diff --git a/Cargo.lock b/Cargo.lock
index eed114e..25755c1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -567,6 +567,15 @@ name = "pylyzer"
 version = "0.0.60"
 dependencies = [
  "els",
+ "erg_common",
+ "erg_compiler",
+ "pylyzer_core",
+]
+
+[[package]]
+name = "pylyzer_core"
+version = "0.0.60"
+dependencies = [
  "erg_common",
  "erg_compiler",
  "py2erg",
diff --git a/Cargo.toml b/Cargo.toml
index e0781a3..3c91f0b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,7 @@ repository.workspace = true
 [workspace]
 members = [
     "crates/py2erg",
+    "crates/pylyzer_core",
 ]
 
 [workspace.package]
@@ -37,19 +38,16 @@ rustpython-ast = { git = "https://github.com/RustPython/Parser", version = "0.4.
 # els = { path = "../erg/crates/els", features = ["py_compat"] }
 
 [features]
-debug = ["erg_compiler/debug", "erg_common/debug", "py2erg/debug"]
-large_thread = ["erg_compiler/large_thread", "erg_common/large_thread", "els/large_thread"]
-pretty = ["erg_compiler/pretty", "erg_common/pretty"]
-backtrace = ["erg_common/backtrace"]
-experimental = ["els/experimental", "erg_compiler/experimental", "erg_common/experimental"]
+debug = ["erg_common/debug", "pylyzer_core/debug"]
+large_thread = ["erg_common/large_thread", "els/large_thread", "pylyzer_core/large_thread"]
+pretty = ["erg_common/pretty", "pylyzer_core/pretty"]
+backtrace = ["erg_common/backtrace", "els/backtrace", "pylyzer_core/backtrace"]
+experimental = ["erg_common/experimental", "els/experimental", "pylyzer_core/experimental"]
 
 [dependencies]
-erg_compiler = { workspace = true }
+pylyzer_core = { version = "0.0.60", path = "./crates/pylyzer_core" }
 erg_common = { workspace = true }
 els = { workspace = true }
-rustpython-parser = { workspace = true }
-rustpython-ast = { workspace = true }
-py2erg = { version = "0.0.60", path = "./crates/py2erg" }
 
-[lib]
-path = "src/lib.rs"
+[dev-dependencies]
+erg_compiler = { workspace = true }
diff --git a/cargo_publish.sh b/cargo_publish.sh
index 625af9f..c96eeee 100755
--- a/cargo_publish.sh
+++ b/cargo_publish.sh
@@ -3,6 +3,9 @@ if [[ "$PWD" == */pylyzer ]]; then
         cd crates/py2erg
         echo "publish py2erg ..."
         cargo publish
+        cd ../pylyzer_core
+        echo "publish pylyzer_core ..."
+        cargo publish
         cd ../../
         cargo publish
         if [ "$1" = "--cargo-only" ]; then
diff --git a/crates/pylyzer_core/Cargo.toml b/crates/pylyzer_core/Cargo.toml
new file mode 100644
index 0000000..80c5299
--- /dev/null
+++ b/crates/pylyzer_core/Cargo.toml
@@ -0,0 +1,24 @@
+[package]
+name = "pylyzer_core"
+version.workspace = true
+authors.workspace = true
+license.workspace = true
+edition.workspace = true
+repository.workspace = true
+
+[features]
+debug = ["erg_compiler/debug", "erg_common/debug", "py2erg/debug"]
+large_thread = ["erg_compiler/large_thread", "erg_common/large_thread"]
+pretty = ["erg_compiler/pretty", "erg_common/pretty"]
+backtrace = ["erg_common/backtrace"]
+experimental = ["erg_compiler/experimental", "erg_common/experimental"]
+
+[dependencies]
+erg_common = { workspace = true }
+erg_compiler = { workspace = true }
+rustpython-parser = { workspace = true }
+rustpython-ast = { workspace = true }
+py2erg = { version = "0.0.60", path = "../py2erg" }
+
+[lib]
+path = "lib.rs"
diff --git a/src/analyze.rs b/crates/pylyzer_core/analyze.rs
similarity index 100%
rename from src/analyze.rs
rename to crates/pylyzer_core/analyze.rs
diff --git a/src/handle_err.rs b/crates/pylyzer_core/handle_err.rs
similarity index 100%
rename from src/handle_err.rs
rename to crates/pylyzer_core/handle_err.rs
diff --git a/crates/pylyzer_core/lib.rs b/crates/pylyzer_core/lib.rs
new file mode 100644
index 0000000..089c42e
--- /dev/null
+++ b/crates/pylyzer_core/lib.rs
@@ -0,0 +1,4 @@
+mod analyze;
+mod handle_err;
+
+pub use analyze::{PythonAnalyzer, SimplePythonParser};
diff --git a/src/copy.rs b/src/copy.rs
index bb7145d..5443299 100644
--- a/src/copy.rs
+++ b/src/copy.rs
@@ -23,7 +23,6 @@ fn copy_dir(from: impl AsRef<Path>, to: impl AsRef<Path>) -> std::io::Result<()>
     Ok(())
 }
 
-#[allow(unused)]
 pub(crate) fn copy_dot_erg() {
     if erg_path().exists() {
         return;
diff --git a/src/lib.rs b/src/lib.rs
deleted file mode 100644
index 67e4046..0000000
--- a/src/lib.rs
+++ /dev/null
@@ -1,6 +0,0 @@
-mod analyze;
-mod config;
-mod copy;
-mod handle_err;
-
-pub use analyze::PythonAnalyzer;
diff --git a/src/main.rs b/src/main.rs
index 24fb89f..0e91c63 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,12 +1,10 @@
-mod analyze;
 mod config;
 mod copy;
-mod handle_err;
 
-use analyze::{PythonAnalyzer, SimplePythonParser};
 use els::Server;
 use erg_common::config::ErgMode;
 use erg_common::spawn::exec_new_thread;
+use pylyzer_core::{PythonAnalyzer, SimplePythonParser};
 
 use crate::copy::copy_dot_erg;
 
diff --git a/tests/test.rs b/tests/test.rs
index f518b14..a91c124 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -4,7 +4,7 @@ use erg_common::config::ErgConfig;
 use erg_common::io::Input;
 use erg_common::spawn::exec_new_thread;
 use erg_compiler::artifact::{CompleteArtifact, IncompleteArtifact};
-use pylyzer::PythonAnalyzer;
+use pylyzer_core::PythonAnalyzer;
 
 pub fn exec_analyzer(file_path: &'static str) -> Result<CompleteArtifact, IncompleteArtifact> {
     let cfg = ErgConfig {