Files
routstr-core/routstr/payment/helpers.py
T
2026-09-04 01:35:43 +02:00

528 lines
17 KiB
Python

import base64
import json
import math
from io import BytesIO
from typing import Any
import httpx
from fastapi import HTTPException, Response
from fastapi.requests import Request
from PIL import Image
from sqlmodel.ext.asyncio.session import AsyncSession
from ..core import get_logger
from ..core.exceptions import UpstreamError
from ..core.redaction import redact_org_ids
from ..core.settings import settings
from ..wallet import (
UntrustedSourceMintError,
classify_redemption_error,
deserialize_token_from_string,
is_trusted_source_mint,
)
logger = get_logger(__name__)
def check_token_balance(headers: dict, body: dict, max_cost_for_model: int) -> None:
if x_cashu := headers.get("x-cashu", None):
cashu_token = x_cashu
logger.debug(
"Using X-Cashu token",
extra={
"token_preview": cashu_token[:20] + "..."
if len(cashu_token) > 20
else cashu_token
},
)
elif auth := headers.get("authorization", None):
logger.debug(
"Skipping preflight token balance check for Authorization header",
extra={
"auth_preview": auth[:20] + "..." if len(auth) > 20 else auth,
},
)
return
else:
logger.error("No authentication token provided")
raise HTTPException(status_code=401, detail="Unauthorized")
# Handle empty token
if not cashu_token:
logger.error("Empty token provided")
raise HTTPException(
status_code=401,
detail={
"error": {
"message": "API key or Cashu token required",
"type": "invalid_request_error",
"code": "missing_api_key",
}
},
)
# Handle regular API keys (sk-*)
if cashu_token.startswith("sk-"):
return
try:
token_obj = deserialize_token_from_string(cashu_token)
except Exception:
# Invalid token format - let the auth system handle it
raise HTTPException(
status_code=401,
detail="Invalid authentication token format",
)
if not is_trusted_source_mint(token_obj.mint):
classified = classify_redemption_error(
UntrustedSourceMintError(f"Untrusted source mint: {token_obj.mint}")
)
assert classified is not None
error_type, status_code, message, error_code = classified
raise HTTPException(
status_code=status_code,
detail={
"error": {"message": message, "type": error_type, "code": error_code}
},
)
amount_msat = (
token_obj.amount if token_obj.unit == "msat" else token_obj.amount * 1000
)
if max_cost_for_model > amount_msat:
raise HTTPException(
status_code=402,
detail={
"reason": "Insufficient balance",
"amount_required_msat": max_cost_for_model,
"model": body.get("model", "unknown"),
"type": "minimum_balance_required",
},
)
async def get_max_cost_for_model(
model: str,
session: AsyncSession,
model_obj: Any | None = None,
) -> int:
"""Get the maximum cost for a specific model from providers with overrides."""
logger.debug(
"Getting max cost for model",
extra={
"model": model,
"fixed_pricing": settings.fixed_pricing,
},
)
if settings.fixed_pricing:
default_cost_msats = settings.fixed_cost_per_request * 1000
logger.debug(
"Using fixed cost pricing",
extra={"cost_msats": default_cost_msats, "model": model},
)
return max(settings.min_request_msat, default_cost_msats)
if not model_obj:
from ..proxy import get_model_instance
model_obj = get_model_instance(model)
if not model_obj:
fallback_msats = settings.fixed_cost_per_request * 1000
logger.warning(
"Model not found in providers or overrides",
extra={
"requested_model": model,
"using_default_cost": fallback_msats,
},
)
return max(settings.min_request_msat, fallback_msats)
if model_obj.sats_pricing:
try:
max_cost = (
model_obj.sats_pricing.max_cost
* 1000
* (1 - settings.tolerance_percentage / 100)
)
logger.debug(
"Found model-specific max cost",
extra={"model": model, "max_cost_msats": max_cost},
)
calculated_msats = int(max_cost)
return max(settings.min_request_msat, calculated_msats)
except Exception as e:
logger.error(
"Error calculating max cost from model pricing",
extra={"model": model, "error": str(e)},
)
logger.warning(
"Model pricing not found, using fixed cost",
extra={
"model": model,
"default_cost_msats": settings.fixed_cost_per_request * 1000,
},
)
return max(settings.min_request_msat, settings.fixed_cost_per_request * 1000)
async def calculate_discounted_max_cost(
max_cost_for_model: int,
body: dict,
model_obj: Any | None = None,
) -> int:
"""Calculate the discounted max cost for a request using model pricing when available."""
if settings.fixed_pricing:
return max_cost_for_model
model = body.get("model", "unknown")
model_pricing = model_obj.sats_pricing if model_obj else None
if not model_pricing:
return max_cost_for_model
tol = settings.tolerance_percentage
tol_factor = max(0.0, 1 - float(tol) / 100.0)
max_prompt_allowed_sats = model_pricing.max_prompt_cost * tol_factor
max_completion_allowed_sats = model_pricing.max_completion_cost * tol_factor
if model_obj:
prompt_token_limit: int | None = None
if model_obj.top_provider and (
model_obj.top_provider.context_length
or model_obj.top_provider.max_completion_tokens
):
cl = model_obj.top_provider.context_length
mct = model_obj.top_provider.max_completion_tokens
if cl and mct:
prompt_token_limit = max(0, cl - mct)
elif cl:
prompt_token_limit = cl
elif mct:
prompt_token_limit = 0
elif model_obj.context_length:
prompt_token_limit = model_obj.context_length
if prompt_token_limit is not None:
max_prompt_allowed_sats = (
prompt_token_limit * model_pricing.prompt * tol_factor
)
adjusted = max_cost_for_model
messages = body.get("messages")
# Estimated over the whole body: a discount driven by message text alone lets
# a caller hide prompt weight elsewhere, shrink the reservation, and be billed
# for work the reservation never covered.
prompt_tokens = estimate_prompt_tokens(body)
if isinstance(messages, list):
image_tokens = await estimate_image_tokens_in_messages(messages)
if image_tokens > 0:
logger.debug(
"Found images in request",
extra={
"model": model,
"image_tokens": image_tokens,
},
)
prompt_tokens += image_tokens
if prompt_tokens > 0:
estimated_prompt_delta_sats = (
max_prompt_allowed_sats - prompt_tokens * model_pricing.prompt
)
if estimated_prompt_delta_sats > 0:
adjusted = adjusted - math.floor(estimated_prompt_delta_sats * 1000)
max_tokens_raw = body.get("max_tokens", None)
if max_tokens_raw is not None:
try:
max_tokens_int = int(max_tokens_raw)
except (TypeError, ValueError):
logger.warning(
"Invalid max_tokens; ignoring in cost adjustment",
extra={"max_tokens": str(max_tokens_raw)[:64], "model": model},
)
else:
estimated_completion_delta_sats = (
max_completion_allowed_sats - max_tokens_int * model_pricing.completion
)
if estimated_completion_delta_sats > 0:
adjusted = adjusted - math.floor(estimated_completion_delta_sats * 1000)
logger.debug(
"Discounted max cost computed",
extra={
"model": model,
"original_msats": max_cost_for_model,
"adjusted_msats": adjusted,
"tolerance_pct": tol,
},
)
return max(settings.min_request_msat, adjusted)
def estimate_tokens(messages: list) -> int:
"""Estimate tokens for text content, excluding image_url fields."""
total = 0
for msg in messages:
if isinstance(msg, dict):
content = msg.get("content")
if isinstance(content, str):
total += len(content)
elif isinstance(content, list):
total += sum(
len(item.get("text", ""))
for item in content
if isinstance(item, dict) and item.get("type") == "text"
)
return total // 3
def _sum_string_chars(node: Any) -> int:
"""Recursively sum the length of every string in the tree, keys included.
Nothing is excluded. Keys count because JSON-schema property names are
forwarded to the provider, and no exclusion rule can be trusted here: every
part of the body is caller-controlled, so any carve-out (by key name or by
value shape) is a place to hide prompt weight for free. Inline image data is
therefore counted as text too, which only makes the discount smaller.
"""
if isinstance(node, str):
return len(node)
if isinstance(node, dict):
return sum(
len(str(key)) + _sum_string_chars(value) for key, value in node.items()
)
if isinstance(node, list):
return sum(_sum_string_chars(item) for item in node)
return 0
def _count_prompt_token_ids(node: Any) -> int:
if isinstance(node, int) and not isinstance(node, bool):
return 1
if isinstance(node, list):
return sum(_count_prompt_token_ids(item) for item in node)
return 0
def estimate_prompt_tokens(body: dict) -> int:
"""Conservatively estimate prompt tokens for the whole provider-bound body.
Every string counts, as do token IDs in legacy ``prompt`` arrays, so no
forwarded field can hide prompt weight and shrink its reservation.
"""
return _sum_string_chars(body) // 3 + _count_prompt_token_ids(body.get("prompt"))
def _get_image_dimensions(image_data: bytes) -> tuple[int, int]:
"""Extract image dimensions from image bytes."""
try:
img = Image.open(BytesIO(image_data))
return img.size
except Exception as e:
logger.warning(
"Failed to get image dimensions, using default",
extra={"error": str(e)},
)
return (512, 512)
async def _fetch_image_from_url(url: str) -> bytes | None:
"""Fetch image from URL."""
try:
async with httpx.AsyncClient(timeout=10.0) as client:
response = await client.get(url)
response.raise_for_status()
return response.content
except Exception as e:
logger.warning(
"Failed to fetch image from URL",
extra={"error": str(e), "url": url[:100]},
)
return None
def _calculate_image_tokens(width: int, height: int, detail: str = "auto") -> int:
"""Calculate image tokens based on OpenAI's vision pricing.
For low detail: 85 tokens
For high detail/auto: 85 base tokens + 170 tokens per 512px tile
"""
if detail == "low":
return 85
if width > 2048 or height > 2048:
aspect_ratio = width / height
if width > height:
width = 2048
height = int(width / aspect_ratio)
else:
height = 2048
width = int(height * aspect_ratio)
if width > 768 or height > 768:
aspect_ratio = width / height
if width > height:
width = 768
height = int(width / aspect_ratio)
else:
height = 768
width = int(height * aspect_ratio)
tiles_width = (width + 511) // 512
tiles_height = (height + 511) // 512
num_tiles = tiles_width * tiles_height
return 85 + (170 * num_tiles)
async def estimate_image_tokens_in_messages(messages: list) -> int:
"""Estimate total tokens for all images in messages.
Supports both base64 encoded images and image URLs.
"""
total_image_tokens = 0
for message in messages:
if not isinstance(message, dict):
continue
content = message.get("content")
if not content:
continue
if isinstance(content, str):
continue
if not isinstance(content, list):
continue
for content_item in content:
if not isinstance(content_item, dict):
continue
content_type = content_item.get("type")
if content_type not in ("image_url", "input_image"):
continue
image_url_data = content_item.get("image_url")
if not image_url_data:
continue
if isinstance(image_url_data, str):
url = image_url_data
detail = "auto"
elif isinstance(image_url_data, dict):
url = image_url_data.get("url", "")
detail = image_url_data.get("detail", "auto")
else:
continue
if not url:
continue
if url.startswith("data:image/"):
try:
header, base64_data = url.split(",", 1)
image_bytes = base64.b64decode(base64_data)
width, height = _get_image_dimensions(image_bytes)
tokens = _calculate_image_tokens(width, height, detail)
total_image_tokens += tokens
logger.debug(
"Calculated tokens for base64 image",
extra={
"width": width,
"height": height,
"detail": detail,
"tokens": tokens,
},
)
except Exception as e:
logger.warning(
"Failed to process base64 image",
extra={"error": str(e)},
)
total_image_tokens += 85
else:
image_bytes_or_none = await _fetch_image_from_url(url)
if image_bytes_or_none:
width, height = _get_image_dimensions(image_bytes_or_none)
tokens = _calculate_image_tokens(width, height, detail)
total_image_tokens += tokens
logger.debug(
"Calculated tokens for URL image",
extra={
"url": url[:100],
"width": width,
"height": height,
"detail": detail,
"tokens": tokens,
},
)
else:
total_image_tokens += 85
return total_image_tokens
def create_error_response(
error_type: str,
message: str,
status_code: int,
request: Request,
token: str | None = None,
code: str | int | None = None,
details: dict[str, object] | None = None,
) -> Response:
"""Create a standardized error response.
``code`` is a stable, machine-readable classification (e.g.
``UPSTREAM_RATE_LIMIT``); when omitted it defaults to the HTTP status code
for backwards compatibility. ``details`` carries optional structured,
redaction-safe context.
"""
error_obj: dict[str, object] = {
"message": redact_org_ids(message),
"type": error_type,
"code": code if code is not None else status_code,
}
if details is not None:
error_obj["details"] = details
return Response(
content=json.dumps(
{
"error": error_obj,
"request_id": getattr(request.state, "request_id", "unknown"),
}
),
status_code=status_code,
media_type="application/json",
headers={"X-Cashu": token} if token else {},
)
def create_upstream_error_response(
error: UpstreamError,
request: Request,
fallback_status: int = 502,
) -> Response:
"""Build an error response from an :class:`UpstreamError`, preserving its
structured ``code``, ``details``, and original ``status_code``."""
return create_error_response(
"upstream_error",
str(error),
error.status_code or fallback_status,
request=request,
code=getattr(error, "code", None),
details=getattr(error, "details", None),
)