diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index cb524a8d..193ba35e 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -5,6 +5,7 @@ edition = "2021"
 license = "MIT"
 description = "PNA(Portable-Network-Archive) decoding and encoding library"
 repository = "https://github.com/ChanTsune/Portable-Network-Archive.git"
+readme = "README.md"
 categories = ["data-structures", "filesystem"]
 keywords = ["pna", "archive", "crypto", "data"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
diff --git a/lib/README.md b/lib/README.md
new file mode 100644
index 00000000..c8dcd62a
--- /dev/null
+++ b/lib/README.md
@@ -0,0 +1,74 @@
+# libpna
+[![test](https://github.com/ChanTsune/Portable-Network-Archive/actions/workflows/test.yml/badge.svg)](https://github.com/ChanTsune/Portable-Network-Archive/actions/workflows/test.yml)
+[![Crates.io][crates-badge]][crates-url]
+
+[crates-badge]: https://img.shields.io/crates/v/libpna.svg
+[crates-url]: https://crates.io/crates/libpna
+
+A pna archive reading/writing library for Rust.
+
+```toml
+# Cargo.toml
+[dependencies]
+libpna = "0.2"
+```
+
+## Reading an archive
+
+```rust
+use libpna::Archive;
+use std::fs::File;
+use std::io::{self, copy, prelude::*};
+
+fn main() -> io::Result<()> {
+    use libpna::ReadOption;
+    let file = File::open("foo.pna")?;
+    let mut archive = Archive::read_header(file)?;
+    for entry in archive.entries() {
+        let entry = entry?;
+        let mut file = File::create(entry.header().path().as_path())?;
+        let mut reader = entry.into_reader(ReadOption::builder().build())?;
+        copy(&mut reader, &mut file)?;
+    }
+    Ok(())
+}
+```
+
+## Writing an archive
+
+```rust
+use libpna::{Archive, EntryBuilder, WriteOption};
+use std::fs::File;
+use std::io::{self, prelude::*};
+
+fn main() -> io::Result<()> {
+    let file = File::create("foo.pna")?;
+    let mut archive = Archive::write_header(file)?;
+    let mut entry_builder = EntryBuilder::new_file(
+        "bar.txt".try_into().unwrap(),
+        WriteOption::builder().build(),
+    )?;
+    entry_builder.write(b"content")?;
+    let entry = entry_builder.build()?;
+    archive.add_entry(entry)?;
+    archive.finalize()?;
+    Ok(())
+}
+```
+
+# License
+
+This project is licensed under either of
+
+* Apache License, Version 2.0, ([LICENSE-APACHE](../LICENSE-APACHE) or
+  http://www.apache.org/licenses/LICENSE-2.0)
+* MIT license ([LICENSE-MIT](../LICENSE-MIT) or
+  http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in this project by you, as defined in the Apache-2.0 license,
+shall be dual licensed as above, without any additional terms or conditions.