diff --git a/Cargo.lock b/Cargo.lock
index 6546590f6c..5639665758 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3643,6 +3643,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sha2",
+ "smol_str",
  "socket2 0.5.3",
  "sync_wrapper",
  "task-local-extensions",
@@ -4709,6 +4710,15 @@ version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "62bb4feee49fdd9f707ef802e22365a35de4b7b299de4763d44bfea899442ff9"
 
+[[package]]
+name = "smol_str"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "74212e6bbe9a4352329b2f68ba3130c15a3f26fe88ff22dbdc6cdd58fa85e99c"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "socket2"
 version = "0.4.9"
diff --git a/Cargo.toml b/Cargo.toml
index cbcb25359d..ba8b49c0e0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -132,6 +132,7 @@ serde_assert = "0.5.0"
 sha2 = "0.10.2"
 signal-hook = "0.3"
 smallvec = "1.11"
+smol_str = { version = "0.2.0", features = ["serde"] }
 socket2 = "0.5"
 strum = "0.24"
 strum_macros = "0.24"
diff --git a/proxy/Cargo.toml b/proxy/Cargo.toml
index 0822718bae..48c8604d86 100644
--- a/proxy/Cargo.toml
+++ b/proxy/Cargo.toml
@@ -69,6 +69,7 @@ webpki-roots.workspace = true
 x509-parser.workspace = true
 native-tls.workspace = true
 postgres-native-tls.workspace = true
+smol_str.workspace = true
 
 workspace_hack.workspace = true
 tokio-util.workspace = true
diff --git a/proxy/src/auth/backend/link.rs b/proxy/src/auth/backend/link.rs
index da43cf11c4..3a77d7e5ca 100644
--- a/proxy/src/auth/backend/link.rs
+++ b/proxy/src/auth/backend/link.rs
@@ -106,7 +106,7 @@ pub(super) async fn authenticate(
         reported_auth_ok: true,
         value: NodeInfo {
             config,
-            aux: db_info.aux.into(),
+            aux: db_info.aux,
             allow_self_signed_compute: false, // caller may override
         },
     })
diff --git a/proxy/src/bin/pg_sni_router.rs b/proxy/src/bin/pg_sni_router.rs
index 2b859fc2db..bedbdbcc83 100644
--- a/proxy/src/bin/pg_sni_router.rs
+++ b/proxy/src/bin/pg_sni_router.rs
@@ -284,5 +284,5 @@ async fn handle_client(
     let client = tokio::net::TcpStream::connect(destination).await?;
 
     let metrics_aux: MetricsAuxInfo = Default::default();
-    proxy::proxy::proxy_pass(tls_stream, client, &metrics_aux).await
+    proxy::proxy::proxy_pass(tls_stream, client, metrics_aux).await
 }
diff --git a/proxy/src/console/messages.rs b/proxy/src/console/messages.rs
index e5f1615b14..837379b21f 100644
--- a/proxy/src/console/messages.rs
+++ b/proxy/src/console/messages.rs
@@ -1,4 +1,5 @@
 use serde::Deserialize;
+use smol_str::SmolStr;
 use std::fmt;
 
 /// Generic error response with human-readable description.
@@ -88,11 +89,11 @@ impl fmt::Debug for DatabaseInfo {
 
 /// Various labels for prometheus metrics.
 /// Also known as `ProxyMetricsAuxInfo` in the console.
-#[derive(Debug, Deserialize, Default)]
+#[derive(Debug, Deserialize, Clone, Default)]
 pub struct MetricsAuxInfo {
-    pub endpoint_id: Box<str>,
-    pub project_id: Box<str>,
-    pub branch_id: Box<str>,
+    pub endpoint_id: SmolStr,
+    pub project_id: SmolStr,
+    pub branch_id: SmolStr,
 }
 
 impl MetricsAuxInfo {
diff --git a/proxy/src/console/provider.rs b/proxy/src/console/provider.rs
index a525de8e53..e735b9f66c 100644
--- a/proxy/src/console/provider.rs
+++ b/proxy/src/console/provider.rs
@@ -229,7 +229,7 @@ pub struct NodeInfo {
     pub config: compute::ConnCfg,
 
     /// Labels for proxy's metrics.
-    pub aux: Arc<MetricsAuxInfo>,
+    pub aux: MetricsAuxInfo,
 
     /// Whether we should accept self-signed certificates (for testing)
     pub allow_self_signed_compute: bool,
diff --git a/proxy/src/console/provider/neon.rs b/proxy/src/console/provider/neon.rs
index 117d0ec190..7828a7d7e4 100644
--- a/proxy/src/console/provider/neon.rs
+++ b/proxy/src/console/provider/neon.rs
@@ -144,7 +144,7 @@ impl Api {
 
             let node = NodeInfo {
                 config,
-                aux: body.aux.into(),
+                aux: body.aux,
                 allow_self_signed_compute: false,
             };
 
diff --git a/proxy/src/proxy.rs b/proxy/src/proxy.rs
index c4bea13f7f..36d01f9acc 100644
--- a/proxy/src/proxy.rs
+++ b/proxy/src/proxy.rs
@@ -877,11 +877,11 @@ async fn prepare_client_connection(
 pub async fn proxy_pass(
     client: impl AsyncRead + AsyncWrite + Unpin,
     compute: impl AsyncRead + AsyncWrite + Unpin,
-    aux: &MetricsAuxInfo,
+    aux: MetricsAuxInfo,
 ) -> anyhow::Result<()> {
     let usage = USAGE_METRICS.register(Ids {
-        endpoint_id: aux.endpoint_id.to_string(),
-        branch_id: aux.branch_id.to_string(),
+        endpoint_id: aux.endpoint_id.clone(),
+        branch_id: aux.branch_id.clone(),
     });
 
     let m_sent = NUM_BYTES_PROXIED_COUNTER.with_label_values(&["tx"]);
@@ -1032,7 +1032,7 @@ impl<S: AsyncRead + AsyncWrite + Unpin> Client<'_, S> {
         // immediately after opening the connection.
         let (stream, read_buf) = stream.into_inner();
         node.stream.write_all(&read_buf).await?;
-        proxy_pass(stream, node.stream, &aux).await
+        proxy_pass(stream, node.stream, aux).await
     }
 }
 
diff --git a/proxy/src/serverless/conn_pool.rs b/proxy/src/serverless/conn_pool.rs
index 2072cadc3a..ca7a9ad0a0 100644
--- a/proxy/src/serverless/conn_pool.rs
+++ b/proxy/src/serverless/conn_pool.rs
@@ -8,6 +8,7 @@ use pbkdf2::{
     Params, Pbkdf2,
 };
 use pq_proto::StartupMessageParams;
+use smol_str::SmolStr;
 use std::{collections::HashMap, net::SocketAddr, sync::Arc};
 use std::{
     fmt,
@@ -41,16 +42,16 @@ const MAX_CONNS_PER_ENDPOINT: usize = 20;
 
 #[derive(Debug, Clone)]
 pub struct ConnInfo {
-    pub username: String,
-    pub dbname: String,
-    pub hostname: String,
-    pub password: String,
-    pub options: Option<String>,
+    pub username: SmolStr,
+    pub dbname: SmolStr,
+    pub hostname: SmolStr,
+    pub password: SmolStr,
+    pub options: Option<SmolStr>,
 }
 
 impl ConnInfo {
     // hm, change to hasher to avoid cloning?
-    pub fn db_and_user(&self) -> (String, String) {
+    pub fn db_and_user(&self) -> (SmolStr, SmolStr) {
         (self.dbname.clone(), self.username.clone())
     }
 }
@@ -70,7 +71,7 @@ struct ConnPoolEntry {
 // Per-endpoint connection pool, (dbname, username) -> DbUserConnPool
 // Number of open connections is limited by the `max_conns_per_endpoint`.
 pub struct EndpointConnPool {
-    pools: HashMap<(String, String), DbUserConnPool>,
+    pools: HashMap<(SmolStr, SmolStr), DbUserConnPool>,
     total_conns: usize,
 }
 
@@ -95,7 +96,7 @@ pub struct GlobalConnPool {
     //
     // That should be a fairly conteded map, so return reference to the per-endpoint
     // pool as early as possible and release the lock.
-    global_pool: DashMap<String, Arc<RwLock<EndpointConnPool>>>,
+    global_pool: DashMap<SmolStr, Arc<RwLock<EndpointConnPool>>>,
 
     /// [`DashMap::len`] iterates over all inner pools and acquires a read lock on each.
     /// That seems like far too much effort, so we're using a relaxed increment counter instead.
@@ -327,7 +328,7 @@ impl GlobalConnPool {
         Ok(())
     }
 
-    fn get_or_create_endpoint_pool(&self, endpoint: &String) -> Arc<RwLock<EndpointConnPool>> {
+    fn get_or_create_endpoint_pool(&self, endpoint: &SmolStr) -> Arc<RwLock<EndpointConnPool>> {
         // fast path
         if let Some(pool) = self.global_pool.get(endpoint) {
             return pool.clone();
@@ -468,7 +469,7 @@ async fn connect_to_compute_once(
 
     let (client, mut connection) = config
         .user(&conn_info.username)
-        .password(&conn_info.password)
+        .password(&*conn_info.password)
         .dbname(&conn_info.dbname)
         .connect_timeout(timeout)
         .connect(tokio_postgres::NoTls)
@@ -482,8 +483,8 @@ async fn connect_to_compute_once(
         info!(%conn_info, %session, "new connection");
     });
     let ids = Ids {
-        endpoint_id: node_info.aux.endpoint_id.to_string(),
-        branch_id: node_info.aux.branch_id.to_string(),
+        endpoint_id: node_info.aux.endpoint_id.clone(),
+        branch_id: node_info.aux.branch_id.clone(),
     };
 
     tokio::spawn(
diff --git a/proxy/src/serverless/sql_over_http.rs b/proxy/src/serverless/sql_over_http.rs
index 25b96668de..6c337a837c 100644
--- a/proxy/src/serverless/sql_over_http.rs
+++ b/proxy/src/serverless/sql_over_http.rs
@@ -182,16 +182,16 @@ fn get_conn_info(
 
     for (key, value) in pairs {
         if key == "options" {
-            options = Some(value.to_string());
+            options = Some(value.into());
             break;
         }
     }
 
     Ok(ConnInfo {
-        username: username.to_owned(),
-        dbname: dbname.to_owned(),
-        hostname: hostname.to_owned(),
-        password: password.to_owned(),
+        username: username.into(),
+        dbname: dbname.into(),
+        hostname: hostname.into(),
+        password: password.into(),
         options,
     })
 }
diff --git a/proxy/src/usage_metrics.rs b/proxy/src/usage_metrics.rs
index 180b5f7199..789a4c680c 100644
--- a/proxy/src/usage_metrics.rs
+++ b/proxy/src/usage_metrics.rs
@@ -6,6 +6,7 @@ use consumption_metrics::{idempotency_key, Event, EventChunk, EventType, CHUNK_S
 use dashmap::{mapref::entry::Entry, DashMap};
 use once_cell::sync::Lazy;
 use serde::{Deserialize, Serialize};
+use smol_str::SmolStr;
 use std::{
     convert::Infallible,
     sync::{
@@ -29,8 +30,8 @@ const DEFAULT_HTTP_REPORTING_TIMEOUT: Duration = Duration::from_secs(60);
 /// because we enrich the event with project_id in the control-plane endpoint.
 #[derive(Eq, Hash, PartialEq, Serialize, Deserialize, Debug, Clone)]
 pub struct Ids {
-    pub endpoint_id: String,
-    pub branch_id: String,
+    pub endpoint_id: SmolStr,
+    pub branch_id: SmolStr,
 }
 
 #[derive(Debug)]
@@ -290,8 +291,8 @@ mod tests {
 
         // register a new counter
         let counter = metrics.register(Ids {
-            endpoint_id: "e1".to_string(),
-            branch_id: "b1".to_string(),
+            endpoint_id: "e1".into(),
+            branch_id: "b1".into(),
         });
 
         // the counter should be observed despite 0 egress