diff --git a/src/sandboxes/setupOpenClaw.ts b/src/sandboxes/setupOpenClaw.ts
index 7f7c480..2fbfb27 100644
--- a/src/sandboxes/setupOpenClaw.ts
+++ b/src/sandboxes/setupOpenClaw.ts
@@ -3,6 +3,30 @@ import { logger } from "@trigger.dev/sdk/v3";
 import { onboardOpenClaw } from "./onboardOpenClaw";
 import { OPENCLAW_DEFAULT_MODEL } from "../consts";
 
+// Constant script body. No interpolation of caller-supplied values — all
+// secrets are read at runtime from process.env inside the sandbox, so a
+// value containing quotes, backslashes, or newlines cannot break out of
+// the shell or the JS string. See: shell-injection fix for accountId.
+const INJECT_ENV_SCRIPT = `
+  const fs = require('fs');
+  const os = require('os');
+  const path = os.homedir() + '/.openclaw/openclaw.json';
+  const c = JSON.parse(fs.readFileSync(path, 'utf8'));
+  c.env = c.env || {};
+  c.env.RECOUP_API_KEY = process.env.RECOUP_API_KEY;
+  c.env.RECOUP_ACCOUNT_ID = process.env.RECOUP_ACCOUNT_ID;
+  if (process.env.GITHUB_TOKEN) {
+    c.env.GITHUB_TOKEN = process.env.GITHUB_TOKEN;
+  }
+  c.tools = c.tools || {};
+  c.tools.profile = 'coding';
+  c.agents = c.agents || {};
+  c.agents.defaults = c.agents.defaults || {};
+  c.agents.defaults.model = c.agents.defaults.model || {};
+  c.agents.defaults.model.primary = process.env.OPENCLAW_DEFAULT_MODEL;
+  fs.writeFileSync(path, JSON.stringify(c, null, 2));
+`;
+
 /**
  * Ensures OpenClaw is onboarded, seeds env vars into the config,
  * and starts the gateway process in the background.
@@ -17,42 +41,31 @@ export async function setupOpenClaw(
 ): Promise<void> {
   await onboardOpenClaw(sandbox);
 
-  // Inject RECOUP env vars into openclaw.json's env block so they're
-  // available to the agent and all tools/subprocesses it spawns.
-  if (!process.env.RECOUP_API_KEY) {
+  const recoupApiKey = process.env.RECOUP_API_KEY;
+  if (!recoupApiKey) {
     throw new Error("Missing RECOUP_API_KEY environment variable");
   }
 
   const githubToken = process.env.GITHUB_TOKEN;
 
   logger.log("Injecting env vars into openclaw.json", {
-    RECOUP_API_KEY: `${process.env.RECOUP_API_KEY.slice(0, 4)}...`,
+    RECOUP_API_KEY: `${recoupApiKey.slice(0, 4)}...`,
     RECOUP_ACCOUNT_ID: accountId,
     GITHUB_TOKEN: githubToken ? "present" : "missing",
   });
 
-  const injectEnv = await sandbox.runCommand({
-    cmd: "sh",
-    args: [
-      "-c",
-      `node -e "
-        const fs = require('fs');
-        const p = require('os').homedir() + '/.openclaw/openclaw.json';
-        const c = JSON.parse(fs.readFileSync(p, 'utf8'));
-        c.env = c.env || {};
-        c.env.RECOUP_API_KEY = '${process.env.RECOUP_API_KEY}';
-        c.env.RECOUP_ACCOUNT_ID = '${accountId}';
-        ${githubToken ? `c.env.GITHUB_TOKEN = '${githubToken}';` : ""}
-        c.tools = c.tools || {};
-        c.tools.profile = 'coding';
-        c.agents = c.agents || {};
-        c.agents.defaults = c.agents.defaults || {};
-        c.agents.defaults.model = c.agents.defaults.model || {};
-        c.agents.defaults.model.primary = '${OPENCLAW_DEFAULT_MODEL}';
-        fs.writeFileSync(p, JSON.stringify(c, null, 2));
-      "`,
-    ],
-  });
+  const injectEnvOpts: Record<string, unknown> = {
+    cmd: "node",
+    args: ["-e", INJECT_ENV_SCRIPT],
+    env: {
+      RECOUP_API_KEY: recoupApiKey,
+      RECOUP_ACCOUNT_ID: accountId,
+      OPENCLAW_DEFAULT_MODEL,
+      ...(githubToken ? { GITHUB_TOKEN: githubToken } : {}),
+    },
+  };
+
+  const injectEnv = await sandbox.runCommand(injectEnvOpts as any);
 
   if (injectEnv.exitCode !== 0) {
     const stderr = (await injectEnv.stderr()) || "";
@@ -82,4 +95,4 @@ export async function setupOpenClaw(
   }
 
   logger.log("OpenClaw gateway started");
-}
+}
\ No newline at end of file