feat: markdown ctx type (#843)

# What

Adds a simple `markdown()` ctx helper method to return a text response
with the correct MIME type.

I will add support for rendering markdown in a separate PR to the
playground.

Author: adaam2

.changeset/dull-ghosts-tap.md

@@ -0,0 +1,6 @@
+---
+"@gram-ai/create-function": patch
+"@gram-ai/functions": patch
+---
+
+Adds markdown() response helper to the functions ctx

examples/complete/pylon-basic/CONTRIBUTING.md

@@ -94,6 +94,16 @@ async execute(ctx, input) {
 }
 ```
 
+#### `ctx.markdown(data)`
+
+Returns a Markdown response:
+
+```typescript
+async execute(ctx, input) {
+  return ctx.markdown("# Heading");
+}
+```
+
 #### `ctx.fail(data, options?)`
 
 Throws an error response (never returns):

ts-framework/create-function/gram-template-gram/CONTRIBUTING.md

@@ -95,6 +95,16 @@ async execute(ctx, input) {
 }
 ```
 
+#### `ctx.markdown(data)`
+
+Returns a Markdown response:
+
+```typescript
+async execute(ctx, input) {
+  return ctx.markdown("# Heading");
+}
+```
+
 #### `ctx.fail(data, options?)`
 
 Throws an error response (never returns):

ts-framework/functions/README.md

@@ -111,6 +111,16 @@ async execute(ctx, input) {
 }
 ```
 
+#### `ctx.markdown(data)`
+
+Returns a markdown response:
+
+```typescript
+async execute(ctx, input) {
+  return ctx.markdown("# Heading");
+}
+```
+
 #### `ctx.html(data)`
 
 Returns an HTML response:

ts-framework/functions/src/framework.test.ts

@@ -158,6 +158,29 @@ test("supports text tools", async () => {
   expect(data).toBe("HELLO!!!");
 });
 
+test("supports markdown tools", async () => {
+  const g = new Gram().tool({
+    name: "shout",
+    description: "Shouts the input",
+    inputSchema: { message: z.string() },
+    async execute(ctx, input) {
+      return ctx.markdown(`# ${input.message.toUpperCase()}!!!`);
+    },
+  });
+
+  const response = await g.handleToolCall({
+    name: "shout",
+    input: { message: "hello" },
+  });
+  expect(response.status).toBe(200);
+  expect(response.headers.get("Content-Type")).toBe(
+    "text/markdown;charset=UTF-8",
+  );
+
+  const data = await response.text();
+  expect(data).toBe("# HELLO!!!");
+});
+
 test("supports html tools", async () => {
   const g = new Gram().tool({
     name: "shout",

ts-framework/functions/src/framework.ts

@@ -138,6 +138,18 @@ class ToolContext<Env> {
     }) as JSONResponse<V>;
   }
 
+  /**
+   * Constructs a Markdown response
+   */
+  markdown<V extends string>(data: V): TextResponse<V> {
+    return new Response(data, {
+      status: 200,
+      headers: {
+        "Content-Type": "text/markdown;charset=UTF-8",
+      },
+    }) as TextResponse<V>;
+  }
+
   /**
    * Constructs a plain text response
    */