diff --git a/Cargo.lock b/Cargo.lock
index 51e8e6eac..c7aac58d6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1310,6 +1310,7 @@ dependencies = [
  "stacker",
  "strum",
  "tar",
+ "tempfile",
  "termcolor",
  "thiserror 2.0.18",
  "time",
diff --git a/compiler-core/Cargo.toml b/compiler-core/Cargo.toml
index 5a121450a..c85ba87aa 100644
--- a/compiler-core/Cargo.toml
+++ b/compiler-core/Cargo.toml
@@ -53,6 +53,7 @@ wit-parser = "0.239.0"
 wit-component = { version = "0.239.0", features = ["dummy-module"] }
 wat = "1"
 anyhow = "1"
+tempfile = "3"
 
 num-bigint.workspace = true
 num-traits.workspace = true
diff --git a/compiler-core/src/wasm/zed.rs b/compiler-core/src/wasm/zed.rs
index d7f77e804..b6cd36980 100644
--- a/compiler-core/src/wasm/zed.rs
+++ b/compiler-core/src/wasm/zed.rs
@@ -40,16 +40,85 @@ pub fn compile_extension_component(
     package_component(core, &resolve, world)
 }
 
+/// Vendored `zed:extension` 0.7.0 WIT (embedded so installed binaries work
+/// without a source tree; `CARGO_MANIFEST_DIR` alone breaks under Nix).
+fn zed_wit_files() -> &'static [(&'static str, &'static str)] {
+    &[
+        (
+            "common.wit",
+            include_str!("../../wit/zed_extension/0.7.0/common.wit"),
+        ),
+        (
+            "context-server.wit",
+            include_str!("../../wit/zed_extension/0.7.0/context-server.wit"),
+        ),
+        (
+            "dap.wit",
+            include_str!("../../wit/zed_extension/0.7.0/dap.wit"),
+        ),
+        (
+            "extension.wit",
+            include_str!("../../wit/zed_extension/0.7.0/extension.wit"),
+        ),
+        (
+            "github.wit",
+            include_str!("../../wit/zed_extension/0.7.0/github.wit"),
+        ),
+        (
+            "http-client.wit",
+            include_str!("../../wit/zed_extension/0.7.0/http-client.wit"),
+        ),
+        (
+            "lsp.wit",
+            include_str!("../../wit/zed_extension/0.7.0/lsp.wit"),
+        ),
+        (
+            "nodejs.wit",
+            include_str!("../../wit/zed_extension/0.7.0/nodejs.wit"),
+        ),
+        (
+            "platform.wit",
+            include_str!("../../wit/zed_extension/0.7.0/platform.wit"),
+        ),
+        (
+            "process.wit",
+            include_str!("../../wit/zed_extension/0.7.0/process.wit"),
+        ),
+        (
+            "slash-command.wit",
+            include_str!("../../wit/zed_extension/0.7.0/slash-command.wit"),
+        ),
+    ]
+}
+
 fn load_zed_world() -> Result<(Resolve, WorldId)> {
     let mut resolve = Resolve::default();
-    // Vendored next to this source tree.
-    let wit_dir = concat!(env!("CARGO_MANIFEST_DIR"), "/wit/zed_extension/0.7.0");
+
+    // Optional override for packaging / tests.
+    if let Ok(dir) = std::env::var("GLEAM_ZED_WIT") {
+        let (pkg, _) = resolve
+            .push_dir(&dir)
+            .with_context(|| format!("failed to parse WIT at GLEAM_ZED_WIT={dir}"))?;
+        let world = resolve
+            .select_world(&[pkg], Some("extension"))
+            .context("zed:extension world not found")?;
+        return Ok((resolve, world));
+    }
+
+    // Materialise embedded WIT into a temp dir for wit-parser's push_dir.
+    let tmp = tempfile::tempdir().context("temp dir for embedded zed WIT")?;
+    for (name, contents) in zed_wit_files() {
+        std::fs::write(tmp.path().join(name), contents)
+            .with_context(|| format!("write embedded wit {name}"))?;
+    }
     let (pkg, _) = resolve
-        .push_dir(wit_dir)
-        .with_context(|| format!("failed to parse vendored WIT at {wit_dir}"))?;
+        .push_dir(tmp.path())
+        .with_context(|| format!("failed to parse embedded zed WIT at {}", tmp.path().display()))?;
     let world = resolve
         .select_world(&[pkg], Some("extension"))
         .context("zed:extension world not found")?;
+    // Keep tmp alive until resolve is done parsing — package is fully loaded.
+    std::mem::forget(tmp);
     Ok((resolve, world))
 }
 
diff --git a/flake.nix b/flake.nix
index 7290d4911..8e7f51579 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,27 +1,123 @@
 {
+  description = "Gleam compiler (wasm / Zed extension support fork)";
+
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    systems.url = "github:nix-systems/default";
     fenix.url = "github:nix-community/fenix";
     fenix.inputs.nixpkgs.follows = "nixpkgs";
   };
 
   outputs =
-    { nixpkgs, fenix, ... }:
+    {
+      self,
+      nixpkgs,
+      systems,
+      fenix,
+      ...
+    }:
     let
-      forAllSystems =
-        function:
-        nixpkgs.lib.genAttrs [
-          "aarch64-darwin"
-        ] (system: function nixpkgs.legacyPackages.${system});
+      forEachSystem = nixpkgs.lib.genAttrs (import systems);
     in
     {
-      devShells = forAllSystems (pkgs: {
-        default = pkgs.mkShell {
-          packages = [
-            fenix.packages.${pkgs.system}.stable.toolchain
-            pkgs.capnproto
-          ];
+      packages = forEachSystem (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+          inherit (pkgs) lib;
+
+          # Recent stable for edition 2024 workspace.
+          rustToolchain =
+            fenix.packages.${system}.stable.toolchain
+              or fenix.packages.${system}.complete.toolchain;
+
+          rustPlatform = pkgs.makeRustPlatform {
+            cargo = rustToolchain;
+            rustc = rustToolchain;
+          };
+
+          gleam = rustPlatform.buildRustPackage {
+            pname = "gleam";
+            version = "1.13.0-rc1";
+            src = lib.cleanSourceWith {
+              src = ./.;
+              filter =
+                path: type:
+                let
+                  base = baseNameOf path;
+                in
+                lib.cleanSourceFilter path type
+                && base != "target"
+                && base != "result"
+                && !(lib.hasSuffix ".wasm" base)
+                && !(lib.hasSuffix ".cwasm" base);
+            };
+
+            cargoLock = {
+              lockFile = ./Cargo.lock;
+            };
+
+            nativeBuildInputs = [
+              pkgs.capnproto
+              pkgs.pkg-config
+            ];
+
+            # Workspace: only build/install the CLI crate.
+            buildAndTestSubdir = "gleam-bin";
+
+            # Full test suite is heavy and needs network / many backends.
+            doCheck = false;
+
+            meta = {
+              description = "Gleam compiler with Wasm / Zed extension export";
+              mainProgram = "gleam";
+              homepage = "https://tangled.org/nandi.uk/gleam";
+              license = lib.licenses.asl20;
+            };
+          };
+        in
+        {
+          default = gleam;
+          inherit gleam;
+        }
+      );
+
+      apps = forEachSystem (system: {
+        default = {
+          type = "app";
+          program = "${self.packages.${system}.gleam}/bin/gleam";
         };
       });
+
+      devShells = forEachSystem (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+          rustToolchain =
+            fenix.packages.${system}.stable.toolchain
+              or fenix.packages.${system}.complete.toolchain;
+        in
+        {
+          default = pkgs.mkShell {
+            packages = [
+              rustToolchain
+              pkgs.capnproto
+              pkgs.pkg-config
+              self.packages.${system}.gleam
+            ];
+            shellHook = ''
+              echo "gleam wasm fork dev shell"
+              echo "  gleam --version  # store build when packages.gleam is built"
+              echo "  cargo build -p gleam"
+            '';
+          };
+        }
+      );
+
+      checks = forEachSystem (system: {
+        package = self.packages.${system}.gleam;
+      });
+
+      formatter = forEachSystem (system: nixpkgs.legacyPackages.${system}.nixfmt-rfc-style);
     };
 }