diff --git a/bin/lib/runner.js b/bin/lib/runner.js
index d0ca4cee..591dc26a 100644
--- a/bin/lib/runner.js
+++ b/bin/lib/runner.js
@@ -22,7 +22,7 @@ function run(cmd, opts = {}) {
     env: { ...process.env, ...opts.env },
   });
   if (result.status !== 0 && !opts.ignoreError) {
-    console.error(`  Command failed (exit ${result.status}): ${cmd.slice(0, 80)}`);
+    console.error(`  Command failed (exit ${result.status}): ${redact(cmd.slice(0, 80))}`);
     process.exit(result.status || 1);
   }
   return result;
@@ -37,7 +37,7 @@ function runInteractive(cmd, opts = {}) {
     env: { ...process.env, ...opts.env },
   });
   if (result.status !== 0 && !opts.ignoreError) {
-    console.error(`  Command failed (exit ${result.status}): ${cmd.slice(0, 80)}`);
+    console.error(`  Command failed (exit ${result.status}): ${redact(cmd.slice(0, 80))}`);
     process.exit(result.status || 1);
   }
   return result;
@@ -54,10 +54,40 @@ function runCapture(cmd, opts = {}) {
     }).trim();
   } catch (err) {
     if (opts.ignoreError) return "";
-    throw err;
+    throw redactError(err);
   }
 }
 
+/**
+ * Redact known secret patterns from a string to prevent accidental leaks
+ * in CLI log and error output. Covers NVIDIA API keys, bearer tokens,
+ * generic API key assignments, and base64-style long tokens.
+ */
+const SECRET_PATTERNS = [
+  /nvapi-[A-Za-z0-9_-]{10,}/g,
+  /nvcf-[A-Za-z0-9_-]{10,}/g,
+  /ghp_[A-Za-z0-9_-]{10,}/g,
+  /(?<=Bearer\s)[A-Za-z0-9_.+/=-]{10,}/gi,
+  /(?<=(?:_KEY|API_KEY|SECRET|TOKEN|PASSWORD|CREDENTIAL)[=: ]['"]?)[A-Za-z0-9_.+/=-]{10,}/gi,
+];
+
+function redact(str) {
+  if (typeof str !== "string") return str;
+  let out = str;
+  for (const pat of SECRET_PATTERNS) {
+    out = out.replace(pat, (match) => match.slice(0, 4) + "*".repeat(Math.min(match.length - 4, 20)));
+  }
+  return out;
+}
+
+function redactError(err) {
+  if (!err || typeof err !== "object") return err;
+  if (typeof err.message === "string") err.message = redact(err.message);
+  if (typeof err.stdout === "string") err.stdout = redact(err.stdout);
+  if (typeof err.stderr === "string") err.stderr = redact(err.stderr);
+  return err;
+}
+
 /**
  * Shell-quote a value for safe interpolation into bash -c strings.
  * Wraps in single quotes and escapes embedded single quotes.
@@ -85,4 +115,4 @@ function validateName(name, label = "name") {
   return name;
 }
 
-module.exports = { ROOT, SCRIPTS, run, runCapture, runInteractive, shellQuote, validateName };
+module.exports = { ROOT, SCRIPTS, redact, run, runCapture, runInteractive, shellQuote, validateName };
diff --git a/test/runner.test.js b/test/runner.test.js
index a0547181..ae546d9b 100644
--- a/test/runner.test.js
+++ b/test/runner.test.js
@@ -141,7 +141,90 @@ describe("runner helpers", () => {
     });
   });
 
+  describe("redact", () => {
+    it("masks NVIDIA API keys", () => {
+      const { redact } = require(runnerPath);
+      expect(redact("key is nvapi-abc123XYZ_def456")).toBe(
+        "key is nvap******************"
+      );
+    });
+
+    it("masks NVCF keys", () => {
+      const { redact } = require(runnerPath);
+      expect(redact("nvcf-abcdef1234567890")).toBe("nvcf*****************");
+    });
+
+    it("masks bearer tokens", () => {
+      const { redact } = require(runnerPath);
+      expect(redact("Authorization: Bearer eyJhbGciOiJIUzI1NiJ9.payload")).toBe(
+        "Authorization: Bearer eyJh********************"
+      );
+    });
+
+    it("masks key assignments in commands", () => {
+      const { redact } = require(runnerPath);
+      expect(redact("export NVIDIA_API_KEY=nvapi-realkey12345")).toContain("nvap");
+      expect(redact("export NVIDIA_API_KEY=nvapi-realkey12345")).not.toContain("realkey12345");
+    });
+
+    it("masks variables ending in _KEY", () => {
+      const { redact } = require(runnerPath);
+      const output = redact('export SERVICE_KEY="supersecretvalue12345"');
+      expect(output).not.toContain("supersecretvalue12345");
+      expect(output).toContain('export SERVICE_KEY="supe');
+    });
+
+    it("masks bare GitHub personal access tokens", () => {
+      const { redact } = require(runnerPath);
+      const output = redact("token ghp_abcdefghijklmnopqrstuvwxyz1234567890");
+      expect(output).toContain("ghp_");
+      expect(output).not.toContain("abcdefghijklmnopqrstuvwxyz1234567890");
+    });
+
+    it("leaves non-secret strings untouched", () => {
+      const { redact } = require(runnerPath);
+      expect(redact("docker run --name my-sandbox")).toBe("docker run --name my-sandbox");
+      expect(redact("openshell sandbox list")).toBe("openshell sandbox list");
+    });
+
+    it("handles non-string input gracefully", () => {
+      const { redact } = require(runnerPath);
+      expect(redact(null)).toBe(null);
+      expect(redact(undefined)).toBe(undefined);
+      expect(redact(42)).toBe(42);
+    });
+  });
+
   describe("regression guards", () => {
+    it("runCapture redacts secrets before rethrowing errors", () => {
+      const originalExecSync = childProcess.execSync;
+      childProcess.execSync = () => {
+        throw new Error(
+          'command failed: export SERVICE_KEY="supersecretvalue12345" ghp_abcdefghijklmnopqrstuvwxyz1234567890'
+        );
+      };
+
+      try {
+        delete require.cache[require.resolve(runnerPath)];
+        const { runCapture } = require(runnerPath);
+
+        let error;
+        try {
+          runCapture("echo nope");
+        } catch (err) {
+          error = err;
+        }
+
+        expect(error).toBeInstanceOf(Error);
+        expect(error.message).toContain("ghp_");
+        expect(error.message).not.toContain("supersecretvalue12345");
+        expect(error.message).not.toContain("abcdefghijklmnopqrstuvwxyz1234567890");
+      } finally {
+        childProcess.execSync = originalExecSync;
+        delete require.cache[require.resolve(runnerPath)];
+      }
+    });
+
     it("nemoclaw.js does not use execSync", () => {
       const fs = require("fs");
       const src = fs.readFileSync(path.join(__dirname, "..", "bin", "nemoclaw.js"), "utf-8");