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Configuration

Tunnel Whisperer uses a single YAML file for all settings. The same file structure is used in every mode -- only the relevant sections are read depending on the configured mode.

Config file paths

Platform Path
Linux /etc/tw/config/config.yaml
macOS /etc/tw/config/config.yaml
Windows C:\ProgramData\tw\config\config.yaml

Override the config directory

Set TW_CONFIG_DIR (or pass the equivalent --config-dir flag, which wins over an inherited env value) to use a custom directory — no root needed:

export TW_CONFIG_DIR=/opt/myapp/tw
# Config file becomes /opt/myapp/tw/config.yaml

Full annotated config

# Operating mode: "relay", "server", or "client".
# Determines which commands are available and which services start.
# The legacy value "admin" is accepted on read and rewritten to "relay".
mode: server

# Log verbosity: debug, info, warn, error.
# Can also be set with --log-level flag (persisted on use).
log_level: info

# Log output format: "text" (default, human-readable) or "json".
# JSON maps attributes to OpenTelemetry semantic-convention names.
# Can also be set with --log-format flag (persisted on use).
log_format: text

# Outbound proxy for all connections (Xray, SSH, Terraform).
# Supported formats:
#   socks5://host:port
#   socks5://user:pass@host:port
#   http://host:port
#   http://user:pass@host:port
# Leave empty for direct connections.
proxy: ""

# Shared transport layer (used by all modes).
xray:
  # Profile identity UUID (VLESS client id). On a server/relay it also derives
  # the server-id (<hostname>-<first 8 hex of uuid>); on a client it is the
  # per-user UUID issued at user creation.
  uuid: "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

  # Domain or IP of the relay server.
  relay_host: relay.example.com

  # HTTPS port on the relay.
  relay_port: 443

  # XHTTP path used by Xray. Default /tw; rewritten to /tw/<server-id> when a
  # relay is provisioned or an invite is granted (tw relay create / tw join).
  path: /tw

  # X.509 client certificate presented to the relay's mutual-TLS gate.
  # Auto-populated at runtime from <config-dir>/client.{crt,key} when present,
  # so you normally leave these empty. See Security → Relay Authentication.
  client_cert_path: ""
  client_key_path: ""

# Server settings (used in server mode; the relay_ssh_* / remote_port fields
# are also used in relay mode for the relay SSH connection, and api_port is
# read in every mode to find a running daemon).
server:
  # Port the internal SSH server listens on.
  ssh_port: 2222

  # Port the gRPC API listens on (CLI-to-daemon communication).
  api_port: 50051

  # Port the web dashboard listens on.
  dashboard_port: 8080

  # Interface the web dashboard binds. Defaults to 127.0.0.1 (local only).
  # The dashboard requires a login token (see `tw dashboard token`), but it is
  # served over cleartext HTTP, so an off-loopback bind is REFUSED unless
  # dashboard_allow_lan is also set. Also settable per run with
  # `tw dashboard --listen`.
  dashboard_listen: 127.0.0.1

  # Explicit opt-in to bind the dashboard off-loopback over cleartext. Only set
  # this behind a TLS terminator on a trusted network — the bearer token and
  # session cookie travel unencrypted otherwise.
  dashboard_allow_lan: false

  # SSH port on the relay server (for the reverse tunnel).
  relay_ssh_port: 22

  # SSH user on the relay server.
  relay_ssh_user: ubuntu

  # Remote port on the relay that maps back to the local SSH port.
  remote_port: 2222

  # Local port the embedded Xray instance listens on. Optional; leave 0
  # to use the built-in default.
  xray_port: 0

  # Port used for temporary Xray tunnel during relay config updates
  # (user creation, user registration). Change if 59000 is in use.
  temp_xray_port: 59000

  # Application templates — reusable port mapping bundles.
  # Used when creating or editing users to pre-fill port mappings.
  applications:
    - name: "web-app"
      mappings:
        - { client_port: 3000, server_port: 3000 }
        - { client_port: 5432, server_port: 5432 }

# Bandwidth analytics (opt-in, works in both modes).
analytics:
  enabled: true
  history_size: 720  # snapshots to keep (default 720 = 1h at 5s intervals)

# Client-only settings (ignored in server/relay mode).
client:
  # SSH user to authenticate as on the server.
  ssh_user: tunnel

  # SSH port on the server (matches server.ssh_port via the tunnel).
  server_ssh_port: 2222

  # Local port the embedded Xray dokodemo-door listens on (default 54001).
  xray_port: 54001

  # Local interface forwarded tunnels bind to.
  # 127.0.0.1 = local only (default); 0.0.0.0 = all interfaces (required
  # when running tw inside a container that publishes ports to the host).
  listen_address: 127.0.0.1

  # Port forwarding rules — each entry creates a local listener.
  tunnels:
    - local_port: 3389
      remote_host: 127.0.0.1
      remote_port: 3389
    - local_port: 8443
      remote_host: 127.0.0.1
      remote_port: 443

  # Client-owned local-port overrides, keyed by server port (remote_port).
  # Set with `tw client set-port`; omitted when empty. Wins over the
  # tunnel's local_port; `tw client connect --map` wins over both for one run.
  port_overrides:
    3389: 13389

# Tamper-evidence signature over (mode, profile identity). Written by
# enrollment / bundle export / relay self-signing — never by hand.
mode_auth:
  sig: "base64-ed25519-signature"
  issuer: "base64-ed25519-public-key"

Field reference

Top-level fields

Field Type Default Description
mode string (empty) Operating mode: relay, server, or client. Legacy admin is migrated to relay on load.
log_level string info Log verbosity. One of debug, info, warn, error.
log_format string text Log output format. text (human-readable) or json (OpenTelemetry semantic-convention attribute names). Also set via --log-format.
proxy string (empty) Outbound proxy URL for all connections.
mode_auth object (absent) Detached ed25519 signature making mode tamper-evident (sig + issuer, both base64). A present-but-invalid signature makes role commands fail; an absent one is legacy-tolerated with a warning (a relay re-signs itself). Not a security boundary — see Security.

xray section

Field Type Default Description
uuid string (empty) Profile identity UUID (Xray VLESS client id). Per-user on clients; on servers/relays it also derives the server-id.
relay_host string (empty) Relay server domain or IP address.
relay_port int 443 HTTPS port on the relay.
path string /tw XHTTP path for the Xray transport. Becomes /tw/<server-id> once a relay is provisioned/joined.
client_cert_path string (empty) Path to the X.509 client certificate (PEM) presented to the relay's mutual-TLS gate. Auto-derived at runtime from <config-dir>/client.crt when present; rarely set by hand. An explicit relative path is resolved against the config dir. See Relay Authentication.
client_key_path string (empty) Path to the private key (PEM) for client_cert_path. Auto-derived from <config-dir>/client.key; relative paths resolve against the config dir.

server section

Field Type Default Description
ssh_port int 2222 Local SSH server listen port.
api_port int 50051 gRPC API listen port (loopback only). Read in every mode to locate a running daemon. Every RPC requires the daemon's bearer token (api.token); the CLI attaches it automatically.
dashboard_port int 8080 Web dashboard listen port. Setting it to 0 (by editing the file — the CLI and API ignore a 0) disables the dashboard for tw server start; tw dashboard always needs a real port.
dashboard_listen string 127.0.0.1 Interface the web dashboard binds to. Default 127.0.0.1 (loopback only). An off-loopback value is refused unless dashboard_allow_lan is also set, because the dashboard serves its login token and cookie over cleartext HTTP. Also settable per run with tw dashboard --listen.
dashboard_allow_lan bool false Explicit opt-in required to bind the dashboard off-loopback over cleartext HTTP. Only enable behind a TLS terminator on a trusted network — otherwise the bearer token/session cookie are exposed.
relay_ssh_port int 22 SSH port on the relay for the reverse tunnel.
relay_ssh_user string ubuntu SSH user on the relay server.
remote_port int 2222 Remote port on the relay forwarded back to local SSH. Enrolled servers get their port assigned by the relay admin (starting at 20000).
xray_port int (empty) Local port the embedded Xray instance listens on. Optional; leave unset to use the built-in default.
temp_xray_port int 59000 Port for the temporary Xray tunnel used during relay config updates (user creation/registration). Change if 59000 is already in use on your system.
applications list (empty) Application templates — reusable port mapping bundles for user creation.

applications[] entry

Field Type Description
name string Unique name for the application template.
mappings list Port mapping rules. Each entry has client_port and server_port.

applications[].mappings[] entry

Field Type Description
client_port int Port the client listens on locally (1-65535).
server_port int Port on the server to forward to (1-65535).

analytics section

Field Type Default Description
enabled bool false Enable bandwidth statistics collection. Opt-in.
history_size int 720 Number of snapshots in the ring buffer. At the default 5-second interval, 720 = 1 hour of history.

Analytics works in both server and client modes. In server mode, stats are tracked per user per port. In client mode, stats are tracked per local port. Changes via the dashboard take effect immediately without a restart.

client section

Field Type Default Description
ssh_user string tunnel SSH user to authenticate as on the server side.
server_ssh_port int 2222 SSH port on the server (reached via the tunnel).
xray_port int 54001 Local port the embedded Xray dokodemo-door listens on.
listen_address string 127.0.0.1 Local interface forwarded tunnels bind to. Set to 0.0.0.0 to expose tunnels on all interfaces — required when tw runs inside a container that publishes ports to the host. Also settable with tw client listen.
tunnels list (empty) Port forwarding rules. Each entry has local_port, remote_host, remote_port.
port_overrides map (empty) Local-port overrides keyed by server port (remote_port). Client-owned — set with tw client set-port or the dashboard Tunnels card; never shipped in bundles.

tunnels[] entry

Field Type Description
local_port int Port to listen on locally (client machine).
remote_host string Target host on the server side (usually 127.0.0.1).
remote_port int Target port on the server side.

contexts.yaml (context index)

Alongside config.yaml, the config dir holds contexts.yaml — the plaintext index of stored contexts (see File Layout). It is managed entirely by the tw config context commands and holds no secrets:

current-context: hetzner-relay
contexts:
  hetzner-relay:
    role: relay          # relay | server | client
    relay: relay.example.com
    id: 3f2a9c1b         # short ID of the profile's xray.uuid
    created: "2026-07-01T10:00:00Z"
  alice:
    role: client
    relay: relay.example.com
    user: alice          # client contexts only: client.ssh_user
    id: 9b1e4d02
    created: "2026-07-02T09:30:00Z"

Editing the config

Prefer the CLI/dashboard over hand-editing: config mutations go through validated setters that persist atomically (tw proxy set, tw client listen, the dashboard settings pages). tw config view prints the active file (add --as-json for JSON output). Note that hand-editing the mode field breaks the mode_auth signature and makes role commands fail.

Config change detection

Tunnel Whisperer computes a SHA-256 hash of the config file at startup. While the daemon is running, the dashboard periodically compares the current file hash against the startup hash.

If they differ, the dashboard displays a notification indicating that the configuration has changed and the server or client needs a restart for the changes to take effect.

Two hashing methods

  • Structured hash (Config.Hash()) -- serializes the parsed config back to YAML and hashes the result. Detects changes to known fields.
  • File hash (FileHash()) -- hashes the raw file bytes on disk. Detects all changes including comments, formatting, and unknown fields.

The file hash is the one used for change detection, so even cosmetic edits will trigger the notification.