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diff --git a/src-tauri/src/core/maven.rs b/src-tauri/src/core/maven.rs
new file mode 100644
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+++ b/src-tauri/src/core/maven.rs
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+//! Maven coordinate parsing and URL construction utilities.
+//!
+//! Mod loaders like Fabric and Forge specify libraries using Maven coordinates
+//! (e.g., `net.fabricmc:fabric-loader:0.14.21`) instead of direct download URLs.
+//! This module provides utilities to parse these coordinates and construct
+//! download URLs for various Maven repositories.
+
+use std::path::PathBuf;
+
+/// Known Maven repository URLs for mod loaders
+pub const MAVEN_CENTRAL: &str = "https://repo1.maven.org/maven2/";
+pub const FABRIC_MAVEN: &str = "https://maven.fabricmc.net/";
+pub const FORGE_MAVEN: &str = "https://maven.minecraftforge.net/";
+pub const MOJANG_LIBRARIES: &str = "https://libraries.minecraft.net/";
+
+/// Represents a parsed Maven coordinate.
+///
+/// Maven coordinates follow the format: `group:artifact:version[:classifier][@extension]`
+/// Examples:
+/// - `net.fabricmc:fabric-loader:0.14.21`
+/// - `org.lwjgl:lwjgl:3.3.1:natives-linux`
+/// - `com.example:artifact:1.0@zip`
+#[derive(Debug, Clone, PartialEq)]
+pub struct MavenCoordinate {
+    pub group: String,
+    pub artifact: String,
+    pub version: String,
+    pub classifier: Option<String>,
+    pub extension: String,
+}
+
+impl MavenCoordinate {
+    /// Parse a Maven coordinate string.
+    ///
+    /// # Arguments
+    /// * `coord` - A string in the format `group:artifact:version[:classifier][@extension]`
+    ///
+    /// # Returns
+    /// * `Some(MavenCoordinate)` if parsing succeeds
+    /// * `None` if the format is invalid
+    ///
+    /// # Examples
+    /// ```
+    /// let coord = MavenCoordinate::parse("net.fabricmc:fabric-loader:0.14.21").unwrap();
+    /// assert_eq!(coord.group, "net.fabricmc");
+    /// assert_eq!(coord.artifact, "fabric-loader");
+    /// assert_eq!(coord.version, "0.14.21");
+    /// ```
+    pub fn parse(coord: &str) -> Option<Self> {
+        // Handle extension suffix (e.g., @zip)
+        let (coord_part, extension) = if let Some(at_idx) = coord.rfind('@') {
+            let ext = &coord[at_idx + 1..];
+            let base = &coord[..at_idx];
+            (base, ext.to_string())
+        } else {
+            (coord, "jar".to_string())
+        };
+
+        let parts: Vec<&str> = coord_part.split(':').collect();
+
+        match parts.len() {
+            3 => Some(MavenCoordinate {
+                group: parts[0].to_string(),
+                artifact: parts[1].to_string(),
+                version: parts[2].to_string(),
+                classifier: None,
+                extension,
+            }),
+            4 => Some(MavenCoordinate {
+                group: parts[0].to_string(),
+                artifact: parts[1].to_string(),
+                version: parts[2].to_string(),
+                classifier: Some(parts[3].to_string()),
+                extension,
+            }),
+            _ => None,
+        }
+    }
+
+    /// Get the relative path for this artifact in a Maven repository.
+    ///
+    /// # Returns
+    /// The path as `group/artifact/version/artifact-version[-classifier].extension`
+    ///
+    /// # Examples
+    /// ```
+    /// let coord = MavenCoordinate::parse("net.fabricmc:fabric-loader:0.14.21").unwrap();
+    /// assert_eq!(coord.to_path(), "net/fabricmc/fabric-loader/0.14.21/fabric-loader-0.14.21.jar");
+    /// ```
+    pub fn to_path(&self) -> String {
+        let group_path = self.group.replace('.', "/");
+        let filename = match &self.classifier {
+            Some(classifier) => {
+                format!(
+                    "{}-{}-{}.{}",
+                    self.artifact, self.version, classifier, self.extension
+                )
+            }
+            None => {
+                format!("{}-{}.{}", self.artifact, self.version, self.extension)
+            }
+        };
+
+        format!(
+            "{}/{}/{}/{}",
+            group_path, self.artifact, self.version, filename
+        )
+    }
+
+    /// Get the local file path for storing this artifact.
+    ///
+    /// # Arguments
+    /// * `libraries_dir` - The base libraries directory
+    ///
+    /// # Returns
+    /// The full path where the library should be stored
+    pub fn to_local_path(&self, libraries_dir: &PathBuf) -> PathBuf {
+        let rel_path = self.to_path();
+        libraries_dir.join(rel_path.replace('/', std::path::MAIN_SEPARATOR_STR))
+    }
+
+    /// Construct the full download URL for this artifact.
+    ///
+    /// # Arguments
+    /// * `base_url` - The Maven repository base URL (e.g., `https://maven.fabricmc.net/`)
+    ///
+    /// # Returns
+    /// The full URL to download the artifact
+    pub fn to_url(&self, base_url: &str) -> String {
+        let base = base_url.trim_end_matches('/');
+        format!("{}/{}", base, self.to_path())
+    }
+}
+
+/// Resolve the download URL for a library.
+///
+/// This function handles both:
+/// 1. Libraries with explicit download URLs (vanilla Minecraft)
+/// 2. Libraries with only Maven coordinates (Fabric/Forge)
+///
+/// # Arguments
+/// * `name` - The Maven coordinate string
+/// * `explicit_url` - An explicit download URL if provided in the library JSON
+/// * `maven_url` - A custom Maven repository URL from the library JSON
+///
+/// # Returns
+/// The resolved download URL
+pub fn resolve_library_url(
+    name: &str,
+    explicit_url: Option<&str>,
+    maven_url: Option<&str>,
+) -> Option<String> {
+    // If there's an explicit URL, use it
+    if let Some(url) = explicit_url {
+        return Some(url.to_string());
+    }
+
+    // Parse the Maven coordinate
+    let coord = MavenCoordinate::parse(name)?;
+
+    // Determine the base Maven URL
+    let base_url = maven_url.unwrap_or_else(|| {
+        // Guess the repository based on group
+        if coord.group.starts_with("net.fabricmc") {
+            FABRIC_MAVEN
+        } else if coord.group.starts_with("net.minecraftforge")
+            || coord.group.starts_with("cpw.mods")
+        {
+            FORGE_MAVEN
+        } else {
+            MOJANG_LIBRARIES
+        }
+    });
+
+    Some(coord.to_url(base_url))
+}
+
+/// Get the local storage path for a library.
+///
+/// # Arguments
+/// * `name` - The Maven coordinate string
+/// * `libraries_dir` - The base libraries directory
+///
+/// # Returns
+/// The path where the library should be stored
+pub fn get_library_path(name: &str, libraries_dir: &PathBuf) -> Option<PathBuf> {
+    let coord = MavenCoordinate::parse(name)?;
+    Some(coord.to_local_path(libraries_dir))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_simple_coordinate() {
+        let coord = MavenCoordinate::parse("net.fabricmc:fabric-loader:0.14.21").unwrap();
+        assert_eq!(coord.group, "net.fabricmc");
+        assert_eq!(coord.artifact, "fabric-loader");
+        assert_eq!(coord.version, "0.14.21");
+        assert_eq!(coord.classifier, None);
+        assert_eq!(coord.extension, "jar");
+    }
+
+    #[test]
+    fn test_parse_with_classifier() {
+        let coord = MavenCoordinate::parse("org.lwjgl:lwjgl:3.3.1:natives-linux").unwrap();
+        assert_eq!(coord.group, "org.lwjgl");
+        assert_eq!(coord.artifact, "lwjgl");
+        assert_eq!(coord.version, "3.3.1");
+        assert_eq!(coord.classifier, Some("natives-linux".to_string()));
+        assert_eq!(coord.extension, "jar");
+    }
+
+    #[test]
+    fn test_parse_with_extension() {
+        let coord = MavenCoordinate::parse("com.example:artifact:1.0@zip").unwrap();
+        assert_eq!(coord.extension, "zip");
+    }
+
+    #[test]
+    fn test_to_path() {
+        let coord = MavenCoordinate::parse("net.fabricmc:fabric-loader:0.14.21").unwrap();
+        assert_eq!(
+            coord.to_path(),
+            "net/fabricmc/fabric-loader/0.14.21/fabric-loader-0.14.21.jar"
+        );
+    }
+
+    #[test]
+    fn test_to_path_with_classifier() {
+        let coord = MavenCoordinate::parse("org.lwjgl:lwjgl:3.3.1:natives-linux").unwrap();
+        assert_eq!(
+            coord.to_path(),
+            "org/lwjgl/lwjgl/3.3.1/lwjgl-3.3.1-natives-linux.jar"
+        );
+    }
+
+    #[test]
+    fn test_to_url() {
+        let coord = MavenCoordinate::parse("net.fabricmc:fabric-loader:0.14.21").unwrap();
+        assert_eq!(
+            coord.to_url(FABRIC_MAVEN),
+            "https://maven.fabricmc.net/net/fabricmc/fabric-loader/0.14.21/fabric-loader-0.14.21.jar"
+        );
+    }
+
+    #[test]
+    fn test_resolve_library_url_explicit() {
+        let url = resolve_library_url(
+            "net.fabricmc:fabric-loader:0.14.21",
+            Some("https://example.com/lib.jar"),
+            None,
+        );
+        assert_eq!(url, Some("https://example.com/lib.jar".to_string()));
+    }
+
+    #[test]
+    fn test_resolve_library_url_fabric() {
+        let url = resolve_library_url("net.fabricmc:fabric-loader:0.14.21", None, None);
+        assert!(url.unwrap().starts_with(FABRIC_MAVEN));
+    }
+}