diff --git a/.gitignore b/.gitignore
index 9687600..e0de86c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,7 @@
 # Binaries
 /bin/
 /dist/
-nock
+/nock
 *.exe
 *.test
 *.out
diff --git a/cmd/nock/main.go b/cmd/nock/main.go
new file mode 100644
index 0000000..ae4eb63
--- /dev/null
+++ b/cmd/nock/main.go
@@ -0,0 +1,196 @@
+// Command nock is the single binary for the nock command launcher. One binary,
+// several modes — the engine is shared; each mode is a thin frontend over it:
+//
+//	nock                 interactive TUI (default)
+//	nock --mcp           Model Context Protocol server over stdio (for AI agents)
+//	nock search <query>  non-interactive search (scriptable; proves the engine)
+//	nock resolve <id>    fill a command's variables and print it
+//	nock serve           team HTTP/SSE server (Milestone 5)
+//	nock import <src>    import arsenal cheatsheets as seed content (Milestone 0/1)
+//	nock version         print build metadata
+//
+// Cheatsheets are loaded from $NOCK_CHEATSHEETS (default ./examples/cheatsheets).
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"os"
+	"os/signal"
+	"strings"
+
+	"github.com/jessn-dev/nock/internal/cheatsheet"
+	"github.com/jessn-dev/nock/internal/engine"
+	"github.com/jessn-dev/nock/internal/fire"
+	"github.com/jessn-dev/nock/internal/history"
+	"github.com/jessn-dev/nock/internal/mcp"
+	"github.com/jessn-dev/nock/internal/tui"
+	"github.com/jessn-dev/nock/internal/vars"
+	"github.com/jessn-dev/nock/internal/version"
+)
+
+func main() {
+	if err := run(os.Args[1:]); err != nil {
+		fmt.Fprintln(os.Stderr, "nock:", err)
+		os.Exit(1)
+	}
+}
+
+func run(args []string) error {
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer stop()
+
+	// Subcommand dispatch. Flags that toggle mode (--mcp, --version) are handled
+	// before subcommands so `nock --mcp` works without a positional verb. The TUI
+	// is the default mode, so a bare invocation or one that leads with a flag
+	// (e.g. `nock --fire=tmux`) is routed to it.
+	if len(args) == 0 || strings.HasPrefix(args[0], "-") && args[0] != "--mcp" &&
+		args[0] != "--version" && args[0] != "-v" && args[0] != "--help" && args[0] != "-h" {
+		return cmdTUI(ctx, args)
+	}
+	switch args[0] {
+	case "--mcp":
+		return cmdMCP(ctx)
+	case "version", "--version", "-v":
+		fmt.Println(version.String())
+		return nil
+	case "search":
+		return cmdSearch(ctx, args[1:])
+	case "resolve":
+		return cmdResolve(ctx, args[1:])
+	case "serve":
+		return fmt.Errorf("serve: team server arrives in Milestone 5")
+	case "import":
+		return fmt.Errorf("import: arsenal importer arrives in Milestone 0/1")
+	case "help", "--help", "-h":
+		printUsage()
+		return nil
+	default:
+		printUsage()
+		return fmt.Errorf("unknown command %q", args[0])
+	}
+}
+
+// loadEngine builds an engine from the configured cheatsheet directory. Load
+// errors are non-fatal — they are reported and whatever parsed is still served.
+func loadEngine(store *vars.Store) *engine.Engine {
+	dir := os.Getenv("NOCK_CHEATSHEETS")
+	if dir == "" {
+		dir = "examples/cheatsheets"
+	}
+	sheets, err := cheatsheet.LoadDir(dir)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "nock: warning loading cheatsheets: %v\n", err)
+	}
+	return engine.New(sheets, store)
+}
+
+func cmdTUI(ctx context.Context, args []string) error {
+	fs := flag.NewFlagSet("nock", flag.ContinueOnError)
+	target := fs.String("fire", string(fire.Stdout),
+		"where a confirmed command is delivered: stdout|tmux")
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+	t, err := fire.Parse(*target)
+	if err != nil {
+		return err
+	}
+
+	// History is best-effort: a path resolution problem disables it rather than
+	// blocking the TUI. NOCK_HISTORY=off yields an empty path (a no-op store).
+	path, err := history.DefaultPath()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "nock: warning, history disabled: %v\n", err)
+	}
+
+	return tui.Run(ctx, loadEngine(vars.New()), tui.Options{
+		History:       history.New(path),
+		DefaultTarget: t,
+	})
+}
+
+func cmdMCP(ctx context.Context) error {
+	return mcp.New(loadEngine(vars.New())).Serve(ctx)
+}
+
+func cmdSearch(_ context.Context, args []string) error {
+	fs := flag.NewFlagSet("search", flag.ContinueOnError)
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+	query := strings.Join(fs.Args(), " ")
+	e := loadEngine(vars.New())
+	results := e.Search(query)
+	if len(results) == 0 {
+		fmt.Println("no matches")
+		return nil
+	}
+	for _, r := range results {
+		fmt.Printf("%-24s [%s] %s\n", r.Command.ID, r.Sheet, r.Command.Command)
+	}
+	return nil
+}
+
+func cmdResolve(_ context.Context, args []string) error {
+	// Hand-parsed so --var bindings work in any position relative to the command id
+	// (the stdlib flag package stops at the first positional argument).
+	store := vars.New()
+	var id string
+	for i := 0; i < len(args); i++ {
+		switch {
+		case args[i] == "--var" || args[i] == "-var":
+			if i+1 >= len(args) {
+				return fmt.Errorf("resolve: --var needs a key=value argument")
+			}
+			i++
+			k, v, ok := strings.Cut(args[i], "=")
+			if !ok {
+				return fmt.Errorf("resolve: bad --var %q, want key=value", args[i])
+			}
+			store.Set(k, v)
+		case strings.HasPrefix(args[i], "--var="):
+			k, v, ok := strings.Cut(strings.TrimPrefix(args[i], "--var="), "=")
+			if !ok {
+				return fmt.Errorf("resolve: bad --var %q, want key=value", args[i])
+			}
+			store.Set(k, v)
+		case id == "":
+			id = args[i]
+		default:
+			return fmt.Errorf("resolve: unexpected argument %q", args[i])
+		}
+	}
+	if id == "" {
+		return fmt.Errorf("resolve: command id required")
+	}
+	e := loadEngine(store)
+	cmd, ok := e.Get(id)
+	if !ok {
+		return fmt.Errorf("resolve: no command with id %q", id)
+	}
+	out, err := e.Resolve(cmd)
+	if err != nil {
+		return err
+	}
+	fmt.Println(out)
+	return nil
+}
+
+func printUsage() {
+	fmt.Fprint(os.Stderr, `nock — AI-aware command launcher
+
+Usage:
+  nock                  start the interactive TUI (default)
+  nock --mcp            run as an MCP server over stdio (for AI agents)
+  nock search <query>   search commands non-interactively
+  nock resolve <id> --var k=v ...   resolve a command's variables
+  nock serve            team server (Milestone 5)
+  nock import <src>     import arsenal cheatsheets (Milestone 0/1)
+  nock version          print build metadata
+
+Environment:
+  NOCK_CHEATSHEETS      cheatsheet directory (default: examples/cheatsheets)
+`)
+}