An effort the model had never heard of

Reported from a live instance, on Bonsai:

  Jinja Exception: Unexpected reasoning effort high. Supported types are
  xhigh (default), medium, and low.

Effort goes out two ways because no single field works, and the second --
chat_template_kwargs -- is not a parameter the server interprets. It is
rendered into the model's own chat template, which does not ignore a value it
does not know: it calls raise_exception, and the request dies before a token.
So a perfectly ordinary option, drawn by this application in its own menu, took
the whole reply with it.

The vocabulary is per model and nobody agrees. gpt-oss takes low/medium/high.
Bonsai takes low/medium/xhigh and refuses high. OpenAI has added minimal, xhigh
and max at different points, and which of them a given model accepts varies
again. One global tuple was going to be wrong for somebody whatever it held.

A model carries its own list now, and the picker, the slash command and the
request builder all read it. A column rather than a key in capabilities_json,
for the reason context_length is one: that dict is rebuilt wholesale from the
submitted checkboxes on every save.

And it corrects itself. A refusal retries the reply once without the effort
rather than losing it -- safe only because the template renders before any
token, so nothing has been emitted, and there is a guard that keeps it that way
-- then narrows the model's list. Bonsai's error states what it does take, so
that is what gets stored.

Note the parser bug, because it is a good one: "high" is a substring of
"xhigh", so reading the advertised list by substring learned `high` from a
sentence explaining that `high` is the problem. Whole words now, with a test
named after it.

/effort reads its levels off the picker instead of a second copy of the list
kept in the browser.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_effort.py

@@ -366,3 +366,93 @@ def test_the_picker_never_says_default(client: TestClient, db, registered):
     assert "Effort: default" not in html
     assert "Effort: off" in html
     assert '<option value="medium" selected>' in html.replace("\n", "").replace("  ", "")
+
+
+# --- A vocabulary that is not the same for every model -----------------------
+#
+# Reported from a real instance, on a model called Bonsai:
+#
+#   Jinja Exception: Unexpected reasoning effort high. Supported types are
+#   xhigh (default), medium, and low.
+#
+# `chat_template_kwargs.reasoning_effort` is rendered into the model's own chat
+# template, and a template that does not know the value calls `raise_exception`
+# rather than ignoring it -- so the whole reply died, from an option this
+# application had drawn in a menu.
+BONSAI_ERROR = (
+    "Jinja Exception: Unexpected reasoning effort high. "
+    "Supported types are xhigh (default), medium, and low."
+)
+
+
+class _FakeModel:
+    def __init__(self, efforts=None):
+        self.reasoning_efforts = efforts or []
+
+
+def test_a_model_that_has_said_nothing_gets_the_common_three():
+    from lembas.services import chat as chat_service
+
+    assert chat_service.efforts_for(_FakeModel()) == ("low", "medium", "high")
+
+
+def test_a_model_can_take_xhigh_and_not_high():
+    from lembas.services import chat as chat_service
+
+    bonsai = _FakeModel(["xhigh", "medium", "low"])
+    assert chat_service.efforts_for(bonsai) == ("low", "medium", "xhigh")
+    assert "high" not in chat_service.efforts_for(bonsai)
+
+
+def test_an_effort_the_model_refuses_is_never_sent():
+    """The check that stops the crash happening at all."""
+    from lembas.services import chat as chat_service
+
+    supported = chat_service.efforts_for(_FakeModel(["xhigh", "medium", "low"]))
+    body: dict = {}
+    chat_service.apply_effort(body, "high", supported)
+    assert body == {}
+
+    chat_service.apply_effort(body, "xhigh", supported)
+    assert body["reasoning_effort"] == "xhigh"
+    assert body["chat_template_kwargs"]["reasoning_effort"] == "xhigh"
+
+
+def test_a_value_this_application_never_heard_of_cannot_reach_a_request():
+    from lembas.services import chat as chat_service
+
+    assert chat_service.efforts_for(_FakeModel(["ludicrous"])) == ("low", "medium", "high")
+
+
+def test_the_refusal_is_recognised_and_the_supported_list_read_out_of_it():
+    from lembas.services import generation
+
+    assert generation._effort_was_refused(BONSAI_ERROR)
+    assert generation._advertised_efforts(BONSAI_ERROR) == ["low", "medium", "xhigh"]
+
+
+def test_the_rejected_value_is_not_collected_as_a_supported_one():
+    """The message names the refused effort first and the supported ones after,
+    so anything reading the whole string would learn `high` from a sentence
+    saying `high` is the problem."""
+    from lembas.services import generation
+
+    assert "high" not in generation._advertised_efforts(BONSAI_ERROR)
+
+
+def test_an_ordinary_failure_is_not_retried_as_an_effort_problem():
+    """Retrying a genuine failure would hide it behind a second request."""
+    from lembas.services import generation
+
+    for message in (
+        "Connection refused.",
+        "The model is still loading.",
+        "context length exceeded",
+    ):
+        assert not generation._effort_was_refused(message)
+
+
+def test_a_model_with_no_advertisement_simply_loses_the_refused_value():
+    from lembas.services import generation
+
+    assert generation._advertised_efforts("Unexpected reasoning effort high.") == []