diff --git a/include/serene/context.h b/include/serene/context.h
index d6c3bb0..a172097 100644
--- a/include/serene/context.h
+++ b/include/serene/context.h
@@ -22,7 +22,6 @@
 #include "serene/diagnostics.h"
 #include "serene/environment.h"
 #include "serene/export.h"
-#include "serene/jit.h"
 #include "serene/jit/engine.h"
 #include "serene/namespace.h"
 #include "serene/passes.h"
@@ -40,6 +39,8 @@
 
 #include <memory>
 
+#define DEFAULT_NS_NAME "serene.user"
+
 namespace serene {
 
 namespace reader {
@@ -127,8 +128,9 @@ public:
 
     // We need to create one empty namespace, so that the JIT can
     // start it's operation.
-    auto ns = makeNamespace(*this, "serene.user", llvm::None);
+    auto ns = makeNamespace(*this, DEFAULT_NS_NAME, llvm::None);
 
+    insertNS(ns);
     // TODO: Get the crash report path dynamically from the cli
     // pm.enableCrashReproducerGeneration("/home/lxsameer/mlir.mlir");
 
@@ -151,8 +153,12 @@ public:
   };
 
   static std::unique_ptr<SereneContext> make() {
-    auto ctx      = std::make_unique<SereneContext>();
-    auto maybeJIT = serene::jit::makeSereneJIT(*ctx);
+    auto ctx = std::make_unique<SereneContext>();
+    auto *ns = ctx->getNS(DEFAULT_NS_NAME);
+
+    assert(ns != nullptr && "Default ns doesn't exit!");
+
+    auto maybeJIT = serene::jit::makeSereneJIT(*ns);
 
     if (!maybeJIT) {
       // TODO: Raise an error here
diff --git a/include/serene/jit/engine.h b/include/serene/jit/engine.h
index 4814ab6..9f74112 100644
--- a/include/serene/jit/engine.h
+++ b/include/serene/jit/engine.h
@@ -90,8 +90,8 @@ class SereneJIT {
   /// and generate LLVM IR
   orc::IRTransformLayer transformLayer;
 
-  /// The AST Layer reads and import the Serene Ast directly to the JIT
-  // SereneAstLayer astLayer;
+  // The AST Layer reads and import the Serene Ast directly to the JIT
+  AstLayer astLayer;
 
   /// NS layer is responsible for adding namespace to the JIT by name.
   /// It will import the entire namespace.
@@ -129,9 +129,10 @@ class SereneJIT {
     return std::move(tsm);
   }
 
+  Namespace &currentNS;
+
 public:
-  SereneJIT(serene::SereneContext &ctx,
-            std::unique_ptr<orc::ExecutionSession> es,
+  SereneJIT(Namespace &entryNS, std::unique_ptr<orc::ExecutionSession> es,
             std::unique_ptr<orc::EPCIndirectionUtils> epciu,
             orc::JITTargetMachineBuilder jtmb, llvm::DataLayout &&dl);
 
@@ -145,6 +146,8 @@ public:
     }
   };
 
+  Namespace &getCurrentNS() { return currentNS; }
+
   const llvm::DataLayout &getDataLayout() const { return dl; }
 
   orc::JITDylib &getMainJITDylib() { return mainJD; }
@@ -161,14 +164,15 @@ public:
   llvm::Error addNS(llvm::StringRef nsname,
                     orc::ResourceTrackerSP rt = nullptr);
 
+  llvm::Error addAst(exprs::Ast &ast, orc::ResourceTrackerSP rt = nullptr);
+
   llvm::Expected<llvm::JITEvaluatedSymbol> lookup(llvm::StringRef name) {
     JIT_LOG("Looking up symbol: " + name);
     return es->lookup({&mainJD}, mangler(name.str()));
   }
 };
 
-llvm::Expected<std::unique_ptr<SereneJIT>>
-makeSereneJIT(serene::SereneContext &ctx);
+llvm::Expected<std::unique_ptr<SereneJIT>> makeSereneJIT(Namespace &ns);
 
 }; // namespace jit
 }; // namespace serene
diff --git a/include/serene/jit/layers.h b/include/serene/jit/layers.h
index a159f08..922d44d 100644
--- a/include/serene/jit/layers.h
+++ b/include/serene/jit/layers.h
@@ -19,6 +19,7 @@
 #ifndef SERENE_JIT_LAYERS_H
 #define SERENE_JIT_LAYERS_H
 
+#include "serene/namespace.h"
 #include "serene/reader/location.h"
 #include "serene/utils.h"
 
@@ -47,16 +48,14 @@ using Ast  = std::vector<Node>;
 
 namespace jit {
 
-class SereneAstLayer;
+class AstLayer;
 
 /// This will compile the ast to llvm ir.
-llvm::orc::ThreadSafeModule compileAst(serene::SereneContext &ctx,
-                                       exprs::Ast &ast);
+llvm::orc::ThreadSafeModule compileAst(Namespace &ns, exprs::Ast &ast);
 
-class SerenAstMaterializationUnit : public orc::MaterializationUnit {
+class AstMaterializationUnit : public orc::MaterializationUnit {
 public:
-  SerenAstMaterializationUnit(SereneContext &ctx, SereneAstLayer &l,
-                              exprs::Ast &ast);
+  AstMaterializationUnit(Namespace &ns, AstLayer &l, exprs::Ast &ast);
 
   llvm::StringRef getName() const override {
     return "SereneAstMaterializationUnit";
@@ -73,51 +72,42 @@ private:
     llvm_unreachable("Serene functions are not overridable");
   }
 
-  serene::SereneContext &ctx;
-  SereneAstLayer &astLayer;
+  Namespace &ns;
+  AstLayer &astLayer;
   exprs::Ast &ast;
 };
 
-// class SereneAstLayer {
-//   SereneContext &ctx;
-//   orc::IRLayer &baseLayer;
-//   orc::MangleAndInterner &mangler;
+class AstLayer {
+  orc::IRLayer &baseLayer;
+  orc::MangleAndInterner &mangler;
 
-//   const llvm::DataLayout &dl;
+public:
+  AstLayer(orc::IRLayer &baseLayer, orc::MangleAndInterner &mangler)
+      : baseLayer(baseLayer), mangler(mangler){};
 
-// public:
-//   SereneAstLayer(SereneContext &ctx, orc::IRLayer &baseLayer,
-//                  orc::MangleAndInterner &mangler, const llvm::DataLayout &dl)
-//       : ctx(ctx), baseLayer(baseLayer), mangler(mangler), dl(dl){};
+  llvm::Error add(orc::ResourceTrackerSP &rt, Namespace &ns, exprs::Ast &ast) {
+    return rt->getJITDylib().define(
+        std::make_unique<AstMaterializationUnit>(ns, *this, ast), rt);
+  }
 
-//   llvm::Error add(orc::ResourceTrackerSP &rt, exprs::Ast &ast) {
-//     return rt->getJITDylib().define(
-//         std::make_unique<SerenAstMaterializationUnit>(ctx, *this, ast), rt);
-//   }
+  void emit(std::unique_ptr<orc::MaterializationResponsibility> mr,
+            Namespace &ns, exprs::Ast &e) {
 
-//   void emit(std::unique_ptr<orc::MaterializationResponsibility> mr,
-//             exprs::Ast &e) {
-//     baseLayer.emit(std::move(mr), compileAst(ctx, e));
-//   }
+    baseLayer.emit(std::move(mr), compileAst(ns, e));
+  }
 
-//   orc::SymbolFlagsMap getInterface(exprs::Ast &e) {
-//     orc::SymbolFlagsMap Symbols;
-//     Symbols[mangler(e.getName())] = llvm::JITSymbolFlags(
-//         llvm::JITSymbolFlags::Exported | llvm::JITSymbolFlags::Callable);
-//     return Symbols;
-//   }
-// };
+  orc::SymbolFlagsMap getInterface(Namespace &ns, exprs::Ast &e);
+};
 
 /// NS Layer ==================================================================
 class NSLayer;
 
 /// This will compile the NS to llvm ir.
-llvm::orc::ThreadSafeModule compileNS(serene::SereneContext &ctx,
-                                      serene::Namespace &ns);
+llvm::orc::ThreadSafeModule compileNS(Namespace &ns);
 
 class NSMaterializationUnit : public orc::MaterializationUnit {
 public:
-  NSMaterializationUnit(SereneContext &ctx, NSLayer &l, serene::Namespace &ns);
+  NSMaterializationUnit(NSLayer &l, Namespace &ns);
 
   llvm::StringRef getName() const override { return "NSMaterializationUnit"; }
 
@@ -129,13 +119,12 @@ private:
                const orc::SymbolStringPtr &sym) override {
     UNUSED(jd);
     UNUSED(sym);
-    UNUSED(ctx);
+    llvm_unreachable("Serene functions are not overridable");
     // TODO: Check the ctx to see whether we need to remove the sym or not
   }
 
-  serene::SereneContext &ctx;
   NSLayer &nsLayer;
-  serene::Namespace &ns;
+  Namespace &ns;
 };
 
 /// NS Layer is responsible for adding namespaces to the JIT
@@ -146,7 +135,7 @@ class NSLayer {
   const llvm::DataLayout &dl;
 
 public:
-  NSLayer(serene::SereneContext &ctx, orc::IRLayer &baseLayer,
+  NSLayer(SereneContext &ctx, orc::IRLayer &baseLayer,
           orc::MangleAndInterner &mangler, const llvm::DataLayout &dl)
       : ctx(ctx), baseLayer(baseLayer), mangler(mangler), dl(dl){};
 
@@ -165,7 +154,7 @@ public:
     // the data layout all the time
     UNUSED(dl);
     LAYER_LOG("Emit namespace");
-    baseLayer.emit(std::move(mr), compileNS(ctx, ns));
+    baseLayer.emit(std::move(mr), compileNS(ns));
   }
 
   orc::SymbolFlagsMap getInterface(serene::Namespace &ns);
diff --git a/include/serene/namespace.h b/include/serene/namespace.h
index f91b110..0122980 100644
--- a/include/serene/namespace.h
+++ b/include/serene/namespace.h
@@ -124,6 +124,8 @@ public:
   errors::OptionalErrors addTree(exprs::Ast &ast);
   exprs::Ast &getTree();
 
+  const std::vector<llvm::StringRef> &getSymList() { return symbolList; };
+
   /// Increase the function counter by one
   uint nextFnCounter();
 
@@ -132,12 +134,16 @@ public:
   // TODO: Fix the return type and use a `llvm::Optional` instead
   /// Generate and return a MLIR ModuleOp tha contains the IR of the namespace
   /// with respect to the compilation phase
-  MaybeModuleOp generate();
+  MaybeModuleOp generate(unsigned offset = 0);
 
   /// Compile the namespace to a llvm module. It will call the
   /// `generate` method of the namespace to generate the IR.
   MaybeModule compileToLLVM();
 
+  /// Compile the given namespace from the given \p offset of AST till the end
+  /// of the trees.
+  MaybeModule compileToLLVMFromOffset(unsigned offset);
+
   /// Run all the passes specified in the context on the given MLIR ModuleOp.
   mlir::LogicalResult runPasses(mlir::ModuleOp &m);
 
diff --git a/src/libserene/jit/engine.cpp b/src/libserene/jit/engine.cpp
index 14cf5a7..62d5606 100644
--- a/src/libserene/jit/engine.cpp
+++ b/src/libserene/jit/engine.cpp
@@ -34,7 +34,7 @@ static void handleLazyCallThroughError() {
   // TODO: terminate ?
 }
 
-SereneJIT::SereneJIT(serene::SereneContext &ctx,
+SereneJIT::SereneJIT(Namespace &entryNS,
                      std::unique_ptr<orc::ExecutionSession> es,
                      std::unique_ptr<orc::EPCIndirectionUtils> epciu,
                      orc::JITTargetMachineBuilder jtmb, llvm::DataLayout &&dl)
@@ -48,13 +48,10 @@ SereneJIT::SereneJIT(serene::SereneContext &ctx,
           *this->es, objectLayer,
           std::make_unique<orc::ConcurrentIRCompiler>(std::move(jtmb))),
       transformLayer(*this->es, compileLayer, optimizeModule),
-      // TODO: Change compileOnDemandLayer to use an optimization layer
-      //       as the parent
-      // compileOnDemandLayer(
-      //     *this->es, compileLayer, this->epciu->getLazyCallThroughManager(),
-      //     [this] { return this->epciu->createIndirectStubsManager(); }),
-      nsLayer(ctx, transformLayer, mangler, dl),
-      mainJD(this->es->createBareJITDylib(ctx.getCurrentNS().name)), ctx(ctx) {
+      astLayer(transformLayer, mangler),
+      nsLayer(entryNS.getContext(), transformLayer, mangler, dl),
+      mainJD(this->es->createBareJITDylib(entryNS.name)),
+      ctx(entryNS.getContext()), currentNS(entryNS) {
   UNUSED(this->ctx);
   mainJD.addGenerator(
       cantFail(orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(
@@ -74,8 +71,15 @@ llvm::Error SereneJIT::addNS(llvm::StringRef nsname,
   return nsLayer.add(rt, nsname);
 };
 
-llvm::Expected<std::unique_ptr<SereneJIT>>
-makeSereneJIT(serene::SereneContext &ctx) {
+llvm::Error SereneJIT::addAst(exprs::Ast &ast, orc::ResourceTrackerSP rt) {
+  if (!rt) {
+    rt = mainJD.getDefaultResourceTracker();
+  }
+
+  return astLayer.add(rt, getCurrentNS(), ast);
+};
+
+llvm::Expected<std::unique_ptr<SereneJIT>> makeSereneJIT(Namespace &ns) {
   auto epc = orc::SelfExecutorProcessControl::Create();
   if (!epc) {
     return epc.takeError();
@@ -102,7 +106,7 @@ makeSereneJIT(serene::SereneContext &ctx) {
     return dl.takeError();
   }
 
-  return std::make_unique<SereneJIT>(ctx, std::move(es), std::move(*epciu),
+  return std::make_unique<SereneJIT>(ns, std::move(es), std::move(*epciu),
                                      std::move(jtmb), std::move(*dl));
 };
 } // namespace serene::jit
diff --git a/src/libserene/jit/layers.cpp b/src/libserene/jit/layers.cpp
index e07c7f2..ffcd3fa 100644
--- a/src/libserene/jit/layers.cpp
+++ b/src/libserene/jit/layers.cpp
@@ -25,30 +25,79 @@
 #include <llvm/ExecutionEngine/Orc/ThreadSafeModule.h>
 #include <llvm/Support/Error.h> // for report_fatal_error
 
+#include <algorithm>
+
 namespace serene::jit {
 
-// llvm::orc::ThreadSafeModule compileAst(serene::SereneContext &ctx,
-//                                        exprs::Ast &ast){
+llvm::orc::ThreadSafeModule compileAst(Namespace &ns, exprs::Ast &ast) {
 
-// };
+  assert(ns.getTree().size() < ast.size() && "Did you add the ast to the NS?");
 
-// SerenAstMaterializationUnit::SerenAstMaterializationUnit(
-//     serene::SereneContext &ctx, SereneAstLayer &l, exprs::Ast &ast)
-//     : MaterializationUnit(l.getInterface(ast), nullptr), ctx(ctx),
-//     astLayer(l),
-//       ast(ast){};
+  LAYER_LOG("Compile in context of namespace: " + ns.name);
+  unsigned offset = ns.getTree().size() - ast.size();
 
-// void SerenAstMaterializationUnit::materialize(
-//     std::unique_ptr<orc::MaterializationResponsibility> r) {
-//   astLayer.emit(std::move(r), ast);
-// }
+  auto maybeModule = ns.compileToLLVMFromOffset(offset);
+
+  if (!maybeModule) {
+    // TODO: Handle failure
+    llvm::report_fatal_error("Couldn't compile lazily JIT'd function");
+  }
+
+  return std::move(maybeModule.getValue());
+};
+
+AstMaterializationUnit::AstMaterializationUnit(Namespace &ns, AstLayer &l,
+                                               exprs::Ast &ast)
+    : MaterializationUnit(l.getInterface(ns, ast), nullptr), ns(ns),
+      astLayer(l), ast(ast){};
+
+void AstMaterializationUnit::materialize(
+    std::unique_ptr<orc::MaterializationResponsibility> r) {
+  astLayer.emit(std::move(r), ns, ast);
+}
+
+orc::SymbolFlagsMap AstLayer::getInterface(Namespace &ns, exprs::Ast &e) {
+  orc::SymbolFlagsMap Symbols;
+  auto symList   = ns.getSymList();
+  unsigned index = symList.size();
+
+  // This probably will change symList
+  auto err = ns.addTree(e);
+
+  if (err) {
+    // TODO: Fix this by a call to diag engine or return the err
+    llvm::outs() << "Fixme: semantic err\n";
+    return Symbols;
+  }
+
+  auto &env            = ns.getRootEnv();
+  auto populateTableFn = [&env, this, &Symbols](auto name) {
+    auto flags     = llvm::JITSymbolFlags::Exported;
+    auto maybeExpr = env.lookup(name.str());
+
+    if (!maybeExpr) {
+      LAYER_LOG("Skiping '" + name + "' symbol");
+      return;
+    }
+
+    auto expr = maybeExpr.getValue();
+
+    if (expr->getType() == exprs::ExprType::Fn) {
+      flags = flags | llvm::JITSymbolFlags::Callable;
+    }
+
+    auto mangledSym = this->mangler(name);
+    LAYER_LOG("Mangle symbol for: " + name + " = " << mangledSym);
+    Symbols[mangledSym] = llvm::JITSymbolFlags(flags);
+  };
+
+  std::for_each(symList.begin() + index, symList.end(), populateTableFn);
+  return Symbols;
+}
 
 /// NS Layer ==================================================================
 
-llvm::orc::ThreadSafeModule compileNS(serene::SereneContext &ctx,
-                                      serene::Namespace &ns) {
-  UNUSED(ctx);
-
+llvm::orc::ThreadSafeModule compileNS(Namespace &ns) {
   LAYER_LOG("Compile namespace: " + ns.name);
 
   auto maybeModule = ns.compileToLLVM();
@@ -61,10 +110,8 @@ llvm::orc::ThreadSafeModule compileNS(serene::SereneContext &ctx,
   return std::move(maybeModule.getValue());
 };
 
-NSMaterializationUnit::NSMaterializationUnit(SereneContext &ctx, NSLayer &l,
-                                             serene::Namespace &ns)
-    : MaterializationUnit(l.getInterface(ns), nullptr), ctx(ctx), nsLayer(l),
-      ns(ns){};
+NSMaterializationUnit::NSMaterializationUnit(NSLayer &l, Namespace &ns)
+    : MaterializationUnit(l.getInterface(ns), nullptr), nsLayer(l), ns(ns){};
 
 void NSMaterializationUnit::materialize(
     std::unique_ptr<orc::MaterializationResponsibility> r) {
@@ -89,7 +136,7 @@ llvm::Error NSLayer::add(orc::ResourceTrackerSP &rt, llvm::StringRef nsname,
 
   LAYER_LOG("Add the materialize unit for: " + nsname);
   return rt->getJITDylib().define(
-      std::make_unique<NSMaterializationUnit>(ctx, *this, *ns), rt);
+      std::make_unique<NSMaterializationUnit>(*this, *ns), rt);
 }
 
 orc::SymbolFlagsMap NSLayer::getInterface(serene::Namespace &ns) {
@@ -104,8 +151,8 @@ orc::SymbolFlagsMap NSLayer::getInterface(serene::Namespace &ns) {
       flags = flags | llvm::JITSymbolFlags::Callable;
     }
 
-    auto mangledSym = mangler(k.getFirst());
-    LAYER_LOG("Mangle symbol for: " + k.getFirst() + " = " << mangledSym);
+    auto mangledSym = mangler(name);
+    LAYER_LOG("Mangle symbol for: " + name + " = " << mangledSym);
     Symbols[mangledSym] = llvm::JITSymbolFlags(flags);
   }
 
diff --git a/src/libserene/namespace.cpp b/src/libserene/namespace.cpp
index c72fd42..f07b6d2 100644
--- a/src/libserene/namespace.cpp
+++ b/src/libserene/namespace.cpp
@@ -117,18 +117,21 @@ uint Namespace::nextFnCounter() { return fn_counter++; };
 
 SereneContext &Namespace::getContext() { return this->ctx; };
 
-MaybeModuleOp Namespace::generate() {
+MaybeModuleOp Namespace::generate(unsigned offset) {
   mlir::OpBuilder builder(&ctx.mlirContext);
   // TODO: Fix the unknown location by pointing to the `ns` form
   auto module = mlir::ModuleOp::create(builder.getUnknownLoc(),
                                        llvm::Optional<llvm::StringRef>(name));
 
+  auto treeSize = getTree().size();
+
   // Walk the AST and call the `generateIR` function of each node.
   // Since nodes will have access to the a reference of the
   // namespace they can use the builder and keep adding more
   // operations to the module via the builder
-  for (auto &x : getTree()) {
-    x->generateIR(*this, module);
+  for (unsigned i = offset; i < treeSize; ++i) {
+    auto &node = getTree()[i];
+    node->generateIR(*this, module);
   }
 
   if (mlir::failed(mlir::verify(module))) {
@@ -182,6 +185,22 @@ MaybeModule Namespace::compileToLLVM() {
   return llvm::None;
 };
 
+MaybeModule Namespace::compileToLLVMFromOffset(unsigned offset) {
+  auto maybeModule = generate(offset);
+
+  if (!maybeModule) {
+    NAMESPACE_LOG("IR generation failed for '" << name << "'");
+    return llvm::None;
+  }
+
+  if (ctx.getTargetPhase() >= CompilationPhase::IR) {
+    mlir::ModuleOp module = maybeModule.getValue().get();
+    return ::serene::slir::compileToLLVMIR(ctx, module);
+  }
+
+  return llvm::None;
+};
+
 Namespace::~Namespace(){};
 
 NSPtr makeNamespace(SereneContext &ctx, llvm::StringRef name,
diff --git a/src/libserene/serene.cpp b/src/libserene/serene.cpp
index 1427b2a..6b9e71f 100644
--- a/src/libserene/serene.cpp
+++ b/src/libserene/serene.cpp
@@ -127,6 +127,14 @@ SERENE_EXPORT exprs::MaybeNode eval(SereneContext &ctx, exprs::Ast &input) {
   auto *f = (int (*)())(intptr_t)sym.getAddress();
 
   f();
+
+  err = ctx.jit->addAst(input);
+  if (err) {
+    llvm::errs() << err;
+    auto e = errors::makeErrorTree(loc, errors::NSLoadError);
+
+    return exprs::makeErrorNode(loc, errors::NSLoadError);
+  }
   return exprs::make<exprs::Number>(loc, "4", false, false);
 };
 
diff --git a/src/serene-repl/serene-repl.cpp b/src/serene-repl/serene-repl.cpp
index 5783d0b..77daf0e 100644
--- a/src/serene-repl/serene-repl.cpp
+++ b/src/serene-repl/serene-repl.cpp
@@ -52,8 +52,7 @@ int main(int argc, char *argv[]) {
 
   llvm::outs() << banner << art;
 
-  auto ctx    = makeSereneContext();
-  auto userNS = makeNamespace(*ctx, "user", llvm::None);
+  auto ctx = makeSereneContext();
 
   applySereneCLOptions(*ctx);
 
@@ -74,7 +73,7 @@ int main(int argc, char *argv[]) {
     // Read line
     std::string line;
     std::string result;
-    std::string prompt = ctx->getCurrentNS().name + "> ";
+    std::string prompt = ctx->jit->getCurrentNS().name + "> ";
 
     auto quit = linenoise::Readline(prompt.c_str(), line);