diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2137e4dd..1001ab6f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -31,7 +31,6 @@ jobs:
     - uses: baptiste0928/cargo-install@v2
       with:
         crate: txtpp
-        features: cli
     - run: task themes:ci client:ci --output group
     - run: task build:client --output group
     - uses: actions/upload-artifact@v3
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index b707003c..361c66ce 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -24,7 +24,6 @@ jobs:
     - uses: baptiste0928/cargo-install@v2
       with:
         crate: txtpp
-        features: cli
     - run: task themes:ci client:ci docs:ci --output group
     - run: task themes:check client:check docs:check --output group
 
diff --git a/Cargo.lock b/Cargo.lock
index d25d4705..e91f75fe 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -379,6 +379,10 @@ dependencies = [
  "wasm-bindgen-futures",
 ]
 
+[[package]]
+name = "compiler-wasm-build"
+version = "0.0.0"
+
 [[package]]
 name = "crc32fast"
 version = "1.3.2"
diff --git a/Cargo.toml b/Cargo.toml
index 1012b52a..4d68e085 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,6 +4,7 @@ members = [
     "compiler-core/",
     "compiler-macros/",
     "compiler-wasm/",
+    "compiler-wasm/build/",
     "web-server/",
 ]
 
diff --git a/Taskfile.yml b/Taskfile.yml
index aac77de2..89b907fe 100644
--- a/Taskfile.yml
+++ b/Taskfile.yml
@@ -88,7 +88,7 @@ tasks:
     - task: client:build
 
   build:wasm:
-    dir: ./compiler-wasm
+    dir: ./compiler-wasm/build
     deps:
     - core:grammar
     cmds:
diff --git a/compiler-core/src/lang/preset/parse.rs b/compiler-core/src/lang/preset/parse.rs
index 01d5c77c..8c439404 100644
--- a/compiler-core/src/lang/preset/parse.rs
+++ b/compiler-core/src/lang/preset/parse.rs
@@ -29,9 +29,15 @@ fn from_pt(pt: &pt::Preset) -> PresetInst {
     }
     let mut args = vec![];
     if let Some(pt_args) = &pt.m_args {
-        args.push(parse_arg(&pt_args.m_first));
+        match &pt_args.m_first {
+            Some(arg) => args.push(parse_arg(arg)),
+            None => args.push("".to_string()),
+        }
         for pt_arg in &pt_args.m_rest {
-            args.push(parse_arg(&pt_arg.m_arg));
+            match &pt_arg.m_arg {
+                Some(arg) => args.push(parse_arg(arg)),
+                None => args.push("".to_string()),
+            }
         }
     }
 
@@ -113,9 +119,7 @@ mod test {
     }
 
     #[test]
-    fn test_empty_args_not_allowed() {
-        assert_eq!(PresetInst::try_parse("hello<>"), None);
-        assert_eq!(PresetInst::try_parse("_hello::world<>"), None);
+    fn test_incomplete_args_not_allowed() {
         assert_eq!(PresetInst::try_parse("_hello::world>"), None);
         assert_eq!(PresetInst::try_parse("_hello::world<"), None);
     }
@@ -172,4 +176,36 @@ mod test {
         assert_eq!(PresetInst::try_parse("hello<world> "), None);
         assert_eq!(PresetInst::try_parse("hello<world>a"), None);
     }
+
+    #[test]
+    fn test_empty_arg() {
+        assert_eq!(
+            PresetInst::try_parse("hello::world<>").unwrap(),
+            PresetInst {
+                name: "hello::world".to_string(),
+                args: vec!["".to_string()],
+            }
+        );
+        assert_eq!(
+            PresetInst::try_parse("hello::world<,,>").unwrap(),
+            PresetInst {
+                name: "hello::world".to_string(),
+                args: vec!["".to_string(), "".to_string(), "".to_string()],
+            }
+        );
+        assert_eq!(
+            PresetInst::try_parse("hello::world<a,,a>").unwrap(),
+            PresetInst {
+                name: "hello::world".to_string(),
+                args: vec!["a".to_string(), "".to_string(), "a".to_string()],
+            }
+        );
+        assert_eq!(
+            PresetInst::try_parse("hello::world<,a,>").unwrap(),
+            PresetInst {
+                name: "hello::world".to_string(),
+                args: vec!["".to_string(), "a".to_string(), "".to_string()],
+            }
+        );
+    }
 }
diff --git a/compiler-core/src/lang/preset/preset.grammar b/compiler-core/src/lang/preset/preset.grammar
index 88244152..29e3da01 100644
--- a/compiler-core/src/lang/preset/preset.grammar
+++ b/compiler-core/src/lang/preset/preset.grammar
@@ -23,15 +23,14 @@ rule SubNamespace(
 
 rule Args(
     _: token Symbol"<",
-    first: ArgText,
+    first: optional ArgText,
     rest: optional ArgListTail+,
-    trailing_comma: optional token Symbol",",
     _: token Symbol">"
 );
 
 rule ArgListTail(
     _: token Symbol",",
-    arg: ArgText
+    arg: optional ArgText
 );
 
 rule ArgText(blocks: ArgBlock+);
diff --git a/compiler-wasm/Cargo.toml b/compiler-wasm/Cargo.toml
index 6ab8ded9..44318ba0 100644
--- a/compiler-wasm/Cargo.toml
+++ b/compiler-wasm/Cargo.toml
@@ -3,7 +3,6 @@ name = "compiler-wasm"
 version = "0.0.0"
 description = "WASM interface of the compiler"
 edition = "2021"
-default-run = "buildwasm"
 
 [dependencies]
 compiler-core = { path = "../compiler-core", features = ["wasm"], default-features = false }
@@ -21,7 +20,3 @@ tsify = { version = "0.4.5", default-features = false, features = ["js"] }
 name = "celercwasm"
 path = "src/lib.rs"
 crate-type = ["cdylib", "lib"]
-
-[[bin]]
-name = "buildwasm"
-path = "src/build.rs"
diff --git a/compiler-wasm/Taskfile.yml b/compiler-wasm/Taskfile.yml
index 6212beed..eca38106 100644
--- a/compiler-wasm/Taskfile.yml
+++ b/compiler-wasm/Taskfile.yml
@@ -3,10 +3,12 @@ version: '3'
 tasks:
   dev:
     desc: Start wasm builds in watch mode
+    dir: build
     cmds:
-    - cargo watch -x run
+    - cargo watch -x run {{.CLI_ARGS}}
 
   build:
     desc: Build debug wasm module
+    dir: build
     cmds:
-    - cargo run
+    - cargo run {{.CLI_ARGS}}
diff --git a/compiler-wasm/build/Cargo.toml b/compiler-wasm/build/Cargo.toml
new file mode 100644
index 00000000..cf02ddc4
--- /dev/null
+++ b/compiler-wasm/build/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "compiler-wasm-build"
+version = "0.0.0"
+description = "Build script for the wasm package"
+edition = "2021"
+default-run = "buildwasm"
+
+[dependencies]
+
+[[bin]]
+name = "buildwasm"
+path = "src/build.rs"
diff --git a/compiler-wasm/src/build.rs b/compiler-wasm/build/src/build.rs
similarity index 89%
rename from compiler-wasm/src/build.rs
rename to compiler-wasm/build/src/build.rs
index 7b118732..76189d45 100644
--- a/compiler-wasm/src/build.rs
+++ b/compiler-wasm/build/src/build.rs
@@ -5,6 +5,7 @@ use std::io::{self, Write};
 use std::path::Path;
 use std::process::Command;
 
+/// Output directory relative to the wasm package (not current dir)
 const OUTPUT_DIR: &str = "../web-client/src/low/celerc";
 
 pub fn main() {
@@ -49,6 +50,7 @@ fn wasm_pack_build() -> io::Result<()> {
 fn build_wasm_pack_command() -> Command {
     let mut command = Command::new("wasm-pack");
     command.args(["build", "--out-dir", OUTPUT_DIR, "--dev"]);
+    command.current_dir("..");
     command
 }
 
@@ -56,12 +58,13 @@ fn build_wasm_pack_command() -> Command {
 fn build_wasm_pack_command() -> Command {
     let mut command = Command::new("wasm-pack");
     command.args(&["build", "--out-dir", OUTPUT_DIR, "--release"]);
+    command.current_dir("..");
     command
 }
 
 fn override_typescript_definitions() -> io::Result<()> {
     println!("generating typescript definitions");
-    let path = Path::new(OUTPUT_DIR).join("celercwasm.d.ts");
+    let path = Path::new("..").join(OUTPUT_DIR).join("celercwasm.d.ts");
     let d_ts = fs::read_to_string(&path)?;
 
     // https://github.com/madonoharu/tsify/issues/37
@@ -76,7 +79,7 @@ fn add_console_log() -> io::Result<()> {
     // open file for appending
     let mut file = fs::OpenOptions::new()
         .append(true)
-        .open(Path::new(OUTPUT_DIR).join("celercwasm.js"))?;
+        .open(Path::new("..").join(OUTPUT_DIR).join("celercwasm.js"))?;
 
     // write to file
     writeln!(