Answers to common questions and solutions for issues you might run into.

Frequently Asked Questions

What authentication methods does Echo support?

Password and SSH key authentication (Ed25519, ECDSA P-256/P-384/P-521, and RSA). Keys can be imported in OpenSSH, PKCS#8, PKCS#8 encrypted, and SEC1 formats — encrypted keys are supported with passphrase entry during import. See the SSH Keys guide for details on key-based authentication.

Does Echo support Mosh?

Yes! When adding or editing a server, tap the connection type dropdown (to the left of the connection field) and choose mosh. Echo can even auto-install mosh-server on the remote host if it isn't already present. You'll need UDP ports 60000–61000 open in the firewall. See the Mosh guide for full details.

Can I use Echo with AI coding agents?

Yes — Echo works well with any terminal-based agent like Claude Code, OpenAI Codex, or Amp. SSH into a machine where your agent is set up and interact with it directly. No special configuration in Echo is needed.

Where are my passwords and keys stored?

All credentials are stored in the iOS Keychain, encrypted at rest by the operating system. They're never stored in plain text or sent anywhere other than the server you're connecting to.

Does Echo validate host keys?

Echo currently accepts server host keys automatically without prompting. This means you won't see a "trust this host?" dialog on first connection. We recommend only connecting to servers on networks you trust.

Connection issues

Connection timed out

The default timeout is 30 seconds. Check that the hostname and port are correct, that the server is reachable from your network, and that any firewalls allow SSH traffic on the port you're using.

Authentication failed (password)

Double check that your username and password are correct. You can edit the server from the server list to update your credentials.

Authentication failed (SSH key)

Make sure your public key is in the ~/.ssh/authorized_keys file on the server. Check that the file permissions are correct: ~/.ssh should be 700 and authorized_keys should be 600. See the SSH Keys guide for more.

RSA key not accepted

If your RSA key starts with -----BEGIN RSA PRIVATE KEY----- (PKCS#1 format), it needs to be converted — this is the only PEM format Echo doesn't support. See Supported key formats for instructions.

Could not agree on encryption algorithms

This error means the server and Echo could not negotiate a common cipher and MAC combination.

Echo currently supports these MACs for aes128-ctr:hmac-sha1, hmac-sha2-256, andhmac-sha2-512.

If your server is restricted to only ETM or UMAC variants such as[email protected],[email protected], or[email protected], Echo will fail to connect before authentication (so password and key auth both fail).

To connect with current Echo builds, allow at least one non-ETM SHA-2 MAC (for example hmac-sha2-256 orhmac-sha2-512) in your SSH server's MACs list.

Mosh issues

For setup instructions, firewall requirements, and advanced settings, see the full Mosh guide.

mosh-server not found

Echo will automatically install mosh-server on most Linux and macOS hosts (amd64, arm64, armv7). Auto-install requires write access to ~/.local/echo/ on the remote host. If it fails, install manually with your package manager: sudo apt install mosh (Debian/Ubuntu), sudo dnf install mosh (Fedora), or brew install mosh (macOS/Homebrew). You can also set a custom binary path in the server's Mosh advanced settings.

Mosh bootstrap failed

The SSH connection succeeded but mosh-server didn't return the expected MOSH CONNECT response. This can happen if mosh-server crashes on startup or if the server's locale settings are incompatible. Verify that mosh-server runs manually on the server: mosh-server new -s -c 256.

Mosh UDP connection times out

The SSH bootstrap succeeded but the UDP session can't be established. This almost always means UDP ports 60000–61000 are blocked by a firewall. Cloud providers (AWS, GCP, Azure, DigitalOcean) require you to explicitly allow UDP traffic on these ports. If your server uses ufw, run: sudo ufw allow 60000:61000/udp. See Firewall & UDP ports for provider-specific instructions.

Session disconnects when switching networks

This is expected — when your device switches Wi-Fi networks or toggles a VPN, the underlying UDP socket is invalidated. Echo detects this and automatically reconnects using saved session state, typically within a few seconds. If the remote mosh-server is still running, the session will resume without losing any terminal state.

Session doesn't survive backgrounding

When Echo goes to the background, it suspends active Mosh sessions and saves their state. On return, it attempts to resume. If the app was suspended for longer than about 10 minutes, or if the remote mosh-server process has timed out, the session may not be recoverable — tap the server to start a fresh connection. See Session persistence for details on how this works.

Display looks garbled or wrong size after rotation

Echo sends a resize signal to the Mosh client whenever the terminal dimensions change. In rare cases, a rapid series of resizes (for example quickly rotating back and forth) may cause a brief visual glitch. Running clear or pressing Ctrl+L will fix it.

Terminal issues

Text wrapping looks wrong after resizing

If you rotate your device or change the split-view layout, the terminal will resize to match. In rare cases, running programs may not immediately update their layout. Running clear or resizing your tmux pane will fix this.

Key repeat isn't working

Echo's custom key repeat settings only apply to the keys in the toolbar above the keyboard. If you want to use the system keyboard's repeat behaviour instead, enable Use System Settings in Settings → Keyboard. You can also turn key repeat off entirely by setting the rate to Off.

Biometric lock

When Require Face ID (or Touch ID) is enabled in Settings, Echo will ask you to authenticate each time the app comes back from the background. This is separate from biometric protection on individual SSH keys — you can use one, both, or neither.

If biometric authentication fails, your device passcode will be offered as a fallback.

Report an Issue

To get in touch about any issue you're experiencing with Echo you can email [email protected] and we'll get back to you as soon as we can.