EX MCP Server

""" Cost estimation utilities for EX MCP. - Reads per-model prices from environment JSON maps - Computes estimated cost from usage tokens - Safe-by-default: if pricing not configured, returns 0.0 ENV - MODEL_INPUT_PRICE_JSON: {"model": dollars_per_MTok_input, ...} - MODEL_OUTPUT_PRICE_JSON: {"model": dollars_per_MTok_output, ...} - MODEL_COSTS_JSON: legacy single-number proxy (treated as output $/MTok) """ from __future__ import annotations import json import os from typing import Optional, Tuple def _load_json_map(env_key: str) -> dict[str, float]: raw = os.getenv(env_key, "{}") try: data = json.loads(raw) if isinstance(data, dict): return {str(k): float(v) for k, v in data.items()} except Exception: pass return {} def get_price_maps() -> Tuple[dict[str, float], dict[str, float]]: """Return (input_prices, output_prices) per model from env. Falls back to MODEL_COSTS_JSON as output prices when MODEL_OUTPUT_PRICE_JSON is empty. """ inp = _load_json_map("MODEL_INPUT_PRICE_JSON") outp = _load_json_map("MODEL_OUTPUT_PRICE_JSON") if not outp: outp = _load_json_map("MODEL_COSTS_JSON") return inp, outp def estimate_cost(model: str, input_tokens: int = 0, output_tokens: int = 0) -> float: """Estimate dollar cost for a call given token usage and env pricing. Returns 0.0 when prices unknown. """ inp, outp = get_price_maps() in_rate = inp.get(model) out_rate = outp.get(model) cost = 0.0 if in_rate is not None and input_tokens: cost += (input_tokens / 1_000_000.0) * in_rate if out_rate is not None and output_tokens: cost += (output_tokens / 1_000_000.0) * out_rate return round(cost, 6)