diff --git a/Cargo.lock b/Cargo.lock
index 7c897e7..95e3e77 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,6 +17,15 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "anyhow"
 version = "1.0.59"
@@ -149,6 +158,17 @@ version = "0.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5827cebf4670468b8772dd191856768aedcb1b0278a04f989f7766351917b9dc"
 
+[[package]]
+name = "derivative"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "encoding_rs"
 version = "0.8.31"
@@ -453,6 +473,12 @@ version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a60c7ce501c71e03a9c9c0d35b861413ae925bd979cc7a4e30d060069aaac8d"
 
+[[package]]
+name = "minimal-lexical"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
+
 [[package]]
 name = "miniz_oxide"
 version = "0.5.3"
@@ -492,6 +518,16 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "nom"
+version = "7.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8903e5a29a317527874d0402f867152a3d21c908bb0b933e416c65e301d4c36"
+dependencies = [
+ "memchr",
+ "minimal-lexical",
+]
+
 [[package]]
 name = "num_cpus"
 version = "1.13.1"
@@ -592,6 +628,25 @@ version = "0.3.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1df8c4ec4b0627e53bdf214615ad287367e482558cf84b109250b37464dc03ae"
 
+[[package]]
+name = "pomsky"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2325e4138bcceff534b0149cb30d08099d2b08f15c65b7bdf7c33b16c5907d4d"
+dependencies = [
+ "nom",
+ "thiserror",
+]
+
+[[package]]
+name = "pomsky-macro"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5997a1ccb23752151a0463191b5b88fa678ce39fa711c64b2a211ede9e1d8166"
+dependencies = [
+ "pomsky",
+]
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -625,6 +680,20 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "pyver"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8437765dce7370ae968d4094568a3ce57a8b74fd51197e9b665560a1ae183d9"
+dependencies = [
+ "anyhow",
+ "derivative",
+ "lazy_static",
+ "pomsky-macro",
+ "regex",
+ "serde",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.20"
@@ -643,6 +712,23 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "regex"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c4eb3267174b8c6c2f654116623910a0fef09c4753f8dd83db29c48a0df988b"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3f87b73ce11b1619a3c6332f45341e0047173771e8b8b73f87bfeefb7b56244"
+
 [[package]]
 name = "remove_dir_all"
 version = "0.5.3"
@@ -695,7 +781,9 @@ version = "0.0.1"
 dependencies = [
  "anyhow",
  "clap",
+ "pyver",
  "reqwest",
+ "serde",
  "strum",
 ]
 
@@ -755,6 +843,20 @@ name = "serde"
 version = "1.0.140"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc855a42c7967b7c369eb5860f7164ef1f6f81c20c7cc1141f2a604e18723b03"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.140"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f2122636b9fe3b81f1cb25099fcf2d3f542cdb1d45940d56c713158884a05da"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
 
 [[package]]
 name = "serde_json"
@@ -866,6 +968,26 @@ version = "0.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b1141d4d61095b28419e22cb0bbf02755f5e54e0526f97f1e3d1d160e60885fb"
 
+[[package]]
+name = "thiserror"
+version = "1.0.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f5f6586b7f764adc0231f4c79be7b920e766bb2f3e51b3661cdb263828f19994"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12bafc5b54507e0149cdf1b145a5d80ab80a90bcd9275df43d4fff68460f6c21"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "tinyvec"
 version = "1.6.0"
diff --git a/Cargo.toml b/Cargo.toml
index 16cfda1..9ef2509 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ anyhow = { version = "1.0.58", features = ["backtrace"] }
 clap = { version = "3.2", features = ["derive"] }
 reqwest = { version = "0.11", features = ["blocking", "json"] }
 strum = { version = "0.24.1", features = ["derive"] }
-
+serde = { version = "1", features = ["derive"] }
+pyver = { version = "1" }
 
 [dev-dependencies]
diff --git a/src/main.rs b/src/main.rs
index fca4f23..e16a942 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,7 @@
 use clap::{AppSettings, Parser};
 
+use pyver::PackageVersion;
+
 /// Python package manager written in Rust
 #[derive(Parser, Debug)]
 #[clap(global_setting = AppSettings::DeriveDisplayOrder)]
@@ -43,7 +45,10 @@ enum Opt {
     Help {},
 }
 
-fn download_package(_package_name: String, _package_index: &str) {}
+fn download_package(_package_name: String, _package_index: &str) {
+    // Version usage example
+    let _ = PackageVersion::new("v1.0");
+}
 
 fn main() {
     let opt = Opt::parse();