diff --git a/compiler/lowerer.ts b/compiler/lowerer.ts
index 53a4077..dde41e2 100644
--- a/compiler/lowerer.ts
+++ b/compiler/lowerer.ts
@@ -432,10 +432,6 @@ export class Lowerer {
         this.locals = new LocalLeaf(this.locals);
         this.scoutFnHeaders(expr.kind.stmts);
         for (const stmt of expr.kind.stmts) {
-            console.log(`sm for stmt ${stmt.kind.type} ${stmt.pos.line}`);
-            if (stmt.kind.type === "assign") {
-                console.log(` - ${stmtToString(stmt)}`);
-            }
             this.addSourceMap(stmt.pos);
             this.lowerStmt(stmt);
         }
diff --git a/runtime/Makefile b/runtime/Makefile
index c4e80d3..99a1669 100644
--- a/runtime/Makefile
+++ b/runtime/Makefile
@@ -20,6 +20,7 @@ all: build_dir $(OUT)
 
 $(OUT): $(CXX_OBJECTS)
 	$(CXX) -o $@ $(CXX_FLAGS) $^
+	git rev-parse HEAD > build/rev
 
 build_dir:
 	mkdir -p build/
diff --git a/web/main.ts b/web/main.ts
index 9a07548..e2eb0f6 100644
--- a/web/main.ts
+++ b/web/main.ts
@@ -17,6 +17,7 @@ const filepath = flags._[0] as string;
 const text = await Deno.readTextFile(filepath);
 
 const runtime = new Runtime(13370);
+await runtime.start();
 
 async function compileProgram(filepath: string) {
     const result = await compiler.compileWithDebug(filepath);
diff --git a/web/runtime.ts b/web/runtime.ts
index 2970d7d..b80e931 100644
--- a/web/runtime.ts
+++ b/web/runtime.ts
@@ -1,12 +1,49 @@
 export class Runtime {
+    private runtimeProcess?: Deno.ChildProcess;
+
     constructor(private port: number) {}
 
+    async checkRuntimeRev() {
+        const currentRev = new TextDecoder().decode(
+            await new Deno.Command("git", { args: ["rev-parse", "HEAD"] })
+                .output()
+                .then((output) => output.stdout),
+        ).trim();
+        const runtimeRev = (await Deno.readTextFile("../runtime/build/rev"))
+            .trim();
+        if (runtimeRev !== currentRev) {
+            console.error(
+                "runtime out-of-date; run 'make' inside runtime/ folder",
+            );
+            Deno.exit(1);
+        }
+    }
+
+    async start() {
+        await this.checkRuntimeRev();
+        this.runtimeProcess = new Deno.Command("../runtime/build/sliger", {
+            args: [],
+            stdout: "piped",
+        }).spawn();
+    }
+
+    stop() {
+        this.runtimeProcess?.kill();
+        this.runtimeProcess = undefined;
+    }
+
     async connect(): Promise<RuntimeConnection> {
-        return new RuntimeConnection(
-            await Deno.connect({
-                port: this.port,
-            }),
-        );
+        return await new Promise((resolve) => {
+            setTimeout(async () => {
+                resolve(
+                    new RuntimeConnection(
+                        await Deno.connect({
+                            port: this.port,
+                        }),
+                    ),
+                );
+            }, 1000);
+        });
     }
 }