/youtube/XGlobals;->getOverride(Z)Z
+                    // move-result p0
+                    RETURN,  // return p0
+                             // :cond_1
+                    CONST_4, // const/4 p0, 0x0
+                    // TODO(Inject):
+                    // invoke-static {p0}, Lfi/razerman/youtube/XGlobals;->getOverride(Z)Z
+                    // move-result p0
+                    RETURN,  // return p0
+                ),
+                Modifier.PUBLIC or Modifier.STATIC,
+                ElementType.Boolean
+            )
+        )
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/net/revanced/patcher/sigscan/SigScanner.kt b/src/main/kotlin/net/revanced/patcher/sigscan/SignatureScanner.kt
similarity index 56%
rename from src/main/kotlin/net/revanced/patcher/sigscan/SigScanner.kt
rename to src/main/kotlin/net/revanced/patcher/sigscan/SignatureScanner.kt
index 505c361..c8eed28 100644
--- a/src/main/kotlin/net/revanced/patcher/sigscan/SigScanner.kt
+++ b/src/main/kotlin/net/revanced/patcher/sigscan/SignatureScanner.kt
@@ -1,8 +1,9 @@
 package net.revanced.patcher.sigscan
 
+import net.revanced.patcher.signatures.Signature
 import org.jf.dexlib2.iface.ClassDef
 
-class SigScanner (sig: Sig) {
+class SignatureScanner(signature: Signature) {
     fun scan(classes: Array<ClassDef>) {
 
     }
diff --git a/src/main/kotlin/net/revanced/patcher/version/YTVersion.kt b/src/main/kotlin/net/revanced/patcher/version/YTVersion.kt
new file mode 100644
index 0000000..bf96244
--- /dev/null
+++ b/src/main/kotlin/net/revanced/patcher/version/YTVersion.kt
@@ -0,0 +1,26 @@
+package net.revanced.patcher.version
+
+import net.revanced.patcher.signatures.SignatureSupplier
+import net.revanced.patcher.signatures.v17_03_38.Sigs
+
+enum class YTVersion(
+    val versionNumber: Triple<Int, Int, Int>,
+    val sigs: SignatureSupplier
+) {
+    V17_03_38(
+        Triple(17, 3, 38),
+        Sigs()
+    );
+
+    companion object {
+        private val vm: Map<Triple<Int, Int, Int>, YTVersion> = buildMap {
+            values().forEach {
+                this[it.versionNumber] = it
+            }
+        }
+
+        fun versionFor(versionNumber: Triple<Int, Int, Int>): YTVersion? {
+            return vm[versionNumber]
+        }
+    }
+}
\ No newline at end of file