diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
new file mode 100644
index 0000000..ada8a24
--- /dev/null
+++ b/.github/FUNDING.yml
@@ -0,0 +1 @@
+custom: https://yggverse.github.io/#donate
\ No newline at end of file
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
new file mode 100644
index 0000000..3dbc639
--- /dev/null
+++ b/.github/workflows/linux.yml
@@ -0,0 +1,27 @@
+name: Linux
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+env:
+  CARGO_TERM_COLOR: always
+  RUSTFLAGS: -Dwarnings
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Run rustfmt
+      run: cargo fmt --all -- --check
+    - name: Run clippy
+      run: cargo clippy --all-targets
+    - name: Build
+      run: cargo build --verbose
+    - name: Run tests
+      run: cargo test --verbose
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..869df07
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/target
+Cargo.lock
\ No newline at end of file
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..c0c0a74
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "yps"
+version = "0.1.0"
+edition = "2024"
+license = "MIT"
+readme = "README.md"
+description = "YPS - Yggdrasil Port Scanner"
+keywords = ["yggdrasil", "tcp", "udp", "search", "crawler"]
+categories = ["network-programming"]
+repository = "https://github.com/YGGverse/yps"
+
+[dependencies]
+anyhow = "1.0"
+clap = { version = "4.5", features = ["derive"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..338dd11
--- /dev/null
+++ b/README.md
@@ -0,0 +1,43 @@
+# YPS - Yggdrasil Port Scanner
+
+![Linux](https://github.com/yggverse/yps/actions/workflows/linux.yml/badge.svg)
+[![Dependencies](https://deps.rs/repo/github/yggverse/yps/status.svg)](https://deps.rs/repo/github/yggverse/yps)
+[![crates.io](https://img.shields.io/crates/v/yps)](https://crates.io/crates/yps)
+
+A simple crawler tool to find open ports for specific services,
+such as web servers or Bitcoin nodes, to connect with [Yggdrasil](https://yggdrasil-network.github.io/).
+
+## Install
+
+* `git clone https://github.com/yggverse/yps.git && cd yps`
+* `cargo build --release`
+* `sudo install target/release/yps /usr/local/bin/yps`
+
+## Usage
+
+``` bash
+sudo yps --tcp -p 80 -p 443
+```
+
+### Options
+
+``` bash
+-d, --debug
+        Print debug information
+-s, --socket <SOCKET>
+        Yggdrasil socket path (unix only) [default: /var/run/yggdrasil.sock]
+-p, --port <PORT>
+        Port(s) to scan
+-u, --udp <UDP>
+        Crawl UDP ports (requires `[host]:port` binding as the value)
+-t, --tcp
+        Crawl TCP ports
+-l, --latency <LATENCY>
+        Pause in seconds before make new request
+    --index-capacity <INDEX_CAPACITY>
+        Optimize memory usage by providing expecting index capacity, according to the current network size [default: 1000]
+-h, --help
+        Print help
+-V, --version
+        Print version
+```
\ No newline at end of file
diff --git a/src/config.rs b/src/config.rs
new file mode 100644
index 0000000..86d8d5b
--- /dev/null
+++ b/src/config.rs
@@ -0,0 +1,34 @@
+use clap::Parser;
+
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+pub struct Config {
+    /// Print debug information
+    #[arg(short, long, default_value_t = false)]
+    pub debug: bool,
+
+    /// Yggdrasil socket path (unix only)
+    #[arg(short, long, default_value_t = String::from("/var/run/yggdrasil.sock"))]
+    pub socket: String,
+
+    /// Port(s) to scan
+    #[arg(short, long)]
+    pub port: Vec<u16>,
+
+    /// Crawl UDP ports (requires `[host]:port` binding as the value)
+    #[arg(short, long)]
+    pub udp: Option<String>,
+
+    /// Crawl TCP ports
+    #[arg(short, long, default_value_t = false)]
+    pub tcp: bool,
+
+    /// Pause in seconds before make new request
+    #[arg(short, long)]
+    pub latency: Option<u64>,
+
+    /// Optimize memory usage by providing expecting index capacity,
+    /// according to the current network size
+    #[arg(long, default_value_t = 1000)]
+    pub index_capacity: usize,
+}
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..c84d851
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,101 @@
+mod config;
+mod udp;
+mod yggdrasil;
+
+use anyhow::Result;
+use config::Config;
+use std::{
+    net::{IpAddr, SocketAddr, TcpStream},
+    time::Duration,
+};
+use udp::Udp;
+use yggdrasil::Yggdrasil;
+
+fn main() -> Result<()> {
+    use clap::Parser;
+    let config = Config::parse();
+    if config.port.is_empty() {
+        panic!("at least one port must be specified for scan!")
+    }
+    if !config.tcp && config.udp.is_none() {
+        panic!("at least one TCP or UDP protocol is required for scan!")
+    }
+    let latency = config.latency.map(Duration::from_secs); // parse once
+    let mut ygg = Yggdrasil::init(&config.socket)?;
+    let mut tcp: Option<Vec<SocketAddr>> = if config.tcp {
+        Some(Vec::with_capacity(config.index_capacity))
+    } else {
+        None
+    };
+    let mut udp = config.udp.as_ref().map(|bind| {
+        let server = Udp::init(bind).unwrap();
+        let index: Vec<SocketAddr> = Vec::with_capacity(config.index_capacity);
+        (index, server)
+    });
+    // get initial peers to crawl
+    if config.debug {
+        println!("get initial peers to crawl...");
+    }
+    let p = ygg.peers()?;
+    if p.status != "success" {
+        todo!()
+    }
+    // start crawler
+    for peer in p.response.unwrap().peers {
+        crawl(peer.key, latency, &config, &mut ygg, &mut tcp, &mut udp)?;
+    }
+    Ok(())
+}
+
+fn crawl(
+    key: String,
+    latency: Option<Duration>,
+    config: &Config,
+    ygg: &mut Yggdrasil,
+    tcp: &mut Option<Vec<SocketAddr>>,
+    udp: &mut Option<(Vec<SocketAddr>, Udp)>,
+) -> Result<()> {
+    if config.debug {
+        println!("get peers for `{}`...", &key);
+    }
+    let p = ygg.remote_peers(key)?;
+    if p.status != "success" {
+        todo!()
+    }
+    for (host, peers) in p.response.unwrap() {
+        for port in &config.port {
+            let address = SocketAddr::new(IpAddr::V6(host), *port);
+            if let Some(index) = tcp {
+                if !index.contains(&address) {
+                    let url = format!("tcp://{address}");
+                    if config.debug {
+                        println!("try `{url}`...");
+                    }
+                    if TcpStream::connect_timeout(&address, Duration::from_secs(1)).is_ok() {
+                        println!("{url}");
+                        index.push(address)
+                    }
+                }
+            }
+            if let Some((index, server)) = udp {
+                let url = format!("udp://{address}");
+                if !index.contains(&address) {
+                    if config.debug {
+                        println!("try `{url}`...");
+                    }
+                    if server.check(address) {
+                        println!("{url}");
+                        index.push(address)
+                    }
+                }
+            }
+        }
+        for k in peers.keys {
+            if let Some(l) = latency {
+                std::thread::sleep(l);
+            }
+            crawl(k, latency, config, ygg, tcp, udp)?;
+        }
+    }
+    Ok(())
+}
diff --git a/src/udp.rs b/src/udp.rs
new file mode 100644
index 0000000..2ffe263
--- /dev/null
+++ b/src/udp.rs
@@ -0,0 +1,33 @@
+use anyhow::Result;
+use std::{
+    net::{SocketAddr, SocketAddrV6, UdpSocket},
+    str::FromStr,
+    time::Duration,
+};
+
+/// Simple UDP server to test peers connection
+pub struct Udp(UdpSocket);
+
+impl Udp {
+    pub fn init(bind: &str) -> Result<Self> {
+        const T: u64 = 1; // @TODO optional
+
+        let this = UdpSocket::bind(SocketAddrV6::from_str(bind)?)?;
+        this.set_write_timeout(Some(Duration::from_secs(T)))?;
+        this.set_read_timeout(Some(Duration::from_secs(T)))?;
+        Ok(Self(this))
+    }
+
+    pub fn check(&self, remote: SocketAddr) -> bool {
+        if self.0.connect(remote).is_err() {
+            return false;
+        }
+        match self.0.send_to(b"test", remote) {
+            Ok(_) => {
+                let mut b = [0; 1];
+                self.0.recv_from(&mut b).is_ok() // @TODO
+            }
+            Err(_) => false,
+        }
+    }
+}
diff --git a/src/yggdrasil.rs b/src/yggdrasil.rs
new file mode 100644
index 0000000..89bab8b
--- /dev/null
+++ b/src/yggdrasil.rs
@@ -0,0 +1,50 @@
+mod api;
+use api::*;
+
+use anyhow::Result;
+use std::{
+    collections::HashMap,
+    io::{Read, Write},
+    net::Ipv6Addr,
+    os::unix::net::UnixStream,
+};
+
+pub struct Yggdrasil(UnixStream);
+
+impl Yggdrasil {
+    pub fn init(path: &str) -> Result<Self> {
+        Ok(Self(UnixStream::connect(path)?))
+    }
+
+    pub fn peers(&mut self) -> Result<Response<LocalPeers>> {
+        let r: Response<LocalPeers> = serde_json::from_slice(
+            &self.request(b"{\"keepalive\":true,\"request\":\"getpeers\"}")?,
+        )?;
+        Ok(r)
+    }
+
+    pub fn remote_peers(
+        &mut self,
+        public_key: String,
+    ) -> Result<Response<HashMap<Ipv6Addr, RemotePeers>>> {
+        let r: Response<HashMap<Ipv6Addr, RemotePeers>> = serde_json::from_slice(&self.request(
+            format!("{{\"keepalive\":true,\"request\":\"debug_remotegetpeers\",\"arguments\":{{\"key\":\"{public_key}\"}}}}")
+                .as_bytes(),
+        )?)?;
+        Ok(r)
+    }
+
+    fn request(&mut self, bytes: &[u8]) -> Result<Vec<u8>> {
+        const L: usize = 1024; // chunk len
+        self.0.write_all(bytes)?;
+        let mut r = Vec::with_capacity(L);
+        loop {
+            let mut b = vec![0; L];
+            let l = self.0.read(&mut b)?; // can't `read_to_end` as no EOF
+            r.extend(&b[..l]);
+            if l < L {
+                return Ok(r);
+            }
+        }
+    }
+}
diff --git a/src/yggdrasil/api.rs b/src/yggdrasil/api.rs
new file mode 100644
index 0000000..e1bcbfb
--- /dev/null
+++ b/src/yggdrasil/api.rs
@@ -0,0 +1,41 @@
+use serde::Deserialize;
+
+#[derive(Deserialize, Debug)]
+pub struct Response<T> {
+    pub response: Option<T>,
+    pub status: String,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct LocalPeers {
+    pub peers: Vec<LocalPeer>,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct LocalPeer {
+    pub key: String,
+    // pub address: std::net::Ipv6Addr,
+    // pub bytes_recvd: Option<u64>,
+    // pub bytes_sent: Option<u64>,
+    // pub inbound: bool,
+    // #[serde(default, deserialize_with = "time")]
+    // pub last_error_time: Option<Duration>,
+    // pub last_error: Option<String>,
+    // #[serde(default, deserialize_with = "time")]
+    // pub latency: Option<Duration>,
+    // pub port: u64,
+    // pub priority: Option<u64>,
+    // pub remote: Option<String>,
+    // pub up: bool,
+    // pub uptime: Option<f64>,
+}
+
+#[derive(Deserialize, Debug)]
+pub struct RemotePeers {
+    pub keys: Vec<String>,
+}
+
+// use std::time::Duration;
+// fn time<'de, D: serde::Deserializer<'de>>(d: D) -> Result<Option<Duration>, D::Error> {
+//     u64::deserialize(d).map(|t| Some(Duration::from_nanos(t)))
+// }