diff --git a/packages/cli/package.json b/packages/cli/package.json
index e97668fe..2bfb1dab 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@openrouter/spawn",
-  "version": "0.20.4",
+  "version": "0.20.5",
   "type": "module",
   "bin": {
     "spawn": "cli.js"
diff --git a/packages/cli/src/aws/aws.ts b/packages/cli/src/aws/aws.ts
index a079d477..b54b86e9 100644
--- a/packages/cli/src/aws/aws.ts
+++ b/packages/cli/src/aws/aws.ts
@@ -1145,7 +1145,7 @@ export async function uploadFile(localPath: string, remotePath: string): Promise
       ...SSH_BASE_OPTS,
       ...keyOpts,
       localPath,
-      `${SSH_USER}@${_state.instanceIp}:${remotePath}`,
+      `${SSH_USER}@${_state.instanceIp}:${normalizedRemote}`,
     ],
     {
       stdio: [
@@ -1176,7 +1176,7 @@ export async function downloadFile(remotePath: string, localPath: string): Promi
     throw new Error(`Invalid remote path: ${remotePath}`);
   }
   const keyOpts = getSshKeyOpts(await ensureSshKeys());
-  const expandedPath = remotePath.replace(/^\$HOME/, "~");
+  const expandedPath = normalizedRemote.replace(/^\$HOME/, "~");
   const proc = Bun.spawn(
     [
       "scp",
diff --git a/packages/cli/src/digitalocean/digitalocean.ts b/packages/cli/src/digitalocean/digitalocean.ts
index ae331e8d..c02aa910 100644
--- a/packages/cli/src/digitalocean/digitalocean.ts
+++ b/packages/cli/src/digitalocean/digitalocean.ts
@@ -4,6 +4,7 @@ import type { CloudInstance, VMConnection } from "../history.js";
 import type { CloudInitTier } from "../shared/agents";
 
 import { mkdirSync, readFileSync } from "node:fs";
+import { normalize } from "node:path";
 import * as p from "@clack/prompts";
 import { getErrorMessage, isNumber, isString, toObjectArray, toRecord } from "@openrouter/spawn-shared";
 import { handleBillingError, isBillingError, showNonBillingError } from "../shared/billing-guidance";
@@ -1307,10 +1308,11 @@ export async function runServer(cmd: string, timeoutSecs?: number, ip?: string):
 
 export async function uploadFile(localPath: string, remotePath: string, ip?: string): Promise<void> {
   const serverIp = ip || _state.serverIp;
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
@@ -1323,7 +1325,7 @@ export async function uploadFile(localPath: string, remotePath: string, ip?: str
       ...SSH_BASE_OPTS,
       ...keyOpts,
       localPath,
-      `root@${serverIp}:${remotePath}`,
+      `root@${serverIp}:${normalizedRemote}`,
     ],
     {
       stdio: [
@@ -1346,17 +1348,18 @@ export async function uploadFile(localPath: string, remotePath: string, ip?: str
 
 export async function downloadFile(remotePath: string, localPath: string, ip?: string): Promise<void> {
   const serverIp = ip || _state.serverIp;
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~$-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~$-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
   }
 
   const keyOpts = getSshKeyOpts(await ensureSshKeys());
-  const expandedPath = remotePath.replace(/^\$HOME/, "~");
+  const expandedPath = normalizedRemote.replace(/^\$HOME/, "~");
 
   const proc = Bun.spawn(
     [
diff --git a/packages/cli/src/gcp/gcp.ts b/packages/cli/src/gcp/gcp.ts
index d8ff6f75..5f81dbe3 100644
--- a/packages/cli/src/gcp/gcp.ts
+++ b/packages/cli/src/gcp/gcp.ts
@@ -4,7 +4,7 @@ import type { CloudInstance, VMConnection } from "../history.js";
 import type { CloudInitTier } from "../shared/agents";
 
 import { existsSync, readFileSync, writeFileSync } from "node:fs";
-import { join } from "node:path";
+import { join, normalize } from "node:path";
 import { isString, toObjectArray } from "@openrouter/spawn-shared";
 import { handleBillingError, isBillingError, showNonBillingError } from "../shared/billing-guidance";
 import { getPackagesForTier, NODE_INSTALL_CMD, needsBun, needsNode } from "../shared/cloud-init";
@@ -997,17 +997,18 @@ export async function uploadFile(localPath: string, remotePath: string): Promise
     logError(`Invalid local path: ${localPath}`);
     throw new Error("Invalid local path");
   }
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~$-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~$-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
   }
   const username = resolveUsername();
   // Expand $HOME on remote side
-  const expandedPath = remotePath.replace(/^\$HOME/, "~");
+  const expandedPath = normalizedRemote.replace(/^\$HOME/, "~");
   const keyOpts = getSshKeyOpts(await ensureSshKeys());
 
   const proc = Bun.spawn(
@@ -1043,16 +1044,17 @@ export async function downloadFile(remotePath: string, localPath: string): Promi
     logError(`Invalid local path: ${localPath}`);
     throw new Error("Invalid local path");
   }
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~$-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~$-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
   }
   const username = resolveUsername();
-  const expandedPath = remotePath.replace(/^\$HOME/, "~");
+  const expandedPath = normalizedRemote.replace(/^\$HOME/, "~");
   const keyOpts = getSshKeyOpts(await ensureSshKeys());
 
   const proc = Bun.spawn(
diff --git a/packages/cli/src/hetzner/hetzner.ts b/packages/cli/src/hetzner/hetzner.ts
index 741472e4..e33d0331 100644
--- a/packages/cli/src/hetzner/hetzner.ts
+++ b/packages/cli/src/hetzner/hetzner.ts
@@ -4,6 +4,7 @@ import type { CloudInstance, VMConnection } from "../history.js";
 import type { CloudInitTier } from "../shared/agents";
 
 import { mkdirSync, readFileSync } from "node:fs";
+import { normalize } from "node:path";
 import { getErrorMessage, isNumber, isString, toObjectArray, toRecord } from "@openrouter/spawn-shared";
 import { handleBillingError, isBillingError, showNonBillingError } from "../shared/billing-guidance";
 import { getPackagesForTier, NODE_INSTALL_CMD, needsBun, needsNode } from "../shared/cloud-init";
@@ -615,10 +616,11 @@ export async function runServer(cmd: string, timeoutSecs?: number, ip?: string):
 
 export async function uploadFile(localPath: string, remotePath: string, ip?: string): Promise<void> {
   const serverIp = ip || _state.serverIp;
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
@@ -632,7 +634,7 @@ export async function uploadFile(localPath: string, remotePath: string, ip?: str
       ...SSH_BASE_OPTS,
       ...keyOpts,
       localPath,
-      `root@${serverIp}:${remotePath}`,
+      `root@${serverIp}:${normalizedRemote}`,
     ],
     {
       stdio: [
@@ -655,17 +657,18 @@ export async function uploadFile(localPath: string, remotePath: string, ip?: str
 
 export async function downloadFile(remotePath: string, localPath: string, ip?: string): Promise<void> {
   const serverIp = ip || _state.serverIp;
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~$-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~$-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
   }
 
   const keyOpts = getSshKeyOpts(await ensureSshKeys());
-  const expandedPath = remotePath.replace(/^\$HOME/, "~");
+  const expandedPath = normalizedRemote.replace(/^\$HOME/, "~");
 
   const proc = Bun.spawn(
     [
diff --git a/packages/cli/src/shared/agent-setup.ts b/packages/cli/src/shared/agent-setup.ts
index 03e3f517..1fc6dfd0 100644
--- a/packages/cli/src/shared/agent-setup.ts
+++ b/packages/cli/src/shared/agent-setup.ts
@@ -5,7 +5,7 @@ import type { AgentConfig } from "./agents";
 import type { Result } from "./ui";
 
 import { unlinkSync, writeFileSync } from "node:fs";
-import { join } from "node:path";
+import { join, normalize } from "node:path";
 import { getErrorMessage } from "@openrouter/spawn-shared";
 import { getTmpDir } from "./paths";
 import { asyncTryCatch, asyncTryCatchIf, isOperationalError, tryCatchIf } from "./result.js";
@@ -64,24 +64,26 @@ async function installAgent(
  * Allows shell variable references ($HOME, ${HOME}) but rejects anything
  * that could break out of double-quoted shell interpolation.
  */
-function validateRemotePath(remotePath: string): void {
+function validateRemotePath(remotePath: string): string {
   // Allow alphanumerics, forward slashes, dots, underscores, tildes, hyphens,
   // and shell variable syntax ($, {, }).  Reject everything else — especially
   // backticks, semicolons, pipes, quotes, newlines, and null bytes.
-  if (!/^[\w/.~${}:-]+$/.test(remotePath)) {
+  const normalizedRemote = normalize(remotePath);
+  if (!/^[\w/.~${}:-]+$/.test(normalizedRemote)) {
     throw new Error(`uploadConfigFile: remotePath contains unsafe characters: ${remotePath}`);
   }
-  // Block path traversal
-  if (remotePath.includes("..")) {
+  // Block path traversal (normalize resolves . segments first)
+  if (normalizedRemote.includes("..")) {
     throw new Error(`uploadConfigFile: remotePath must not contain "..": ${remotePath}`);
   }
+  return normalizedRemote;
 }
 
 /**
  * Upload a config file to the remote machine via a temp file and mv.
  */
 async function uploadConfigFile(runner: CloudRunner, content: string, remotePath: string): Promise<void> {
-  validateRemotePath(remotePath);
+  const safePath = validateRemotePath(remotePath);
 
   const tmpFile = join(getTmpDir(), `spawn_config_${Date.now()}_${Math.random().toString(36).slice(2)}`);
   writeFileSync(tmpFile, content, {
@@ -97,7 +99,7 @@ async function uploadConfigFile(runner: CloudRunner, content: string, remotePath
             const tempRemote = `/tmp/spawn_config_${Date.now()}`;
             await runner.uploadFile(tmpFile, tempRemote);
             await runner.runServer(
-              `mkdir -p $(dirname "${remotePath}") && chmod 600 ${shellQuote(tempRemote)} && mv ${shellQuote(tempRemote)} "${remotePath}"`,
+              `mkdir -p $(dirname "${safePath}") && chmod 600 ${shellQuote(tempRemote)} && mv ${shellQuote(tempRemote)} "${safePath}"`,
             );
           })(),
         ),
diff --git a/packages/cli/src/sprite/sprite.ts b/packages/cli/src/sprite/sprite.ts
index e518b351..810bd7f9 100644
--- a/packages/cli/src/sprite/sprite.ts
+++ b/packages/cli/src/sprite/sprite.ts
@@ -3,7 +3,7 @@
 import type { VMConnection } from "../history.js";
 
 import { existsSync } from "node:fs";
-import { join } from "node:path";
+import { join, normalize } from "node:path";
 import { getErrorMessage } from "@openrouter/spawn-shared";
 import { getUserHome } from "../shared/paths";
 import { asyncTryCatch } from "../shared/result.js";
@@ -506,10 +506,11 @@ async function runSpriteSilent(cmd: string): Promise<void> {
  * The -file flag format is "localpath:remotepath".
  */
 export async function uploadFileSprite(localPath: string, remotePath: string): Promise<void> {
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
@@ -518,7 +519,7 @@ export async function uploadFileSprite(localPath: string, remotePath: string): P
   const spriteCmd = getSpriteCmd()!;
   // Generate a random temp path on remote to prevent symlink attacks
   const tempRandom = crypto.randomUUID().replace(/-/g, "").slice(0, 16);
-  const basename = remotePath.split("/").pop() || "file";
+  const basename = normalizedRemote.split("/").pop() || "file";
   const tempRemote = `/tmp/sprite_upload_${basename}_${tempRandom}`;
 
   await spriteRetry("sprite upload", async () => {
@@ -534,7 +535,7 @@ export async function uploadFileSprite(localPath: string, remotePath: string): P
         "--",
         "bash",
         "-c",
-        `mkdir -p $(dirname '${remotePath}') && mv '${tempRemote}' '${remotePath}'`,
+        `mkdir -p $(dirname '${normalizedRemote}') && mv '${tempRemote}' '${normalizedRemote}'`,
       ],
       {
         stdio: [
@@ -555,17 +556,18 @@ export async function uploadFileSprite(localPath: string, remotePath: string): P
 
 /** Download a file from the remote sprite by catting it to stdout. */
 export async function downloadFileSprite(remotePath: string, localPath: string): Promise<void> {
+  const normalizedRemote = normalize(remotePath);
   if (
-    !/^[a-zA-Z0-9/_.~$-]+$/.test(remotePath) ||
-    remotePath.includes("..") ||
-    remotePath.split("/").some((s) => s.startsWith("-"))
+    !/^[a-zA-Z0-9/_.~$-]+$/.test(normalizedRemote) ||
+    normalizedRemote.includes("..") ||
+    normalizedRemote.split("/").some((s) => s.startsWith("-"))
   ) {
     logError(`Invalid remote path: ${remotePath}`);
     throw new Error("Invalid remote path");
   }
 
   const spriteCmd = getSpriteCmd()!;
-  const expandedPath = remotePath.replace(/^\$HOME/, "~");
+  const expandedPath = normalizedRemote.replace(/^\$HOME/, "~");
 
   await spriteRetry("sprite download", async () => {
     const proc = Bun.spawn(