diff --git a/Cargo.lock b/Cargo.lock
index 806b3a4..d0e9d6e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -792,9 +792,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.5.3"
+version = "1.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce5f1ceb7f74abbce32601642fcf8e8508a8a8991e0621c7d750295b9095702b"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -1220,9 +1220,9 @@ dependencies = [
 
 [[package]]
 name = "url"
-version = "2.2.1"
+version = "2.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ccd964113622c8e9322cfac19eb1004a07e636c545f325da085d5cdde6f1f8b"
+checksum = "a507c383b2d33b5fc35d1861e77e6b383d158b2da5e14fe51b83dfedf6fd578c"
 dependencies = [
  "form_urlencoded",
  "idna",
diff --git a/client/src/data_store.rs b/client/src/data_store.rs
index c69b590..dc59b06 100644
--- a/client/src/data_store.rs
+++ b/client/src/data_store.rs
@@ -135,7 +135,7 @@ mod tests {
         static ref BASE_PEERS: Vec<Peer> = vec![Peer {
             id: 0,
             contents: PeerContents {
-                name: "blah".to_string(),
+                name: "blah".parse().unwrap(),
                 ip: "10.0.0.1".parse().unwrap(),
                 cidr_id: 1,
                 public_key: "abc".to_string(),
@@ -144,6 +144,7 @@ mod tests {
                 is_disabled: false,
                 is_redeemed: true,
                 persistent_keepalive_interval: None,
+                invite_expires: None,
             }
         }];
         static ref BASE_CIDRS: Vec<Cidr> = vec![Cidr {
diff --git a/docker-tests/run-docker-tests.sh b/docker-tests/run-docker-tests.sh
index 38b75ef..dafdc72 100755
--- a/docker-tests/run-docker-tests.sh
+++ b/docker-tests/run-docker-tests.sh
@@ -38,6 +38,7 @@ SERVER_CONTAINER=$(cmd docker run -itd --rm \
     --cap-add NET_ADMIN \
     innernet-server)
 
+info "server started as $SERVER_CONTAINER"
 info "Waiting for server to initialize."
 cmd sleep 10
 
@@ -49,6 +50,7 @@ PEER1_CONTAINER=$(cmd docker create --rm -it \
     --env INTERFACE=evilcorp \
     --cap-add NET_ADMIN \
     innernet)
+info "peer1 started as $PEER1_CONTAINER"
 cmd docker cp "$tmp_dir/peer1.toml" "$PEER1_CONTAINER:/app/invite.toml"
 cmd docker start "$PEER1_CONTAINER"
 sleep 5
@@ -75,6 +77,7 @@ cmd docker exec "$PEER1_CONTAINER" innernet \
     --admin false \
     --auto-ip \
     --save-config "/app/peer2.toml" \
+    --invite-expires "30d" \
     --yes
 cmd docker cp "$PEER1_CONTAINER:/app/peer2.toml" "$tmp_dir"
 
@@ -85,6 +88,7 @@ PEER2_CONTAINER=$(docker create --rm -it \
     --cap-add NET_ADMIN \
     --env INTERFACE=evilcorp \
     innernet)
+info "peer2 started as $PEER2_CONTAINER"
 cmd docker cp "$tmp_dir/peer2.toml" "$PEER2_CONTAINER:/app/invite.toml"
 cmd docker start "$PEER2_CONTAINER"
 sleep 10
diff --git a/docker-tests/start-server.sh b/docker-tests/start-server.sh
index c6e29af..05a9cac 100755
--- a/docker-tests/start-server.sh
+++ b/docker-tests/start-server.sh
@@ -7,8 +7,19 @@ innernet-server new \
     --external-endpoint "172.18.1.1:51820" \
     --listen-port 51820
 
-innernet-server add-cidr evilcorp --name "humans" --cidr "10.66.1.0/24" --parent "evilcorp" --yes
+innernet-server add-cidr evilcorp \
+    --name "humans" \
+    --cidr "10.66.1.0/24" \
+    --parent "evilcorp" \
+    --yes
 
-innernet-server add-peer evilcorp --name "admin" --cidr "humans" --admin true --auto-ip --save-config "peer1.toml" --yes
+innernet-server add-peer evilcorp \
+    --name "admin" \
+    --cidr "humans" \
+    --admin true \
+    --auto-ip \
+    --save-config "peer1.toml" \
+    --invite-expires "30d" \
+    --yes
 
 innernet-server serve evilcorp
diff --git a/server/src/api/admin/cidr.rs b/server/src/api/admin/cidr.rs
index c035683..5b7ee1d 100644
--- a/server/src/api/admin/cidr.rs
+++ b/server/src/api/admin/cidr.rs
@@ -64,10 +64,10 @@ mod tests {
     use crate::{test, DatabasePeer};
     use anyhow::Result;
     use bytes::Buf;
-    use shared::Cidr;
+    use shared::{Cidr, Error};
 
     #[tokio::test]
-    async fn test_cidr_add() -> Result<()> {
+    async fn test_cidr_add() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let old_cidrs = DatabaseCidr::list(&server.db().lock())?;
@@ -95,7 +95,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_cidr_name_uniqueness() -> Result<()> {
+    async fn test_cidr_name_uniqueness() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let contents = CidrContents {
@@ -125,7 +125,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_cidr_create_auth() -> Result<()> {
+    async fn test_cidr_create_auth() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let contents = CidrContents {
@@ -143,7 +143,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_cidr_bad_parent() -> Result<()> {
+    async fn test_cidr_bad_parent() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let contents = CidrContents {
@@ -171,7 +171,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_cidr_overlap() -> Result<()> {
+    async fn test_cidr_overlap() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let contents = CidrContents {
@@ -188,7 +188,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_cidr_delete_fail_with_child_cidr() -> Result<()> {
+    async fn test_cidr_delete_fail_with_child_cidr() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let experimental_cidr = DatabaseCidr::create(
@@ -241,7 +241,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_cidr_delete_fail_with_peer_inside() -> Result<()> {
+    async fn test_cidr_delete_fail_with_peer_inside() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let experimental_cidr = DatabaseCidr::create(
diff --git a/server/src/api/admin/peer.rs b/server/src/api/admin/peer.rs
index cd32770..98eb3a2 100644
--- a/server/src/api/admin/peer.rs
+++ b/server/src/api/admin/peer.rs
@@ -94,12 +94,11 @@ mod handlers {
 mod tests {
     use super::*;
     use crate::test;
-    use anyhow::Result;
     use bytes::Buf;
-    use shared::Peer;
+    use shared::{Error, Peer};
 
     #[tokio::test]
-    async fn test_add_peer() -> Result<()> {
+    async fn test_add_peer() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let old_peers = DatabasePeer::list(&server.db().lock())?;
@@ -125,21 +124,13 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_add_peer_with_invalid_name() -> Result<()> {
-        let server = test::Server::new()?;
-
-        let peer = test::developer_peer_contents("devel oper", "10.80.64.4")?;
-
-        let res = server
-            .form_request(test::ADMIN_PEER_IP, "POST", "/v1/admin/peers", &peer)
-            .await;
-
-        assert_eq!(res.status(), StatusCode::BAD_REQUEST);
+    async fn test_add_peer_with_invalid_name() -> Result<(), Error> {
+        assert!(test::developer_peer_contents("devel oper", "10.80.64.4").is_err());
         Ok(())
     }
 
     #[tokio::test]
-    async fn test_add_peer_with_duplicate_name() -> Result<()> {
+    async fn test_add_peer_with_duplicate_name() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let old_peers = DatabasePeer::list(&server.db().lock())?;
@@ -161,7 +152,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_add_peer_with_duplicate_ip() -> Result<()> {
+    async fn test_add_peer_with_duplicate_ip() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let old_peers = DatabasePeer::list(&server.db().lock())?;
@@ -183,7 +174,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_add_peer_with_outside_cidr_range_ip() -> Result<()> {
+    async fn test_add_peer_with_outside_cidr_range_ip() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let old_peers = DatabasePeer::list(&server.db().lock())?;
@@ -217,7 +208,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_add_peer_from_non_admin() -> Result<()> {
+    async fn test_add_peer_from_non_admin() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let peer = test::developer_peer_contents("developer3", "10.80.64.4")?;
@@ -233,12 +224,12 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_update_peer_from_admin() -> Result<()> {
+    async fn test_update_peer_from_admin() -> Result<(), Error> {
         let server = test::Server::new()?;
         let old_peer = DatabasePeer::get(&server.db.lock(), test::DEVELOPER1_PEER_ID)?;
 
         let change = PeerContents {
-            name: "new-peer-name".to_string(),
+            name: "new-peer-name".parse()?,
             ..old_peer.contents.clone()
         };
 
@@ -255,12 +246,12 @@ mod tests {
         assert_eq!(res.status(), StatusCode::NO_CONTENT);
 
         let new_peer = DatabasePeer::get(&server.db.lock(), test::DEVELOPER1_PEER_ID)?;
-        assert_eq!(new_peer.name, "new-peer-name");
+        assert_eq!(&*new_peer.name, "new-peer-name");
         Ok(())
     }
 
     #[tokio::test]
-    async fn test_update_peer_from_non_admin() -> Result<()> {
+    async fn test_update_peer_from_non_admin() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let peer = test::developer_peer_contents("developer3", "10.80.64.4")?;
@@ -281,7 +272,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_list_all_peers_from_admin() -> Result<()> {
+    async fn test_list_all_peers_from_admin() -> Result<(), Error> {
         let server = test::Server::new()?;
         let res = server
             .request(test::ADMIN_PEER_IP, "GET", "/v1/admin/peers")
@@ -291,7 +282,7 @@ mod tests {
 
         let whole_body = hyper::body::aggregate(res).await?;
         let peers: Vec<Peer> = serde_json::from_reader(whole_body.reader())?;
-        let peer_names = peers.iter().map(|p| &p.contents.name).collect::<Vec<_>>();
+        let peer_names = peers.iter().map(|p| &*p.contents.name).collect::<Vec<_>>();
         // An admin peer should see all the peers.
         assert_eq!(
             &[
@@ -309,7 +300,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_list_all_peers_from_non_admin() -> Result<()> {
+    async fn test_list_all_peers_from_non_admin() -> Result<(), Error> {
         let server = test::Server::new()?;
         let res = server
             .request(test::DEVELOPER1_PEER_IP, "GET", "/v1/admin/peers")
@@ -321,7 +312,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_delete() -> Result<()> {
+    async fn test_delete() -> Result<(), Error> {
         let server = test::Server::new()?;
         let old_peers = DatabasePeer::list(&server.db().lock())?;
 
@@ -344,7 +335,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_delete_from_non_admin() -> Result<()> {
+    async fn test_delete_from_non_admin() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let old_peers = DatabasePeer::list(&server.db().lock())?;
@@ -367,7 +358,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_delete_unknown_id() -> Result<()> {
+    async fn test_delete_unknown_id() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let res = server
diff --git a/server/src/api/user.rs b/server/src/api/user.rs
index e37948e..ddb0b27 100644
--- a/server/src/api/user.rs
+++ b/server/src/api/user.rs
@@ -80,43 +80,37 @@ mod handlers {
         let old_public_key = wgctrl::Key::from_base64(&selected_peer.public_key)
             .map_err(|_| ServerError::WireGuard)?;
 
-        if selected_peer.is_redeemed {
-            Ok(Response::builder()
-                .status(StatusCode::GONE)
-                .body(Body::empty())?)
-        } else {
-            selected_peer.redeem(&conn, &form.public_key)?;
+        selected_peer.redeem(&conn, &form.public_key)?;
 
-            if cfg!(not(test)) {
-                let interface = session.context.interface;
+        if cfg!(not(test)) {
+            let interface = session.context.interface;
 
-                // If we were to modify the WireGuard interface immediately, the HTTP response wouldn't
-                // get through. Instead, we need to wait a reasonable amount for the HTTP response to
-                // flush, then update the interface.
-                //
-                // The client is also expected to wait the same amount of time after receiving a success
-                // response from /redeem.
-                //
-                // This might be avoidable if we were able to run code after we were certain the response
-                // had flushed over the TCP socket, but that isn't easily accessible from this high-level
-                // web framework.
-                tokio::task::spawn(async move {
-                    tokio::time::sleep(*REDEEM_TRANSITION_WAIT).await;
-                    log::info!(
-                        "WireGuard: adding new peer {}, removing old pubkey {}",
-                        &*selected_peer,
-                        old_public_key.to_base64()
-                    );
-                    DeviceConfigBuilder::new()
-                        .remove_peer_by_key(&old_public_key)
-                        .add_peer((&*selected_peer).into())
-                        .apply(&interface)
-                        .map_err(|e| log::error!("{:?}", e))
-                        .ok();
-                });
-            }
-            status_response(StatusCode::NO_CONTENT)
+            // If we were to modify the WireGuard interface immediately, the HTTP response wouldn't
+            // get through. Instead, we need to wait a reasonable amount for the HTTP response to
+            // flush, then update the interface.
+            //
+            // The client is also expected to wait the same amount of time after receiving a success
+            // response from /redeem.
+            //
+            // This might be avoidable if we were able to run code after we were certain the response
+            // had flushed over the TCP socket, but that isn't easily accessible from this high-level
+            // web framework.
+            tokio::task::spawn(async move {
+                tokio::time::sleep(*REDEEM_TRANSITION_WAIT).await;
+                log::info!(
+                    "WireGuard: adding new peer {}, removing old pubkey {}",
+                    &*selected_peer,
+                    old_public_key.to_base64()
+                );
+                DeviceConfigBuilder::new()
+                    .remove_peer_by_key(&old_public_key)
+                    .add_peer((&*selected_peer).into())
+                    .apply(&interface)
+                    .map_err(|e| log::error!("{:?}", e))
+                    .ok();
+            });
         }
+        status_response(StatusCode::NO_CONTENT)
     }
 
     /// Redeems an invitation. An invitation includes a WireGuard keypair generated by either the server
@@ -147,14 +141,15 @@ mod handlers {
 
 #[cfg(test)]
 mod tests {
+    use std::time::{Duration, SystemTime};
+
     use super::*;
     use crate::{db::DatabaseAssociation, test};
-    use anyhow::Result;
     use bytes::Buf;
-    use shared::{AssociationContents, CidrContents, EndpointContents};
+    use shared::{AssociationContents, CidrContents, EndpointContents, Error};
 
     #[tokio::test]
-    async fn test_get_state_from_developer1() -> Result<()> {
+    async fn test_get_state_from_developer1() -> Result<(), Error> {
         let server = test::Server::new()?;
         let res = server
             .request(test::DEVELOPER1_PEER_IP, "GET", "/v1/user/state")
@@ -164,7 +159,7 @@ mod tests {
 
         let whole_body = hyper::body::aggregate(res).await?;
         let State { peers, .. } = serde_json::from_reader(whole_body.reader())?;
-        let mut peer_names = peers.iter().map(|p| &p.contents.name).collect::<Vec<_>>();
+        let mut peer_names = peers.iter().map(|p| &*p.contents.name).collect::<Vec<_>>();
         peer_names.sort();
         // Developers should see only peers in infra CIDR and developer CIDR.
         assert_eq!(
@@ -176,7 +171,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_override_endpoint() -> Result<()> {
+    async fn test_override_endpoint() -> Result<(), Error> {
         let server = test::Server::new()?;
         assert_eq!(
             server
@@ -222,7 +217,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_list_peers_from_unknown_ip() -> Result<()> {
+    async fn test_list_peers_from_unknown_ip() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         // Request comes from an unknown IP.
@@ -234,7 +229,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_list_peers_for_developer_subcidr() -> Result<()> {
+    async fn test_list_peers_for_developer_subcidr() -> Result<(), Error> {
         let server = test::Server::new()?;
         {
             let db = server.db.lock();
@@ -286,7 +281,7 @@ mod tests {
             assert_eq!(res.status(), StatusCode::OK);
             let whole_body = hyper::body::aggregate(res).await?;
             let State { peers, .. } = serde_json::from_reader(whole_body.reader())?;
-            let mut peer_names = peers.iter().map(|p| &p.contents.name).collect::<Vec<_>>();
+            let mut peer_names = peers.iter().map(|p| &*p.contents.name).collect::<Vec<_>>();
             peer_names.sort();
             // Developers should see only peers in infra CIDR and developer CIDR.
             assert_eq!(
@@ -304,7 +299,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_redeem() -> Result<()> {
+    async fn test_redeem() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let experimental_cidr = DatabaseCidr::create(
@@ -323,6 +318,7 @@ mod tests {
             false,
         )?;
         peer_contents.is_redeemed = false;
+        peer_contents.invite_expires = Some(SystemTime::now() + Duration::from_secs(100));
         let _experiment_peer = DatabasePeer::create(&server.db().lock(), peer_contents)?;
 
         // Step 1: Ensure that before redeeming, other endpoints aren't yet accessible.
@@ -363,4 +359,49 @@ mod tests {
         assert_eq!(res.status(), StatusCode::OK);
         Ok(())
     }
+
+    #[tokio::test]
+    async fn test_redeem_expired() -> Result<(), Error> {
+        let server = test::Server::new()?;
+
+        let experimental_cidr = DatabaseCidr::create(
+            &server.db().lock(),
+            CidrContents {
+                name: "experimental".to_string(),
+                cidr: test::EXPERIMENTAL_CIDR.parse()?,
+                parent: Some(test::ROOT_CIDR_ID),
+            },
+        )?;
+
+        let mut peer_contents = test::peer_contents(
+            "experiment-peer",
+            test::EXPERIMENT_SUBCIDR_PEER_IP,
+            experimental_cidr.id,
+            false,
+        )?;
+        peer_contents.is_redeemed = false;
+        peer_contents.invite_expires = Some(SystemTime::now() - Duration::from_secs(1));
+        let _experiment_peer = DatabasePeer::create(&server.db().lock(), peer_contents)?;
+
+        // Step 1: Ensure that before redeeming, other endpoints aren't yet accessible.
+        let res = server
+            .request(test::EXPERIMENT_SUBCIDR_PEER_IP, "GET", "/v1/user/state")
+            .await;
+        assert_eq!(res.status(), StatusCode::UNAUTHORIZED);
+
+        // Step 2: Ensure that redemption works.
+        let body = RedeemContents {
+            public_key: "YBVIgpfLbi/knrMCTEb0L6eVy0daiZnJJQkxBK9s+2I=".into(),
+        };
+        let res = server
+            .form_request(
+                test::EXPERIMENT_SUBCIDR_PEER_IP,
+                "POST",
+                "/v1/user/redeem",
+                &body,
+            )
+            .await;
+        assert_eq!(res.status(), StatusCode::UNAUTHORIZED);
+        Ok(())
+    }
 }
diff --git a/server/src/db/mod.rs b/server/src/db/mod.rs
index 55087a4..60a7912 100644
--- a/server/src/db/mod.rs
+++ b/server/src/db/mod.rs
@@ -5,3 +5,30 @@ pub mod peer;
 pub use association::DatabaseAssociation;
 pub use cidr::DatabaseCidr;
 pub use peer::DatabasePeer;
+use rusqlite::params;
+
+const INVITE_EXPIRATION_VERSION: usize = 1;
+
+pub const CURRENT_VERSION: usize = INVITE_EXPIRATION_VERSION;
+
+pub fn auto_migrate(conn: &rusqlite::Connection) -> Result<(), rusqlite::Error> {
+    let old_version: usize = conn.pragma_query_value(None, "user_version", |r| r.get(0))?;
+
+    if old_version < INVITE_EXPIRATION_VERSION {
+        conn.execute(
+            "ALTER TABLE peers ADD COLUMN invite_expires INTEGER",
+            params![],
+        )?;
+    }
+
+    conn.pragma_update(None, "user_version", &CURRENT_VERSION)?;
+    if old_version != CURRENT_VERSION {
+        log::info!(
+            "migrated db version from {} to {}",
+            old_version,
+            CURRENT_VERSION
+        );
+    }
+
+    Ok(())
+}
diff --git a/server/src/db/peer.rs b/server/src/db/peer.rs
index 4e755fc..3e1a487 100644
--- a/server/src/db/peer.rs
+++ b/server/src/db/peer.rs
@@ -7,6 +7,7 @@ use shared::{Peer, PeerContents, PERSISTENT_KEEPALIVE_INTERVAL_SECS};
 use std::{
     net::IpAddr,
     ops::{Deref, DerefMut},
+    time::{Duration, SystemTime},
 };
 use structopt::lazy_static;
 
@@ -20,6 +21,7 @@ pub static CREATE_TABLE_SQL: &str = "CREATE TABLE peers (
       is_admin        INTEGER DEFAULT 0 NOT NULL,   /* Admin capabilities are per-peer, not per-CIDR.                   */
       is_disabled     INTEGER DEFAULT 0 NOT NULL,   /* Is the peer disabled? (peers cannot be deleted)                  */
       is_redeemed     INTEGER DEFAULT 0 NOT NULL,   /* Has the peer redeemed their invite yet?                          */
+      invite_expires  INTEGER,                      /* The UNIX time that an invited peer can no longer redeem.         */
       FOREIGN KEY (cidr_id)
          REFERENCES cidrs (id)
             ON UPDATE RESTRICT
@@ -68,6 +70,7 @@ impl DatabasePeer {
             is_admin,
             is_disabled,
             is_redeemed,
+            invite_expires,
             ..
         } = &contents;
         log::info!("creating peer {:?}", contents);
@@ -88,10 +91,15 @@ impl DatabasePeer {
             return Err(ServerError::InvalidQuery);
         }
 
+        let invite_expires = invite_expires
+            .map(|t| t.duration_since(SystemTime::UNIX_EPOCH).ok())
+            .flatten()
+            .map(|t| t.as_secs());
+
         conn.execute(
-            "INSERT INTO peers (name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8)",
+            "INSERT INTO peers (name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed, invite_expires) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9)",
             params![
-                name,
+                &**name,
                 ip.to_string(),
                 cidr_id,
                 &public_key,
@@ -99,6 +107,7 @@ impl DatabasePeer {
                 is_admin,
                 is_disabled,
                 is_redeemed,
+                invite_expires,
             ],
         )?;
         let id = conn.last_insert_rowid();
@@ -137,7 +146,7 @@ impl DatabasePeer {
                 is_disabled = ?4
             WHERE id = ?5",
             params![
-                new_contents.name,
+                &*new_contents.name,
                 new_contents
                     .endpoint
                     .as_ref()
@@ -163,6 +172,14 @@ impl DatabasePeer {
     }
 
     pub fn redeem(&mut self, conn: &Connection, pubkey: &str) -> Result<(), ServerError> {
+        if self.is_redeemed {
+            return Err(ServerError::Gone);
+        }
+
+        if matches!(self.invite_expires, Some(time) if time < SystemTime::now()) {
+            return Err(ServerError::Unauthorized);
+        }
+
         match conn.execute(
             "UPDATE peers SET is_redeemed = 1, public_key = ?1 WHERE id = ?2 AND is_redeemed = 0",
             params![pubkey, self.id],
@@ -178,7 +195,10 @@ impl DatabasePeer {
 
     fn from_row(row: &rusqlite::Row) -> Result<Self, rusqlite::Error> {
         let id = row.get(0)?;
-        let name = row.get(1)?;
+        let name = row
+            .get::<_, String>(1)?
+            .parse()
+            .map_err(|_| rusqlite::Error::ExecuteReturnedResults)?;
         let ip: IpAddr = row
             .get::<_, String>(2)?
             .parse()
@@ -191,6 +211,10 @@ impl DatabasePeer {
         let is_admin = row.get(6)?;
         let is_disabled = row.get(7)?;
         let is_redeemed = row.get(8)?;
+        let invite_expires = row
+            .get::<_, Option<u64>>(9)?
+            .map(|unixtime| SystemTime::UNIX_EPOCH + Duration::from_secs(unixtime));
+
         let persistent_keepalive_interval = Some(PERSISTENT_KEEPALIVE_INTERVAL_SECS);
 
         Ok(Peer {
@@ -205,6 +229,7 @@ impl DatabasePeer {
                 is_admin,
                 is_disabled,
                 is_redeemed,
+                invite_expires,
             },
         }
         .into())
@@ -213,7 +238,7 @@ impl DatabasePeer {
     pub fn get(conn: &Connection, id: i64) -> Result<Self, ServerError> {
         let result = conn.query_row(
             "SELECT
-            id, name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed
+            id, name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed, invite_expires
             FROM peers
             WHERE id = ?1",
             params![id],
@@ -226,7 +251,7 @@ impl DatabasePeer {
     pub fn get_from_ip(conn: &Connection, ip: IpAddr) -> Result<Self, rusqlite::Error> {
         let result = conn.query_row(
             "SELECT
-            id, name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed
+            id, name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed, invite_expires
             FROM peers
             WHERE ip = ?1",
             params![ip.to_string()],
@@ -264,7 +289,7 @@ impl DatabasePeer {
                     UNION
                     SELECT id FROM cidrs, associated_subcidrs WHERE cidrs.parent=associated_subcidrs.cidr_id
                 )
-                SELECT DISTINCT peers.id, peers.name, peers.ip, peers.cidr_id, peers.public_key, peers.endpoint, peers.is_admin, peers.is_disabled, peers.is_redeemed
+                SELECT DISTINCT peers.id, peers.name, peers.ip, peers.cidr_id, peers.public_key, peers.endpoint, peers.is_admin, peers.is_disabled, peers.is_redeemed, peers.invite_expires
                 FROM peers
                 JOIN associated_subcidrs ON peers.cidr_id=associated_subcidrs.cidr_id
                 WHERE peers.is_disabled = 0 AND peers.is_redeemed = 1;",
@@ -277,10 +302,23 @@ impl DatabasePeer {
 
     pub fn list(conn: &Connection) -> Result<Vec<Self>, ServerError> {
         let mut stmt = conn.prepare_cached(
-            "SELECT id, name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed FROM peers",
+            "SELECT id, name, ip, cidr_id, public_key, endpoint, is_admin, is_disabled, is_redeemed, invite_expires FROM peers",
         )?;
         let peer_iter = stmt.query_map(params![], Self::from_row)?;
 
         Ok(peer_iter.collect::<Result<_, _>>()?)
     }
+
+    pub fn delete_expired_invites(conn: &Connection) -> Result<usize, ServerError> {
+        let unix_now = SystemTime::now()
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .expect("Something is horribly wrong with system time.");
+        let deleted = conn.execute(
+            "DELETE FROM peers
+            WHERE is_redeemed = 0 AND invite_expires < ?1",
+            params![unix_now.as_secs()],
+        )?;
+
+        Ok(deleted)
+    }
 }
diff --git a/server/src/endpoints.rs b/server/src/endpoints.rs
deleted file mode 100644
index 852e8c5..0000000
--- a/server/src/endpoints.rs
+++ /dev/null
@@ -1,63 +0,0 @@
-use parking_lot::RwLock;
-use wgctrl::{DeviceInfo, InterfaceName};
-
-use std::{
-    collections::HashMap,
-    io,
-    net::SocketAddr,
-    sync::{
-        mpsc::{sync_channel, SyncSender, TryRecvError},
-        Arc,
-    },
-    thread,
-    time::Duration,
-};
-
-pub struct Endpoints {
-    pub endpoints: Arc<RwLock<HashMap<String, SocketAddr>>>,
-    stop_tx: SyncSender<()>,
-}
-
-impl std::ops::Deref for Endpoints {
-    type Target = RwLock<HashMap<String, SocketAddr>>;
-
-    fn deref(&self) -> &Self::Target {
-        &self.endpoints
-    }
-}
-
-impl Endpoints {
-    pub fn new(iface: &InterfaceName) -> Result<Self, io::Error> {
-        let endpoints = Arc::new(RwLock::new(HashMap::new()));
-        let (stop_tx, stop_rx) = sync_channel(1);
-
-        let iface = iface.to_owned();
-        let thread_endpoints = endpoints.clone();
-        log::info!("spawning endpoint watch thread.");
-        if cfg!(not(test)) {
-            thread::spawn(move || loop {
-                if matches!(stop_rx.try_recv(), Ok(_) | Err(TryRecvError::Disconnected)) {
-                    break;
-                }
-                if let Ok(info) = DeviceInfo::get_by_name(&iface) {
-                    for peer in info.peers {
-                        if let Some(endpoint) = peer.config.endpoint {
-                            thread_endpoints
-                                .write()
-                                .insert(peer.config.public_key.to_base64(), endpoint);
-                        }
-                    }
-                }
-
-                thread::sleep(Duration::from_secs(1));
-            });
-        }
-        Ok(Self { endpoints, stop_tx })
-    }
-}
-
-impl Drop for Endpoints {
-    fn drop(&mut self) {
-        let _ = self.stop_tx.send(());
-    }
-}
diff --git a/server/src/error.rs b/server/src/error.rs
index e3edd2c..16541c4 100644
--- a/server/src/error.rs
+++ b/server/src/error.rs
@@ -14,6 +14,9 @@ pub enum ServerError {
     #[error("invalid query")]
     InvalidQuery,
 
+    #[error("endpoint gone")]
+    Gone,
+
     #[error("internal database error")]
     Database(#[from] rusqlite::Error),
 
@@ -39,6 +42,7 @@ impl<'a> From<&'a ServerError> for StatusCode {
         match error {
             Unauthorized => StatusCode::UNAUTHORIZED,
             NotFound => StatusCode::NOT_FOUND,
+            Gone => StatusCode::GONE,
             InvalidQuery | Json(_) => StatusCode::BAD_REQUEST,
             // Special-case the constraint violation situation.
             Database(rusqlite::Error::SqliteFailure(libsqlite3_sys::Error { code, .. }, ..))
diff --git a/server/src/initialize.rs b/server/src/initialize.rs
index 227d93c..39c4422 100644
--- a/server/src/initialize.rs
+++ b/server/src/initialize.rs
@@ -4,8 +4,7 @@ use dialoguer::{theme::ColorfulTheme, Input};
 use indoc::printdoc;
 use rusqlite::{params, Connection};
 use shared::{
-    prompts::{self, hostname_validator},
-    CidrContents, Endpoint, PeerContents, PERSISTENT_KEEPALIVE_INTERVAL_SECS,
+    prompts, CidrContents, Endpoint, Hostname, PeerContents, PERSISTENT_KEEPALIVE_INTERVAL_SECS,
 };
 use wgctrl::KeyPair;
 
@@ -17,6 +16,8 @@ fn create_database<P: AsRef<Path>>(
     conn.execute(db::peer::CREATE_TABLE_SQL, params![])?;
     conn.execute(db::association::CREATE_TABLE_SQL, params![])?;
     conn.execute(db::cidr::CREATE_TABLE_SQL, params![])?;
+    conn.pragma_update(None, "user_version", &db::CURRENT_VERSION)?;
+
     Ok(conn)
 }
 
@@ -24,7 +25,7 @@ fn create_database<P: AsRef<Path>>(
 pub struct InitializeOpts {
     /// The network name (ex: evilcorp)
     #[structopt(long)]
-    pub network_name: Option<String>,
+    pub network_name: Option<Hostname>,
 
     /// The network CIDR (ex: 10.42.0.0/16)
     #[structopt(long)]
@@ -78,7 +79,7 @@ fn populate_database(conn: &Connection, db_init_data: DbInitData) -> Result<(),
     let _me = DatabasePeer::create(
         &conn,
         PeerContents {
-            name: SERVER_NAME.into(),
+            name: SERVER_NAME.parse()?,
             ip: db_init_data.our_ip,
             cidr_id: server_cidr.id,
             public_key: db_init_data.public_key_base64,
@@ -87,6 +88,7 @@ fn populate_database(conn: &Connection, db_init_data: DbInitData) -> Result<(),
             is_disabled: false,
             is_redeemed: true,
             persistent_keepalive_interval: Some(PERSISTENT_KEEPALIVE_INTERVAL_SECS),
+            invite_expires: None,
         },
     )
     .map_err(|_| "failed to create innernet peer.".to_string())?;
@@ -104,13 +106,12 @@ pub fn init_wizard(conf: &ServerConfig, opts: InitializeOpts) -> Result<(), Erro
         )
     })?;
 
-    let name: String = if let Some(name) = opts.network_name {
+    let name: Hostname = if let Some(name) = opts.network_name {
         name
     } else {
         println!("Here you'll specify the network CIDR, which will encompass the entire network.");
         Input::with_theme(&theme)
             .with_prompt("Network name")
-            .validate_with(hostname_validator)
             .interact()?
     };
 
diff --git a/server/src/main.rs b/server/src/main.rs
index 16762ca..841f47b 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -3,12 +3,12 @@ use dialoguer::Confirm;
 use hyper::{http, server::conn::AddrStream, Body, Request, Response};
 use indoc::printdoc;
 use ipnetwork::IpNetwork;
-use parking_lot::Mutex;
+use parking_lot::{Mutex, RwLock};
 use rusqlite::Connection;
 use serde::{Deserialize, Serialize};
 use shared::{AddCidrOpts, AddPeerOpts, IoErrorContext, INNERNET_PUBKEY_HEADER};
 use std::{
-    collections::VecDeque,
+    collections::{HashMap, VecDeque},
     convert::TryInto,
     env,
     fs::File,
@@ -17,6 +17,7 @@ use std::{
     ops::Deref,
     path::{Path, PathBuf},
     sync::Arc,
+    time::Duration,
 };
 use structopt::StructOpt;
 use subtle::ConstantTimeEq;
@@ -24,7 +25,6 @@ use wgctrl::{DeviceConfigBuilder, DeviceInfo, InterfaceName, Key, PeerConfigBuil
 
 pub mod api;
 pub mod db;
-pub mod endpoints;
 pub mod error;
 #[cfg(test)]
 mod test;
@@ -33,7 +33,6 @@ pub mod util;
 mod initialize;
 
 use db::{DatabaseCidr, DatabasePeer};
-pub use endpoints::Endpoints;
 pub use error::ServerError;
 use initialize::InitializeOpts;
 use shared::{prompts, wg, CidrTree, Error, Interface, SERVER_CONFIG_DIR, SERVER_DATABASE_DIR};
@@ -81,11 +80,12 @@ enum Command {
 }
 
 pub type Db = Arc<Mutex<Connection>>;
+pub type Endpoints = Arc<RwLock<HashMap<String, SocketAddr>>>;
 
 #[derive(Clone)]
 pub struct Context {
     pub db: Db,
-    pub endpoints: Arc<Endpoints>,
+    pub endpoints: Arc<RwLock<HashMap<String, SocketAddr>>>,
     pub interface: InterfaceName,
     pub public_key: Key,
 }
@@ -206,7 +206,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
             }
         },
         Command::Uninstall { interface } => uninstall(&interface, &conf)?,
-        Command::Serve { interface } => serve(&interface, &conf).await?,
+        Command::Serve { interface } => serve(*interface, &conf).await?,
         Command::AddPeer { interface, args } => add_peer(&interface, &conf, args)?,
         Command::AddCidr { interface, args } => add_cidr(&interface, &conf, args)?,
     }
@@ -230,7 +230,7 @@ fn open_database_connection(
     let conn = Connection::open(&database_path)?;
     // Foreign key constraints aren't on in SQLite by default. Enable.
     conn.pragma_update(None, "foreign_keys", &1)?;
-
+    db::auto_migrate(&conn)?;
     Ok(conn)
 }
 
@@ -334,9 +334,45 @@ fn uninstall(interface: &InterfaceName, conf: &ServerConfig) -> Result<(), Error
     Ok(())
 }
 
-async fn serve(interface: &InterfaceName, conf: &ServerConfig) -> Result<(), Error> {
-    let config = ConfigFile::from_file(conf.config_path(interface))?;
-    let conn = open_database_connection(interface, conf)?;
+fn spawn_endpoint_refresher(interface: InterfaceName) -> Endpoints {
+    let endpoints = Arc::new(RwLock::new(HashMap::new()));
+    tokio::task::spawn({
+        let endpoints = endpoints.clone();
+        async move {
+            let mut interval = tokio::time::interval(Duration::from_secs(10));
+            loop {
+                interval.tick().await;
+                if let Ok(info) = DeviceInfo::get_by_name(&interface) {
+                    for peer in info.peers {
+                        if let Some(endpoint) = peer.config.endpoint {
+                            endpoints
+                                .write()
+                                .insert(peer.config.public_key.to_base64(), endpoint);
+                        }
+                    }
+                }
+            }
+        }
+    });
+    endpoints
+}
+
+fn spawn_expired_invite_sweeper(db: Db) {
+    tokio::task::spawn(async move {
+        let mut interval = tokio::time::interval(Duration::from_secs(10));
+        loop {
+            interval.tick().await;
+            match DatabasePeer::delete_expired_invites(&db.lock()) {
+                Ok(deleted) => log::info!("Deleted {} expired peer invitations.", deleted),
+                Err(e) => log::error!("Failed to delete expired peer invitations: {}", e),
+            }
+        }
+    });
+}
+
+async fn serve(interface: InterfaceName, conf: &ServerConfig) -> Result<(), Error> {
+    let config = ConfigFile::from_file(conf.config_path(&interface))?;
+    let conn = open_database_connection(&interface, conf)?;
 
     let peers = DatabasePeer::list(&conn)?;
     let peer_configs = peers
@@ -346,7 +382,7 @@ async fn serve(interface: &InterfaceName, conf: &ServerConfig) -> Result<(), Err
 
     log::info!("bringing up interface.");
     wg::up(
-        interface,
+        &interface,
         &config.private_key,
         IpNetwork::new(config.address, config.network_cidr_prefix)?,
         Some(config.listen_port),
@@ -357,22 +393,23 @@ async fn serve(interface: &InterfaceName, conf: &ServerConfig) -> Result<(), Err
         .add_peers(&peer_configs)
         .apply(&interface)?;
 
-    let endpoints = Arc::new(Endpoints::new(&interface)?);
-
     log::info!("{} peers added to wireguard interface.", peers.len());
 
     let public_key = wgctrl::Key::from_base64(&config.private_key)?.generate_public();
     let db = Arc::new(Mutex::new(conn));
+    let endpoints = spawn_endpoint_refresher(interface);
+    spawn_expired_invite_sweeper(db.clone());
+
     let context = Context {
         db,
-        interface: *interface,
+        interface,
         endpoints,
         public_key,
     };
 
     log::info!("innernet-server {} starting.", VERSION);
 
-    let listener = get_listener((config.address, config.listen_port).into(), interface)?;
+    let listener = get_listener((config.address, config.listen_port).into(), &interface)?;
 
     let make_svc = hyper::service::make_service_fn(move |socket: &AddrStream| {
         let remote_addr = socket.remote_addr();
@@ -492,7 +529,7 @@ mod tests {
     use std::path::Path;
 
     #[test]
-    fn test_init_wizard() -> Result<()> {
+    fn test_init_wizard() -> Result<(), Error> {
         // This runs init_wizard().
         let server = test::Server::new()?;
 
@@ -502,7 +539,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_with_session_disguised_with_headers() -> Result<()> {
+    async fn test_with_session_disguised_with_headers() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let req = Request::builder()
@@ -525,7 +562,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_incorrect_public_key() -> Result<()> {
+    async fn test_incorrect_public_key() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let key = Key::generate_private().generate_public();
@@ -547,7 +584,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_unparseable_public_key() -> Result<()> {
+    async fn test_unparseable_public_key() -> Result<(), Error> {
         let server = test::Server::new()?;
 
         let req = Request::builder()
diff --git a/server/src/test.rs b/server/src/test.rs
index 3a6804e..943b543 100644
--- a/server/src/test.rs
+++ b/server/src/test.rs
@@ -1,17 +1,16 @@
 #![allow(dead_code)]
 use crate::{
     db::{DatabaseCidr, DatabasePeer},
-    endpoints::Endpoints,
     initialize::{init_wizard, InitializeOpts},
-    Context, ServerConfig,
+    Context, Db, Endpoints, ServerConfig,
 };
-use anyhow::{anyhow, Result};
+use anyhow::anyhow;
 use hyper::{header::HeaderValue, http, Body, Request, Response};
-use parking_lot::Mutex;
+use parking_lot::{Mutex, RwLock};
 use rusqlite::Connection;
 use serde::Serialize;
-use shared::{Cidr, CidrContents, PeerContents};
-use std::{net::SocketAddr, path::PathBuf, sync::Arc};
+use shared::{Cidr, CidrContents, Error, PeerContents};
+use std::{collections::HashMap, net::SocketAddr, path::PathBuf, sync::Arc};
 use tempfile::TempDir;
 use wgctrl::{InterfaceName, Key, KeyPair};
 
@@ -44,8 +43,8 @@ pub const USER1_PEER_ID: i64 = 5;
 pub const USER2_PEER_ID: i64 = 6;
 
 pub struct Server {
-    pub db: Arc<Mutex<Connection>>,
-    endpoints: Arc<Endpoints>,
+    pub db: Db,
+    endpoints: Endpoints,
     interface: InterfaceName,
     conf: ServerConfig,
     public_key: Key,
@@ -54,7 +53,7 @@ pub struct Server {
 }
 
 impl Server {
-    pub fn new() -> Result<Self> {
+    pub fn new() -> Result<Self, Error> {
         let test_dir = tempfile::tempdir()?;
         let test_dir_path = test_dir.path();
 
@@ -68,7 +67,7 @@ impl Server {
         };
 
         let opts = InitializeOpts {
-            network_name: Some(interface.clone()),
+            network_name: Some(interface.parse()?),
             network_cidr: Some(ROOT_CIDR.parse()?),
             external_endpoint: Some("155.155.155.155:54321".parse().unwrap()),
             listen_port: Some(54321),
@@ -116,7 +115,7 @@ impl Server {
         );
 
         let db = Arc::new(Mutex::new(db));
-        let endpoints = Arc::new(Endpoints::new(&interface)?);
+        let endpoints = Arc::new(RwLock::new(HashMap::new()));
 
         Ok(Self {
             conf,
@@ -192,7 +191,7 @@ impl Server {
     }
 }
 
-pub fn create_cidr(db: &Connection, name: &str, cidr_str: &str) -> Result<Cidr> {
+pub fn create_cidr(db: &Connection, name: &str, cidr_str: &str) -> Result<Cidr, Error> {
     let cidr = DatabaseCidr::create(
         db,
         CidrContents {
@@ -214,11 +213,11 @@ pub fn peer_contents(
     ip_str: &str,
     cidr_id: i64,
     is_admin: bool,
-) -> Result<PeerContents> {
+) -> Result<PeerContents, Error> {
     let public_key = KeyPair::generate().public;
 
     Ok(PeerContents {
-        name: name.to_string(),
+        name: name.parse()?,
         ip: ip_str.parse()?,
         cidr_id,
         public_key: public_key.to_base64(),
@@ -227,21 +226,22 @@ pub fn peer_contents(
         persistent_keepalive_interval: None,
         is_disabled: false,
         is_redeemed: true,
+        invite_expires: None,
     })
 }
 
-pub fn admin_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents> {
+pub fn admin_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents, Error> {
     peer_contents(name, ip_str, ADMIN_CIDR_ID, true)
 }
 
-pub fn infra_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents> {
+pub fn infra_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents, Error> {
     peer_contents(name, ip_str, INFRA_CIDR_ID, false)
 }
 
-pub fn developer_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents> {
+pub fn developer_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents, Error> {
     peer_contents(name, ip_str, DEVELOPER_CIDR_ID, false)
 }
 
-pub fn user_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents> {
+pub fn user_peer_contents(name: &str, ip_str: &str) -> Result<PeerContents, Error> {
     peer_contents(name, ip_str, USER_CIDR_ID, false)
 }
diff --git a/shared/src/prompts.rs b/shared/src/prompts.rs
index 630b5e9..e278db6 100644
--- a/shared/src/prompts.rs
+++ b/shared/src/prompts.rs
@@ -7,29 +7,14 @@ use colored::*;
 use dialoguer::{theme::ColorfulTheme, Confirm, Input, Select};
 use ipnetwork::IpNetwork;
 use lazy_static::lazy_static;
-use regex::Regex;
-use std::net::{IpAddr, SocketAddr};
+use std::{
+    net::{IpAddr, SocketAddr},
+    time::SystemTime,
+};
 use wgctrl::{InterfaceName, KeyPair};
 
 lazy_static! {
     pub static ref THEME: ColorfulTheme = ColorfulTheme::default();
-
-    /// Regex to match the requirements of hostname(7), needed to have peers also be reachable hostnames.
-    /// Note that the full length also must be maximum 63 characters, which this regex does not check.
-    static ref PEER_NAME_REGEX: Regex = Regex::new(r"^([a-z0-9]-?)*[a-z0-9]$").unwrap();
-}
-
-pub fn is_valid_hostname(name: &str) -> bool {
-    name.len() < 64 && PEER_NAME_REGEX.is_match(name)
-}
-
-#[allow(clippy::ptr_arg)]
-pub fn hostname_validator(name: &String) -> Result<(), &'static str> {
-    if is_valid_hostname(name) {
-        Ok(())
-    } else {
-        Err("not a valid hostname")
-    }
 }
 
 /// Bring up a prompt to create a new CIDR. Returns the peer request.
@@ -200,10 +185,7 @@ pub fn add_peer(
     let name = if let Some(ref name) = args.name {
         name.clone()
     } else {
-        Input::with_theme(&*THEME)
-            .with_prompt("Name")
-            .validate_with(hostname_validator)
-            .interact()?
+        Input::with_theme(&*THEME).with_prompt("Name").interact()?
     };
 
     let is_admin = if let Some(is_admin) = args.admin {
@@ -215,6 +197,15 @@ pub fn add_peer(
             .interact()?
     };
 
+    let invite_expires = if let Some(ref invite_expires) = args.invite_expires {
+        invite_expires.clone()
+    } else {
+        Input::with_theme(&*THEME)
+            .with_prompt("Invite expires after")
+            .default("14d".parse()?)
+            .interact()?
+    };
+
     let default_keypair = KeyPair::generate();
     let peer_request = PeerContents {
         name,
@@ -226,6 +217,7 @@ pub fn add_peer(
         is_disabled: false,
         is_redeemed: false,
         persistent_keepalive_interval: Some(PERSISTENT_KEEPALIVE_INTERVAL_SECS),
+        invite_expires: Some(SystemTime::now() + invite_expires.into()),
     };
 
     Ok(
diff --git a/shared/src/types.rs b/shared/src/types.rs
index d7f9d0f..f3fb01f 100644
--- a/shared/src/types.rs
+++ b/shared/src/types.rs
@@ -1,5 +1,6 @@
-use crate::prompts::hostname_validator;
 use ipnetwork::IpNetwork;
+use lazy_static::lazy_static;
+use regex::Regex;
 use serde::{Deserialize, Serialize};
 use std::{
     fmt::{self, Display, Formatter},
@@ -7,6 +8,7 @@ use std::{
     ops::Deref,
     path::Path,
     str::FromStr,
+    time::{Duration, SystemTime},
     vec,
 };
 use structopt::StructOpt;
@@ -22,8 +24,9 @@ impl FromStr for Interface {
     type Err = String;
 
     fn from_str(name: &str) -> Result<Self, Self::Err> {
-        let name = name.to_string();
-        hostname_validator(&name)?;
+        if !Hostname::is_valid(name) {
+            return Err("interface name is not a valid hostname".into());
+        }
         let name = name
             .parse()
             .map_err(|e: InvalidInterfaceName| e.to_string())?;
@@ -284,7 +287,7 @@ pub struct InstallOpts {
 pub struct AddPeerOpts {
     /// Name of new peer
     #[structopt(long)]
-    pub name: Option<String>,
+    pub name: Option<Hostname>,
 
     /// Specify desired IP of new peer (within parent CIDR)
     #[structopt(long, conflicts_with = "auto-ip")]
@@ -309,6 +312,10 @@ pub struct AddPeerOpts {
     /// Save the config to the given location
     #[structopt(long)]
     pub save_config: Option<String>,
+
+    /// Invite expiration period (eg. "30d", "7w", "2h", "60m", "1000s")
+    #[structopt(long)]
+    pub invite_expires: Option<Timestring>,
 }
 
 #[derive(Debug, Clone, PartialEq, StructOpt)]
@@ -341,7 +348,7 @@ pub struct AddAssociationOpts {
 
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
 pub struct PeerContents {
-    pub name: String,
+    pub name: Hostname,
     pub ip: IpAddr,
     pub cidr_id: i64,
     pub public_key: String,
@@ -350,6 +357,7 @@ pub struct PeerContents {
     pub is_admin: bool,
     pub is_disabled: bool,
     pub is_redeemed: bool,
+    pub invite_expires: Option<SystemTime>,
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
@@ -481,6 +489,93 @@ pub struct State {
     pub cidrs: Vec<Cidr>,
 }
 
+#[derive(Clone, Debug, PartialEq)]
+pub struct Timestring {
+    timestring: String,
+    seconds: u64,
+}
+
+impl Display for Timestring {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(&self.timestring)
+    }
+}
+
+impl FromStr for Timestring {
+    type Err = &'static str;
+
+    fn from_str(timestring: &str) -> Result<Self, Self::Err> {
+        if timestring.len() < 2 {
+            Err("timestring isn't long enough!")
+        } else {
+            let (n, suffix) = timestring.split_at(timestring.len() - 1);
+            let n: u64 = n.parse().map_err(|_| {
+                "invalid timestring (a number followed by a time unit character, eg. '15m')"
+            })?;
+            let multiplier = match suffix {
+                "s" => Ok(1),
+                "m" => Ok(60),
+                "h" => Ok(60 * 60),
+                "d" => Ok(60 * 60 * 24),
+                "w" => Ok(60 * 60 * 24 * 7),
+                _ => Err("invalid timestring suffix (must be one of 's', 'm', 'h', 'd', or 'w')"),
+            }?;
+
+            Ok(Self {
+                timestring: timestring.to_string(),
+                seconds: n * multiplier,
+            })
+        }
+    }
+}
+
+impl From<Timestring> for Duration {
+    fn from(timestring: Timestring) -> Self {
+        Duration::from_secs(timestring.seconds)
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct Hostname(String);
+
+lazy_static! {
+    /// Regex to match the requirements of hostname(7), needed to have peers also be reachable hostnames.
+    /// Note that the full length also must be maximum 63 characters, which this regex does not check.
+    static ref HOSTNAME_REGEX: Regex = Regex::new(r"^([a-z0-9]-?)*[a-z0-9]$").unwrap();
+}
+
+impl Hostname {
+    pub fn is_valid(name: &str) -> bool {
+        name.len() < 64 && HOSTNAME_REGEX.is_match(name)
+    }
+}
+
+impl FromStr for Hostname {
+    type Err = &'static str;
+
+    fn from_str(name: &str) -> Result<Self, Self::Err> {
+        if Self::is_valid(name) {
+            Ok(Self(name.to_string()))
+        } else {
+            Err("invalid hostname")
+        }
+    }
+}
+
+impl Deref for Hostname {
+    type Target = str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Display for Hostname {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
 pub trait IoErrorContext<T> {
     fn with_path<P: AsRef<Path>>(self, path: P) -> Result<T, WrappedIoError>;
     fn with_str<S: Into<String>>(self, context: S) -> Result<T, WrappedIoError>;
@@ -526,7 +621,7 @@ mod tests {
         let peer = Peer {
             id: 1,
             contents: PeerContents {
-                name: "peer1".to_owned(),
+                name: "peer1".parse().unwrap(),
                 ip,
                 cidr_id: 1,
                 public_key: PUBKEY.to_owned(),
@@ -535,6 +630,7 @@ mod tests {
                 is_admin: false,
                 is_disabled: false,
                 is_redeemed: true,
+                invite_expires: None,
             },
         };
         let builder =
@@ -552,7 +648,7 @@ mod tests {
         let peer = Peer {
             id: 1,
             contents: PeerContents {
-                name: "peer1".to_owned(),
+                name: "peer1".parse().unwrap(),
                 ip,
                 cidr_id: 1,
                 public_key: PUBKEY.to_owned(),
@@ -561,6 +657,7 @@ mod tests {
                 is_admin: false,
                 is_disabled: false,
                 is_redeemed: true,
+                invite_expires: None,
             },
         };
         let builder =