Add Haiku and Opus model choices to prompt CLI

README.md

@@ -26,6 +26,8 @@ spritesmith prompt --kind vector --format svg --operation-id emblem-v1 --out emb
 spritesmith prompt --kind vector --format png --out emblem.png 'A golden shield emblem'
 ```
 
+Use `--model haiku` (the default) or `--model opus` to choose the reasoning model. The API freezes this choice with the request, including retries. Both use medium reasoning effort.
+
 Flags come before the prompt. Use the web app to attach reference images, work with several sprites in a session, and publish revisions.
 
 The service creates and reviews vector animations through its agent workflow. This client downloads the default pose as SVG or PNG; the web app also exports animation sheets and frames.

cmd/spritesmith/main.go

@@ -18,6 +18,7 @@ var revision = "unknown"
 const defaultAPIBase = "http://127.0.0.1:8080"
 
 type commonFlags struct {
+	model       *string
 	operationID *string
 	apiBase     *string
 	out         *string
@@ -64,6 +65,7 @@ func runPrompt(args []string) int {
 // Folded into run* they were untestable, and losing a line there is invisible:
 // dropping OutputPath makes --out do nothing, and the CLI still prints a path
 // and still writes a PNG, just never the one that was asked for.
+
 func parsePrompt(args []string) (apiBase string, req client.Request, ok bool) {
 	fs, flags := newCommandFlags("prompt")
 	terminated := promptFlagsTerminated(args, fs)
@@ -82,6 +84,7 @@ func parsePrompt(args []string) (apiBase string, req client.Request, ok bool) {
 
 	return *flags.apiBase, client.Request{
 		OperationID: *flags.operationID,
+		Model:       *flags.model,
 		Mode:        client.ModePrompt,
 		Prompt:      prompt,
 		OutputPath:  outputPath(flags),
@@ -145,6 +148,7 @@ func newCommandFlags(name string) (*flag.FlagSet, commonFlags) {
 	fs := flag.NewFlagSet(name, flag.ContinueOnError)
 	fs.SetOutput(os.Stderr)
 	flags := commonFlags{
+		model:       fs.String("model", "haiku", "reasoning model: haiku (default) or opus"),
 		operationID: fs.String("operation-id", "", "reuse the same logical generation after an interrupted submission"),
 		apiBase:     fs.String("api", envDefault("SPRITESMITH_API_BASE", defaultAPIBase), "spritesmith API base URL"),
 		out:         fs.String("out", "", "output filename"),

cmd/spritesmith/main_test.go

@@ -310,3 +310,16 @@ func TestHelpSaysAnExistingFileIsNotOverwritten(t *testing.T) {
 		t.Errorf("--help does not say what happens when the output path is taken:\n%s", out.String())
 	}
 }
+
+func TestPromptModelChoice(t *testing.T) {
+	for _, model := range []string{"haiku", "opus"} {
+		_, req, ok := parsePrompt([]string{"--model", model, "a tiny slime"})
+		if !ok || req.Model != model {
+			t.Fatalf("model selection lost: %+v", req)
+		}
+	}
+	_, req, ok := parsePrompt([]string{"a tiny slime"})
+	if !ok || req.Model != "haiku" {
+		t.Fatal("default must be haiku")
+	}
+}

internal/client/client.go

@@ -42,6 +42,7 @@ const (
 const DefaultOutputPath = "spritesmith.png"
 
 type Request struct {
+	Model       string
 	Kind        string
 	Format      string
 	OperationID string
@@ -66,6 +67,17 @@ type Client struct {
 }
 
 func (c Client) Process(req Request) (Response, error) {
+	model := req.Model
+	switch model {
+	case "", "haiku":
+		model = "anthropic/claude-haiku-5.5"
+	case "opus":
+		model = "anthropic/claude-opus-5.5"
+	case "anthropic/claude-haiku-5.5", "anthropic/claude-opus-5.5":
+	default:
+		return Response{}, errors.New("model must be haiku or opus")
+	}
+
 	if req.Kind == "" {
 		req.Kind = "vector"
 	}
@@ -123,6 +135,10 @@ func (c Client) Process(req Request) (Response, error) {
 		return Response{}, err
 	}
 
+	if err := writer.WriteField("agent_model", model); err != nil {
+		return Response{}, err
+	}
+
 	endpoint := "/v1/prompt"
 	switch req.Mode {
 	case ModePrompt:

internal/client/client_test.go

@@ -934,3 +934,20 @@ func TestTheDefaultOutputNameIsTheOneEverythingElseExpects(t *testing.T) {
 		t.Errorf("cli/.gitignore does not list %q, so `make cli` leaves a result in the source tree:\n%s", DefaultOutputPath, ignore)
 	}
 }
+
+func TestReasoningModelChoiceReachesAPI(t *testing.T) {
+	for _, tc := range []struct{ selected, want string }{{"", "anthropic/claude-haiku-5.5"}, {"haiku", "anthropic/claude-haiku-5.5"}, {"opus", "anthropic/claude-opus-5.5"}} {
+		api := &recordingAPI{}
+		srv := httptest.NewServer(api)
+		req := promptRequest(t)
+		req.Model = tc.selected
+		if _, err := (Client{BaseURL: srv.URL}).Process(req); err != nil {
+			srv.Close()
+			t.Fatal(err)
+		}
+		srv.Close()
+		if got := api.form.Get("agent_model"); got != tc.want {
+			t.Fatalf("selection %q sent %q, want %q", tc.selected, got, tc.want)
+		}
+	}
+}