diff --git a/api.go b/api.go
index ef1e51c..54fbca4 100644
--- a/api.go
+++ b/api.go
@@ -26,6 +26,7 @@ var exports = map[string]lua.LGFunction {
 	"complete": hlcomplete,
 	"cwd": hlcwd,
 	"exec": hlexec,
+	"runnerMode": hlrunnerMode,
 	"goro": hlgoro,
 	"multiprompt": hlmlprompt,
 	"prependPath": hlprependPath,
@@ -106,6 +107,10 @@ Check out the {blue}{bold}guide{reset} command to get started.
 	util.Document(L, hshcomp, "Completions interface for Hilbish.")
 	L.SetField(mod, "completion", hshcomp)
 
+	runnerModule := runnerModeLoader(L)
+	util.Document(L, runnerModule, "Runner/exec interface for Hilbish.")
+	L.SetField(mod, "runner", runnerModule)
+
 	jobs = newJobHandler()
 
 	L.Push(mod)
@@ -172,7 +177,7 @@ func unsetVimMode() {
 func hlrun(L *lua.LState) int {
 	var exitcode uint8
 	cmd := L.CheckString(1)
-	err := execCommand(cmd, true)
+	err := execCommand(cmd)
 
 	if code, ok := interp.IsExitStatus(err); ok {
 		exitcode = code
@@ -466,3 +471,29 @@ func hlinputMode(L *lua.LState) int {
 	}
 	return 0
 }
+
+// runnerMode(mode)
+// Sets the execution/runner mode for interactive Hilbish. This determines whether
+// Hilbish wll try to run input as Lua and/or sh or only do one of either.
+// Accepted values for mode are hybrid (the default), hybridRev (sh first then Lua),
+// sh, and lua. It also accepts a function, to which if it is passed one
+// will call it to execute user input instead.
+func hlrunnerMode(L *lua.LState) int {
+	mode := L.CheckAny(1)
+	switch mode.Type() {
+		case lua.LTString:
+			switch mode.String() {
+				// no fallthrough doesnt work so eh
+				case "hybrid": fallthrough
+				case "hybridRev": fallthrough
+				case "lua": fallthrough
+				case "sh":
+					runnerMode = mode
+				default: L.RaiseError("execMode: expected either a function or hybrid, hybridRev, lua, sh. Received %v", mode)
+			}
+		case lua.LTFunction: runnerMode = mode
+		default: L.RaiseError("execMode: expected either a function or hybrid, hybridRev, lua, sh. Received %v", mode)
+	}
+
+	return 0
+}
diff --git a/docs/runner-mode.txt b/docs/runner-mode.txt
new file mode 100644
index 0000000..69d0e17
--- /dev/null
+++ b/docs/runner-mode.txt
@@ -0,0 +1,33 @@
+Hilbish is *unique,* when interactive it first attempts to run input as
+Lua and then tries shell script. But if you're normal, you wouldn't
+really be using Hilbish anyway but you'd also not want this
+(or maybe want Lua only in some cases.)
+
+The "runner mode" of Hilbish is customizable via `hilbish.runnerMode`,
+which determines how Hilbish will run user input. By default, this is
+set to `hybrid` which is the previously mentioned behaviour of running Lua
+first then going to shell script. If you want the reverse order, you can
+set it to `hybridRev` and for isolated modes there is `sh` and `lua`
+respectively.
+
+You can also set it to a function, which will be called everytime Hilbish
+needs to run interactive input. For example, you can set this to a simple
+function to compile and evaluate Fennel, and now you can run Fennel.
+You can even mix it with sh to make a hybrid mode with Lua replaced by
+Fennel.
+
+An example:
+hilbish.runnerMode(function(input)
+	local ok = pcall(fennel.eval, input)
+	if ok then
+		return 0, nil
+	end
+
+	return hilbish.runner.sh(input)
+end)
+
+The `hilbish.runner` interface is an alternative to using `hilbish.runnerMode`
+and also provides the sh and Lua runner functions that Hilbish itself uses.
+A runner function is expected to return 2 values: the exit code, and an error.
+The exit code has to be a number, it will be 0 otherwise and the error can be
+`nil` to indicate no error.
diff --git a/exec.go b/exec.go
index feda0e4..0a0ab74 100644
--- a/exec.go
+++ b/exec.go
@@ -24,13 +24,80 @@ import (
 )
 
 var errNotExec = errors.New("not executable")
+var runnerMode lua.LValue = lua.LString("hybrid")
 
 func runInput(input string, priv bool) {
 	running = true
 	cmdString := aliases.Resolve(input)
-
 	hooks.Em.Emit("command.preexec", input, cmdString)
 
+	if runnerMode.Type() == lua.LTString {
+		switch runnerMode.String() {
+			case "hybrid":
+				_, err := handleLua(cmdString)
+				if err == nil {
+					cmdFinish(0, cmdString, priv)
+					return
+				}
+				exitCode, err := handleSh(cmdString)
+				if err != nil {
+					fmt.Fprintln(os.Stderr, err)
+				}
+				cmdFinish(exitCode, cmdString, priv)
+			case "hybridRev":
+				_, err := handleSh(cmdString)
+				if err == nil {
+					cmdFinish(0, cmdString, priv)
+					return
+				}
+				exitCode, err := handleLua(cmdString)
+				if err != nil {
+					fmt.Fprintln(os.Stderr, err)
+				}
+				cmdFinish(exitCode, cmdString, priv)
+			case "lua":
+				exitCode, err := handleLua(cmdString)
+				if err != nil {
+					fmt.Fprintln(os.Stderr, err)
+				}
+				cmdFinish(exitCode, cmdString, priv)
+			case "sh":
+				exitCode, err := handleSh(cmdString)
+				if err != nil {
+					fmt.Fprintln(os.Stderr, err)
+				}
+				cmdFinish(exitCode, cmdString, priv)
+		}
+	} else {
+		// can only be a string or function so
+		err := l.CallByParam(lua.P{
+			Fn: runnerMode,
+			NRet: 2,
+			Protect: true,
+		}, lua.LString(cmdString))
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			cmdFinish(124, cmdString, priv)
+			return
+		}
+
+		luaexitcode := l.Get(-2) // first return value (makes sense right i love stacks)
+		runErr := l.Get(-1)
+		l.Pop(2)
+
+		var exitCode uint8
+		if code, ok := luaexitcode.(lua.LNumber); luaexitcode != lua.LNil && ok {
+			exitCode = uint8(code)
+		}
+
+		if runErr != lua.LNil {
+			fmt.Fprintln(os.Stderr, runErr)
+		}
+		cmdFinish(exitCode, cmdString, priv)
+	}
+}
+
+func handleLua(cmdString string) (uint8, error) {
 	// First try to load input, essentially compiling to bytecode
 	fn, err := l.LoadString(cmdString)
 	if err != nil && noexecute {
@@ -41,7 +108,7 @@ func runInput(input string, priv bool) {
 			}
 		}
 	*/
-		return
+		return 125, err
 	}
 	// And if there's no syntax errors and -n isnt provided, run
 	if !noexecute {
@@ -49,12 +116,14 @@ func runInput(input string, priv bool) {
 		err = l.PCall(0, lua.MultRet, nil)
 	}
 	if err == nil {
-		cmdFinish(0, cmdString, priv)
-		return
+		return 0, nil
 	}
 
-	// Last option: use sh interpreter
-	err = execCommand(cmdString, priv)
+	return 125, err
+}
+
+func handleSh(cmdString string) (uint8, error) {
+	err := execCommand(cmdString)
 	if err != nil {
 		// If input is incomplete, start multiline prompting
 		if syntax.IsIncomplete(err) {
@@ -63,34 +132,31 @@ func runInput(input string, priv bool) {
 				if err != nil {
 					break
 				}
-				err = execCommand(cmdString, priv)
-				if syntax.IsIncomplete(err) || strings.HasSuffix(input, "\\") {
+				err = execCommand(cmdString)
+				if syntax.IsIncomplete(err) || strings.HasSuffix(cmdString, "\\") {
 					continue
 				} else if code, ok := interp.IsExitStatus(err); ok {
-					cmdFinish(code, cmdString, priv)
+					return code, nil
 				} else if err != nil {
-					cmdFinish(1, cmdString, priv)
-					fmt.Fprintln(os.Stderr, err)
+					return 126, err
 				} else {
-					cmdFinish(0, cmdString, priv)
+					return 0, nil
 				}
-				break
 			}
 		} else {
 			if code, ok := interp.IsExitStatus(err); ok {
-				cmdFinish(code, cmdString, priv)
+				return code, nil
 			} else {
-				cmdFinish(126, cmdString, priv)
-				fmt.Fprintln(os.Stderr, err)
+				return 126, err
 			}
 		}
-	} else {
-		cmdFinish(0, cmdString, priv)
 	}
+
+	return 0, nil
 }
 
 // Run command in sh interpreter
-func execCommand(cmd string, priv bool) error {
+func execCommand(cmd string) error {
 	file, err := syntax.NewParser().Parse(strings.NewReader(cmd), "")
 	if err != nil {
 		return err
@@ -141,7 +207,6 @@ func execCommand(cmd string, priv bool) error {
 				exitcode = uint8(code)
 			}
 
-			cmdFinish(exitcode, argstring, priv)
 			return interp.NewExitStatus(exitcode)
 		}
 
diff --git a/runnermode.go b/runnermode.go
new file mode 100644
index 0000000..6d632ec
--- /dev/null
+++ b/runnermode.go
@@ -0,0 +1,46 @@
+package main
+
+import (
+	"github.com/yuin/gopher-lua"
+)
+
+func runnerModeLoader(L *lua.LState) *lua.LTable {
+	exports := map[string]lua.LGFunction{
+		"sh": shRunner,
+		"lua": luaRunner,
+		"setMode": hlrunnerMode,
+	}
+
+	mod := L.SetFuncs(L.NewTable(), exports)
+	L.SetField(mod, "mode", runnerMode)
+
+	return mod
+}
+
+func shRunner(L *lua.LState) int {
+	cmd := L.CheckString(1)
+	exitCode, err := handleSh(cmd)
+	var luaErr lua.LValue = lua.LNil
+	if err != nil {
+		luaErr = lua.LString(err.Error())
+	}
+
+	L.Push(lua.LNumber(exitCode))
+	L.Push(luaErr)
+
+	return 2
+}
+
+func luaRunner(L *lua.LState) int {
+	cmd := L.CheckString(1)
+	exitCode, err := handleLua(cmd)
+	var luaErr lua.LValue = lua.LNil
+	if err != nil {
+		luaErr = lua.LString(err.Error())
+	}
+
+	L.Push(lua.LNumber(exitCode))
+	L.Push(luaErr)
+
+	return 2
+}