Repro detail (Windows/OpenSSH): the health-check command can return quoted output, e.g. RAW_STDOUT="\"ping\"\r\n" instead of plain ping. With strict equality this marks an alive connection as Dead; with normalization + includes('ping') it reports correctly as active.

Thanks for catching this — the bug is real. cmd.exe echoes the surrounding quotes literally, so echo "ping" returns "ping" and the old strict === 'ping' check marked a perfectly healthy Windows/OpenSSH session as Dead, which then tears down and rebuilds a pooled connection for nothing.

Before merging I'd like to fold in two refinements. Here's the why for each:

1. Fix the root cause, not only the symptom: echo ping (no quotes)

Normalizing the output is good defense-in-depth, but the quotes only appear because the command itself wraps the token in quotes and cmd.exe doesn't strip them. echo ping (unquoted) emits a bare ping consistently across bash, cmd.exe and PowerShell, so we remove the variance at the source and the normalizer becomes a safety net rather than the primary mechanism.

2. Extract the parsing into a pure, unit-tested function

The PR description says npm test passes — but the existing suite never exercised ping() at all, so it couldn't have caught this regression and can't protect against a future one. I pulled the logic into an exported isPingAlive(stdout) so it's testable without a live SSH connection, and added tests/test-ssh-ping.js (wired into npm test) covering the quoted/escaped/CRLF/case variants — including your exact repro "\"ping\"\r\n".

async ping() {
  try {
    // Use `echo ping` WITHOUT quotes: cmd.exe echoes surrounding quotes
    // literally (outputs `"ping"`), which broke the strict equality check and
    // marked healthy Windows/OpenSSH sessions as dead. Output handling lives
    // in isPingAlive() so it can be unit-tested without a live connection.
    const result = await this.execCommand('echo ping', { timeout: 5000 });
    return isPingAlive(result.stdout);
  } catch (error) {
    return false;
  }
}

// Validate liveness-probe output across shells (bash, cmd.exe, PowerShell).
// Normalize CRLF, stray quotes/backslashes and case before matching so quoted
// or escaped variants (e.g. `"ping"`, `\"ping\"\r\n`) still count as alive.
// `includes` (not strict `===`) is deliberate: a liveness probe should err
// toward "alive" — a false positive merely lets the next real command
// reconnect, whereas a false negative needlessly tears down a healthy pooled
// connection.
export function isPingAlive(stdout) {
  const normalized = (stdout || '')
    .replace(/[\r\n]+/g, ' ')
    .replace(/["'`\\]/g, '')
    .trim()
    .toLowerCase();
  return normalized.includes('ping');
}

On keeping your includes('ping') (rather than tightening it back to ===): that's intentional and I kept it. For a liveness probe, erring toward "alive" is the correct bias — a false positive just means the next real command reconnects, whereas a false negative needlessly drops a healthy connection. Guarding the stdout || '' also makes it null/undefined-safe.

Please test on a real Windows host 🙏

I could only validate the JS logic on macOS, and that's exactly the limitation here: Unix shells strip the quotes, so on Linux/macOS both echo "ping" and echo ping print ping — the bug is not reproducible off Windows. So:

• node tests/test-ssh-ping.js and npm test pass here (14/14 for the new suite), and a stubbed "\"ping\"\r\n" confirms ping() now returns true.
• Could you confirm against a real Windows/OpenSSH target — ideally both cmd.exe and PowerShell default shells — that ssh_connection_status reports the session as active with the echo ping variant? That's the one path I can't exercise from here.

Happy to push these changes onto the branch if you'd prefer — just let me know.

@bvisible Thanks — I implemented your refinements on this PR branch and tested against a real Windows/OpenSSH host (toliman).

What I changed:

• ping() now uses echo ping (no quotes)
• extracted/exported isPingAlive(stdout)
• added tests/test-ssh-ping.js
• wired it into npm test as test:ping

Validation done:

• npm test passes with the new ping suite
• Windows real-host check via this MCP setup: ssh_connection_status remains ✅ Active after reconnect and repeated status checks (no false Dead regression)
• I also reproduced the quoted-output behavior ("ping" variants) and confirmed isPingAlive() handles it correctly.

Pushed commit: ac2d88e.