Recover from the symptom without creating a second problem.

Start at the connection boundary, verify authoritative remote state, and never repeat a consequential action only because its result was unclear.

Open the user guide

Connection symptoms

Symptom	Safe next step
Host unreachable	Confirm the phone and host network/VPN, exact hostname, port, firewall, and overlay policy. Test ordinary SSH independently. Do not expose port 22 publicly.
Authentication fails	Verify the separate username field. For keys, confirm the matching public line and safe `authorized_keys` permissions. A key passphrase is not the server password.
Host key changed	Stop and compare the new fingerprint through an independent trusted channel. Do not replace the pin merely to continue.

Herdr, sessions, and providers

If Herdr or sessions are missing, sign in as the same SSH user and run:

herdr status
herdr session list --json
herdr api schema --json

Confirm the intended named session and supported protocol. If an agent will not launch, confirm the selected provider is installed and authenticated on the host. HerdRanger cannot install or log in to providers.

When an action may have happened

Treat a disconnected or malformed mutation result as unknown. Inspect authoritative Herdr state before creating, starting, stopping, renaming, closing, deleting, or sending again.

Do not retry blindly. HerdRanger intentionally avoids automatic mutation and terminal-input retries because repeating one can duplicate work or affect the wrong target.

Important limitations

For upstream behavior, use the official Herdr, Android, Tailscale, and NetBird documentation. Each link opens in a new tab.

Notifications are best effort and may be delayed or suppressed by Android.
Visible output and local history are bounded; neither is a guaranteed complete transcript.
Herdr 0.9.0 cannot rename sessions or cancel an acknowledged queued prompt.
Recognition quality and language support depend on the Android speech provider.
Tailscale SSH, NetBird SSH, SSH certificates, agent forwarding, and keyboard-interactive MFA are not validated/supported in this build.
Connectivity success does not prove an agent provider is installed or authenticated.

Prepare a safe support report

Reproduce once only if safe.
Open Settings → Support → Open support page.
Use the public support form; the app does not attach diagnostics or files.
Review every field before submitting.
Add app/Android version, device model, screen, action, expected result, actual result, approximate time, and safe error text.

The app does not generate or attach diagnostics or files. Never submit passwords, private keys, pairing codes, server names or addresses, SSH usernames, host fingerprints, backup files or passwords, prompts, terminal output, transcripts, agent output, or unredacted screenshots.

Open the HerdRanger support form.