hyperlight-dev · simongdavies · Mar 27, 2026
diff --git a/.gitattributes b/.gitattributes
@@ -0,0 +1,23 @@
+# Force LF line endings everywhere — no platform-specific CRLF nonsense.
+# This ensures consistent diffs across Linux, macOS, and Windows.
+* text=auto eol=lf
+
+# Explicitly mark binary files so git doesn't try to normalize them
+*.node binary
+*.wasm binary
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.pptx binary
+*.xlsx binary
+*.docx binary
+*.zip binary
+*.tar binary
+*.gz binary
+*.tgz binary
+*.exe binary
+*.dll binary
+*.so binary
+*.dylib binary
diff --git a/.github/workflows/pr-validate.yml b/.github/workflows/pr-validate.yml
@@ -83,11 +83,8 @@ jobs:
         run: just test-all
 
   # Build and test on all hypervisor configurations (1ES runners have Rust + just)
-  # NOTE: Windows WHP support is temporarily disabled pending upstream
-  # hyperlight fix for multiple SurrogateProcessManager instances.
-  # See: https://github.com/hyperlight-dev/hyperagent/issues/1
   build-and-test:
-    name: Build & Test (${{ matrix.hypervisor }}-${{ matrix.config }})
+    name: Build & Test (${{ matrix.build }})
     needs: [docs-pr]
     if: needs.docs-pr.outputs.docs-only != 'true'
     strategy:
@@ -98,6 +95,8 @@ jobs:
           - linux-kvm-release
           - linux-mshv-debug
           - linux-mshv-release
+          - windows-whp-debug
+          - windows-whp-release
         include:
           - build: linux-kvm-debug
             os: [self-hosted, Linux, X64, "1ES.Pool=hld-kvm-amd"]
@@ -115,6 +114,14 @@ jobs:
             os: [self-hosted, Linux, X64, "1ES.Pool=hld-azlinux3-mshv-amd"]
             hypervisor: mshv
             config: release
+          - build: windows-whp-debug
+            os: [self-hosted, Windows, X64, "1ES.Pool=hld-win2022-amd"]
+            hypervisor: whp
+            config: debug
+          - build: windows-whp-release
+            os: [self-hosted, Windows, X64, "1ES.Pool=hld-win2022-amd"]
+            hypervisor: whp
+            config: release
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v6
@@ -142,7 +149,7 @@ jobs:
         if: matrix.config == 'release'
         uses: actions/upload-artifact@v7
         with:
-          name: hyperagent-linux-x64-${{ matrix.hypervisor }}
+          name: hyperagent-${{ matrix.build }}
           path: dist/
           retention-days: 7
 

diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
@@ -24,7 +24,7 @@ jobs:
   # Test on all hypervisor configurations before publishing
   # NOTE: Windows WHP temporarily disabled (see pr-validate.yml)
   test:
-    name: Test (${{ matrix.hypervisor }})
+    name: Test (${{ matrix.build }})
     strategy:
       fail-fast: true
       matrix:

diff --git a/Justfile b/Justfile
@@ -37,7 +37,7 @@ runtime-dir := justfile_dir() / "src" / "sandbox" / "runtime"
 # -D__wasi__=1 to disable pthreads. Uses cargo metadata to find the
 # include/ dir from the hyperlight-js-runtime dependency.
 # Fails loudly if resolution fails — empty CFLAGS causes cryptic build errors.
-runtime-cflags := `node -e "var m=JSON.parse(require('child_process').execSync('cargo +1.89 metadata --format-version 1 --manifest-path src/sandbox/runtime/Cargo.toml',{encoding:'utf8',stdio:['pipe','pipe','inherit'],maxBuffer:20*1024*1024}));var p=m.packages.find(function(p){return p.name==='hyperlight-js-runtime'});if(!p){process.stderr.write('ERROR: hyperlight-js-runtime not found in cargo metadata\n');process.exit(1)}console.log('-I'+require('path').join(require('path').dirname(p.manifest_path),'include')+' -D__wasi__=1')"`
+runtime-cflags := `node -e "var m=JSON.parse(require('child_process').execSync('cargo +1.89 metadata --format-version 1 --manifest-path src/sandbox/runtime/Cargo.toml',{encoding:'utf8',stdio:['pipe','pipe','inherit'],maxBuffer:20*1024*1024}));var p=m.packages.find(function(p){return p.name==='hyperlight-js-runtime'});if(!p){process.stderr.write('ERROR: hyperlight-js-runtime not found in cargo metadata\n');process.exit(1)}var inc=require('path').join(require('path').dirname(p.manifest_path),'include').split(require('path').sep).join('/');console.log('-I'+inc+' -D__wasi__=1')"`
 
 # Export HYPERLIGHT_CFLAGS so cargo-hyperlight picks them up when building runtimes
 export HYPERLIGHT_CFLAGS := runtime-cflags
@@ -71,6 +71,12 @@ resolve-hyperlight-dir:
     fi
     echo "$dir"
 
+# Resolve hyperlight-js workspace root (Windows variant).
+[private]
+[windows]
+resolve-hyperlight-dir:
+    node -e "var m=JSON.parse(require('child_process').execSync('cargo +1.89 metadata --format-version 1 --manifest-path src/sandbox/runtime/Cargo.toml',{encoding:'utf8',stdio:['pipe','pipe','pipe'],maxBuffer:20*1024*1024}));var p=m.packages.find(function(p){return p.name==='hyperlight-js-runtime'});if(p)console.log(require('path').resolve(require('path').dirname(p.manifest_path),'..','..'));else{process.stderr.write('hyperlight-js-runtime not found');process.exit(1)}"
+
 # Install required Rust toolchains and cargo subcommands.
 # Cross-platform (Linux/macOS/Windows) — no bash required.
 [private]
@@ -84,8 +90,7 @@ ensure-tools:
 # 2. Discovers the hyperlight-js workspace from Cargo's checkout
 # 3. Builds the NAPI addon with our custom runtime embedded
 # 4. Symlinks deps/js-host-api → checkout/src/js-host-api for npm file: dep
-# NOTE: [unix] only — Windows support is disabled pending upstream fix (issue #1).
-# When Windows lands, add [windows] variants using mklink /J for junctions.
+# NOTE: [unix] only — add [windows] variant below for Windows WHP support.
 [private]
 [unix]
 build-hyperlight target="debug": (build-runtime-release)
@@ -101,6 +106,13 @@ build-hyperlight target="debug": (build-runtime-release)
     ln -sfn "${hl_dir}/src/js-host-api" "{{hyperlight-link}}"
     echo "🔗 deps/js-host-api → ${hl_dir}/src/js-host-api"
 
+# Build hyperlight-js NAPI addon (Windows variant — PowerShell + junction link).
+# All statements on one line because just runs each line as a separate pwsh -Command.
+[private]
+[windows]
+build-hyperlight target="debug": (build-runtime-release)
+    $hl_dir = just resolve-hyperlight-dir; Push-Location (Join-Path $hl_dir "src" "hyperlight-js"); cargo clean -p hyperlight-js 2>$null; Pop-Location; Push-Location $hl_dir; just build {{ if target == "debug" { "" } else { target } }}; Pop-Location; $linkPath = [IO.Path]::GetFullPath("{{hyperlight-link}}"); $targetPath = Join-Path $hl_dir "src" "js-host-api"; New-Item -ItemType Directory -Path (Split-Path $linkPath) -Force | Out-Null; if (Test-Path $linkPath) { cmd /c rmdir /q $linkPath 2>$null }; cmd /c mklink /J $linkPath $targetPath; Write-Output "🔗 deps/js-host-api → $targetPath"
+
 # Build the hyperlight-analysis-guest NAPI addon (debug)
 [private]
 build-analysis-guest:
@@ -165,9 +177,15 @@ start *ARGS: install
     npx tsx src/agent/index.ts {{ARGS}}
 
 # Run with crash diagnostics (generates crash report .json files on SIGSEGV)
+[unix]
 start-debug *ARGS: install
     NODE_OPTIONS="--report-on-signal --report-on-fatalerror --report-directory=$HOME/.hyperagent/logs" npx tsx src/agent/index.ts {{ARGS}}
 
+# Run with crash diagnostics (Windows variant)
+[windows]
+start-debug *ARGS: install
+    $env:NODE_OPTIONS="--report-on-signal --report-on-fatalerror --report-directory=$env:USERPROFILE/.hyperagent/logs"; npx tsx src/agent/index.ts {{ARGS}}
+
 # Run the agent with release-built native addon (faster sandbox execution)
 start-release *ARGS: install-release
     npx tsx src/agent/index.ts {{ARGS}}

diff --git a/README.md b/README.md
@@ -10,13 +10,13 @@ Ask the agent to compute things, and it writes & runs JavaScript in a hardware-i
 
 ### Prerequisites
 
-- **Linux with KVM**, **Azure Linux with MSHV**, or **WSL2 with KVM** (hardware virtualization required)
+- **Linux with KVM**, **Azure Linux with MSHV**, **Windows with WHP**, or **WSL2 with KVM** (hardware virtualization required)
 - **GitHub authentication** (see [below](#github-authentication))
 - **Docker** (for containerized option)
 - **Node.js 22+** (for npm install / source builds only)
 - **Rust + just** (for source builds only — see [Contributing](#contributing))
 
-**NOTE:** HyperAgent does not currently run on macOS [due to this issue](https://github.com/hyperlight-dev/hyperlight/issues/45). Native Windows support (WHP) is planned — for now, use [WSL2 with KVM](https://learn.microsoft.com/en-us/windows/wsl/install) on Windows.
+**NOTE:** HyperAgent does not currently run on macOS [due to this issue](https://github.com/hyperlight-dev/hyperlight/issues/45).
 
 ### GitHub Authentication
 

diff --git a/builtin-modules/ooxml-core.json b/builtin-modules/ooxml-core.json
@@ -3,7 +3,7 @@
   "description": "Shared OOXML infrastructure - units, colors, themes, Content_Types, relationships",
   "author": "system",
   "mutable": false,
-  "sourceHash": "sha256:24c8441a3504052f",
+  "sourceHash": "sha256:1e939013c13555bc",
   "dtsHash": "sha256:9f88e7c59a56854c",
   "importStyle": "named",
   "hints": {

diff --git a/builtin-modules/pptx-charts.json b/builtin-modules/pptx-charts.json
@@ -3,7 +3,7 @@
   "description": "OOXML DrawingML chart generation - bar, pie, line charts for PPTX presentations",
   "author": "system",
   "mutable": false,
-  "sourceHash": "sha256:029765ed53b96536",
+  "sourceHash": "sha256:5c521ce93ff39626",
   "dtsHash": "sha256:5f653830226c3554",
   "importStyle": "named",
   "hints": {

diff --git a/builtin-modules/pptx-tables.json b/builtin-modules/pptx-tables.json
@@ -3,12 +3,14 @@
   "description": "Styled tables for PPTX presentations - headers, borders, alternating rows",
   "author": "system",
   "mutable": false,
-  "sourceHash": "sha256:399b5349b1c8c187",
+  "sourceHash": "sha256:0739a7db5a8ab428",
   "dtsHash": "sha256:82d903ffbf4dfb1e",
   "importStyle": "named",
   "hints": {
     "overview": "Table generation for PPTX. Always used with ha:pptx.",
-    "relatedModules": ["ha:pptx"],
+    "relatedModules": [
+      "ha:pptx"
+    ],
     "criticalRules": [
       "comparisonTable: options array must not be empty, each option needs {name, values}"
     ],

diff --git a/builtin-modules/pptx.json b/builtin-modules/pptx.json
@@ -3,7 +3,7 @@
   "description": "PowerPoint PPTX presentation builder - slides, text, shapes, themes, layouts",
   "author": "system",
   "mutable": false,
-  "sourceHash": "sha256:a13871a41506a523",
+  "sourceHash": "sha256:093b19522e994756",
   "dtsHash": "sha256:2107e369816b4bd5",
   "importStyle": "named",
   "hints": {

diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -26,8 +26,8 @@
     "fmt": "prettier --write \"src/**/*.ts\" \"tests/**/*.ts\" \"plugins/**/*.ts\" \"builtin-modules/**/*.js\"",
     "fmt:check": "prettier --check \"src/**/*.ts\" \"tests/**/*.ts\" \"plugins/**/*.ts\" \"builtin-modules/**/*.js\"",
     "check": "npm run fmt:check && npm run typecheck && npm run test",
-    "prepare": "[ ! -f scripts/build-modules.js ] || npm run build:modules",
-    "postinstall": "[ ! -f scripts/patch-vscode-jsonrpc.js ] || (node scripts/patch-vscode-jsonrpc.js && node scripts/check-native-runtime.js)"
+    "prepare": "node -e \"if(require('fs').existsSync('scripts/build-modules.js'))require('child_process').execSync('npm run build:modules',{stdio:'inherit'})\"",
+    "postinstall": "node -e \"var fs=require('fs'),cp=require('child_process');if(fs.existsSync('scripts/patch-vscode-jsonrpc.js')){cp.execSync('node scripts/patch-vscode-jsonrpc.js',{stdio:'inherit'});cp.execSync('node scripts/check-native-runtime.js',{stdio:'inherit'})}\""
   },
   "dependencies": {
     "@github/copilot-sdk": "^0.1.32",

diff --git a/plugins/fs-read/index.ts b/plugins/fs-read/index.ts
@@ -235,14 +235,12 @@ export function createHostFunctions(
   // on the length parameter. Not configurable by design.
   const maxReadChunkBytes = MAX_READ_CHUNK_KB * 1024;
 
-  // Platform guard: O_NOFOLLOW is POSIX-only. If the platform doesn't
-  // support it (Windows), fail loudly rather than silently losing
-  // symlink protection — O_NOFOLLOW is required.
-  if (FS_CONSTANTS.O_NOFOLLOW === undefined) {
-    throw new Error(
-      "[fs-read] O_NOFOLLOW not supported on this platform — cannot guarantee symlink safety",
-    );
-  }
+  // O_NOFOLLOW atomically rejects symlinks at open() on POSIX.
+  // On Windows it doesn't exist — we rely on the lstatSync pre-check
+  // in validatePath() plus a post-open fstatSync/lstatSync comparison.
+  // The residual TOCTOU window is narrow and requires symlink creation
+  // privileges (SeCreateSymbolicLinkPrivilege or Developer Mode).
+  const O_NOFOLLOW = FS_CONSTANTS.O_NOFOLLOW ?? 0;
 
   // ── Host function implementations ────────────────────────────
 

diff --git a/plugins/fs-write/index.ts b/plugins/fs-write/index.ts
@@ -198,11 +198,12 @@ export function createHostFunctions(
     safeNumericConfig(cfg.maxWriteSizeKb, 20480, MAX_SIZE_LIMIT_KB) * 1024;
   const maxWriteChunkBytes = MAX_WRITE_CHUNK_KB * 1024;
 
-  if (FS_CONSTANTS.O_NOFOLLOW === undefined) {
-    throw new Error(
-      "[fs-write] O_NOFOLLOW not supported on this platform — cannot guarantee symlink safety",
-    );
-  }
+  // O_NOFOLLOW atomically rejects symlinks at open() on POSIX.
+  // On Windows it doesn't exist — we rely on the lstatSync pre-check
+  // in validatePath() plus a post-open fstatSync/lstatSync comparison.
+  // The residual TOCTOU window is narrow and requires symlink creation
+  // privileges (SeCreateSymbolicLinkPrivilege or Developer Mode).
+  const O_NOFOLLOW = FS_CONSTANTS.O_NOFOLLOW ?? 0;
 
   const maxEntries = Math.floor(
     safeNumericConfig(cfg.maxEntries, 500, MAX_ENTRIES_LIMIT),