fix #1: separate error message for cache and api key

src/embed_papers/searcher.py

@@ -267,7 +267,7 @@ def _get_client(self) -> Any:
         key = self.resolved_api_key
         if not key:
             raise CacheMissRequiresApiKeyError(
-                "Embeddings cache not found. Set OPENAI_API_KEY (or pass api_key) to create conference cache."
+                "OpenAI API key required to compute embeddings. Set OPENAI_API_KEY (or pass api_key)."
             )
 
         from openai import OpenAI
@@ -309,7 +309,7 @@ def compute_embeddings(self, force: bool = False) -> np.ndarray:
 
         if self.require_api_key_on_cache_miss and not self.resolved_api_key:
             raise CacheMissRequiresApiKeyError(
-                "No cache for this venue/model and no API key found. Set OPENAI_API_KEY to build cache."
+                "No cached embeddings for this venue/model and no API key found. Set OPENAI_API_KEY to build cache."
             )
 
         _log(f"Computing embeddings ({self.model_name})...")

src/embed_papers/viewer/app.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+import os
 from html import escape
 from pathlib import Path
 from typing import Any
@@ -337,6 +338,12 @@ def _render_sidebar_form() -> dict[str, Any] | None:
             st.error("Upload a valid examples JSON file before running search.")
             return None
 
+        if not os.getenv("OPENAI_API_KEY"):
+            st.error(
+                "OPENAI_API_KEY is required to embed queries/examples. Set it in your shell and restart the app."
+            )
+            return None
+
     return {
         "conference": conference,
         "year": int(year),