feature: add railway version command with build metadata

build.rs

@@ -5,8 +5,41 @@ fn main() {
     println!("cargo:rerun-if-changed=src/gql/subscriptions/strings");
     println!("cargo:rerun-if-changed=src/gql/schema.json");
 
+    // Rebuild when git HEAD changes
+    println!("cargo:rerun-if-changed=.git/HEAD");
+
     // Expose the compile-time target triple so the self-updater fetches the
     // correct release asset (respects ABI: gnu vs musl, msvc vs gnu, etc.).
     let target = std::env::var("TARGET").unwrap();
     println!("cargo:rustc-env=BUILD_TARGET={target}");
+
+    // Expose git commit hash
+    let git_sha = std::process::Command::new("git")
+        .args(["rev-parse", "--short", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|output| String::from_utf8(output.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    println!("cargo:rustc-env=GIT_SHA={}", git_sha);
+
+    // Expose build date (ISO 8601 format in UTC)
+    let build_date = std::process::Command::new("date")
+        .args(["-u", "+%Y-%m-%dT%H:%M:%SZ"])
+        .output()
+        .ok()
+        .and_then(|output| String::from_utf8(output.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    println!("cargo:rustc-env=BUILD_DATE={}", build_date);
+
+    // Expose rustc version
+    let rustc_version = std::process::Command::new("rustc")
+        .args(["--version"])
+        .output()
+        .ok()
+        .and_then(|output| String::from_utf8(output.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    println!("cargo:rustc-env=RUSTC_VERSION={}", rustc_version);
 }

src/commands/mod.rs

@@ -46,6 +46,7 @@ pub mod unlink;
 pub mod up;
 pub mod upgrade;
 pub mod variable;
+pub mod version;
 pub mod volume;
 pub mod whoami;
 

src/commands/version.rs

@@ -0,0 +1,78 @@
+use serde::Serialize;
+
+use super::*;
+use crate::util::check_update::check_update;
+
+/// Display version information
+#[derive(Parser)]
+pub struct Args {
+    /// Output in JSON format
+    #[clap(long)]
+    json: bool,
+}
+
+#[derive(Serialize)]
+struct VersionJson {
+    version: String,
+    git_sha: String,
+    build_date: String,
+    rust_version: String,
+    target: String,
+    update_available: Option<String>,
+}
+
+pub async fn command(args: Args) -> Result<()> {
+    let version = env!("CARGO_PKG_VERSION").to_string();
+    let git_sha = env!("GIT_SHA").to_string();
+    let build_date = env!("BUILD_DATE").to_string();
+    let target = env!("BUILD_TARGET").to_string();
+    let rust_version = env!("RUSTC_VERSION").to_string();
+
+    // Check for updates (non-blocking, don't fail if check fails)
+    let update_available = check_update(false).await.ok().flatten();
+
+    if args.json {
+        let output = VersionJson {
+            version: version.clone(),
+            git_sha: git_sha.clone(),
+            build_date: build_date.clone(),
+            rust_version: rust_version.clone(),
+            target: target.clone(),
+            update_available: update_available.clone(),
+        };
+        println!("{}", serde_json::to_string_pretty(&output)?);
+        return Ok(());
+    }
+
+    // Human-readable output
+    println!(
+        "{} {}",
+        "Railway CLI".purple().bold(),
+        version.green().bold()
+    );
+    println!();
+    println!("{}", "Build Info:".bold());
+    println!("  Version:    {}", version);
+    println!("  Commit:     {}", git_sha.dimmed());
+    println!("  Build Date: {}", build_date);
+    println!("  Rust:       {}", rust_version);
+    println!("  Target:     {}", target);
+    println!();
+    println!("{}", "Update Status:".bold());
+    match update_available {
+        Some(new_version) => {
+            println!(
+                "  {} New version available: {} -> {}",
+                "*".yellow(),
+                version.red(),
+                new_version.green()
+            );
+            println!("  Run {} to upgrade", "`railway upgrade`".cyan());
+        }
+        None => {
+            println!("  {} You are on the latest version", "*".green());
+        }
+    }
+
+    Ok(())
+}

src/main.rs

@@ -62,6 +62,7 @@ commands!(
     unlink,
     up,
     upgrade,
+    version,
     variable(variables, vars, var),
     whoami,
     volume,