diff --git a/src/commands/config.ts b/src/commands/config.ts
index f53b390..ad3471d 100644
--- a/src/commands/config.ts
+++ b/src/commands/config.ts
@@ -1,41 +1,39 @@
 import { die } from "../fmt.ts"
 import * as config from "../config.ts"
 
-const KEYS: Record<string, { default: string; description: string; normalize: (v: string) => string; validate: (v: string) => string | null }> = {
-  memory: {
-    default: "16G",
-    description: "Container memory limit (e.g. 4G, 16G, 32G, 64G)",
-    normalize: (v) => v.toUpperCase(),
-    validate: (v) => /^[1-9]\d*[GMgm]$/.test(v) ? null : "Must be a number followed by G or M (e.g. 16G)",
-  },
+const VALID_KEYS = ["memory"] as const
+type Key = (typeof VALID_KEYS)[number]
+
+function validateMemory(v: string): string {
+  if (!/^[1-9]\d*[GMgm]$/.test(v)) die("Must be a number followed by G or M (e.g. 16G)")
+  return v.toUpperCase()
 }
 
 export async function action(args: string[]) {
   if (args.length === 0) {
     const cfg = await config.load()
-    for (const [key, meta] of Object.entries(KEYS)) {
-      const val = cfg[key as keyof config.Config]
-      const display = val ?? `${meta.default} (default)`
+    for (const key of VALID_KEYS) {
+      const val = cfg[key]
+      const display = val ?? `${config.DEFAULTS[key]} (default)`
       console.log(`${key} = ${display}`)
-      console.log(`  ${meta.description}`)
     }
     return
   }
 
   const [key, ...rest] = args
-  if (!(key in KEYS)) die(`Unknown config key: ${key}\nAvailable keys: ${Object.keys(KEYS).join(", ")}`)
+  if (!VALID_KEYS.includes(key as Key)) die(`Unknown config key: ${key}\nAvailable keys: ${VALID_KEYS.join(", ")}`)
 
   if (rest.length === 0) {
-    const val = await config.get(key as keyof config.Config)
-    console.log(val ?? `${KEYS[key].default} (default)`)
+    const val = await config.get(key as Key)
+    console.log(val ?? `${config.DEFAULTS[key as Key]} (default)`)
     return
   }
 
   if (rest.length > 1) die(`Too many arguments. Usage: sandlot config ${key} <value>`)
-  const meta = KEYS[key]
-  const error = meta.validate(rest[0])
-  if (error) die(error)
-  const normalized = meta.normalize(rest[0])
-  await config.set(key as keyof config.Config, normalized)
-  console.log(`${key} = ${normalized}`)
+
+  if (key === "memory") {
+    const normalized = validateMemory(rest[0])
+    await config.set("memory", normalized)
+    console.log(`memory = ${normalized}`)
+  }
 }
diff --git a/src/config.ts b/src/config.ts
index d547247..437b9e9 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -4,6 +4,10 @@ import { dirname, join } from "path"
 
 const CONFIG_PATH = join(homedir(), ".config", "sandlot", "config.json")
 
+export const DEFAULTS = {
+  memory: "16G",
+} as const
+
 export interface Config {
   memory?: string
 }
@@ -13,9 +17,7 @@ export async function load(): Promise<Config> {
   if (!(await file.exists())) return {}
   const raw = await file.json()
   if (typeof raw !== "object" || raw === null || Array.isArray(raw)) return {}
-  const cfg: Config = {}
-  if (typeof raw.memory === "string") cfg.memory = raw.memory
-  return cfg
+  return raw as Config
 }
 
 export async function save(config: Config): Promise<void> {
diff --git a/src/vm.ts b/src/vm.ts
index 3475bcf..b284313 100644
--- a/src/vm.ts
+++ b/src/vm.ts
@@ -4,7 +4,7 @@ import { homedir } from "os"
 import { dirname, join } from "path"
 import { requireApiKey } from "./env.ts"
 import { info } from "./fmt.ts"
-import { get as getConfig } from "./config.ts"
+import { get as getConfig, DEFAULTS } from "./config.ts"
 
 const DEBUG = !!process.env.DEBUG
 const CONTAINER_NAME = "sandlot"
@@ -67,7 +67,7 @@ function hostMounts(home: string): { dev: boolean; code: boolean } {
 /** Pull the image and start the container in detached mode. */
 async function createContainer(home: string): Promise<void> {
   const mounts = hostMounts(home)
-  const memory = (await getConfig("memory")) ?? "16G"
+  const memory = (await getConfig("memory")) ?? DEFAULTS.memory
   const args = ["container", "run", "-d", "--name", CONTAINER_NAME, "-m", memory]
   if (mounts.dev) args.push("--mount", `type=bind,source=${home}/dev,target=/host/dev,readonly`)
   if (mounts.code) args.push("--mount", `type=bind,source=${home}/code,target=/host/code,readonly`)