diff --git a/packages/tiers/src/utils/proxyRotator.ts b/packages/tiers/src/utils/proxyRotator.ts
index 03c3135..60d36b4 100644
--- a/packages/tiers/src/utils/proxyRotator.ts
+++ b/packages/tiers/src/utils/proxyRotator.ts
@@ -3,7 +3,6 @@
 // fetches or trusts any third-party proxy list.
 
 import { readFileSync } from "node:fs"
-import type { ProxyEndpointInput } from "@trawl/types"
 
 const COOLDOWN_MS = 5 * 60 * 1000 // 5 minutes — matches the plan's "time-boxed cooldown"
 
@@ -16,25 +15,30 @@ const COOLDOWN_MS = 5 * 60 * 1000 // 5 minutes — matches the plan's "time-boxe
 // Returns undefined for null/undefined/empty/non-string-non-object inputs.
 // Credentials (if present in the object form) are URL-encoded and embedded into the URL
 // so downstream code keeps treating proxy as a single string.
-export function normalizeProxy(input: ProxyEndpointInput | null | undefined): string | undefined {
-  if (input == null) return undefined
+export function normalizeProxy(input?: unknown) {
+  if (input == null) return
   if (typeof input === "string") {
     const trimmed = input.trim()
     return trimmed ? trimmed : undefined
   }
-  if (typeof input === "object") {
+  if (typeof input === "object" && input) {
+    const endpoint = input as Record<string, unknown>
     const server =
-      typeof input.url === "string" ? input.url : typeof input.server === "string" ? input.server : undefined
-    if (!server) return undefined
-    const user = typeof input.username === "string" && input.username.length > 0 ? input.username : undefined
-    const pass = typeof input.password === "string" && input.password.length > 0 ? input.password : undefined
+      typeof endpoint.url === "string"
+        ? endpoint.url
+        : typeof endpoint.server === "string"
+          ? endpoint.server
+          : undefined
+    if (!server) return
+    const user = typeof endpoint.username === "string" && endpoint.username.length > 0 ? endpoint.username : undefined
+    const pass = typeof endpoint.password === "string" && endpoint.password.length > 0 ? endpoint.password : undefined
     if (!user && !pass) return server
     const schemeMatch = server.match(/^([a-z][a-z0-9+\-.]*:\/\/)(.*)$/i)
     if (!schemeMatch) return server
     const creds = `${encodeURIComponent(user ?? "")}:${encodeURIComponent(pass ?? "")}`
     return `${schemeMatch[1]}${creds}@${schemeMatch[2]}`
   }
-  return undefined
+  return
 }
 
 interface ProxyState {
@@ -53,9 +57,9 @@ export class ProxyPool {
 
   // Builds a pool from a comma-separated env var and/or a line-delimited file (one proxy
   // per line, '#' comments allowed). A single URL still works — it's just a 1-element list.
-  // Returns null if neither source yields any proxies, so callers can treat "no proxy
+  // Returns undefined if neither source yields any proxies, so callers can treat "no proxy
   // configured" the same way they did with the old single-string PROXY_URL/RESIDENTIAL_PROXY_URL.
-  static fromEnv(urlListEnv?: string, fileEnv?: string): ProxyPool | null {
+  static fromEnv(urlListEnv?: string, fileEnv?: string) {
     const urls: string[] = []
     if (urlListEnv) {
       urls.push(
@@ -76,7 +80,7 @@ export class ProxyPool {
         console.warn(`[proxy] failed to read proxy list file ${fileEnv}:`, err instanceof Error ? err.message : err)
       }
     }
-    return urls.length > 0 ? new ProxyPool(urls) : null
+    return urls.length > 0 ? new ProxyPool(urls) : undefined
   }
 
   get size(): number {
@@ -91,9 +95,9 @@ export class ProxyPool {
   // Sticky-per-domain: reuse the same proxy for repeat requests to a domain (consistency
   // helps avoid re-triggering challenges); falls back to round-robin across available
   // proxies for new domains or once the sticky proxy has been marked bad.
-  next(domain?: string): string | null {
+  next(domain?: string) {
     const available = this.available()
-    if (available.length === 0) return null
+    if (available.length === 0) return
 
     if (domain) {
       const sticky = this.stickyByDomain.get(domain)
@@ -106,9 +110,9 @@ export class ProxyPool {
     return proxy.url
   }
 
-  random(): string | null {
+  random() {
     const available = this.available()
-    if (available.length === 0) return null
+    if (available.length === 0) return
     return available[Math.floor(Math.random() * available.length)].url
   }
 
diff --git a/packages/tiers/tests/normalizeProxy.test.ts b/packages/tiers/tests/normalizeProxy.test.ts
index f5047c9..ecfae82 100644
--- a/packages/tiers/tests/normalizeProxy.test.ts
+++ b/packages/tiers/tests/normalizeProxy.test.ts
@@ -127,7 +127,7 @@ describe("normalizeProxy", () => {
     })
 
     test("non-string url field → undefined", () => {
-      expect(normalizeProxy({ url: 42 as unknown as string })).toBeUndefined()
+      expect(normalizeProxy({ url: 42 })).toBeUndefined()
     })
   })
 })
diff --git a/packages/tiers/tests/proxyPool.test.ts b/packages/tiers/tests/proxyPool.test.ts
index 3bc5d02..8b9ec71 100644
--- a/packages/tiers/tests/proxyPool.test.ts
+++ b/packages/tiers/tests/proxyPool.test.ts
@@ -33,12 +33,12 @@ describe("ProxyPool", () => {
     expect(after).toBeTruthy()
   })
 
-  test("returns null once every proxy is marked bad", () => {
+  test("returns undefined once every proxy is marked bad", () => {
     const pool = new ProxyPool(["http://p1:8080", "http://p2:8080"])
     pool.markBad("http://p1:8080")
     pool.markBad("http://p2:8080")
-    expect(pool.next("example.com")).toBeNull()
-    expect(pool.random()).toBeNull()
+    expect(pool.next("example.com")).toBeUndefined()
+    expect(pool.random()).toBeUndefined()
   })
 
   test("random() returns one of the configured proxies", () => {
@@ -49,10 +49,10 @@ describe("ProxyPool", () => {
     }
   })
 
-  test("returns null for an empty pool", () => {
+  test("returns undefined for an empty pool", () => {
     const pool = new ProxyPool([])
-    expect(pool.next()).toBeNull()
-    expect(pool.random()).toBeNull()
+    expect(pool.next()).toBeUndefined()
+    expect(pool.random()).toBeUndefined()
     expect(pool.size).toBe(0)
   })
 
@@ -74,9 +74,9 @@ describe("ProxyPool", () => {
       expect(pool?.size).toBe(3)
     })
 
-    test("returns null when neither source has any proxies", () => {
-      expect(ProxyPool.fromEnv(undefined, undefined)).toBeNull()
-      expect(ProxyPool.fromEnv("", "")).toBeNull()
+    test("returns undefined when neither source has any proxies", () => {
+      expect(ProxyPool.fromEnv()).toBeUndefined()
+      expect(ProxyPool.fromEnv("", "")).toBeUndefined()
     })
 
     test("reads proxies from a line-delimited file, ignoring comments and blank lines", () => {