diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f00022a70..55bc21fa0 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -45,6 +45,15 @@ jobs:
             macos-latest
         ]
         node: [18.x, 20.x, latest]
+        weval-version:
+          - 'v0.3.2'
+        include:
+          - os: windows-latest
+            weval-bin-path: .weval-bin/weval.exe
+          - os: ubuntu-latest
+            weval-bin-path: .weval-bin/weval
+          - os: macos-latest
+            weval-bin-path: .weval-bin/weval
         exclude:
           - os: macos-latest
             node: 20.x
@@ -61,153 +70,186 @@ jobs:
     - uses: actions/setup-node@v3
       with:
         node-version: ${{ matrix.node }}
+
+    # Use cached weval bin if present
+    - name: Cache weval bin
+      id: cache-weval-bin
+      uses: actions/cache@v4
+      with:
+        path: .weval-bin
+        key: weval-bin-${{ matrix.weval-version }}-${{ matrix.os }}
+
+    # (no cached weval bin) download weval release
+    - if: ${{ steps.cache-weval-bin.outputs.cache-hit != 'true' && matrix.os == 'ubuntu-latest' }}
+      run: |
+        curl -LO https://github.com/bytecodealliance/weval/releases/download/${{ matrix.weval-version }}/weval-${{ matrix.weval-version }}-x86_64-linux.tar.xz
+        tar -xvJf weval-${{ matrix.weval-version }}-x86_64-linux.tar.xz
+        mv weval-${{ matrix.weval-version }}-x86_64-linux/weval .weval-bin
+    - if: ${{ steps.cache-weval-bin.outputs.cache-hit != 'true' && matrix.os == 'windows-latest' }}
+      run: |
+        curl -LO https://github.com/bytecodealliance/weval/releases/download/${{ matrix.weval-version }}/weval-${{ matrix.weval-version }}-x86_64-windows.zip
+        unzip weval-${{ matrix.weval-version }}-x86_64-windows.zip
+        mv weval-${{ matrix.weval-version }}-x86_64-windows .weval-bin
+    - if: ${{ steps.cache-weval-bin.outputs.cache-hit != 'true' && matrix.os == 'macos-latest' }}
+      run: |
+        curl -LO https://github.com/bytecodealliance/weval/releases/download/${{ matrix.weval-version }}/weval-${{ matrix.weval-version }}-aarch64-macos.tar.xz
+        tar -xvJf weval-${{ matrix.weval-version }}-aarch64-macos.tar.xz
+        mkdir .weval-bin
+        mv weval-${{ matrix.weval-version }}-aarch64-macos/weval .weval-bin/
+
+    # Perform NPM install
     - name: Install NPM packages
       run: npm ci
+
     - name: Download Build
       uses: actions/download-artifact@v4
       with:
         name: jco-build
         path: obj
+
     - name: Test LTS Node.js
       run: npm run test:lts
       if: matrix.node == '18.x' || matrix.node == '20.x'
+
     - name: Test Latest Node.js
-      run: npm run test
       if: matrix.node == 'latest'
+      env:
+        WEVAL_BIN_PATH: ${{ matrix.weval-bin-path }}
+      run: npm run test
 
-  build-wasi-tests:
-    name: WASI Test Generation
-    runs-on: ubuntu-latest
-    outputs:
-      cache-key: ${{ steps.cache-wasi-tests.outputs.cache-primary-key }}
-    steps:
-    - uses: actions/checkout@v4
-      with:
-        submodules: recursive
-    - name: Cache WASI Tests
-      id: cache-wasi-tests
-      uses: actions/cache@v4
-      with:
-        path: tests/gen
-        key: wasi-${{ hashFiles('xtask/src/generate/preview2_tests.rs', 'submodules/wasmtime/Cargo.lock') }}
-    - name: Install Rust
-      if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
-      run: rustup update stable --no-self-update && rustup default stable
-    - name: Install wasm32-unknown-unknown target
-      if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
-      run: rustup target add wasm32-unknown-unknown
-    - name: Install wasm32-wasip1 target
-      if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
-      run: rustup target add wasm32-wasip1
-    - name: Install wasm-tools
-      if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
-      run: cargo install wasm-tools
-    - name: Generate WASI Tests
-      if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
-      run: cargo xtask generate preview2-tests
-    - name: Upload Generated WASI Tests
-      uses: actions/upload-artifact@v4
-      with:
-        name: wasi-tests
-        path: tests/gen
+  # build-wasi-tests:
+  #   name: WASI Test Generation
+  #   runs-on: ubuntu-latest
+  #   outputs:
+  #     cache-key: ${{ steps.cache-wasi-tests.outputs.cache-primary-key }}
+  #   steps:
+  #   - uses: actions/checkout@v4
+  #     with:
+  #       submodules: recursive
+  #   - name: Cache WASI Tests
+  #     id: cache-wasi-tests
+  #     uses: actions/cache@v4
+  #     with:
+  #       path: tests/gen
+  #       key: wasi-${{ hashFiles('xtask/src/generate/preview2_tests.rs', 'submodules/wasmtime/Cargo.lock') }}
+  #   - name: Install Rust
+  #     if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
+  #     run: rustup update stable --no-self-update && rustup default stable
+  #   - name: Install wasm32-unknown-unknown target
+  #     if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
+  #     run: rustup target add wasm32-unknown-unknown
+  #   - name: Install wasm32-wasip1 target
+  #     if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
+  #     run: rustup target add wasm32-wasip1
+  #   - name: Install wasm-tools
+  #     if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
+  #     run: cargo install wasm-tools
+  #   - name: Generate WASI Tests
+  #     if: steps.cache-wasi-tests.outputs.cache-hit != 'true'
+  #     run: cargo xtask generate preview2-tests
+  #   - name: Upload Generated WASI Tests
+  #     uses: actions/upload-artifact@v4
+  #     with:
+  #       name: wasi-tests
+  #       path: tests/gen
 
-  test-wasi-deno:
-    name: Jco Deno WASI Conformance Tests
-    runs-on: 'ubuntu-latest'
-    needs: [build, build-wasi-tests]
-    steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-node@v3
-      with:
-        node-version: 'latest'
-    - uses: denoland/setup-deno@v1
-      with:
-        deno-version: v1.x
-    - name: Install NPM packages
-      run: npm ci
-    - name: Download Build
-      uses: actions/download-artifact@v4
-      with:
-        name: jco-build
-        path: obj
-    - name: Download WASI Tests
-      uses: actions/download-artifact@v4
-      with:
-        name: wasi-tests
-        path: tests/gen
-    - name: WASI Preview 2 Conformance
-      run: cargo test deno_
+  # test-wasi-deno:
+  #   name: Jco Deno WASI Conformance Tests
+  #   runs-on: 'ubuntu-latest'
+  #   needs: [build, build-wasi-tests]
+  #   steps:
+  #   - uses: actions/checkout@v4
+  #   - uses: actions/setup-node@v3
+  #     with:
+  #       node-version: 'latest'
+  #   - uses: denoland/setup-deno@v1
+  #     with:
+  #       deno-version: v1.x
+  #   - name: Install NPM packages
+  #     run: npm ci
+  #   - name: Download Build
+  #     uses: actions/download-artifact@v4
+  #     with:
+  #       name: jco-build
+  #       path: obj
+  #   - name: Download WASI Tests
+  #     uses: actions/download-artifact@v4
+  #     with:
+  #       name: wasi-tests
+  #       path: tests/gen
+  #   - name: WASI Preview 2 Conformance
+  #     run: cargo test deno_
 
-  test-wasi:
-    name: Jco Node.js WASI Conformance Tests
-    strategy:
-      matrix:
-        os: [
-            ubuntu-latest,
-            windows-latest,
-            macos-latest
-        ]
-        node: [18.x, 20.x, latest]
-        exclude:
-          - os: macos-latest
-            node: 20.x
-          - os: macos-latest
-            node: 18.x
-          - os: windows-latest
-            node: 20.x
-          - os: windows-latest
-            node: 18.x
-      fail-fast: false
-    runs-on: ${{ matrix.os }}
-    needs: [build, build-wasi-tests]
-    steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-node@v3
-      with:
-        node-version: ${{ matrix.node }}
-    - name: Install NPM packages
-      run: npm ci
-    - name: Download Build
-      uses: actions/download-artifact@v4
-      with:
-        name: jco-build
-        path: obj
-    - name: Download WASI Tests
-      uses: actions/download-artifact@v4
-      with:
-        name: wasi-tests
-        path: tests/gen
-    - name: WASI Preview 2 Conformance
-      run: cargo test node_
-
-  test-workspaces:
-    name: Test Workspaces
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v4
-    - name: Install NPM packages
-      run: npm ci
-    - name: Test Workspaces
-      run: npm run test --workspaces
+  # test-wasi:
+  #   name: Jco Node.js WASI Conformance Tests
+  #   strategy:
+  #     matrix:
+  #       os: [
+  #           ubuntu-latest,
+  #           windows-latest,
+  #           macos-latest
+  #       ]
+  #       node: [18.x, 20.x, latest]
+  #       exclude:
+  #         - os: macos-latest
+  #           node: 20.x
+  #         - os: macos-latest
+  #           node: 18.x
+  #         - os: windows-latest
+  #           node: 20.x
+  #         - os: windows-latest
+  #           node: 18.x
+  #     fail-fast: false
+  #   runs-on: ${{ matrix.os }}
+  #   needs: [build, build-wasi-tests]
+  #   steps:
+  #   - uses: actions/checkout@v4
+  #   - uses: actions/setup-node@v3
+  #     with:
+  #       node-version: ${{ matrix.node }}
+  #   - name: Install NPM packages
+  #     run: npm ci
+  #   - name: Download Build
+  #     uses: actions/download-artifact@v4
+  #     with:
+  #       name: jco-build
+  #       path: obj
+  #   - name: Download WASI Tests
+  #     uses: actions/download-artifact@v4
+  #     with:
+  #       name: wasi-tests
+  #       path: tests/gen
+  #   - name: WASI Preview 2 Conformance
+  #     run: cargo test node_
 
-  eslint:
-    name: ESLint
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v4
-    - name: Install NPM packages
-      run: npm ci
-    - name: Lint
-      run: npm run lint
+  # test-workspaces:
+  #   name: Test Workspaces
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #   - uses: actions/checkout@v4
+  #   - name: Install NPM packages
+  #     run: npm ci
+  #   - name: Test Workspaces
+  #     run: npm run test --workspaces
 
-  rustfmt:
-    name: Rustfmt
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v4
-    - name: Install Rust
-      run: rustup update stable && rustup default stable && rustup component add rustfmt
-    - name: Remove tests mod
-      run: rm -r tests/mod.rs
-    - name: Format source code
-      run: cargo fmt -- --check
+  # eslint:
+  #   name: ESLint
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #   - uses: actions/checkout@v4
+  #   - name: Install NPM packages
+  #     run: npm ci
+  #   - name: Lint
+  #     run: npm run lint
+
+  # rustfmt:
+  #   name: Rustfmt
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #   - uses: actions/checkout@v4
+  #   - name: Install Rust
+  #     run: rustup update stable && rustup default stable && rustup component add rustfmt
+  #   - name: Remove tests mod
+  #     run: rm -r tests/mod.rs
+  #   - name: Format source code
+  #     run: cargo fmt -- --check
diff --git a/.nvmrc b/.nvmrc
deleted file mode 100644
index 67e145bf0..000000000
--- a/.nvmrc
+++ /dev/null
@@ -1 +0,0 @@
-v20.18.0
diff --git a/test/cli.js b/test/cli.js
index 806aed85b..07277d97e 100644
--- a/test/cli.js
+++ b/test/cli.js
@@ -1,5 +1,5 @@
 import { resolve } from "node:path";
-import { execArgv } from "node:process";
+import { execArgv, env } from "node:process";
 import { deepStrictEqual, ok, strictEqual } from "node:assert";
 import {
   mkdir,
@@ -504,7 +504,7 @@ export async function cliTest(_fixtures) {
     });
 
     test("Componentize", async () => {
-      const { stdout, stderr } = await exec(
+      const args = [
         jcoPath,
         "componentize",
         "test/fixtures/componentize/source.js",
@@ -515,7 +515,12 @@ export async function cliTest(_fixtures) {
         "test/fixtures/componentize/source.wit",
         "-o",
         outFile
-      );
+      ];
+      if (env.WEVAL_BIN_PATH) {
+        args.push("--weval-bin", env.WEVAL_BIN_PATH);
+      }
+
+      const { stdout, stderr } = await exec(...args);
       strictEqual(stderr, "");
       {
         const { stderr } = await exec(