feat: add Windows platform support

install.ps1

@@ -0,0 +1,113 @@
+#Requires -Version 5.1
+<#
+.SYNOPSIS
+    Install cship — Claude Code statusline tool for Windows.
+.DESCRIPTION
+    Downloads the cship binary from GitHub Releases, installs it to
+    %LOCALAPPDATA%\Programs\cship\, writes a default cship.toml, and
+    registers the statusline in Claude Code's settings.json.
+#>
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+
+$REPO    = "stephenleo/cship"
+$INSTALL_DIR = Join-Path $env:LOCALAPPDATA "Programs\cship"
+$BIN     = Join-Path $INSTALL_DIR "cship.exe"
+$CONFIG_DIR  = Join-Path $env:USERPROFILE ".config"
+$CONFIG_FILE = Join-Path $CONFIG_DIR "cship.toml"
+$SETTINGS    = Join-Path $env:APPDATA "Claude\settings.json"
+
+# --- Arch detection ---
+$arch = $env:PROCESSOR_ARCHITECTURE
+if ($arch -eq "AMD64") {
+    $TARGET = "x86_64-pc-windows-msvc"
+} elseif ($arch -eq "ARM64") {
+    $TARGET = "aarch64-pc-windows-msvc"
+} else {
+    Write-Error "Unsupported architecture: $arch"
+    exit 1
+}
+
+# --- Fetch latest release tag ---
+Write-Host "Fetching latest cship release..."
+$releaseUrl = "https://api.github.com/repos/$REPO/releases/latest"
+$release = Invoke-RestMethod -Uri $releaseUrl -UseBasicParsing
+$tag = $release.tag_name
+$assetName = "cship-$TARGET.exe"
+$downloadUrl = $release.assets |
+    Where-Object { $_.name -eq $assetName } |
+    Select-Object -ExpandProperty browser_download_url
+
+if (-not $downloadUrl) {
+    Write-Error "Asset '$assetName' not found in release $tag. Available assets:`n$($release.assets.name -join "`n")"
+    exit 1
+}
+
+# --- Download ---
+Write-Host "Downloading $assetName ($tag)..."
+New-Item -ItemType Directory -Force -Path $INSTALL_DIR | Out-Null
+Invoke-WebRequest -Uri $downloadUrl -OutFile $BIN -UseBasicParsing
+Write-Host "Installed to: $BIN"
+
+# --- Add to PATH (offer) ---
+$currentPath = [Environment]::GetEnvironmentVariable("PATH", "User")
+if ($currentPath -notlike "*$INSTALL_DIR*") {
+    $add = Read-Host "Add $INSTALL_DIR to your PATH? [Y/n]"
+    if ($add -ne "n" -and $add -ne "N") {
+        [Environment]::SetEnvironmentVariable(
+            "PATH",
+            "$currentPath;$INSTALL_DIR",
+            "User"
+        )
+        $env:PATH += ";$INSTALL_DIR"
+        Write-Host "Added to PATH (effective in new shells)."
+    }
+}
+
+# --- Write default cship.toml ---
+if (-not (Test-Path $CONFIG_FILE)) {
+    New-Item -ItemType Directory -Force -Path $CONFIG_DIR | Out-Null
+    @'
+[cship]
+lines = ["$cship.model $cship.cost"]
+
+[cship.model]
+disabled = false
+
+[cship.cost]
+disabled = false
+'@ | Set-Content -Path $CONFIG_FILE -Encoding UTF8
+    Write-Host "Config written to: $CONFIG_FILE"
+} else {
+    Write-Host "Config already exists at $CONFIG_FILE — skipping."
+}
+
+# --- Register statusline in Claude Code settings.json ---
+$claudeDir = Split-Path $SETTINGS
+if (-not (Test-Path $claudeDir)) {
+    Write-Host "Claude Code settings directory not found at $claudeDir — skipping settings update."
+    Write-Host "Authenticate in Claude Code first, then re-run this script."
+} elseif (-not (Test-Path $SETTINGS)) {
+    # Create minimal settings.json
+    New-Item -ItemType Directory -Force -Path $claudeDir | Out-Null
+    '{"statusline": "cship"}' | Set-Content -Path $SETTINGS -Encoding UTF8
+    Write-Host "Created settings.json with statusline entry."
+} else {
+    $json = Get-Content $SETTINGS -Raw | ConvertFrom-Json
+    if (-not $json.PSObject.Properties["statusline"]) {
+        $json | Add-Member -NotePropertyName "statusline" -NotePropertyValue "cship"
+    } else {
+        $json.statusline = "cship"
+    }
+    $json | ConvertTo-Json -Depth 10 | Set-Content -Path $SETTINGS -Encoding UTF8
+    Write-Host "Updated settings.json with statusline entry."
+}
+
+# --- First-run preview ---
+Write-Host ""
+Write-Host "Running 'cship explain' as a first-run preview..."
+& $BIN explain
+
+Write-Host ""
+Write-Host "cship $tag installed successfully."
+Write-Host "Restart Claude Code for the statusline to take effect."

src/config.rs

@@ -289,10 +289,8 @@ pub fn load_with_source(
     }
 
     // Step 3: Global fallback — check ~/.config/cship.toml before ~/.config/starship.toml
-    if let Ok(home) = std::env::var("HOME") {
-        let cship_global = std::path::Path::new(&home)
-            .join(".config")
-            .join("cship.toml");
+    if let Some(home) = crate::platform::home_dir() {
+        let cship_global = home.join(".config").join("cship.toml");
         if cship_global.exists() {
             let config = load_cship_toml(&cship_global).unwrap_or_else(|e| {
                 tracing::warn!("cship: failed to load global dedicated config: {e}");
@@ -303,9 +301,7 @@ pub fn load_with_source(
                 source: ConfigSource::DedicatedFile(cship_global),
             };
         }
-        let global = std::path::Path::new(&home)
-            .join(".config")
-            .join("starship.toml");
+        let global = home.join(".config").join("starship.toml");
         if global.exists() {
             let config = load_from_path(&global).unwrap_or_else(|e| {
                 tracing::warn!("cship: failed to load global config: {e}");

src/passthrough.rs

@@ -355,18 +355,20 @@ mod tests {
         assert!(result.is_none());
     }
 
+    // Unix-only: faking a `starship` binary requires a +x shell script, which has no
+    // simple equivalent on Windows (Command::new resolves only .exe, not .cmd/.bat).
+    // The env-injection logic itself (cmd.env) is platform-independent.
+    #[cfg(unix)]
     #[test]
     fn test_render_passthrough_injects_cship_model_env_var() {
         use std::fs;
-        #[cfg(unix)]
         use std::os::unix::fs::PermissionsExt;
 
         let dir = std::env::temp_dir().join("cship_test_cship_env");
         fs::create_dir_all(&dir).unwrap();
+
         let script = dir.join("starship");
-        // Script: print CSHIP_MODEL env var, exit 0
         fs::write(&script, "#!/bin/sh\nprintf '%s' \"$CSHIP_MODEL\"\n").unwrap();
-        #[cfg(unix)]
         fs::set_permissions(&script, fs::Permissions::from_mode(0o755)).unwrap();
 
         let _guard = PATH_MUTEX.lock().unwrap();

src/platform.rs

@@ -92,19 +92,47 @@ pub fn get_oauth_token() -> Result<String, String> {
 /// Returns `None` if the file is absent, unreadable, or malformed.
 #[cfg(target_os = "linux")]
 fn read_credentials_file() -> Option<String> {
-    let home = std::env::var("HOME").ok()?;
-    let path = std::path::Path::new(&home)
-        .join(".claude")
-        .join(".credentials.json");
+    let home = home_dir()?;
+    let path = home.join(".claude").join(".credentials.json");
     let contents = std::fs::read_to_string(&path).ok()?;
     extract_access_token(contents.trim())
 }
 
-#[cfg(not(any(target_os = "macos", target_os = "linux")))]
-compile_error!("cship: get_oauth_token() is only supported on macOS and Linux");
+/// Returns the user's effective home directory, checked in priority order:
+/// 1. `CLAUDE_HOME` env var (explicit override for non-standard installs, all platforms)
+/// 2. `HOME` env var (Unix standard; also set by Git Bash / WSL on Windows)
+/// 3. `USERPROFILE` env var (Windows native; Claude Code stores .claude here)
+pub(crate) fn home_dir() -> Option<std::path::PathBuf> {
+    for var in ["CLAUDE_HOME", "HOME", "USERPROFILE"] {
+        if let Ok(h) = std::env::var(var)
+            && !h.is_empty()
+        {
+            return Some(std::path::PathBuf::from(h));
+        }
+    }
+    None
+}
+
+#[cfg(target_os = "windows")]
+pub fn get_oauth_token() -> Result<String, String> {
+    let home = home_dir().ok_or_else(|| {
+        "Cannot locate home directory — set CLAUDE_HOME to your .claude folder parent".to_string()
+    })?;
+    let path = home.join(".claude").join(".credentials.json");
+    let contents = std::fs::read_to_string(&path).map_err(|_| {
+        format!(
+            "Claude Code credentials not found at {} — authenticate in Claude Code first",
+            path.display()
+        )
+    })?;
+    extract_access_token(contents.trim()).ok_or_else(|| {
+        "Claude Code credentials found but access token could not be parsed — credential may be malformed".into()
+    })
+}
 
 /// Inner implementation with injectable command name for testability.
 /// `tool` is the binary; `args` are the arguments passed to it.
+#[cfg(not(target_os = "windows"))]
 fn get_oauth_token_with_cmd(tool: &str, args: &[&str]) -> Result<String, String> {
     use std::process::Command;
 
@@ -151,6 +179,7 @@ fn extract_access_token(json: &str) -> Option<String> {
 }
 
 /// Return the platform-specific install hint for a missing credential tool.
+#[cfg(not(target_os = "windows"))]
 fn install_hint(tool: &str) -> String {
     match tool {
         "secret-tool" => {
@@ -171,6 +200,7 @@ mod tests {
 
     // These tests exercise the Linux path only; macOS path is validated by code review.
 
+    #[cfg(not(target_os = "windows"))]
     #[test]
     fn test_tool_not_found_returns_install_hint() {
         // A non-existent binary triggers io::ErrorKind::NotFound on spawn.
@@ -184,6 +214,7 @@ mod tests {
         );
     }
 
+    #[cfg(not(target_os = "windows"))]
     #[test]
     fn test_nonzero_exit_returns_credential_not_found_error() {
         // `/bin/sh -c "exit 1"` always exits with code 1 — simulates "credential not found".
@@ -197,6 +228,7 @@ mod tests {
         );
     }
 
+    #[cfg(not(target_os = "windows"))]
     #[test]
     fn test_successful_token_extraction() {
         // Use `/bin/sh` (absolute path, present on both macOS and Linux) to emit a JSON blob.
@@ -255,12 +287,14 @@ mod tests {
         assert_eq!(result, Some("sk-ant-file-token".to_string()));
     }
 
+    #[cfg(not(target_os = "windows"))]
     #[test]
     fn test_install_hint_secret_tool() {
         let hint = install_hint("secret-tool");
         assert!(hint.contains("sudo apt install libsecret-tools"), "{hint}");
     }
 
+    #[cfg(not(target_os = "windows"))]
     #[test]
     fn test_install_hint_security() {
         let hint = install_hint("security");

src/uninstall.rs

@@ -2,21 +2,27 @@
 //! Intentionally leaves `[cship.*]` sections in `starship.toml` intact (FR44).
 
 pub fn run() {
-    let home = match std::env::var("HOME") {
-        Ok(h) if !h.is_empty() => h,
-        _ => {
-            println!("HOME is not set — cannot determine paths. Aborting uninstall.");
+    let home = match crate::platform::home_dir() {
+        Some(h) => h,
+        None => {
+            println!("Cannot determine home directory — set CLAUDE_HOME. Aborting uninstall.");
             return;
         }
     };
-    let home = std::path::PathBuf::from(home);
     remove_binary(&home);
     remove_statusline_from_settings(&home);
     remove_cache_directories(&home);
 }
 
 fn remove_binary(home: &std::path::Path) {
-    for bin in [home.join(".local/bin/cship"), home.join(".cargo/bin/cship")] {
+    #[cfg(not(target_os = "windows"))]
+    let candidates = [home.join(".local/bin/cship"), home.join(".cargo/bin/cship")];
+    #[cfg(target_os = "windows")]
+    let candidates = [
+        home.join(".cargo/bin/cship.exe"),
+        home.join(r".local\bin\cship.exe"),
+    ];
+    for bin in candidates {
         if bin.exists() {
             match std::fs::remove_file(&bin) {
                 Ok(()) => println!("Removed: {}", bin.display()),
@@ -109,14 +115,20 @@ mod tests {
     #[test]
     fn test_remove_binary_present() {
         with_tempdir(|home| {
+            let bin_name = if cfg!(target_os = "windows") {
+                "cship.exe"
+            } else {
+                "cship"
+            };
+
             let local_bin = home.join(".local/bin");
             std::fs::create_dir_all(&local_bin).unwrap();
-            let local_path = local_bin.join("cship");
+            let local_path = local_bin.join(bin_name);
             std::fs::write(&local_path, b"fake binary").unwrap();
 
             let cargo_bin = home.join(".cargo/bin");
             std::fs::create_dir_all(&cargo_bin).unwrap();
-            let cargo_path = cargo_bin.join("cship");
+            let cargo_path = cargo_bin.join(bin_name);
             std::fs::write(&cargo_path, b"fake binary").unwrap();
 
             remove_binary(home);
@@ -223,9 +235,15 @@ mod tests {
     #[test]
     fn test_run_with_empty_home_does_not_panic() {
         let _guard = HOME_MUTEX.lock().unwrap_or_else(|e| e.into_inner());
-        // SAFETY: guarded by HOME_MUTEX; no other threads read HOME concurrently.
-        unsafe { std::env::set_var("HOME", "") };
+        // SAFETY: guarded by HOME_MUTEX; no other threads read these env vars concurrently.
+        unsafe {
+            std::env::set_var("HOME", "");
+            std::env::set_var("USERPROFILE", "");
+            std::env::set_var("CLAUDE_HOME", "");
+        };
         // Should print message and return, not panic or touch root paths
         run();
+        // Restore to avoid poisoning other tests
+        unsafe { std::env::remove_var("CLAUDE_HOME") };
     }
 }

tests/cli.rs

@@ -824,20 +824,21 @@ fn test_native_renders_alongside_passthrough_not_installed() {
 
 // ── Story 4.2: Cache and CSHIP_* env var integration tests ────────────────
 
+// Unix-only: faking a `starship` binary requires a +x shell script, which has no
+// simple equivalent on Windows (Command::new resolves only .exe, not .cmd/.bat).
+#[cfg(unix)]
 #[test]
 fn test_passthrough_env_vars_injected_via_cship_model() {
     // Create a fake starship script that echoes $CSHIP_MODEL to stdout.
     // Uses .env("PATH", ...) on the cship subprocess rather than mutating
     // the test process's global PATH — safe for parallel test execution.
     use std::fs;
-    #[cfg(unix)]
     use std::os::unix::fs::PermissionsExt;
 
     let dir = std::env::temp_dir().join("cship_inttest_cship_env");
     fs::create_dir_all(&dir).unwrap();
     let script = dir.join("starship");
     fs::write(&script, "#!/bin/sh\nprintf '%s' \"$CSHIP_MODEL\"\n").unwrap();
-    #[cfg(unix)]
     fs::set_permissions(&script, fs::Permissions::from_mode(0o755)).unwrap();
 
     let json = r#"{"session_id":"test","cwd":"/tmp","transcript_path":"/tmp/cship_inttest_tp.jsonl","version":"1.0","exceeds_200k_tokens":false,"model":{"id":"claude-opus-4-6","display_name":"IntTestModel"},"workspace":{"current_dir":"/tmp","project_dir":"/tmp"},"output_style":{"name":"default"},"cost":{"total_cost_usd":0.0}}"#;