Cursor AvailableModels returned protobuf; JSON catalog unava

Error message

Cursor AvailableModels returned protobuf; JSON catalog unavailable for this client version

What it means

Error "Cursor AvailableModels returned protobuf; JSON catalog unavailable for this client version" thrown in diegosouzapw/OmniRoute.

Source

Thrown at src/lib/providerModels/cursorAvailableModels.ts:177

  const url = `${CURSOR_CONFIG.apiEndpoint}${CURSOR_CONFIG.modelsEndpoint}`;
  const fetchImpl = options.fetchImpl || fetch;
  const response = await fetchImpl(url, {
    method: "POST",
    headers,
    body: "{}",
    signal,
  });

  if (!response.ok) {
    const text = await response.text().catch(() => "");
    throw new Error(
      `Cursor AvailableModels failed: ${response.status}${text ? ` ${text.slice(0, 200)}` : ""}`
    );
  }

  const contentType = response.headers.get("content-type") || "";
  if (contentType.includes("proto") || contentType.includes("protobuf")) {
    throw new Error(
      "Cursor AvailableModels returned protobuf; JSON catalog unavailable for this client version"
    );
  }

  const payload = await response.json();
  const models = normalizeCursorAvailableModelsPayload(payload);
  if (models.length === 0) {
    throw new Error("Cursor AvailableModels returned no models");
  }
  return models;
}

View on GitHub (pinned to a179ffed5b)

When it happens

Trigger: Thrown at src/lib/providerModels/cursorAvailableModels.ts:177 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of diegosouzapw/OmniRoute@a179ffed5b (2026-08-25). Data as JSON: /api/errors/70e6cdfe74e8eb4f. Report an issue: GitHub.