feat: add resources and meta to mcp manifests (#674)

Add resources to functions manifest for any resources that are defined
on the mcp sdk.

Additionally, add handleResources export to the mcp server template, so
calls will be proxied for functions defined in the SDK

Author: qstearns

.changeset/wet-banks-join.md

@@ -0,0 +1,5 @@
+---
+"@gram-ai/functions": minor
+---
+
+allow for defining resources in mcp builds of gram functions

.mise-tasks/start/server.sh

@@ -2,7 +2,6 @@
 
 #MISE dir="{{ config_root }}/server"
 #MISE description="Start up the API server"
-#MISE sources=["server/**/*.go"]
 
 GIT_SHA=$(git rev-parse HEAD)
 
@@ -11,4 +10,4 @@ if [ -f "../config.local.toml" ]; then
     CONFIG_ARGS=(--config-file ../config.local.toml)
 fi
 
-go run -ldflags="-X github.com/speakeasy-api/gram/server/cmd/gram.GitSHA=${GIT_SHA} -X goa.design/clue/health.Version=${GIT_SHA}" main.go start "${CONFIG_ARGS[@]}" "$@"
+go run -ldflags="-X github.com/speakeasy-api/gram/server/cmd/gram.GitSHA=${GIT_SHA} -X goa.design/clue/health.Version=${GIT_SHA}" main.go start "${CONFIG_ARGS[@]}" "$@"

ts-framework/create-function/gram-template-mcp/src/functions.ts

@@ -26,3 +26,20 @@ export async function handleToolCall(call: {
     headers: { "Content-Type": "application/json; mcp=tools_call" },
   });
 }
+
+export async function handleResources(call: {
+  uri: string;
+  input: string;
+  _meta?: Record<string, unknown>;
+}): Promise<Response> {
+  const response = await client.readResource({
+    uri: call.uri,
+    _meta: call._meta,
+  });
+
+  const body = JSON.stringify(response);
+  return new Response(body, {
+    status: 200,
+    headers: { "Content-Type": "application/json" },
+  });
+}

ts-framework/create-function/gram-template-mcp/src/mcp.ts

@@ -20,3 +20,24 @@ server.registerTool(
     };
   },
 );
+
+server.registerResource(
+  "a-cool-photo",
+  "resources://a-cool-photo",
+  {
+    mimeType: "image/jpg",
+    description: "This photo is really something",
+    title: "A Cool Photo",
+  },
+  async (uri) => {
+    let res = await fetch("https://picsum.photos/200/300.jpg");
+    return {
+      contents: [
+        {
+          uri: uri.href,
+          blob: Buffer.from(await res.arrayBuffer()).toString("base64"),
+        },
+      ],
+    };
+  },
+);

ts-framework/functions/src/build/mcp.ts

@@ -2,6 +2,11 @@ import { writeFile, open, stat, mkdir } from "node:fs/promises";
 import { join, resolve } from "node:path";
 import esbuild from "esbuild";
 import archiver from "archiver";
+import {
+  McpError,
+  ErrorCode as McpErrorCode,
+} from "@modelcontextprotocol/sdk/types.js";
+import type { Client } from "@modelcontextprotocol/sdk/client";
 
 export type BuildMCPServerResult = {
   files: Array<{ path: string; size: number }>;
@@ -60,6 +65,14 @@ async function buildFunctionsManifest(options: {
     name: string;
     description?: string | undefined;
     inputSchema: unknown;
+    _meta?: unknown;
+  }>;
+  resources?: Array<{
+    name: string;
+    description?: string | undefined;
+    uri: string;
+    mimeType?: string | undefined;
+    _meta?: unknown;
   }>;
 }> {
   const cwd = options.cwd ?? process.cwd();
@@ -92,16 +105,61 @@ async function buildFunctionsManifest(options: {
   await server.connect(serverTransport);
   await mcpClient.connect(clientTransport);
 
-  const res = await mcpClient.listTools();
-  const tools = res.tools.map((tool) => {
-    return {
-      name: tool.name,
-      description: tool.description,
-      inputSchema: tool.inputSchema,
-    };
-  });
+  let tools = await collectTools(mcpClient);
+  let resources = await collectResources(mcpClient);
+
+  return { version: "0.0.0", tools, resources };
+}
+
+async function collectTools(client: Client) {
+  try {
+    const res = await client.listTools();
+    return res.tools.map((tool) => {
+      return {
+        name: tool.name,
+        description: tool.description,
+        inputSchema: tool.inputSchema,
+        meta: {
+          "gram.ai/kind": "mcp-passthrough",
+          ...tool._meta,
+        },
+      };
+    });
+  } catch (err) {
+    if (err instanceof McpError && err.code === McpErrorCode.MethodNotFound) {
+      console.warn("No tools registered");
+    } else {
+      throw err;
+    }
+    return [];
+  }
+}
+
+async function collectResources(client: Client) {
+  try {
+    const resourcesResponse = await client.listResources();
+    return resourcesResponse.resources.map((resource) => {
+      return {
+        name: resource.name,
+        description: resource.description,
+        uri: resource.uri,
+        mimeType: resource.mimeType,
+        title: resource.title,
+        meta: {
+          "gram.ai/kind": "mcp-passthrough",
+          ...resource._meta,
+        },
+      };
+    });
+  } catch (err) {
+    if (err instanceof McpError && err.code === McpErrorCode.MethodNotFound) {
+      console.warn("No tools registered");
+    } else {
+      throw err;
+    }
+  }
 
-  return { version: "0.0.0", tools };
+  return [];
 }
 
 async function bundleFunction(options: {