diff --git a/src/backend/platform_target.rs b/src/backend/platform_target.rs
index 531e780974..8430f0de9b 100644
--- a/src/backend/platform_target.rs
+++ b/src/backend/platform_target.rs
@@ -31,3 +31,39 @@ impl PlatformTarget {
         self.platform.to_key()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_platform_target_creation() {
+        let platform = Platform::parse("linux-x64").unwrap();
+        let target = PlatformTarget::new(platform.clone());
+
+        assert_eq!(target.platform, platform);
+        assert_eq!(target.os_name(), "linux");
+        assert_eq!(target.arch_name(), "x64");
+        assert_eq!(target.qualifier(), None);
+        assert_eq!(target.to_key(), "linux-x64");
+    }
+
+    #[test]
+    fn test_platform_target_with_qualifier() {
+        let platform = Platform::parse("linux-x64-musl").unwrap();
+        let target = PlatformTarget::new(platform);
+
+        assert_eq!(target.os_name(), "linux");
+        assert_eq!(target.arch_name(), "x64");
+        assert_eq!(target.qualifier(), Some("musl"));
+        assert_eq!(target.to_key(), "linux-x64-musl");
+    }
+
+    #[test]
+    fn test_from_current() {
+        let target = PlatformTarget::from_current();
+        let current_platform = Platform::current();
+
+        assert_eq!(target.platform, current_platform);
+    }
+}
diff --git a/src/plugins/core/bun.rs b/src/plugins/core/bun.rs
index 46af233ed6..e221b498c7 100644
--- a/src/plugins/core/bun.rs
+++ b/src/plugins/core/bun.rs
@@ -15,7 +15,10 @@ use crate::http::HTTP;
 use crate::install_context::InstallContext;
 use crate::toolset::ToolVersion;
 use crate::ui::progress_report::SingleReport;
-use crate::{backend::Backend, config::Config};
+use crate::{
+    backend::{Backend, GitHubReleaseInfo, ReleaseType, platform_target::PlatformTarget},
+    config::Config,
+};
 use crate::{file, github, plugins};
 
 #[derive(Debug)]
@@ -116,44 +119,108 @@ impl Backend for BunPlugin {
 
         Ok(tv)
     }
-}
 
-fn os() -> &'static str {
-    if cfg!(target_os = "macos") {
-        "darwin"
-    } else if cfg!(target_os = "linux") {
-        "linux"
-    } else {
-        &OS
+    // ========== Lockfile Metadata Fetching Implementation ==========
+
+    async fn get_github_release_info(
+        &self,
+        tv: &ToolVersion,
+        target: &PlatformTarget,
+    ) -> Result<Option<GitHubReleaseInfo>> {
+        let version = &tv.version;
+
+        // Build the asset pattern for Bun's GitHub releases
+        // Pattern: bun-{os}-{arch}.zip (where arch may include variants like -musl, -baseline)
+        let os_name = Self::map_os_to_bun(target.os_name());
+        let arch_name = Self::get_bun_arch_for_target(target);
+        let asset_pattern = format!("bun-{os_name}-{arch_name}.zip");
+
+        Ok(Some(GitHubReleaseInfo {
+            repo: "oven-sh/bun".to_string(),
+            asset_pattern: Some(asset_pattern),
+            api_url: Some(format!(
+                "https://github.com/oven-sh/bun/releases/download/bun-v{version}"
+            )),
+            release_type: ReleaseType::GitHub,
+        }))
     }
 }
 
-fn arch() -> &'static str {
-    if cfg!(target_arch = "x86_64") {
-        if cfg!(target_env = "musl") {
-            if cfg!(target_feature = "avx2") {
-                "x64-musl"
-            } else {
-                "x64-musl-baseline"
+impl BunPlugin {
+    /// Map our platform OS names to Bun's naming convention
+    fn map_os_to_bun(os: &str) -> &str {
+        match os {
+            "macos" => "darwin",
+            "linux" => "linux",
+            "windows" => "windows",
+            other => other,
+        }
+    }
+
+    /// Map our platform arch names to Bun's naming convention
+    /// Note: This handles simple cases. Complex musl/baseline variants are handled in arch()
+    fn map_arch_to_bun(arch: &str) -> &str {
+        match arch {
+            "x64" => "x64",
+            "arm64" | "aarch64" => "aarch64",
+            other => other,
+        }
+    }
+
+    /// Get the full Bun arch string for a target platform
+    /// This handles musl, baseline, and other variants based on platform qualifiers
+    fn get_bun_arch_for_target(target: &PlatformTarget) -> String {
+        let base_arch = Self::map_arch_to_bun(target.arch_name());
+
+        // Handle qualifiers like musl, baseline, etc.
+        if let Some(qualifier) = target.qualifier() {
+            match qualifier {
+                "musl" => format!("{}-musl", base_arch),
+                "musl-baseline" => format!("{}-musl-baseline", base_arch),
+                "baseline" => format!("{}-baseline", base_arch),
+                other => format!("{}-{}", base_arch, other),
             }
-        } else if cfg!(target_feature = "avx2") {
-            "x64"
         } else {
-            "x64-baseline"
+            base_arch.to_string()
         }
-    } else if cfg!(target_arch = "aarch64") {
-        if cfg!(target_env = "musl") {
-            "aarch64-musl"
-        } else if cfg!(windows) {
-            "x64"
+    }
+
+    /// Get the full Bun arch string with variants (musl, baseline, etc.)
+    fn get_bun_arch_with_variants() -> &'static str {
+        if cfg!(target_arch = "x86_64") {
+            if cfg!(target_env = "musl") {
+                if cfg!(target_feature = "avx2") {
+                    "x64-musl"
+                } else {
+                    "x64-musl-baseline"
+                }
+            } else if cfg!(target_feature = "avx2") {
+                "x64"
+            } else {
+                "x64-baseline"
+            }
+        } else if cfg!(target_arch = "aarch64") {
+            if cfg!(target_env = "musl") {
+                "aarch64-musl"
+            } else if cfg!(windows) {
+                "x64"
+            } else {
+                "aarch64"
+            }
         } else {
-            "aarch64"
+            &ARCH
         }
-    } else {
-        &ARCH
     }
 }
 
+fn os() -> &'static str {
+    BunPlugin::map_os_to_bun(&OS)
+}
+
+fn arch() -> &'static str {
+    BunPlugin::get_bun_arch_with_variants()
+}
+
 fn bun_bin_name() -> &'static str {
     if cfg!(windows) { "bun.exe" } else { "bun" }
 }
diff --git a/src/plugins/core/node.rs b/src/plugins/core/node.rs
index d72ef4cc39..a5971b8ade 100644
--- a/src/plugins/core/node.rs
+++ b/src/plugins/core/node.rs
@@ -1,4 +1,4 @@
-use crate::backend::{Backend, VersionCacheManager};
+use crate::backend::{Backend, VersionCacheManager, platform_target::PlatformTarget};
 use crate::build_time::built_info;
 use crate::cache::CacheManagerBuilder;
 use crate::cli::args::BackendArg;
@@ -534,6 +534,75 @@ impl Backend for NodePlugin {
             })
             .clone()
     }
+
+    // ========== Lockfile Metadata Fetching Implementation ==========
+
+    async fn get_tarball_url(
+        &self,
+        tv: &ToolVersion,
+        target: &PlatformTarget,
+    ) -> Result<Option<String>> {
+        let version = &tv.version;
+        let settings = Settings::get();
+
+        // Build platform-specific filename like Node.js does
+        let slug = self.build_platform_slug(version, target);
+        let filename = if target.os_name() == "windows" {
+            format!("{slug}.zip")
+        } else {
+            format!("{slug}.tar.gz")
+        };
+
+        // Use Node.js mirror URL to construct download URL
+        let url = settings
+            .node
+            .mirror_url()
+            .join(&format!("v{version}/{filename}"))
+            .map_err(|e| eyre::eyre!("Failed to construct Node.js download URL: {e}"))?;
+
+        Ok(Some(url.to_string()))
+    }
+}
+
+impl NodePlugin {
+    /// Map OS name from Platform to Node.js convention
+    fn map_os(os_name: &str) -> &str {
+        match os_name {
+            "macos" => "darwin",
+            "linux" => "linux",
+            "windows" => "win",
+            other => other,
+        }
+    }
+
+    /// Map arch name from Platform to Node.js convention
+    fn map_arch(arch_name: &str) -> &str {
+        match arch_name {
+            "x86" => "x86",
+            "x64" => "x64",
+            "arm" => "armv7l",
+            "arm64" => "arm64",
+            "aarch64" => "arm64",
+            "loongarch64" => "loong64",
+            "riscv64" => "riscv64",
+            other => other,
+        }
+    }
+
+    /// Build platform-specific slug for Node.js downloads
+    /// This mirrors the logic from BuildOpts::new() and slug() function
+    fn build_platform_slug(&self, version: &str, target: &PlatformTarget) -> String {
+        let settings = Settings::get();
+
+        let os = Self::map_os(target.os_name());
+        let arch = Self::map_arch(target.arch_name());
+
+        if let Some(flavor) = &settings.node.flavor {
+            format!("node-v{version}-{os}-{arch}-{flavor}")
+        } else {
+            format!("node-v{version}-{os}-{arch}")
+        }
+    }
 }
 
 #[derive(Debug)]
@@ -620,38 +689,16 @@ fn make_install_cmd() -> String {
 }
 
 fn os() -> &'static str {
-    if cfg!(target_os = "linux") {
-        "linux"
-    } else if cfg!(target_os = "macos") {
-        "darwin"
-    } else if cfg!(target_os = "windows") {
-        "win"
-    } else {
-        built_info::CFG_OS
-    }
+    NodePlugin::map_os(built_info::CFG_OS)
 }
 
 fn arch(settings: &Settings) -> &str {
     let arch = settings.arch();
-    if arch == "x86" {
-        "x86"
-    } else if arch == "x64" {
-        "x64"
-    } else if arch == "arm" {
-        if cfg!(target_feature = "v6") {
-            "armv6l"
-        } else {
-            "armv7l"
-        }
-    } else if arch == "loongarch64" {
-        "loong64"
-    } else if arch == "riscv64" {
-        "riscv64"
-    } else if arch == "aarch64" {
-        "arm64"
-    } else {
-        arch
+    // Special handling for ARM with target features
+    if arch == "arm" && cfg!(target_feature = "v6") {
+        return "armv6l";
     }
+    NodePlugin::map_arch(arch)
 }
 
 fn slug(v: &str) -> String {