feat(backend): add tRPC with Hono adapter

- Add @trpc/server, @hono/trpc-server, zod dependencies
- Create tRPC context with BetterAuth session
- Create router with publicProcedure and protectedProcedure
- Mount tRPC at /trpc/* via Hono adapter

Co-authored-by: Ona <no-reply@ona.com>

apps/aris-backend/package.json

@@ -12,9 +12,12 @@
 		"@aris/core": "workspace:*",
 		"@aris/source-location": "workspace:*",
 		"@aris/source-weatherkit": "workspace:*",
+		"@hono/trpc-server": "^0.3",
+		"@trpc/server": "^11",
 		"better-auth": "^1",
 		"hono": "^4",
-		"pg": "^8"
+		"pg": "^8",
+		"zod": "^3"
 	},
 	"devDependencies": {
 		"@types/pg": "^8"

apps/aris-backend/src/server.ts

@@ -1,6 +1,9 @@
+import { trpcServer } from "@hono/trpc-server"
 import { Hono } from "hono"
 
 import { registerAuthHandlers } from "./auth/http.ts"
+import { createContext } from "./trpc/context.ts"
+import { appRouter } from "./trpc/router.ts"
 
 const app = new Hono()
 
@@ -8,6 +11,14 @@ app.get("/health", (c) => c.json({ status: "ok" }))
 
 registerAuthHandlers(app)
 
+app.use(
+	"/trpc/*",
+	trpcServer({
+		router: appRouter,
+		createContext,
+	}),
+)
+
 export default {
 	port: 3000,
 	fetch: app.fetch,

apps/aris-backend/src/trpc/context.ts

@@ -0,0 +1,14 @@
+import type { FetchCreateContextFnOptions } from "@trpc/server/adapters/fetch"
+
+import { auth } from "../auth/index.ts"
+
+export async function createContext(opts: FetchCreateContextFnOptions) {
+	const session = await auth.api.getSession({ headers: opts.req.headers })
+
+	return {
+		user: session?.user ?? null,
+		session: session?.session ?? null,
+	}
+}
+
+export type Context = Awaited<ReturnType<typeof createContext>>

apps/aris-backend/src/trpc/router.ts

@@ -0,0 +1,5 @@
+import { router } from "./trpc.ts"
+
+export const appRouter = router({})
+
+export type AppRouter = typeof appRouter

apps/aris-backend/src/trpc/trpc.ts

@@ -0,0 +1,22 @@
+import { initTRPC, TRPCError } from "@trpc/server"
+
+import type { Context } from "./context.ts"
+
+const t = initTRPC.context<Context>().create()
+
+export const router = t.router
+export const publicProcedure = t.procedure
+
+const isAuthed = t.middleware(({ ctx, next }) => {
+	if (!ctx.user || !ctx.session) {
+		throw new TRPCError({ code: "UNAUTHORIZED" })
+	}
+	return next({
+		ctx: {
+			user: ctx.user,
+			session: ctx.session,
+		},
+	})
+})
+
+export const protectedProcedure = t.procedure.use(isAuthed)