diff --git a/agents/hermes/Dockerfile.base b/agents/hermes/Dockerfile.base
index 76248bf340a..f8be3ab8569 100644
--- a/agents/hermes/Dockerfile.base
+++ b/agents/hermes/Dockerfile.base
@@ -165,6 +165,16 @@ RUN printf '%s\n' \
 # New Hermes integrations should be installed by the agent workflow when they
 # are enabled rather than shipped in the base image by default.
 # Root Node dependencies provide Hermes browser tooling such as agent-browser.
+# The WhatsApp adapter ships a separate Node project under
+# scripts/whatsapp-bridge whose dependencies Hermes otherwise installs lazily
+# on the first `hermes whatsapp` run. That lazy `npm install` targets
+# /opt/hermes/scripts/whatsapp-bridge/node_modules, which is root-owned and
+# read-only for the sandbox user at runtime, so it fails with EACCES before the
+# QR pairing screen is reached (#4764). Bake the bridge's node_modules into the
+# image here, alongside the ui-tui/web installs, so runtime pairing needs no
+# writes under /opt/hermes. If a future Hermes tarball removes the lockfile,
+# skip rather than doing a nondeterministic dependency resolve during image
+# build.
 RUN pip3 install --no-cache-dir --break-system-packages "uv==${UV_VERSION}"
 RUN mkdir -p /opt/hermes \
     && curl -fsSL "https://github.com/NousResearch/hermes-agent/archive/refs/tags/${HERMES_VERSION}.tar.gz" -o /tmp/hermes.tar.gz \
@@ -192,6 +202,14 @@ RUN set -eu; \
             echo "Skipping optional Hermes UI package ${ui_dir}: package-lock.json not found"; \
         fi; \
     done \
+    && bridge_dir=scripts/whatsapp-bridge \
+    && if [ -f "${bridge_dir}/package-lock.json" ]; then \
+        npm ci --prefix "${bridge_dir}" --prefer-offline --no-audit --no-fund; \
+    elif [ -f "${bridge_dir}/package.json" ]; then \
+        echo "Skipping optional Hermes bridge ${bridge_dir}: package-lock.json not found"; \
+    else \
+        echo "Skipping optional Hermes bridge ${bridge_dir}: no package manifest found"; \
+    fi \
     && rm -rf ui-tui/node_modules web/node_modules /tmp/camoufox-* \
     && ln -sf /opt/hermes/.venv/bin/hermes /usr/local/bin/hermes \
     && ln -sf /opt/hermes/.venv/bin/hermes-agent /usr/local/bin/hermes-agent \
diff --git a/test/hermes-share-mount-deps.test.ts b/test/hermes-share-mount-deps.test.ts
index 35183141210..f5b27b66eae 100644
--- a/test/hermes-share-mount-deps.test.ts
+++ b/test/hermes-share-mount-deps.test.ts
@@ -1,10 +1,10 @@
 // SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+import { spawnSync } from "node:child_process";
 import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
-import { spawnSync } from "node:child_process";
 import { describe, expect, it } from "vitest";
 
 const ROOT = path.resolve(import.meta.dirname, "..");
@@ -42,13 +42,25 @@ function runLoggedShell(command: string, tmp: string) {
   return { result, calls };
 }
 
-function runHermesInstallLayer(command: string, tmp: string) {
+function runHermesInstallLayer(
+  command: string,
+  tmp: string,
+  opts: { whatsappBridge?: "lockfile" | "package-json" } = {},
+) {
   const fixture = path.join(tmp, "hermes");
   const logPath = path.join(tmp, "calls.log");
   const scriptPath = path.join(tmp, "run-hermes-install-layer.sh");
   fs.mkdirSync(path.join(fixture, "web"), { recursive: true });
   fs.writeFileSync(path.join(fixture, "package-lock.json"), "{}\n");
   fs.writeFileSync(path.join(fixture, "web", "package-lock.json"), "{}\n");
+  if (opts.whatsappBridge) {
+    const bridgeDir = path.join(fixture, "scripts", "whatsapp-bridge");
+    fs.mkdirSync(bridgeDir, { recursive: true });
+    fs.writeFileSync(path.join(bridgeDir, "package.json"), "{}\n");
+    if (opts.whatsappBridge === "lockfile") {
+      fs.writeFileSync(path.join(bridgeDir, "package-lock.json"), "{}\n");
+    }
+  }
 
   const script = [
     "#!/usr/bin/env bash",
@@ -72,9 +84,10 @@ function runHermesInstallLayer(command: string, tmp: string) {
     '      echo "missing lockfile for ${prefix}" >&2',
     "      return 42",
     "    }",
+    '    mkdir -p "${prefix}/node_modules"',
     "  fi",
     "}",
-    'rm() { printf "rm %s\\n" "$*" >> "$call_log"; }',
+    'rm() { printf "rm %s\\n" "$*" >> "$call_log"; command rm "$@"; }',
     'ln() { printf "ln %s\\n" "$*" >> "$call_log"; }',
     'export HERMES_UV_EXTRAS="messaging"',
     command,
@@ -124,4 +137,70 @@ describe("Hermes share mount package parity (#2947)", () => {
       fs.rmSync(tmp, { recursive: true, force: true });
     }
   });
+
+  it("pre-installs the WhatsApp bridge node_modules with npm ci when a lockfile ships (#4764)", () => {
+    const dockerfile = fs.readFileSync(HERMES_DOCKERFILE_BASE, "utf-8");
+    const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "nemoclaw-hermes-wa-bridge-"));
+    const bridgeNodeModules = path.join(
+      tmp,
+      "hermes",
+      "scripts",
+      "whatsapp-bridge",
+      "node_modules",
+    );
+    const webNodeModules = path.join(tmp, "hermes", "web", "node_modules");
+
+    try {
+      const command = extractHermesInstallCommand(dockerfile);
+      const { result, calls } = runHermesInstallLayer(command, tmp, {
+        whatsappBridge: "lockfile",
+      });
+
+      expect(result.status, result.stderr).toBe(0);
+      // Baking the bridge deps at build time means the runtime `hermes whatsapp`
+      // never needs to mkdir node_modules under read-only /opt/hermes.
+      expect(calls).toContain(
+        "npm ci --prefix scripts/whatsapp-bridge --prefer-offline --no-audit --no-fund",
+      );
+      expect(fs.existsSync(bridgeNodeModules)).toBe(true);
+      expect(fs.existsSync(webNodeModules)).toBe(false);
+    } finally {
+      fs.rmSync(tmp, { recursive: true, force: true });
+    }
+  });
+
+  it("skips the WhatsApp bridge install when package.json ships without a lockfile (#4764)", () => {
+    const dockerfile = fs.readFileSync(HERMES_DOCKERFILE_BASE, "utf-8");
+    const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "nemoclaw-hermes-wa-bridge-nolock-"));
+
+    try {
+      const command = extractHermesInstallCommand(dockerfile);
+      const { result, calls } = runHermesInstallLayer(command, tmp, {
+        whatsappBridge: "package-json",
+      });
+
+      expect(result.status, result.stderr).toBe(0);
+      expect(calls).not.toContain("--prefix scripts/whatsapp-bridge");
+      expect(result.stdout).toContain(
+        "Skipping optional Hermes bridge scripts/whatsapp-bridge: package-lock.json not found",
+      );
+    } finally {
+      fs.rmSync(tmp, { recursive: true, force: true });
+    }
+  });
+
+  it("skips the WhatsApp bridge install when the project is absent (#4764)", () => {
+    const dockerfile = fs.readFileSync(HERMES_DOCKERFILE_BASE, "utf-8");
+    const tmp = fs.mkdtempSync(path.join(os.tmpdir(), "nemoclaw-hermes-wa-bridge-skip-"));
+
+    try {
+      const command = extractHermesInstallCommand(dockerfile);
+      const { result, calls } = runHermesInstallLayer(command, tmp);
+
+      expect(result.status, result.stderr).toBe(0);
+      expect(calls).not.toContain("--prefix scripts/whatsapp-bridge");
+    } finally {
+      fs.rmSync(tmp, { recursive: true, force: true });
+    }
+  });
 });