fix: keep dollar sequences intact in harness inputs

src/harness.ts

@@ -128,9 +128,9 @@ function buildInvocationArgs(
   modelArgs: readonly string[] | undefined,
   model: string | undefined,
 ): string[] {
-  const args = template.map((arg) => arg.replaceAll("{prompt}", prompt));
+  const args = template.map((arg) => arg.replaceAll("{prompt}", () => prompt));
   if (model !== undefined && modelArgs) {
-    args.push(...modelArgs.map((arg) => arg.replaceAll("{model}", model)));
+    args.push(...modelArgs.map((arg) => arg.replaceAll("{model}", () => model)));
   }
   return args;
 }
@@ -420,7 +420,7 @@ export abstract class Harness {
     if (!template) return null;
     return {
       command,
-      args: template.map((arg) => arg.replaceAll("{search}", search ?? "")),
+      args: template.map((arg) => arg.replaceAll("{search}", () => search ?? "")),
     };
   }
 

test/invoke.test.ts

@@ -56,6 +56,31 @@ class FakeCursor extends Harness {
 }
 
 describe("normalized invocation", () => {
+  it("preserves replacement tokens in prompts across invocation modes", () => {
+    const prompt = "Explain $$, $&, $`, $', $1 and {prompt}";
+    const claude = getHarness("claude");
+    const codex = getHarness("codex");
+
+    for (const built of [
+      claude.buildInvocation(prompt),
+      claude.buildInvocation(prompt, { structured: true }),
+      claude.buildInvocation(prompt, { tools: true }),
+      claude.buildInvocation(prompt, { tools: true, structured: true }),
+      codex.buildInvocation(prompt, { readOnly: true }),
+      codex.buildInvocation(prompt, { readOnly: true, structured: true }),
+    ]) {
+      expect(built?.args).toContain(prompt);
+    }
+  });
+
+  it("delivers replacement tokens unchanged to the child process", async () => {
+    const prompt = "Explain $$, $&, $`, $', $1 and {prompt}";
+    const result = await new FakeCursor().invoke(prompt, { structured: true });
+
+    expect(result.exitCode).toBe(0);
+    expect(JSON.parse(result.stdout)).toEqual({ advisor: prompt });
+  });
+
   it("keeps the Claude advisor prompt outside the variadic tools option", () => {
     const claude = getHarness("claude");
     expect(claude.buildInvocation("answer this")).toEqual({

test/models.test.ts

@@ -44,6 +44,24 @@ describe("model listing", () => {
     });
   });
 
+  it("preserves replacement tokens in model names", () => {
+    const model = "custom/$$-$&-$`-$'-$1-{model}";
+
+    expect(new Pi().buildInvocation("answer this", { model })).toEqual({
+      command: "pi",
+      args: ["-p", "--no-tools", "answer this", "--model", model],
+    });
+  });
+
+  it("preserves replacement tokens in model search filters", () => {
+    const search = "$$ $& $` $' $1 {search}";
+
+    expect(new Pi().buildModelListInvocation(search)).toEqual({
+      command: "pi",
+      args: ["--list-models", search],
+    });
+  });
+
   it("adds an explicit model to a Pi run invocation", () => {
     const pi = new Pi();