feat: add slowapi throttling

app/routers/converters.py

@@ -3,11 +3,16 @@
 from typing import Literal
 
 import selfies as sf
+from fastapi import FastAPI
 from fastapi import APIRouter
 from fastapi import HTTPException
 from fastapi import Query
 from fastapi import status
+from fastapi import Request
 from fastapi.responses import Response
+from slowapi import Limiter, _rate_limit_exceeded_handler
+from slowapi.util import get_remote_address
+from slowapi.errors import RateLimitExceeded
 from rdkit import Chem
 from STOUT import translate_forward
 from STOUT import translate_reverse
@@ -39,6 +44,16 @@
 from app.schemas.error import ErrorResponse
 from app.schemas.error import NotFoundModel
 
+# Create the Limiter instance
+limiter = Limiter(key_func=get_remote_address)
+
+# Initialize FastAPI app
+app = FastAPI()
+
+# Add the middleware to handle rate limit exceeded errors
+app.state.limiter = limiter
+app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
+
 router = APIRouter(
     prefix="/convert",
     tags=["convert"],
@@ -88,7 +103,9 @@ def get_health() -> HealthCheck:
         422: {"description": "Unprocessable Entity", "model": ErrorResponse},
     },
 )
+@limiter.limit("20/minute")
 async def create2d_coordinates(
+    request: Request,
     smiles: str = Query(
         title="SMILES",
         description="SMILES representation of the molecule",
@@ -157,7 +174,9 @@ async def create2d_coordinates(
         422: {"description": "Unprocessable Entity", "model": ErrorResponse},
     },
 )
+@limiter.limit("20/minute")
 async def create3d_coordinates(
+    request: Request,
     smiles: str = Query(
         title="SMILES",
         description="SMILES representation of the molecule",
@@ -173,7 +192,7 @@ async def create3d_coordinates(
         },
     ),
     toolkit: Literal["rdkit", "openbabel"] = Query(
-        default="rdkit",
+        default="openbabel",
         description="Cheminformatics toolkit used in the backend",
     ),
 ):
@@ -184,7 +203,7 @@ async def create3d_coordinates(
     Parameters:
     - **SMILES**: required (str): The SMILES representation of the molecule.
     - **toolkit**: optional (str): The molecule toolkit to use.
-        - Supported values: "rdkit" (default) & "openbabel".
+        - Supported values: "rdkit"  & "openbabel" (default).
 
     Returns:
     - molblock (str): The generated mol block with 3D coordinates as a plain text response.
@@ -221,7 +240,9 @@ async def create3d_coordinates(
         422: {"description": "Unprocessable Entity", "model": ErrorResponse},
     },
 )
+@limiter.limit("10/minute")
 async def iupac_name_or_selfies_to_smiles(
+    request: Request,
     input_text: str = Query(
         title="Input IUPAC name or SELFIES",
         description="IUPAC name or SELFIES representation of the molecule",

app/routers/depict.py

@@ -3,13 +3,17 @@
 from typing import Literal
 from typing import Optional
 
+from fastapi import FastAPI
 from fastapi import APIRouter
 from fastapi import HTTPException
 from fastapi import Query
 from fastapi import Request
 from fastapi import status
 from fastapi.responses import Response
 from fastapi.templating import Jinja2Templates
+from slowapi import Limiter, _rate_limit_exceeded_handler
+from slowapi.util import get_remote_address
+from slowapi.errors import RateLimitExceeded
 
 from app.modules.depiction import get_cdk_depiction
 from app.modules.depiction import get_rdkit_depiction
@@ -24,6 +28,15 @@
 from app.schemas.error import NotFoundModel
 
 templates = Jinja2Templates(directory="app/templates")
+# Create the Limiter instance
+limiter = Limiter(key_func=get_remote_address)
+
+# Initialize FastAPI app
+app = FastAPI()
+
+# Add the middleware to handle rate limit exceeded errors
+app.state.limiter = limiter
+app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)
 
 router = APIRouter(
     prefix="/depict",
@@ -193,6 +206,7 @@ async def depict_2d_molecule(
         422: {"description": "Unprocessable Entity", "model": ErrorResponse},
     },
 )
+@limiter.limit("25/minute")
 async def depict_3d_molecule(
     request: Request,
     smiles: str = Query(

docs/requirements.txt

@@ -32,3 +32,4 @@ unicodedata2==15.0.0
 uvicorn>=0.15.0,<0.16.0
 websockets==10.4
 mapchiral
+slowapi

requirements.txt

@@ -25,3 +25,4 @@ tensorflow==2.12.0
 unicodedata2==15.0.0
 websockets==10.4
 mapchiral
+slowapi