feat(cli): add elysia + aisdk support and fix fastify ai example

apps/cli/src/constants.ts

@@ -92,7 +92,7 @@ export const dependencyVersionMap = {
 
 	"@elysiajs/cors": "^1.3.3",
 	"@elysiajs/trpc": "^1.1.0",
-	elysia: "^1.3.20",
+	"elysia": "^1.3.21",
 
 	"@hono/node-server": "^1.14.4",
 	"@hono/trpc-server": "^0.4.0",
@@ -108,12 +108,12 @@ export const dependencyVersionMap = {
 
 	turbo: "^2.5.4",
 
-	ai: "^5.0.9",
-	"@ai-sdk/google": "^2.0.3",
-	"@ai-sdk/vue": "^2.0.9",
-	"@ai-sdk/svelte": "^3.0.9",
-	"@ai-sdk/react": "^2.0.9",
-	streamdown: "^1.1.6",
+	"ai": "^5.0.39",
+	"@ai-sdk/google": "^2.0.13",
+	"@ai-sdk/vue": "^2.0.39",
+	"@ai-sdk/svelte": "^3.0.39",
+	"@ai-sdk/react": "^2.0.39",
+	streamdown: "^1.2.0",
 
 	"@orpc/server": "^1.8.6",
 	"@orpc/client": "^1.8.6",

apps/cli/src/prompts/examples.ts

@@ -33,10 +33,6 @@ export async function getExamplesChoice(
 
 	if (database === "none") return [];
 
-	const noFrontendSelected = !frontends || frontends.length === 0;
-
-	if (noFrontendSelected) return [];
-
 	let response: Examples[] | symbol = [];
 	const options: { value: Examples; label: string; hint: string }[] = [];
 

apps/cli/src/utils/compatibility-rules.ts

@@ -157,11 +157,10 @@ export function isExampleTodoAllowed(
 }
 
 export function isExampleAIAllowed(
-	backend?: ProjectConfig["backend"],
+	_backend?: ProjectConfig["backend"],
 	frontends: Frontend[] = [],
 ) {
 	const includesSolid = frontends.includes("solid");
-	if (backend === "elysia") return false;
 	if (includesSolid) return false;
 	return true;
 }
@@ -226,11 +225,6 @@ export function validateExamplesCompatibility(
 			"The 'todo' example requires a database if a backend (other than Convex) is present. Cannot use --examples todo when database is 'none' and a backend is selected.",
 		);
 	}
-	if (examplesArr.includes("ai") && backend === "elysia") {
-		exitWithError(
-			"The 'ai' example is not compatible with the Elysia backend.",
-		);
-	}
 	if (examplesArr.includes("ai") && (frontend ?? []).includes("solid")) {
 		exitWithError(
 			"The 'ai' example is not compatible with the Solid frontend.",

apps/cli/templates/backend/server/elysia/src/index.ts.hbs

@@ -4,6 +4,10 @@ import { node } from "@elysiajs/node";
 {{/if}}
 import { Elysia } from "elysia";
 import { cors } from "@elysiajs/cors";
+{{#if (includes examples "ai")}}
+import { google } from "@ai-sdk/google";
+import { convertToModelMessages, streamText } from "ai";
+{{/if}}
 {{#if (eq api "trpc")}}
 import { createContext } from "./lib/context";
 import { appRouter } from "./routers/index";
@@ -94,6 +98,18 @@ const app = new Elysia()
     });
     return res;
   })
+{{/if}}
+{{#if (includes examples "ai")}}
+  .post("/ai", async (context) => {
+    const body = await context.request.json();
+    const uiMessages = body.messages || [];
+    const result = streamText({
+      model: google("gemini-2.0-flash"),
+      messages: convertToModelMessages(uiMessages)
+    });
+
+    return result.toUIMessageStreamResponse();
+  })
 {{/if}}
   .get("/", () => "OK")
   .listen(3000, () => {

apps/cli/templates/backend/server/fastify/src/index.ts.hbs

@@ -158,15 +158,14 @@ interface AiRequestBody {
   messages: UIMessage[];
 }
 
-fastify.post('/ai', async function (request, reply) {
-  // there are some issues with the ai sdk and fastify, docs: https://ai-sdk.dev/cookbook/api-servers/fastify
+fastify.post('/ai', async function (request) {
   const { messages } = request.body as AiRequestBody;
   const result = streamText({
     model: google('gemini-1.5-flash'),
     messages: convertToModelMessages(messages),
   });
 
-  return result.pipeUIMessageStreamToResponse(reply.raw);
+  return result.toUIMessageStreamResponse();
 });
 {{/if}}
 

apps/web/src/app/(home)/new/_components/utils.ts

@@ -912,13 +912,6 @@ export const analyzeStackCompatibility = (
 						"Todo example removed (requires a database but 'None' was selected)",
 				});
 			}
-			if (nextStack.backend === "elysia" && nextStack.examples.includes("ai")) {
-				incompatibleExamples.push("ai");
-				changes.push({
-					category: "examples",
-					message: "AI example removed (not compatible with Elysia backend)",
-				});
-			}
 			if (isSolid && nextStack.examples.includes("ai")) {
 				incompatibleExamples.push("ai");
 				changes.push({
@@ -942,19 +935,6 @@ export const analyzeStackCompatibility = (
 					notes.database.hasIssue = true;
 					notes.examples.hasIssue = true;
 				}
-				if (
-					nextStack.backend === "elysia" &&
-					uniqueIncompatibleExamples.includes("ai")
-				) {
-					notes.backend.notes.push(
-						"AI example is not compatible with Elysia. It will be removed.",
-					);
-					notes.examples.notes.push(
-						"AI example is not compatible with Elysia. It will be removed.",
-					);
-					notes.backend.hasIssue = true;
-					notes.examples.hasIssue = true;
-				}
 				if (isSolid && uniqueIncompatibleExamples.includes("ai")) {
 					notes.webFrontend.notes.push(
 						"AI example is not compatible with Solid. It will be removed.",
@@ -1551,9 +1531,6 @@ export const getDisabledReason = (
 	}
 
 	if (category === "examples" && optionId === "ai") {
-		if (finalStack.backend === "elysia") {
-			return "AI example is not compatible with Elysia backend. Try Hono, Express, or Fastify.";
-		}
 		if (finalStack.webFrontend.includes("solid")) {
 			return "AI example is not compatible with Solid frontend. Try React-based frontends.";
 		}