diff --git a/src/main.rs b/src/main.rs
index 976efb9..e2773cc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,17 +1,8 @@
 #![feature(let_chains)]
 #![feature(extend_one)]
 
-use std::path::Path;
-use std::sync::{
-    Arc, Mutex, RwLock,
-    atomic::{AtomicUsize, Ordering},
-};
-
 use anyhow::Result;
 use clap::{Parser, Subcommand};
-use log::{debug, trace};
-use tokio::process::Command;
-use tokio::sync::{Semaphore, mpsc};
 
 use nixcp::NixCp;
 
@@ -60,138 +51,14 @@ enum Commands {
 async fn main() -> Result<()> {
     env_logger::init();
     let cli = Cli::parse();
-    let mut nixcp = NixCp::new();
-    nixcp.add_upstreams(&cli.upstream_caches)?;
+    let nixcp = Box::leak(Box::new(NixCp::with_upstreams(&cli.upstream_caches)?));
 
     match &cli.command {
         Commands::Push { package } => {
             nixcp.paths_from_package(package).await?;
+            nixcp.run().await;
         }
     }
 
     Ok(())
-
-    /*
-        let (cacheable_tx, mut cacheable_rx) = mpsc::channel(cli.uploader_concurrency.into());
-
-        println!("spawning check_upstream");
-
-        println!("spawning uploader");
-        handles.push(tokio::spawn(async move {
-            uploader(&mut cacheable_rx, binary_cache, cli.uploader_concurrency).await;
-        }));
-
-        // make sure all threads are done
-        for handle in handles {
-            handle.await.unwrap();
-        }
-    */
-}
-
-// filter out store paths that exist in upstream caches
-async fn check_upstream(
-    store_paths: Arc<RwLock<Vec<String>>>,
-    cacheable_tx: mpsc::Sender<String>,
-    concurrency: u8,
-    upstream_caches: Arc<Vec<String>>,
-) {
-    let concurrency = Arc::new(Semaphore::new(concurrency.into()));
-    let c_store_paths = Arc::clone(&store_paths);
-    let store_paths = c_store_paths.read().unwrap().clone();
-
-    for store_path in store_paths {
-        let tx = cacheable_tx.clone();
-        let upstream_caches = Arc::clone(&upstream_caches);
-        let concurrency = Arc::clone(&concurrency);
-
-        tokio::spawn(async move {
-            let _permit = concurrency.acquire().await.unwrap();
-            let basename = Path::new(&store_path)
-                .file_name()
-                .unwrap()
-                .to_str()
-                .unwrap()
-                .to_string();
-            let hash = basename.split("-").next().unwrap();
-
-            let mut hit = false;
-            for upstream in upstream_caches.as_ref() {
-                let mut uri = upstream.clone();
-                uri.push_str(format!("/{}.narinfo", hash).as_str());
-
-                let res_status = reqwest::Client::new()
-                    .head(uri)
-                    .send()
-                    .await
-                    .map(|x| x.status());
-
-                if let Ok(res_status) = res_status
-                    && res_status.is_success()
-                {
-                    debug!("{} was a hit upstream: {}", store_path, upstream);
-                    hit = true;
-                    break;
-                }
-            }
-            if !hit {
-                trace!("sending {}", store_path);
-                tx.send(store_path).await.unwrap();
-            }
-        });
-    }
-}
-
-async fn uploader(
-    cacheable_rx: &mut mpsc::Receiver<String>,
-    binary_cache: String,
-    concurrency: u8,
-) {
-    let upload_count = Arc::new(AtomicUsize::new(0));
-    let failures: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
-    let concurrency = Arc::new(Semaphore::new(concurrency.into()));
-    let mut handles = Vec::new();
-
-    loop {
-        if let Some(path_to_upload) = cacheable_rx.recv().await {
-            let concurrency = Arc::clone(&concurrency);
-            let failures = Arc::clone(&failures);
-            let binary_cache = binary_cache.clone();
-            let upload_count = Arc::clone(&upload_count);
-
-            handles.push(tokio::spawn(async move {
-                let _permit = concurrency.acquire().await.unwrap();
-                println!("uploading: {}", path_to_upload);
-                if Command::new("nix")
-                    .arg("copy")
-                    .arg("--to")
-                    .arg(&binary_cache)
-                    .arg(&path_to_upload)
-                    .output()
-                    .await
-                    .is_err()
-                {
-                    println!("WARN: upload failed: {}", path_to_upload);
-                    failures.lock().unwrap().push(path_to_upload);
-                } else {
-                    upload_count.fetch_add(1, Ordering::Relaxed);
-                }
-            }));
-        } else {
-            // make sure all threads are done
-            for handle in handles {
-                handle.await.unwrap();
-            }
-            println!("uploaded {} paths", upload_count.load(Ordering::Relaxed));
-
-            let failures = failures.lock().unwrap();
-            if !failures.is_empty() {
-                println!("failed to upload these paths: ");
-                for failure in failures.iter() {
-                    print!("{}", failure);
-                }
-                println!();
-            }
-            break;
-        }
-    }
 }
diff --git a/src/nixcp.rs b/src/nixcp.rs
index 74e9fa5..057af55 100644
--- a/src/nixcp.rs
+++ b/src/nixcp.rs
@@ -1,64 +1,135 @@
-use std::sync::Arc;
+use std::{
+    iter::once,
+    sync::{
+        Arc, Mutex,
+        atomic::{AtomicUsize, Ordering},
+    },
+};
 
 use crate::path_info::PathInfo;
 use anyhow::{Context, Result};
-use log::info;
-use tokio::sync::{Semaphore, mpsc};
+use log::{info, warn};
+use tokio::{
+    process::Command,
+    sync::{RwLock, Semaphore, mpsc},
+};
 use url::Url;
 
 pub struct NixCp {
     upstream_caches: Arc<Vec<Url>>,
-    store_paths: Vec<PathInfo>,
+    store_paths: Arc<RwLock<Vec<PathInfo>>>,
 }
 
 impl NixCp {
-    pub fn new() -> Self {
-        Self {
-            upstream_caches: vec![Url::parse("https://cache.nixos.org").unwrap()],
-            store_paths: Vec::new(),
-        }
-    }
-
-    pub fn add_upstreams(&mut self, upstreams: &[String]) -> Result<()> {
-        self.upstream_caches.reserve(upstreams.len());
-        for upstream in upstreams {
-            self.upstream_caches
+    pub fn with_upstreams(new_upstreams: &[String]) -> Result<Self> {
+        let mut upstreams = Vec::with_capacity(new_upstreams.len() + 1);
+        for upstream in new_upstreams
+            .iter()
+            .chain(once(&"https://cache.nixos.org".to_string()))
+        {
+            upstreams
                 .push(Url::parse(upstream).context(format!("failed to parse {upstream} as url"))?);
         }
-        Ok(())
+        Ok(Self {
+            upstream_caches: Arc::new(upstreams),
+            store_paths: Arc::new(RwLock::new(Vec::new())),
+        })
     }
 
     pub async fn paths_from_package(&mut self, package: &str) -> Result<()> {
         let path_info = PathInfo::from_path(package).await?;
-        self.store_paths = path_info.get_closure().await?;
-        info!("found {} store paths", self.store_paths.len());
+        self.store_paths
+            .write()
+            .await
+            .extend(path_info.get_closure().await?);
+        info!("found {} store paths", self.store_paths.read().await.len());
 
         Ok(())
     }
 
-    pub async fn run(&mut self) {}
+    pub async fn run(&'static self) {
+        let (tx, rx) = mpsc::channel(10);
+        let tx = Arc::new(tx);
+        tokio::spawn(self.filter_from_upstream(tx));
+        tokio::spawn(self.uploader("".to_string(), rx));
+    }
 
     /// filter paths that are on upstream and send to `tx`
-    async fn filter_from_upstream(&self, tx: mpsc::Sender<&PathInfo>) {
+    async fn filter_from_upstream(&self, tx: Arc<mpsc::Sender<String>>) {
         let permits = Arc::new(Semaphore::new(10));
-        let mut handles = Vec::new();
-        for path in &self.store_paths {
+        let mut handles = Vec::with_capacity(10);
+        let store_paths = self.store_paths.read().await.clone();
+
+        for path in store_paths.into_iter() {
             if path.check_upstream_signature(&self.upstream_caches) {
                 continue;
             }
-            let permits = permits.clone();
-            let tx = tx.clone();
-            handles.push(tokio::spawn(async move {
-                let _permit = permits.acquire().await.unwrap();
+            handles.push({
+                let permits = permits.clone();
+                let tx = tx.clone();
+                let upstream_caches = self.upstream_caches.clone();
+                tokio::spawn(async move {
+                    let _permit = permits.acquire().await.unwrap();
 
-                if !path.check_upstream_hit(&self.upstream_caches).await {
-                    tx.send(path);
-                }
-            }));
+                    if !path.check_upstream_hit(upstream_caches.as_slice()).await {
+                        tx.send(path.to_string()).await.unwrap();
+                    }
+                })
+            });
         }
 
         for handle in handles {
             handle.await.unwrap();
         }
     }
+
+    async fn uploader(&self, cache: String, mut rx: mpsc::Receiver<String>) {
+        let upload_count = Arc::new(AtomicUsize::new(0));
+        let failures: Arc<Mutex<Vec<String>>> = Arc::new(Mutex::new(Vec::new()));
+        let permits = Arc::new(Semaphore::new(10));
+        let mut handles = Vec::with_capacity(10);
+
+        loop {
+            if let Some(path_to_upload) = rx.recv().await {
+                let permits = Arc::clone(&permits);
+                let failures = Arc::clone(&failures);
+                let binary_cache = cache.clone();
+                let upload_count = Arc::clone(&upload_count);
+
+                handles.push(tokio::spawn(async move {
+                    let _permit = permits.acquire().await.unwrap();
+                    info!("uploading: {}", path_to_upload.to_string());
+                    if Command::new("nix")
+                        .arg("copy")
+                        .arg("--to")
+                        .arg(&binary_cache)
+                        .arg(&path_to_upload.to_string())
+                        .output()
+                        .await
+                        .is_err()
+                    {
+                        warn!("upload failed: {}", path_to_upload);
+                        failures.lock().unwrap().push(path_to_upload);
+                    } else {
+                        upload_count.fetch_add(1, Ordering::Relaxed);
+                    }
+                }));
+            } else {
+                // make sure all threads are done
+                for handle in handles {
+                    handle.await.unwrap();
+                }
+                println!("uploaded {} paths", upload_count.load(Ordering::Relaxed));
+
+                let failures = failures.lock().unwrap();
+                if !failures.is_empty() {
+                    warn!("failed to upload these paths: ");
+                    for failure in failures.iter() {
+                        warn!("{}", failure);
+                    }
+                }
+                break;
+            }
+        }
+    }
 }
diff --git a/src/path_info.rs b/src/path_info.rs
index 1213c1b..e1cf25a 100644
--- a/src/path_info.rs
+++ b/src/path_info.rs
@@ -8,7 +8,7 @@ use tokio::process::Command;
 use url::Url;
 
 // nix path-info --derivation --json
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct PathInfo {
     deriver: String,
@@ -103,6 +103,12 @@ impl PathInfo {
     }
 }
 
+impl ToString for PathInfo {
+    fn to_string(&self) -> String {
+        self.path.clone()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;