diff --git a/build.gradle b/build.gradle
index 482a77e..3350c16 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,5 +17,6 @@ repositories {
 
 dependencies {
 	implementation 'org.jetbrains.kotlin:kotlin-stdlib'
+	compile "com.xenomachina:kotlin-argparser:$kotlin_argparser_version"
 	testImplementation 'junit:junit:4.12'
 }
diff --git a/gradle.properties b/gradle.properties
index a2e9a1f..12b23dd 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1 +1,2 @@
 kotlinVersion=1.3.70
+kotlin_argparser_version=2.0.7
\ No newline at end of file
diff --git a/src/main/kotlin/me/msoucy/gbat/Main.kt b/src/main/kotlin/me/msoucy/gbat/Main.kt
index 091e877..6520703 100644
--- a/src/main/kotlin/me/msoucy/gbat/Main.kt
+++ b/src/main/kotlin/me/msoucy/gbat/Main.kt
@@ -1,5 +1,81 @@
 package me.msoucy.gbat
 
-fun main(args: Array<String>) {
-	println("Hello world")
+import java.io.File
+import java.lang.System
+import kotlin.text.startsWith
+
+import com.xenomachina.argparser.ArgParser
+import com.xenomachina.argparser.InvalidArgumentException
+import com.xenomachina.argparser.default
+import com.xenomachina.argparser.mainBody
+
+val REALLY_LONG_TIME = 864000
+val DEFAULT_INTERESTING_RES = mutableListOf(
+	"\\.java$",
+	"\\.cs$",
+	"\\.py$",
+	"\\.c$",
+	"\\.cpp$",
+	"\\.h$",
+	"\\.hpp$",
+	"\\.pl$",
+	"\\.perl$",
+	"\\.rb$",
+	"\\.sh$",
+	"\\.js$"
+)
+
+fun validateGit(exe : String) : String {
+    val os = System.getProperty("os.name")
+    var fullexe = if(os.startsWith("Windows") && !exe.endsWith(".exe")) {
+        exe + ".exe"
+    } else exe
+    var file = File(fullexe)
+	if(file.canRead()) {
+        return file.absolutePath
+    }
+    for(path in System.getenv("PATH").split(";")) {
+        file = File(path, fullexe)
+        if(file.canRead()) {
+            return file.absolutePath
+        }
+    }
+    throw InvalidArgumentException("Provided git executable does not exist")	
+}
+
+class GbatArgs(parser: ArgParser) {
+	// Input options
+	val interesting by parser.adding("--interesting", "-I",
+		help="Regular expression to determine which files should be included in calculations.",
+		initialValue=DEFAULT_INTERESTING_RES
+		) { this }
+	val not_interesting by parser.adding("--not-interesting", "-N",
+		help="Regular expression to determine which files should not be included in calculations.")
+	val case_sensitive by parser.flagging("Use case sensitive regexps when determining interesting files (default is case-insensitive)")
+	val departed by parser.storing("--departed-file", "-D", help="File listing departed devs, one per line").default<String?>(null)
+	val risk_file by parser.storing("--bus-risk-file", help="File of dev=float lines (e.g. ejorgensen=0.4) with custom bus risks for devs").default<String?>(null)
+	val default_bus_risk by parser.storing("--default-bus-risk", help="Default risk that a dev will be hit by a bus in your analysis timeframe (defaults to 0.1).").default(0.1)
+
+	// Multiprocessing options
+	val num_git_procs by parser.storing("--num-git-procs", help="The number of git processes to run simultaneously (defaults to 3)") { toInt() }.default(3)
+	val num_analyzer_procs by parser.storing("--num-analyzer-procs", help="The number of analyzer processes to run (defaults to 3)") { toInt() }.default(3)
+
+	// Tuning options
+	val risk_threshold by parser.storing("--risk-threshold", help="Threshold past which to summarize risk (defaults to default bus risk cubed)") {toDouble()}.default<Double?>(null)
+	val creation_constant by parser.storing("--knowledge-creation-constant", help="How much knowledge a changed line should create if a new line creates 1 (defaults to 0.1)") {toDouble()}.default<Double?>(null)
+
+	// Misc options
+	val git_exe by parser.storing("--git-exe", help="Path to the git executable", transform=::validateGit).default("git").addValidator { validateGit(value) }
+	val verbose by parser.flagging("--verbose", "-v", help="Print comforting output")
+	val output by parser.storing("Output directory for data files and html summary (defaults to \"output\"), error if already exists").default("output")
+
+	// Directory
+	val root by parser.positional("The root directory to inspect")
+}
+
+fun main(args: Array<String>) = mainBody {
+	ArgParser(args).parseInto(::GbatArgs).run {
+		println("Hello world")
+		println(validateGit(git_exe))
+	}
 }