diff --git a/bin/chat-fastapi.py b/bin/chat-fastapi.py
index c7169ce..c49a9f1 100644
--- a/bin/chat-fastapi.py
+++ b/bin/chat-fastapi.py
@@ -11,18 +11,12 @@
 from fastapi import FastAPI, Request, Response
 from fastapi.responses import HTMLResponse, RedirectResponse
 
-from util.secrets import get_secret, load_secrets_to_environ
+from util.secrets import SECRET_NAMES, get_secret, load_secrets_to_environ
 
 load_dotenv()
-load_secrets_to_environ(
-    [
-        "CHAINLIT_AUTH_SECRET",
-        "OAUTH_AUTH0_CLIENT_SECRET",
-        "OAUTH_GOOGLE_CLIENT_SECRET",
-        "OPENAI_API_KEY",
-        "TAVILY_API_KEY",
-    ]
-)
+# The same list chat-chainlit uses. This was a second, hand-maintained copy
+# that had already drifted from it in both directions.
+load_secrets_to_environ(SECRET_NAMES)
 
 app = FastAPI()
 
diff --git a/env_template b/env_template
index 9ec2303..f98d680 100644
--- a/env_template
+++ b/env_template
@@ -40,3 +40,16 @@ LOCALE=en_US
 TIMEZONE=America/Toronto
 # The guest instance's public URI, served alongside the authenticated one.
 CHAINLIT_URI_NO_LOGIN=
+
+# OAuth sign-in. Only the providers whose CLIENT_ID is set are offered; leave a
+# pair blank to disable that provider. The *_SECRET values can be supplied as
+# Docker secrets instead (see the note at the top).
+#OAUTH_AUTH0_CLIENT_ID=
+#OAUTH_AUTH0_CLIENT_SECRET=
+#OAUTH_AUTH0_DOMAIN=
+#OAUTH_GOOGLE_CLIENT_ID=
+#OAUTH_GOOGLE_CLIENT_SECRET=
+#OAUTH_ORCID_CLIENT_ID=
+#OAUTH_ORCID_CLIENT_SECRET=
+# Signs the session cookie. Required for any OAuth provider to work.
+#CHAINLIT_AUTH_SECRET=
diff --git a/src/util/secrets.py b/src/util/secrets.py
index 16a04ef..11ab66c 100644
--- a/src/util/secrets.py
+++ b/src/util/secrets.py
@@ -118,14 +118,26 @@ def load_secrets_to_environ(names: Iterable[str]) -> None:
 
 # The values worth mounting rather than passing as environment variables. Names
 # match env_template, so a deployment can move one across without renaming it.
+# This is the ONE list. compose.yaml's `secrets:` block must be a subset of it --
+# tests/util/test_secrets.py asserts that, because the failure is silent: a
+# secret declared in compose and missing here is mounted into the container and
+# never read, so the value falls back to the environment. A deployment that
+# moved a secret OUT of its .env and into a Docker secret would then lose it,
+# and the first symptom is a login that stops working.
+#
+# That had already happened: compose.yaml declared the two OAuth secrets and
+# this tuple did not list them.
 SECRET_NAMES = (
+    "CHAINLIT_AUTH_SECRET",
+    "CLOUDFLARE_SECRET_KEY",
+    "LITERAL_API_KEY",
+    "OAUTH_AUTH0_CLIENT_SECRET",
+    "OAUTH_GOOGLE_CLIENT_SECRET",
+    "OAUTH_ORCID_CLIENT_SECRET",
     "OPENAI_API_KEY",
-    "POSTGRES_PASSWORD",
     "PGADMIN_DEFAULT_PASSWORD",
-    "CLOUDFLARE_SECRET_KEY",
+    "POSTGRES_PASSWORD",
     "TAVILY_API_KEY",
-    "CHAINLIT_AUTH_SECRET",
-    "LITERAL_API_KEY",
 )
 
 
diff --git a/tests/util/test_secrets.py b/tests/util/test_secrets.py
index 622821c..30ee9a1 100644
--- a/tests/util/test_secrets.py
+++ b/tests/util/test_secrets.py
@@ -124,16 +124,51 @@ def test_missing_secrets_directory_is_not_an_error(
     assert get_secret("OPENAI_API_KEY") == "sk-from-env"
 
 
+def test_every_secret_compose_declares_is_one_the_app_loads() -> None:
+    """The drift that had already happened, now a tripwire.
+
+    compose.yaml declared OAUTH_AUTH0_CLIENT_SECRET and
+    OAUTH_GOOGLE_CLIENT_SECRET; SECRET_NAMES did not list them. A secret in that
+    gap is mounted into the container and never read, so its value silently
+    falls back to the environment -- and a deployment that moved it out of .env
+    and into a Docker secret would lose it. The first symptom is a login that
+    stops working, a long way from the cause.
+    """
+    import yaml
+
+    compose = yaml.safe_load(
+        (Path(__file__).parent.parent.parent / "compose.yaml").read_text()
+    )
+    declared = set(compose.get("secrets") or {})
+    missing = sorted(declared - set(SECRET_NAMES))
+    assert not missing, (
+        f"compose.yaml mounts these but nothing loads them: {missing}. "
+        "Add them to SECRET_NAMES in src/util/secrets.py."
+    )
+
+
+def test_only_one_list_of_secret_names_exists() -> None:
+    """chat-fastapi.py kept its own hand-maintained copy, which had drifted from
+    SECRET_NAMES in both directions -- it was missing four and had one extra."""
+    source = (
+        Path(__file__).parent.parent.parent / "bin" / "chat-fastapi.py"
+    ).read_text()
+    assert "load_secrets_to_environ(SECRET_NAMES)" in source
+    assert '"OPENAI_API_KEY",' not in source, "no second literal list"
+
+
 def test_the_secret_names_are_ones_the_deployment_actually_uses() -> None:
     """A name here that no template mentions would never be mounted."""
     template = Path(__file__).parent.parent.parent / "env_template"
     declared = template.read_text()
-    unknown = [
-        n
-        for n in SECRET_NAMES
-        if n not in declared and n not in {"CHAINLIT_AUTH_SECRET", "LITERAL_API_KEY"}
-    ]
-    assert not unknown, f"not in env_template: {unknown}"
+    # LITERAL_API_KEY is the one exception: it configures the Literal AI
+    # integration, which no deployment here uses yet, so it is loadable but
+    # undocumented on purpose.
+    unknown = [n for n in SECRET_NAMES if n not in declared and n != "LITERAL_API_KEY"]
+    assert not unknown, (
+        f"in SECRET_NAMES but absent from env_template: {unknown}. "
+        "An operator cannot supply a setting nobody told them about."
+    )
 
 
 def test_db_uri_uses_the_socket_and_never_tcp(