feat: add railway telemetry command (enable/disable/status) (#802)

Adds a user-friendly CLI command to manage telemetry preferences,
stored persistently in ~/.railway/preferences.json. Previously the
only way to opt out was via environment variables.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/commands/mod.rs

@@ -37,6 +37,7 @@ pub mod shell;
 pub mod ssh;
 pub mod starship;
 pub mod status;
+pub mod telemetry_cmd;
 pub mod unlink;
 pub mod up;
 pub mod upgrade;

src/commands/telemetry_cmd.rs

@@ -0,0 +1,56 @@
+use super::*;
+use crate::telemetry::{Preferences, is_telemetry_disabled_by_env};
+
+/// Manage telemetry preferences
+#[derive(Parser)]
+pub struct Args {
+    #[clap(subcommand)]
+    command: Commands,
+}
+
+#[derive(Parser)]
+enum Commands {
+    /// Enable telemetry data collection
+    Enable,
+    /// Disable telemetry data collection
+    Disable,
+    /// Show current telemetry status
+    Status,
+}
+
+pub async fn command(args: Args) -> Result<()> {
+    match args.command {
+        Commands::Enable => {
+            let mut prefs = Preferences::read();
+            prefs.telemetry_disabled = false;
+            prefs.write();
+            println!("{}", "Telemetry enabled.".green());
+        }
+        Commands::Disable => {
+            let mut prefs = Preferences::read();
+            prefs.telemetry_disabled = true;
+            prefs.write();
+            println!("{}", "Telemetry disabled.".yellow());
+        }
+        Commands::Status => {
+            let prefs = Preferences::read();
+            let env_disabled = is_telemetry_disabled_by_env();
+
+            if env_disabled {
+                println!(
+                    "Telemetry is {} (disabled by environment variable)",
+                    "disabled".yellow()
+                );
+            } else if prefs.telemetry_disabled {
+                println!(
+                    "Telemetry is {} (disabled via {})",
+                    "disabled".yellow(),
+                    "railway telemetry disable".bold()
+                );
+            } else {
+                println!("Telemetry is {}", "enabled".green());
+            }
+        }
+    }
+    Ok(())
+}

src/main.rs

@@ -51,6 +51,7 @@ commands!(
     ssh,
     starship,
     status,
+    telemetry_cmd(telemetry),
     unlink,
     up,
     upgrade,

src/telemetry.rs

@@ -42,7 +42,7 @@ pub fn show_notice_if_needed() {
     }
 
     eprintln!(
-        "{}\nYou can opt out by setting RAILWAY_NO_TELEMETRY=1 or DO_NOT_TRACK=1 in your environment.\n{}",
+        "{}\nYou can opt out by running `railway telemetry disable` or by setting RAILWAY_NO_TELEMETRY=1 in your environment.\n{}",
         "Railway now collects CLI usage data to improve the developer experience.".bold(),
         format!("Learn more: {}", "https://docs.railway.com/cli/telemetry").dimmed(),
     );
@@ -71,10 +71,42 @@ fn env_var_is_truthy(name: &str) -> bool {
         .unwrap_or(false)
 }
 
-fn is_telemetry_disabled() -> bool {
+#[derive(serde::Serialize, serde::Deserialize, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct Preferences {
+    #[serde(default)]
+    pub telemetry_disabled: bool,
+}
+
+impl Preferences {
+    fn path() -> Option<std::path::PathBuf> {
+        dirs::home_dir().map(|h| h.join(".railway/preferences.json"))
+    }
+
+    pub fn read() -> Self {
+        Self::path()
+            .and_then(|p| std::fs::read_to_string(p).ok())
+            .and_then(|s| serde_json::from_str(&s).ok())
+            .unwrap_or_default()
+    }
+
+    pub fn write(&self) {
+        if let Some(path) = Self::path() {
+            let _ = serde_json::to_string(self)
+                .ok()
+                .map(|contents| std::fs::write(path, contents));
+        }
+    }
+}
+
+pub fn is_telemetry_disabled_by_env() -> bool {
     env_var_is_truthy("DO_NOT_TRACK") || env_var_is_truthy("RAILWAY_NO_TELEMETRY")
 }
 
+fn is_telemetry_disabled() -> bool {
+    is_telemetry_disabled_by_env() || Preferences::read().telemetry_disabled
+}
+
 pub async fn send(event: CliTrackEvent) {
     if is_telemetry_disabled() {
         return;