Spaces:
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Running on Zero
File size: 4,846 Bytes
1a2024f 1f70bb6 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | """App-layer API key for the THOX Space fleet.
Why app-layer and not Hugging Face's edge gate
----------------------------------------------
Flipping a Space to private makes HF answer **404** to an unauthenticated caller, which
reads as "the app is broken" rather than "you are not signed in", and the edge gate eats
the `Authorization` header of anything proxying through it. Checking the key in the app
keeps the Space public — so `/health`, the Gradio UI and the model card stay reachable —
while `/v1/*` behaves the way every OpenAI client already expects: `Authorization: Bearer
<key>`, and a real `401` with a `WWW-Authenticate` header when it is wrong.
Fail-closed
-----------
If `THOX_API_KEY` is unset the endpoint refuses everything with 503 rather than serving
openly. An unset secret is a deployment mistake, and the failure mode of guessing wrong
here is a public, uncapped inference endpoint — so the safe direction is down.
`/health` deliberately stays open: liveness has to be checkable without a credential.
It must therefore never echo the key back — see `redact()`.
"""
from __future__ import annotations
import hmac
import os
from fastapi.responses import JSONResponse
ENV_VAR = "THOX_API_KEY"
def configured_key() -> str:
return (os.environ.get(ENV_VAR) or "").strip()
def is_configured() -> bool:
return bool(configured_key())
def redact(text: str) -> str:
"""Strip the key out of anything that might reach a log or an open endpoint."""
key = configured_key()
if key and key in text:
return text.replace(key, "***redacted***")
return text
def _deny(message: str, code: str, status: int = 401) -> JSONResponse:
return JSONResponse(
status_code=status,
headers={"WWW-Authenticate": "Bearer"},
content={"error": {"message": message, "type": "invalid_request_error",
"param": None, "code": code}},
)
def presented_key(request) -> str:
"""Read the key the caller sent. `Authorization: Bearer` first, `X-API-Key` second."""
auth = request.headers.get("authorization") or ""
if auth[:7].lower() == "bearer ":
return auth[7:].strip()
return (request.headers.get("x-api-key") or "").strip()
def check(request):
"""Return None when the caller may proceed, or the JSONResponse to send back."""
expected = configured_key()
if not expected:
return _deny(
f"This endpoint is not configured: {ENV_VAR} is unset on the Space. "
"Set it as a Space secret.",
"no_api_key_configured",
503,
)
presented = presented_key(request)
if not presented:
return _deny(
"Missing API key. Send 'Authorization: Bearer <key>'.",
"missing_api_key",
)
# Constant time: a short-circuiting == leaks the length of the matching prefix.
if not hmac.compare_digest(presented, expected):
return _deny("Incorrect API key provided.", "invalid_api_key")
return None
# --------------------------------------------------------------------------------------
# OpenAI-shaped validation errors
# --------------------------------------------------------------------------------------
def openai_validation_handler(request, exc):
"""FastAPI answers a bad body with `422 {"detail": [...]}`; OpenAI uses
`400 {"error": {...}}`. A client that reads `error.message` sees nothing in the
former, so translate."""
try:
first = exc.errors()[0]
where = ".".join(str(p) for p in first.get("loc", ()) if p != "body")
message = f"{first.get('msg', 'Invalid request')}" + (f" (at '{where}')" if where else "")
param = where or None
except Exception: # noqa: BLE001
message, param = "Invalid request body.", None
return JSONResponse(
status_code=400,
content={"error": {"message": message, "type": "invalid_request_error",
"param": param, "code": None}},
)
def install(app) -> None:
"""Attach the handler to the app that will actually serve the request.
This has to be Gradio's app, not the FastAPI instance the routes were declared on:
Starlette resolves exception handlers against the app whose middleware stack is
running, and the routes are grafted onto Gradio's router. Clearing
`middleware_stack` forces a rebuild so a handler added after `launch()` is picked up
-- adding to the dict alone would be silently ignored, because the stack that closed
over the old handler map is already built.
"""
from fastapi.exceptions import RequestValidationError
app.add_exception_handler(RequestValidationError, openai_validation_handler)
app.middleware_stack = None
print("[thox] installed OpenAI-shaped validation error handler", flush=True)
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