diff --git a/proxy/src/auth.rs b/proxy/src/auth.rs
index dfea84953b..58dceb3bb6 100644
--- a/proxy/src/auth.rs
+++ b/proxy/src/auth.rs
@@ -7,6 +7,7 @@ mod credentials;
 pub use credentials::ClientCredentials;
 
 mod password_hack;
+pub use password_hack::parse_endpoint_param;
 use password_hack::PasswordHackPayload;
 
 mod flow;
@@ -44,10 +45,10 @@ pub enum AuthErrorImpl {
     #[error(
         "Endpoint ID is not specified. \
         Either please upgrade the postgres client library (libpq) for SNI support \
-        or pass the endpoint ID (first part of the domain name) as a parameter: '?options=project%3D<endpoint-id>'. \
+        or pass the endpoint ID (first part of the domain name) as a parameter: '?options=endpoint%3D<endpoint-id>'. \
         See more at https://neon.tech/sni"
     )]
-    MissingProjectName,
+    MissingEndpointName,
 
     #[error("password authentication failed for user '{0}'")]
     AuthFailed(Box<str>),
@@ -88,7 +89,7 @@ impl UserFacingError for AuthError {
             AuthFailed(_) => self.to_string(),
             BadAuthMethod(_) => self.to_string(),
             MalformedPassword(_) => self.to_string(),
-            MissingProjectName => self.to_string(),
+            MissingEndpointName => self.to_string(),
             Io(_) => "Internal error".to_string(),
         }
     }
diff --git a/proxy/src/auth/backend/hacks.rs b/proxy/src/auth/backend/hacks.rs
index d45806461e..dcc93ec04c 100644
--- a/proxy/src/auth/backend/hacks.rs
+++ b/proxy/src/auth/backend/hacks.rs
@@ -52,8 +52,8 @@ pub async fn password_hack(
         .authenticate()
         .await?;
 
-    info!(project = &payload.project, "received missing parameter");
-    creds.project = Some(payload.project);
+    info!(project = &payload.endpoint, "received missing parameter");
+    creds.project = Some(payload.endpoint);
 
     let mut node = api.wake_compute(extra, creds).await?;
     node.config.password(payload.password);
diff --git a/proxy/src/auth/credentials.rs b/proxy/src/auth/credentials.rs
index b21cd79ddf..6787d82b71 100644
--- a/proxy/src/auth/credentials.rs
+++ b/proxy/src/auth/credentials.rs
@@ -1,6 +1,7 @@
 //! User credentials used in authentication.
 
-use crate::error::UserFacingError;
+use crate::{auth::password_hack::parse_endpoint_param, error::UserFacingError};
+use itertools::Itertools;
 use pq_proto::StartupMessageParams;
 use std::collections::HashSet;
 use thiserror::Error;
@@ -61,7 +62,15 @@ impl<'a> ClientCredentials<'a> {
         // Project name might be passed via PG's command-line options.
         let project_option = params
             .options_raw()
-            .and_then(|mut options| options.find_map(|opt| opt.strip_prefix("project=")))
+            .and_then(|options| {
+                // We support both `project` (deprecated) and `endpoint` options for backward compatibility.
+                // However, if both are present, we don't exactly know which one to use.
+                // Therefore we require that only one of them is present.
+                options
+                    .filter_map(parse_endpoint_param)
+                    .at_most_one()
+                    .ok()?
+            })
             .map(|name| name.to_string());
 
         let project_from_domain = if let Some(sni_str) = sni {
@@ -177,6 +186,51 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn parse_endpoint_from_options() -> anyhow::Result<()> {
+        let options = StartupMessageParams::new([
+            ("user", "john_doe"),
+            ("options", "-ckey=1 endpoint=bar -c geqo=off"),
+        ]);
+
+        let creds = ClientCredentials::parse(&options, None, None)?;
+        assert_eq!(creds.user, "john_doe");
+        assert_eq!(creds.project.as_deref(), Some("bar"));
+
+        Ok(())
+    }
+
+    #[test]
+    fn parse_three_endpoints_from_options() -> anyhow::Result<()> {
+        let options = StartupMessageParams::new([
+            ("user", "john_doe"),
+            (
+                "options",
+                "-ckey=1 endpoint=one endpoint=two endpoint=three -c geqo=off",
+            ),
+        ]);
+
+        let creds = ClientCredentials::parse(&options, None, None)?;
+        assert_eq!(creds.user, "john_doe");
+        assert!(creds.project.is_none());
+
+        Ok(())
+    }
+
+    #[test]
+    fn parse_when_endpoint_and_project_are_in_options() -> anyhow::Result<()> {
+        let options = StartupMessageParams::new([
+            ("user", "john_doe"),
+            ("options", "-ckey=1 endpoint=bar project=foo -c geqo=off"),
+        ]);
+
+        let creds = ClientCredentials::parse(&options, None, None)?;
+        assert_eq!(creds.user, "john_doe");
+        assert!(creds.project.is_none());
+
+        Ok(())
+    }
+
     #[test]
     fn parse_projects_identical() -> anyhow::Result<()> {
         let options = StartupMessageParams::new([("user", "john_doe"), ("options", "project=baz")]);
diff --git a/proxy/src/auth/flow.rs b/proxy/src/auth/flow.rs
index 4b982c0c5e..190abc9b2e 100644
--- a/proxy/src/auth/flow.rs
+++ b/proxy/src/auth/flow.rs
@@ -91,7 +91,7 @@ impl<S: AsyncRead + AsyncWrite + Unpin> AuthFlow<'_, S, PasswordHack> {
             // the user neither enabled SNI nor resorted to any other method
             // for passing the project name we rely on. We should show them
             // the most helpful error message and point to the documentation.
-            .ok_or(AuthErrorImpl::MissingProjectName)?;
+            .ok_or(AuthErrorImpl::MissingEndpointName)?;
 
         Ok(payload)
     }
diff --git a/proxy/src/auth/password_hack.rs b/proxy/src/auth/password_hack.rs
index 639809e18a..33441e8c88 100644
--- a/proxy/src/auth/password_hack.rs
+++ b/proxy/src/auth/password_hack.rs
@@ -6,27 +6,55 @@
 use bstr::ByteSlice;
 
 pub struct PasswordHackPayload {
-    pub project: String,
+    pub endpoint: String,
     pub password: Vec<u8>,
 }
 
 impl PasswordHackPayload {
     pub fn parse(bytes: &[u8]) -> Option<Self> {
         // The format is `project=<utf-8>;<password-bytes>`.
-        let mut iter = bytes.strip_prefix(b"project=")?.splitn_str(2, ";");
-        let project = iter.next()?.to_str().ok()?.to_owned();
+        let mut iter = bytes.splitn_str(2, ";");
+        let endpoint = iter.next()?.to_str().ok()?;
+        let endpoint = parse_endpoint_param(endpoint)?.to_owned();
         let password = iter.next()?.to_owned();
 
-        Some(Self { project, password })
+        Some(Self { endpoint, password })
     }
 }
 
+pub fn parse_endpoint_param(bytes: &str) -> Option<&str> {
+    bytes
+        .strip_prefix("project=")
+        .or_else(|| bytes.strip_prefix("endpoint="))
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
     #[test]
-    fn parse_password_hack_payload() {
+    fn parse_endpoint_param_fn() {
+        let input = "";
+        assert!(parse_endpoint_param(input).is_none());
+
+        let input = "project=";
+        assert_eq!(parse_endpoint_param(input), Some(""));
+
+        let input = "project=foobar";
+        assert_eq!(parse_endpoint_param(input), Some("foobar"));
+
+        let input = "endpoint=";
+        assert_eq!(parse_endpoint_param(input), Some(""));
+
+        let input = "endpoint=foobar";
+        assert_eq!(parse_endpoint_param(input), Some("foobar"));
+
+        let input = "other_option=foobar";
+        assert!(parse_endpoint_param(input).is_none());
+    }
+
+    #[test]
+    fn parse_password_hack_payload_project() {
         let bytes = b"";
         assert!(PasswordHackPayload::parse(bytes).is_none());
 
@@ -34,13 +62,33 @@ mod tests {
         assert!(PasswordHackPayload::parse(bytes).is_none());
 
         let bytes = b"project=;";
-        let payload = PasswordHackPayload::parse(bytes).expect("parsing failed");
-        assert_eq!(payload.project, "");
+        let payload: PasswordHackPayload =
+            PasswordHackPayload::parse(bytes).expect("parsing failed");
+        assert_eq!(payload.endpoint, "");
         assert_eq!(payload.password, b"");
 
         let bytes = b"project=foobar;pass;word";
         let payload = PasswordHackPayload::parse(bytes).expect("parsing failed");
-        assert_eq!(payload.project, "foobar");
+        assert_eq!(payload.endpoint, "foobar");
+        assert_eq!(payload.password, b"pass;word");
+    }
+
+    #[test]
+    fn parse_password_hack_payload_endpoint() {
+        let bytes = b"";
+        assert!(PasswordHackPayload::parse(bytes).is_none());
+
+        let bytes = b"endpoint=";
+        assert!(PasswordHackPayload::parse(bytes).is_none());
+
+        let bytes = b"endpoint=;";
+        let payload = PasswordHackPayload::parse(bytes).expect("parsing failed");
+        assert_eq!(payload.endpoint, "");
+        assert_eq!(payload.password, b"");
+
+        let bytes = b"endpoint=foobar;pass;word";
+        let payload = PasswordHackPayload::parse(bytes).expect("parsing failed");
+        assert_eq!(payload.endpoint, "foobar");
         assert_eq!(payload.password, b"pass;word");
     }
 }
diff --git a/proxy/src/compute.rs b/proxy/src/compute.rs
index d277940a12..480acb88d9 100644
--- a/proxy/src/compute.rs
+++ b/proxy/src/compute.rs
@@ -1,4 +1,4 @@
-use crate::{cancellation::CancelClosure, error::UserFacingError};
+use crate::{auth::parse_endpoint_param, cancellation::CancelClosure, error::UserFacingError};
 use futures::{FutureExt, TryFutureExt};
 use itertools::Itertools;
 use pq_proto::StartupMessageParams;
@@ -279,7 +279,7 @@ fn filtered_options(params: &StartupMessageParams) -> Option<String> {
     #[allow(unstable_name_collisions)]
     let options: String = params
         .options_raw()?
-        .filter(|opt| !opt.starts_with("project="))
+        .filter(|opt| parse_endpoint_param(opt).is_none())
         .intersperse(" ") // TODO: use impl from std once it's stabilized
         .collect();
 
diff --git a/test_runner/regress/test_proxy.py b/test_runner/regress/test_proxy.py
index ee6349436b..ae914e384e 100644
--- a/test_runner/regress/test_proxy.py
+++ b/test_runner/regress/test_proxy.py
@@ -5,16 +5,18 @@ import pytest
 from fixtures.neon_fixtures import PSQL, NeonProxy, VanillaPostgres
 
 
-def test_proxy_select_1(static_proxy: NeonProxy):
+@pytest.mark.parametrize("option_name", ["project", "endpoint"])
+def test_proxy_select_1(static_proxy: NeonProxy, option_name: str):
     """
     A simplest smoke test: check proxy against a local postgres instance.
     """
 
-    out = static_proxy.safe_psql("select 1", options="project=generic-project-name")
+    out = static_proxy.safe_psql("select 1", options=f"{option_name}=generic-project-name")
     assert out[0][0] == 1
 
 
-def test_password_hack(static_proxy: NeonProxy):
+@pytest.mark.parametrize("option_name", ["project", "endpoint"])
+def test_password_hack(static_proxy: NeonProxy, option_name: str):
     """
     Check the PasswordHack auth flow: an alternative to SCRAM auth for
     clients which can't provide the project/endpoint name via SNI or `options`.
@@ -23,11 +25,12 @@ def test_password_hack(static_proxy: NeonProxy):
     user = "borat"
     password = "password"
     static_proxy.safe_psql(
-        f"create role {user} with login password '{password}'", options="project=irrelevant"
+        f"create role {user} with login password '{password}'",
+        options=f"{option_name}=irrelevant",
     )
 
     # Note the format of `magic`!
-    magic = f"project=irrelevant;{password}"
+    magic = f"{option_name}=irrelevant;{password}"
     static_proxy.safe_psql("select 1", sslsni=0, user=user, password=magic)
 
     # Must also check that invalid magic won't be accepted.
@@ -56,55 +59,62 @@ async def test_link_auth(vanilla_pg: VanillaPostgres, link_proxy: NeonProxy):
     assert out == "42"
 
 
-def test_proxy_options(static_proxy: NeonProxy):
+@pytest.mark.parametrize("option_name", ["project", "endpoint"])
+def test_proxy_options(static_proxy: NeonProxy, option_name: str):
     """
     Check that we pass extra `options` to the PostgreSQL server:
-    * `project=...` shouldn't be passed at all (otherwise postgres will raise an error).
+    * `project=...` and `endpoint=...` shouldn't be passed at all
+    * (otherwise postgres will raise an error).
     * everything else should be passed as-is.
     """
 
-    options = "project=irrelevant -cproxytest.option=value"
+    options = f"{option_name}=irrelevant -cproxytest.option=value"
     out = static_proxy.safe_psql("show proxytest.option", options=options)
     assert out[0][0] == "value"
 
-    options = "-c proxytest.foo=\\ str project=irrelevant"
+    options = f"-c proxytest.foo=\\ str {option_name}=irrelevant"
     out = static_proxy.safe_psql("show proxytest.foo", options=options)
     assert out[0][0] == " str"
 
 
-def test_auth_errors(static_proxy: NeonProxy):
+@pytest.mark.parametrize("option_name", ["project", "endpoint"])
+def test_auth_errors(static_proxy: NeonProxy, option_name: str):
     """
     Check that we throw very specific errors in some unsuccessful auth scenarios.
     """
 
     # User does not exist
     with pytest.raises(psycopg2.Error) as exprinfo:
-        static_proxy.connect(user="pinocchio", options="project=irrelevant")
+        static_proxy.connect(user="pinocchio", options=f"{option_name}=irrelevant")
     text = str(exprinfo.value).strip()
     assert text.endswith("password authentication failed for user 'pinocchio'")
 
     static_proxy.safe_psql(
-        "create role pinocchio with login password 'magic'", options="project=irrelevant"
+        "create role pinocchio with login password 'magic'",
+        options=f"{option_name}=irrelevant",
     )
 
     # User exists, but password is missing
     with pytest.raises(psycopg2.Error) as exprinfo:
-        static_proxy.connect(user="pinocchio", password=None, options="project=irrelevant")
+        static_proxy.connect(user="pinocchio", password=None, options=f"{option_name}=irrelevant")
     text = str(exprinfo.value).strip()
     assert text.endswith("password authentication failed for user 'pinocchio'")
 
     # User exists, but password is wrong
     with pytest.raises(psycopg2.Error) as exprinfo:
-        static_proxy.connect(user="pinocchio", password="bad", options="project=irrelevant")
+        static_proxy.connect(user="pinocchio", password="bad", options=f"{option_name}=irrelevant")
     text = str(exprinfo.value).strip()
     assert text.endswith("password authentication failed for user 'pinocchio'")
 
     # Finally, check that the user can connect
-    with static_proxy.connect(user="pinocchio", password="magic", options="project=irrelevant"):
+    with static_proxy.connect(
+        user="pinocchio", password="magic", options=f"{option_name}=irrelevant"
+    ):
         pass
 
 
-def test_forward_params_to_client(static_proxy: NeonProxy):
+@pytest.mark.parametrize("option_name", ["project", "endpoint"])
+def test_forward_params_to_client(static_proxy: NeonProxy, option_name: str):
     """
     Check that we forward all necessary PostgreSQL server params to client.
     """
@@ -130,7 +140,7 @@ def test_forward_params_to_client(static_proxy: NeonProxy):
         where name = any(%s)
     """
 
-    with static_proxy.connect(options="project=irrelevant") as conn:
+    with static_proxy.connect(options=f"{option_name}=irrelevant") as conn:
         with conn.cursor() as cur:
             cur.execute(query, (reported_params_subset,))
             for name, value in cur.fetchall():
@@ -138,17 +148,18 @@ def test_forward_params_to_client(static_proxy: NeonProxy):
                 assert conn.get_parameter_status(name) == value
 
 
+@pytest.mark.parametrize("option_name", ["project", "endpoint"])
 @pytest.mark.timeout(5)
-def test_close_on_connections_exit(static_proxy: NeonProxy):
+def test_close_on_connections_exit(static_proxy: NeonProxy, option_name: str):
     # Open two connections, send SIGTERM, then ensure that proxy doesn't exit
     # until after connections close.
-    with static_proxy.connect(options="project=irrelevant"), static_proxy.connect(
-        options="project=irrelevant"
+    with static_proxy.connect(options=f"{option_name}=irrelevant"), static_proxy.connect(
+        options=f"{option_name}=irrelevant"
     ):
         static_proxy.terminate()
         with pytest.raises(subprocess.TimeoutExpired):
             static_proxy.wait_for_exit(timeout=2)
         # Ensure we don't accept any more connections
         with pytest.raises(psycopg2.OperationalError):
-            static_proxy.connect(options="project=irrelevant")
+            static_proxy.connect(options=f"{option_name}=irrelevant")
     static_proxy.wait_for_exit()