diff --git a/apps/aris-backend/package.json b/apps/aris-backend/package.json
index e0702d8..e33baf2 100644
--- a/apps/aris-backend/package.json
+++ b/apps/aris-backend/package.json
@@ -14,10 +14,10 @@
 		"@aris/source-weatherkit": "workspace:*",
 		"@hono/trpc-server": "^0.3",
 		"@trpc/server": "^11",
+		"arktype": "^2.1.29",
 		"better-auth": "^1",
 		"hono": "^4",
-		"pg": "^8",
-		"zod": "^3"
+		"pg": "^8"
 	},
 	"devDependencies": {
 		"@types/pg": "^8"
diff --git a/apps/aris-backend/src/location/router.ts b/apps/aris-backend/src/location/router.ts
new file mode 100644
index 0000000..a76ad88
--- /dev/null
+++ b/apps/aris-backend/src/location/router.ts
@@ -0,0 +1,33 @@
+import { TRPCError } from "@trpc/server"
+import { type } from "arktype"
+
+import { UserNotFoundError } from "../lib/error.ts"
+import type { TRPC } from "../trpc/router.ts"
+import type { LocationService } from "./service.ts"
+
+const locationInput = type({
+	lat: "number",
+	lng: "number",
+	accuracy: "number",
+	timestamp: "Date",
+})
+
+export function createLocationRouter(t: TRPC, { locationService }: { locationService: LocationService }) {
+	return t.router({
+		update: t.procedure.input(locationInput).mutation(({ input, ctx }) => {
+			try {
+				locationService.updateUserLocation(ctx.user.id, {
+					lat: input.lat,
+					lng: input.lng,
+					accuracy: input.accuracy,
+					timestamp: input.timestamp,
+				})
+			} catch (error) {
+				if (error instanceof UserNotFoundError) {
+					throw new TRPCError({ code: "NOT_FOUND", message: error.message })
+				}
+				throw error
+			}
+		}),
+	})
+}
diff --git a/apps/aris-backend/src/server.ts b/apps/aris-backend/src/server.ts
index 287c8ca..ff40f3e 100644
--- a/apps/aris-backend/src/server.ts
+++ b/apps/aris-backend/src/server.ts
@@ -2,22 +2,33 @@ import { trpcServer } from "@hono/trpc-server"
 import { Hono } from "hono"
 
 import { registerAuthHandlers } from "./auth/http.ts"
+import { LocationService } from "./location/service.ts"
 import { createContext } from "./trpc/context.ts"
-import { appRouter } from "./trpc/router.ts"
+import { createTRPCRouter } from "./trpc/router.ts"
 
-const app = new Hono()
+function main() {
+	const locationService = new LocationService()
 
-app.get("/health", (c) => c.json({ status: "ok" }))
+	const trpcRouter = createTRPCRouter({ locationService })
 
-registerAuthHandlers(app)
+	const app = new Hono()
 
-app.use(
-	"/trpc/*",
-	trpcServer({
-		router: appRouter,
-		createContext,
-	}),
-)
+	app.get("/health", (c) => c.json({ status: "ok" }))
+
+	registerAuthHandlers(app)
+
+	app.use(
+		"/trpc/*",
+		trpcServer({
+			router: trpcRouter,
+			createContext,
+		}),
+	)
+
+	return app
+}
+
+const app = main()
 
 export default {
 	port: 3000,
diff --git a/apps/aris-backend/src/trpc/router.ts b/apps/aris-backend/src/trpc/router.ts
index 2b99062..74d60d5 100644
--- a/apps/aris-backend/src/trpc/router.ts
+++ b/apps/aris-backend/src/trpc/router.ts
@@ -1,5 +1,47 @@
-import { router } from "./trpc.ts"
+import { initTRPC, TRPCError } from "@trpc/server"
 
-export const appRouter = router({})
+import { createLocationRouter } from "../location/router.ts"
+import type { LocationService } from "../location/service.ts"
+import type { Context } from "./context.ts"
 
-export type AppRouter = typeof appRouter
+interface AuthedContext {
+	user: NonNullable<Context["user"]>
+	session: NonNullable<Context["session"]>
+}
+
+function createTRPC() {
+	const t = initTRPC.context<Context>().create()
+
+	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,
+			},
+		})
+	})
+
+	return {
+		router: t.router,
+		procedure: t.procedure.use(isAuthed),
+	}
+}
+
+export type TRPC = ReturnType<typeof createTRPC>
+
+export interface TRPCRouterDeps {
+	locationService: LocationService
+}
+
+export function createTRPCRouter({ locationService }: TRPCRouterDeps) {
+	const t = createTRPC()
+
+	return t.router({
+		location: createLocationRouter(t, { locationService }),
+	})
+}
+
+export type TRPCRouter = ReturnType<typeof createTRPCRouter>
diff --git a/apps/aris-backend/src/trpc/trpc.ts b/apps/aris-backend/src/trpc/trpc.ts
deleted file mode 100644
index 368c742..0000000
--- a/apps/aris-backend/src/trpc/trpc.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-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)
diff --git a/bun.lock b/bun.lock
index 78740e9..c3085e8 100644
--- a/bun.lock
+++ b/bun.lock
@@ -22,10 +22,10 @@
         "@aris/source-weatherkit": "workspace:*",
         "@hono/trpc-server": "^0.3",
         "@trpc/server": "^11",
+        "arktype": "^2.1.29",
         "better-auth": "^1",
         "hono": "^4",
         "pg": "^8",
-        "zod": "^3",
       },
       "devDependencies": {
         "@types/pg": "^8",
@@ -204,12 +204,6 @@
 
     "xtend": ["xtend@4.0.2", "", {}, "sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ=="],
 
-    "zod": ["zod@3.25.76", "", {}, "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ=="],
-
-    "@better-auth/core/zod": ["zod@4.3.6", "", {}, "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg=="],
-
-    "better-auth/zod": ["zod@4.3.6", "", {}, "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg=="],
-
-    "better-call/zod": ["zod@4.3.6", "", {}, "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg=="],
+    "zod": ["zod@4.3.6", "", {}, "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg=="],
   }
 }