diff --git a/.github/workflows/wasm.yaml b/.github/workflows/wasm.yaml
new file mode 100644
index 0000000..125eee2
--- /dev/null
+++ b/.github/workflows/wasm.yaml
@@ -0,0 +1,140 @@
+name: Compile WASM
+
+on: [push, pull_request, workflow_dispatch]
+
+env:
+  GHC_WASM_META_FLAVOUR: '9.10'
+  GHC_WASM_META_COMMIT_HASH: '7927129e42bcd6a54b9e06e26455803fa4878261'
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-22.04
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        path: als
+        submodules: recursive
+
+    - name: Compute cache key
+      run: echo "CI_CACHE_KEY=${{ runner.os }}-${{ runner.arch }}-${{ env.GHC_WASM_META_COMMIT_HASH }}-flavor-${{ env.GHC_WASM_META_FLAVOUR }}" >> "$GITHUB_ENV"
+
+    - name: Try to restore cached .ghc-wasm
+      id: ghc-wasm-cache-restore
+      uses: actions/cache/restore@v4
+      with:
+        path: ~/.ghc-wasm
+        key: ghc-wasm-${{ env.CI_CACHE_KEY }}
+
+    - name: Try to restore cached native cabal
+      id: native-cabal-cache-restore
+      uses: actions/cache/restore@v4
+      with:
+        path: |
+          ~/.config/cabal
+          ~/.cache/cabal
+        key: native-cabal-${{ env.CI_CACHE_KEY }}
+
+    - name: Try to restore cached dist-newstyle
+      id: dist-newstyle-cache-restore
+      uses: actions/cache/restore@v4
+      with:
+        path: als/dist-newstyle
+        key: dist-newstyle-${{ env.CI_CACHE_KEY }}-${{ hashFiles('als/dist-newstyle/**') }}
+        restore-keys: |
+          dist-newstyle-${{ env.CI_CACHE_KEY }}-
+
+    - name: Clone and setup ghc-wasm-meta
+      id: ghc-wasm-setup
+      if: steps.ghc-wasm-cache-restore.outputs.cache-matched-key == ''
+      run: |
+        mkdir ghc-wasm-meta
+        cd ghc-wasm-meta
+        git config --global init.defaultBranch dontcare
+        git config --global advice.detachedHead false
+        git init
+        git remote add origin https://gitlab.haskell.org/haskell-wasm/ghc-wasm-meta.git
+        git fetch origin ${{ env.GHC_WASM_META_COMMIT_HASH }} --depth=1
+        git checkout FETCH_HEAD
+        FLAVOUR=${{ env.GHC_WASM_META_FLAVOUR }} ./setup.sh
+
+    - name: Add ghc-wasm-meta to PATH
+      run: ~/.ghc-wasm/add_to_github_path.sh
+
+    # setup script also updates package store near the end
+    - name: Update wasm32 cabal
+      if: steps.ghc-wasm-setup.outcome == 'success' || steps.ghc-wasm-setup.outcome == 'skipped'
+      run: wasm32-wasi-cabal update
+
+    - name: Install native utilities
+      run: |
+        echo ">>> Update cabal"
+        ~/.ghc-wasm/cabal/bin/cabal update
+        echo ">>> Install alex and happy"
+        ~/.ghc-wasm/cabal/bin/cabal install alex-3.5.0.0 happy-1.20.1.1
+
+    - name: Run cabal configure
+      working-directory: './als'
+      run: wasm32-wasi-cabal configure --flag=Agda-2-7-0-1
+
+    - name: 'Build dep: lsp-types'
+      uses: nick-fields/retry@v3
+      id: build-dep-lsp-types
+      with:
+        timeout_minutes: 10
+        max_attempts: 2
+        command: cd als && wasm32-wasi-cabal build lib:lsp-types
+
+    - name: 'Build dep: agda'
+      id: build-dep-agda
+      working-directory: './als'
+      run: wasm32-wasi-cabal build lib:agda
+
+    - name: Cache dist-newstyle
+      uses: actions/cache/save@v4
+      if: steps.build-dep-lsp-types.outcome == 'success' && steps.build-dep-agda.outcome == 'success'
+      with:
+        path: als/dist-newstyle
+        key: dist-newstyle-${{ env.CI_CACHE_KEY }}-${{ hashFiles('als/dist-newstyle/**') }}
+
+    - name: Build every dependency else
+      working-directory: './als'
+      run: |
+        cd wasm-submodules/network
+        autoreconf -i
+        cd ../..
+        wasm32-wasi-cabal build --dependencies-only
+
+    - name: Build als
+      working-directory: './als'
+      run: |
+        mkdir ~/out
+        wasm32-wasi-cabal build
+        cp $(wasm32-wasi-cabal list-bin als) ~/out
+
+    - name: Clean up native/wasm cabal logs
+      run: rm -rf ~/.cache/cabal/logs ~/.ghc-wasm/.cabal/logs
+
+    - name: Cache native cabal
+      uses: actions/cache/save@v4
+      if: steps.ghc-wasm-setup.outcome == 'success'
+      with:
+        path: |
+          ~/.config/cabal
+          ~/.cache/cabal
+        key: ${{ steps.native-cabal-cache-restore.outputs.cache-primary-key }}
+
+    - name: Cache ghc-wasm-meta
+      uses: actions/cache/save@v4
+      if: steps.ghc-wasm-setup.outcome == 'success'
+      with:
+        path: ~/.ghc-wasm
+        key: ${{ steps.ghc-wasm-cache-restore.outputs.cache-primary-key }}
+
+    - name: Upload artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: als
+        path: ~/out
+        include-hidden-files: true
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..c80f1dd
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,16 @@
+[submodule "wasm-submodules/agda"]
+	path = wasm-submodules/agda
+    url = git@github.com:agda-web/agda.git
+[submodule "wasm-submodules/foundation"]
+	path = wasm-submodules/foundation
+	url = git@github.com:haskell-wasm/foundation.git
+[submodule "wasm-submodules/network"]
+	path = wasm-submodules/network
+	url = https://github.com/haskell-wasm/network
+[submodule "wasm-submodules/network-simple-0.4.2"]
+	path = wasm-submodules/network-simple-0.4.2
+	url = https://github.com/k0001/network-simple
+[submodule "wasm-submodules/lsp"]
+	path = wasm-submodules/lsp
+	url = git@github.com:agda-web/lsp.git
+
diff --git a/BUILDING_WASM.md b/BUILDING_WASM.md
new file mode 100644
index 0000000..6b76b2b
--- /dev/null
+++ b/BUILDING_WASM.md
@@ -0,0 +1,27 @@
+# How to build for WASM
+
+1. Setup a working ghc (tested with v9.10) with WASM backend and wasm32-wasi-cabal.
+2. `cd` into `wasm-submodules/network` and run `autoreconf -i`.
+3. In the project root, run `wasm32-wasi-cabal build`.
+
+The process might output the following:
+
+```
+[442 of 452] Compiling Language.LSP.Protocol.Message.Types ( src/Language/LSP/Protocol/Message/Types.hs, /home/qbane/agda-project/haskell-lsp-wasm/dist-newstyle/build/wasm32-wasi/ghc-9.10.1.20250207/lsp-types-2.3.0.1/build/Language/LSP/Protocol/Message/Types.o, /home/qbane/agda-project/haskell-lsp-wasm/dist-newstyle/build/wasm32-wasi/ghc-9.10.1.20250207/lsp-types-2.3.0.1/build/Language/LSP/Protocol/Message/Types.dyn_o )
+
+wasm://wasm/001e3c92:1
+
+
+RuntimeError: table index is out of bounds
+    at wasm://wasm/001e3c92:wasm-function[586]:0x45e40
+    at wasm://wasm/001e3c92:wasm-function[365]:0x286e1
+    at wasm://wasm/001e3c92:wasm-function[595]:0x46135
+    at process.processImmediate (node:internal/timers:491:21)
+
+Node.js v22.14.0
+```
+
+At this moment, you should terminate the process and run it again.
+This is a known issue ([ghc#26106](https://gitlab.haskell.org/ghc/ghc/-/issues/26106)). If this does *not* occur to you or you can fix it, please report to that issue.
+
+If everything works properly, it should build a `als.wasm`.
diff --git a/agda-language-server.cabal b/agda-language-server.cabal
index d970f61..a4865f7 100644
--- a/agda-language-server.cabal
+++ b/agda-language-server.cabal
@@ -5,7 +5,7 @@ cabal-version: 1.12
 -- see: https://github.com/sol/hpack
 
 name:           agda-language-server
-version:        0.2.7.0.1.4
+version:        0.2.7.0.1.5
 synopsis:       An implementation of language server protocal (LSP) for Agda 2.
 description:    Please see the README on GitHub at <https://github.com/agda/agda-language-server#readme>
 category:       Development
@@ -94,13 +94,12 @@ library
     , lsp-types >=2
     , mtl
     , network
-    , network-simple
+    , network-simple == 0.4.2
     , prettyprinter
     , process
     , stm
     , strict
     , text
-    , text-icu
   default-language: Haskell2010
   if flag(Agda-2-6-3)
     build-depends:
@@ -111,6 +110,9 @@ library
   if flag(Agda-2-7-0-1)
     build-depends:
         Agda ==2.7.0.1
+  if arch(wasm32)
+    build-depends:
+        unix >=2.8.0.0 && <2.9
 
 executable als
   main-is: Main.hs
@@ -123,7 +125,7 @@ executable als
       OverloadedStrings
       PatternSynonyms
       TypeOperators
-  ghc-options: -Wincomplete-patterns -Wunused-do-bind -Wunused-foralls -Wwarnings-deprecations -Wwrong-do-bind -Wmissing-fields -Wmissing-methods -Wmissing-pattern-synonym-signatures -Wmissing-signatures -threaded -rtsopts -with-rtsopts=-N -Werror=incomplete-patterns -fno-warn-orphans
+  ghc-options: -Wincomplete-patterns -Wunused-do-bind -Wunused-foralls -Wwarnings-deprecations -Wwrong-do-bind -Wmissing-fields -Wmissing-methods -Wmissing-pattern-synonym-signatures -Wmissing-signatures -rtsopts -Werror=incomplete-patterns -fno-warn-orphans
   build-depends:
       Agda
     , aeson
@@ -137,13 +139,12 @@ executable als
     , lsp-types >=2
     , mtl
     , network
-    , network-simple
+    , network-simple == 0.4.2
     , prettyprinter
     , process
     , stm
     , strict
     , text
-    , text-icu
   default-language: Haskell2010
   if flag(Agda-2-6-3)
     build-depends:
@@ -195,7 +196,7 @@ test-suite als-test
       OverloadedStrings
       PatternSynonyms
       TypeOperators
-  ghc-options: -Wincomplete-patterns -Wunused-do-bind -Wunused-foralls -Wwarnings-deprecations -Wwrong-do-bind -Wmissing-fields -Wmissing-methods -Wmissing-pattern-synonym-signatures -Wmissing-signatures -threaded -rtsopts -with-rtsopts=-N -Werror=incomplete-patterns -fno-warn-orphans
+  ghc-options: -Wincomplete-patterns -Wunused-do-bind -Wunused-foralls -Wwarnings-deprecations -Wwrong-do-bind -Wmissing-fields -Wmissing-methods -Wmissing-pattern-synonym-signatures -Wmissing-signatures -rtsopts -Werror=incomplete-patterns -fno-warn-orphans
   build-depends:
       Agda
     , aeson
@@ -209,7 +210,7 @@ test-suite als-test
     , lsp-types >=2
     , mtl
     , network
-    , network-simple
+    , network-simple == 0.4.2
     , prettyprinter
     , process
     , stm
@@ -219,7 +220,6 @@ test-suite als-test
     , tasty-hunit
     , tasty-quickcheck
     , text
-    , text-icu
   default-language: Haskell2010
   if flag(Agda-2-6-3)
     build-depends:
diff --git a/app/Main.hs b/app/Main.hs
index ba3291d..dd22719 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -38,4 +38,4 @@ main = do
         else do
           _ <- run options
           -- _ <- run
-          return ()
\ No newline at end of file
+          return ()
diff --git a/cabal.project b/cabal.project
new file mode 100644
index 0000000..78a8cd0
--- /dev/null
+++ b/cabal.project
@@ -0,0 +1,8 @@
+packages:
+  .
+  wasm-submodules/agda
+  wasm-submodules/foundation/basement
+  wasm-submodules/network
+  wasm-submodules/network-simple-0.4.2
+  wasm-submodules/lsp/lsp-types
+
diff --git a/package.yaml b/package.yaml
index 5bc37cc..63e85e4 100644
--- a/package.yaml
+++ b/package.yaml
@@ -68,7 +68,6 @@ dependencies:
   - strict
   - stm
   - text
-  - text-icu
   - process
   - prettyprinter
 
diff --git a/src/Options.hs b/src/Options.hs
index b0b700e..e77a432 100644
--- a/src/Options.hs
+++ b/src/Options.hs
@@ -76,7 +76,9 @@ versionNumber = 5
 
 versionString :: String
 versionString =
-#if MIN_VERSION_Agda(2,7,0)
+#ifdef wasm32_HOST_ARCH
+  "Agda v2.7.0.1 Language Server (WebAssembly build) v" <> show versionNumber
+#elif MIN_VERSION_Agda(2,7,0)
   "Agda v2.7.0.1 Language Server v" <> show versionNumber
 #elif MIN_VERSION_Agda(2,6,4)
   "Agda v2.6.4.3 Language Server v" <> show versionNumber
diff --git a/src/Server.hs b/src/Server.hs
index c9b1ffc..e92225e 100644
--- a/src/Server.hs
+++ b/src/Server.hs
@@ -28,6 +28,12 @@ import qualified Server.Handler as Handler
 import Switchboard (Switchboard, agdaCustomMethod)
 import qualified Switchboard
 
+#if defined(wasm32_HOST_ARCH)
+import Agda.Utils.IO (catchIO)
+import System.IO (hPutStrLn, stderr)
+import System.Posix.IO (stdInput, setFdOption, FdOption (..))
+#endif
+
 --------------------------------------------------------------------------------
 
 run :: Options -> IO Int
@@ -44,6 +50,10 @@ run options = do
       -- Switchboard.destroy switchboard
       return 0
     Nothing -> do
+      #if defined(wasm32_HOST_ARCH)
+      liftIO $ setFdOption stdInput NonBlockingRead True
+        `catchIO` (\ e -> hPutStrLn stderr $ "Failed to enable nonblocking on stdin: " ++ (show e) ++ "\nThe WASM module might not behave correctly.")
+      #endif
       runServer (serverDefn options)
   where
     serverDefn :: Options -> ServerDefinition Config
diff --git a/wasm-submodules/agda b/wasm-submodules/agda
new file mode 160000
index 0000000..87cac9c
--- /dev/null
+++ b/wasm-submodules/agda
@@ -0,0 +1 @@
+Subproject commit 87cac9ce17932321dc1a0fdaed83436de22fa0aa
diff --git a/wasm-submodules/foundation b/wasm-submodules/foundation
new file mode 160000
index 0000000..8e6dd48
--- /dev/null
+++ b/wasm-submodules/foundation
@@ -0,0 +1 @@
+Subproject commit 8e6dd48527fb429c1922083a5030ef88e3d58dd3
diff --git a/wasm-submodules/lsp b/wasm-submodules/lsp
new file mode 160000
index 0000000..9baf76e
--- /dev/null
+++ b/wasm-submodules/lsp
@@ -0,0 +1 @@
+Subproject commit 9baf76e6d9965a3b6e8b3ecfcdf33c62b5628fd8
diff --git a/wasm-submodules/network b/wasm-submodules/network
new file mode 160000
index 0000000..1dc8708
--- /dev/null
+++ b/wasm-submodules/network
@@ -0,0 +1 @@
+Subproject commit 1dc870889eee4ac733335ced4e274b4dfe8ed369
diff --git a/wasm-submodules/network-simple-0.4.2 b/wasm-submodules/network-simple-0.4.2
new file mode 160000
index 0000000..2c3ab6e
--- /dev/null
+++ b/wasm-submodules/network-simple-0.4.2
@@ -0,0 +1 @@
+Subproject commit 2c3ab6e7aa2a86be692c55bf6081161d83d50c34