diff --git a/crates/extension/src/extension_manifest.rs b/crates/extension/src/extension_manifest.rs
index 9d8a841686..b4416db574 100644
--- a/crates/extension/src/extension_manifest.rs
+++ b/crates/extension/src/extension_manifest.rs
@@ -64,6 +64,8 @@ pub struct ExtensionManifest {
     #[serde(default)]
     pub authors: Vec<String>,
     #[serde(default)]
+    pub capabilities: Vec<ExtensionCapability>,
+    #[serde(default)]
     pub lib: LibManifestEntry,
 
     #[serde(default)]
@@ -82,6 +84,28 @@ pub struct ExtensionManifest {
     pub snippets: Option<PathBuf>,
 }
 
+/// A capability for an extension.
+#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize)]
+#[serde(tag = "kind")]
+pub enum ExtensionCapability {
+    /// The capability to download a file from a server.
+    #[serde(rename = "download-file")]
+    DownloadFile {
+        /// The host name of the server from which the file will be downloaded (e.g., `github.com`).
+        host: String,
+        /// The path prefix to the file that will be downloaded.
+        ///
+        /// Any path that starts with this prefix will be allowed.
+        path_prefix: String,
+    },
+    /// The capability to install a package from npm.
+    #[serde(rename = "npm:install")]
+    NpmInstall {
+        /// The name of the package.
+        package: String,
+    },
+}
+
 #[derive(Clone, Default, PartialEq, Eq, Debug, Deserialize, Serialize)]
 pub struct LibManifestEntry {
     pub kind: Option<ExtensionLibraryKind>,
@@ -186,6 +210,7 @@ fn manifest_from_old_manifest(
         repository: manifest_json.repository,
         authors: manifest_json.authors,
         schema_version: SchemaVersion::ZERO,
+        capabilities: Vec::new(),
         lib: Default::default(),
         themes: {
             let mut themes = manifest_json.themes.into_values().collect::<Vec<_>>();
diff --git a/crates/extension/src/extension_store_test.rs b/crates/extension/src/extension_store_test.rs
index d4227c05f9..1a6fb253f0 100644
--- a/crates/extension/src/extension_store_test.rs
+++ b/crates/extension/src/extension_store_test.rs
@@ -150,6 +150,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
                         authors: Vec::new(),
                         repository: None,
                         themes: Default::default(),
+                        capabilities: Vec::new(),
                         lib: Default::default(),
                         languages: vec!["languages/erb".into(), "languages/ruby".into()],
                         grammars: [
@@ -181,6 +182,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
                             "themes/monokai-pro.json".into(),
                             "themes/monokai.json".into(),
                         ],
+                        capabilities: Vec::new(),
                         lib: Default::default(),
                         languages: Default::default(),
                         grammars: BTreeMap::default(),
@@ -344,6 +346,7 @@ async fn test_extension_store(cx: &mut TestAppContext) {
                 authors: vec![],
                 repository: None,
                 themes: vec!["themes/gruvbox.json".into()],
+                capabilities: Vec::new(),
                 lib: Default::default(),
                 languages: Default::default(),
                 grammars: BTreeMap::default(),
diff --git a/extensions/gleam/extension.toml b/extensions/gleam/extension.toml
index 7cedbca5d4..6fac2ade2e 100644
--- a/extensions/gleam/extension.toml
+++ b/extensions/gleam/extension.toml
@@ -6,6 +6,10 @@ schema_version = 1
 authors = ["Marshall Bowers <elliott.codes@gmail.com>"]
 repository = "https://github.com/zed-industries/zed"
 
+capabilities = [
+    { kind = "download-file", host = "github.com", path_prefix = "gleam-lang/gleam" },
+]
+
 [language_servers.gleam]
 name = "Gleam LSP"
 language = "Gleam"