fix: validate summarizer inputs and add missing torch dependency

tools/summarizer/app.py

@@ -1,5 +1,5 @@
-from fastapi import FastAPI
-from pydantic import BaseModel
+from fastapi import FastAPI, HTTPException
+from pydantic import BaseModel, Field
 from transformers import AutoTokenizer, AutoModelForSeq2SeqLM
 from cachetools import TTLCache
 import hashlib
@@ -9,7 +9,10 @@ import torch
 app = FastAPI(title="Local Summarizer")
 
 MODEL_NAME = "sshleifer/distilbart-cnn-12-6"
+MAX_INPUT_CHARS = 20000
 
+# The local summarizer is intentionally simple, but we still validate request sizes
+# so accidental giant pastes do not cause avoidable latency or memory spikes.
 tokenizer = AutoTokenizer.from_pretrained(MODEL_NAME)
 model = AutoModelForSeq2SeqLM.from_pretrained(MODEL_NAME)
 model.eval()
@@ -19,9 +22,9 @@ cache = TTLCache(maxsize=1024, ttl=60 * 60)  # 1 hour cache
 
 
 class SummarizeRequest(BaseModel):
-    text: str
-    max_length: int = 160
-    min_length: int = 45
+    text: str = Field(min_length=1, max_length=MAX_INPUT_CHARS)
+    max_length: int = Field(default=160, ge=24, le=256)
+    min_length: int = Field(default=45, ge=8, le=180)
 
 
 def _key(text: str, max_length: int, min_length: int) -> str:
@@ -64,8 +67,6 @@ _TECH = [
     "rest",
 ]
 
-
-
 _SOFT = [
     "communication",
     "collaboration",
@@ -80,6 +81,7 @@ _SOFT = [
     "detail oriented",
 ]
 
+
 def _strip_html(text: str) -> str:
     # Good enough for job descriptions pasted from the web.
     text = re.sub(r"<\s*br\s*/?>", "\n", text, flags=re.IGNORECASE)
@@ -114,7 +116,7 @@ def _role_focused_excerpt(text: str) -> dict:
     }
 
     def match_heading(s: str):
-        sl = s.lower().strip(":- ")
+        sl = s.lower().strip(":-\x7f ")
         for k, words in headings.items():
             for w in words:
                 if sl == w or sl.startswith(w + " "):
@@ -201,6 +203,9 @@ def _model_summarize(text: str, max_length: int, min_length: int) -> str:
 
 @app.post("/summarize")
 async def summarize(req: SummarizeRequest):
+    if req.min_length >= req.max_length:
+        raise HTTPException(status_code=400, detail="min_length must be smaller than max_length.")
+
     key = _key(req.text, req.max_length, req.min_length)
     if key in cache:
         return {"summary": cache[key], "cached": True}

tools/summarizer/requirements.txt

@@ -3,3 +3,4 @@ uvicorn[standard]==0.34.0
 transformers==4.48.3
 cachetools==5.5.2
 pydantic==2.10.6
+torch==2.6.0