diff --git a/src/auto-reply/commands-registry.args.test.ts b/src/auto-reply/commands-registry.args.test.ts
new file mode 100644
index 000000000..91075a1bd
--- /dev/null
+++ b/src/auto-reply/commands-registry.args.test.ts
@@ -0,0 +1,97 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  buildCommandTextFromArgs,
+  parseCommandArgs,
+  resolveCommandArgMenu,
+  serializeCommandArgs,
+} from "./commands-registry.js";
+import type { ChatCommandDefinition } from "./commands-registry.types.js";
+
+describe("commands registry args", () => {
+  it("parses positional args and captureRemaining", () => {
+    const command: ChatCommandDefinition = {
+      key: "debug",
+      description: "debug",
+      textAliases: [],
+      scope: "both",
+      argsParsing: "positional",
+      args: [
+        { name: "action", description: "action", type: "string" },
+        { name: "path", description: "path", type: "string" },
+        { name: "value", description: "value", type: "string", captureRemaining: true },
+      ],
+    };
+
+    const args = parseCommandArgs(command, "set foo bar baz");
+    expect(args?.values).toEqual({ action: "set", path: "foo", value: "bar baz" });
+  });
+
+  it("serializes args via raw first, then values", () => {
+    const command: ChatCommandDefinition = {
+      key: "model",
+      description: "model",
+      textAliases: [],
+      scope: "both",
+      argsParsing: "positional",
+      args: [{ name: "model", description: "model", type: "string", captureRemaining: true }],
+    };
+
+    expect(serializeCommandArgs(command, { raw: "gpt-5.2-codex" })).toBe("gpt-5.2-codex");
+    expect(serializeCommandArgs(command, { values: { model: "gpt-5.2-codex" } })).toBe(
+      "gpt-5.2-codex",
+    );
+    expect(buildCommandTextFromArgs(command, { values: { model: "gpt-5.2-codex" } })).toBe(
+      "/model gpt-5.2-codex",
+    );
+  });
+
+  it("resolves auto arg menus when missing a choice arg", () => {
+    const command: ChatCommandDefinition = {
+      key: "cost",
+      description: "cost",
+      textAliases: [],
+      scope: "both",
+      argsMenu: "auto",
+      argsParsing: "positional",
+      args: [
+        {
+          name: "mode",
+          description: "mode",
+          type: "string",
+          choices: ["on", "off"],
+        },
+      ],
+    };
+
+    const menu = resolveCommandArgMenu({ command, args: undefined, cfg: {} as never });
+    expect(menu?.arg.name).toBe("mode");
+    expect(menu?.choices).toEqual(["on", "off"]);
+  });
+
+  it("does not show menus when arg already provided", () => {
+    const command: ChatCommandDefinition = {
+      key: "cost",
+      description: "cost",
+      textAliases: [],
+      scope: "both",
+      argsMenu: "auto",
+      argsParsing: "positional",
+      args: [
+        {
+          name: "mode",
+          description: "mode",
+          type: "string",
+          choices: ["on", "off"],
+        },
+      ],
+    };
+
+    const menu = resolveCommandArgMenu({
+      command,
+      args: { values: { mode: "on" } },
+      cfg: {} as never,
+    });
+    expect(menu).toBeNull();
+  });
+});
diff --git a/src/markdown/code-spans.ts b/src/markdown/code-spans.ts
index 8644c90a0..1077ee755 100644
--- a/src/markdown/code-spans.ts
+++ b/src/markdown/code-spans.ts
@@ -19,10 +19,7 @@ export type CodeSpanIndex = {
   isInside: (index: number) => boolean;
 };
 
-export function buildCodeSpanIndex(
-  text: string,
-  inlineState?: InlineCodeState,
-): CodeSpanIndex {
+export function buildCodeSpanIndex(text: string, inlineState?: InlineCodeState): CodeSpanIndex {
   const fenceSpans = parseFenceSpans(text);
   const startState = inlineState
     ? { open: inlineState.open, ticks: inlineState.ticks }