File size: 7,923 Bytes
2021f39 | 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 | #!/usr/bin/env python3
# Minimal MCP-style tools server.
# Endpoints:
# - GET /health
# - GET /tools -> list available tools and schemas
# - POST /call -> {"tool": "calculator", "input": "sqrt(144)"}
import os
import re
import ast
import math
import json
from typing import Dict, Any
import requests
from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
import uvicorn
from prometheus_client import Counter, Histogram, make_asgi_app
from opentelemetry import trace
from opentelemetry.sdk.resources import Resource
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import SimpleSpanProcessor
from opentelemetry.sdk.trace.export import ConsoleSpanExporter
PORT = int(os.getenv("PORT", "7001"))
app = FastAPI(title="Nova Tools MCP", version="0.1.0")
app.add_middleware(
CORSMiddleware,
allow_origins=["*"],
allow_credentials=True,
allow_methods=["*"],
allow_headers=["*"],
)
REQUESTS = Counter("mcp_requests_total", "MCP requests", ["route"])
LATENCY = Histogram("mcp_request_latency_seconds", "Latency", ["route"])
# OTel tracer to console
resource = Resource.create({"service.name": "nova-tools-mcp"})
provider = TracerProvider(resource=resource)
provider.add_span_processor(SimpleSpanProcessor(ConsoleSpanExporter()))
trace.set_tracer_provider(provider)
tracer = trace.get_tracer(__name__)
def safe_calc_eval(expr: str) -> str:
allowed_funcs = {
'sqrt': math.sqrt, 'log': math.log, 'log10': math.log10,
'sin': math.sin, 'cos': math.cos, 'tan': math.tan,
'exp': math.exp, 'pow': math.pow, 'abs': abs,
'floor': math.floor, 'ceil': math.ceil
}
allowed_names = {'pi': math.pi, 'e': math.e, **allowed_funcs}
def eval_node(node: ast.AST):
if isinstance(node, ast.Expression):
return eval_node(node.body)
if isinstance(node, ast.Constant) and isinstance(node.value, (int, float)):
return node.value
if isinstance(node, ast.UnaryOp) and isinstance(node.op, (ast.UAdd, ast.USub)):
val = eval_node(node.operand)
return +val if isinstance(node.op, ast.UAdd) else -val
if isinstance(node, ast.BinOp) and isinstance(node.op, (ast.Add, ast.Sub, ast.Mult, ast.Div, ast.Mod, ast.Pow, ast.FloorDiv)):
left, right = eval_node(node.left), eval_node(node.right)
return {
ast.Add: lambda a, b: a + b,
ast.Sub: lambda a, b: a - b,
ast.Mult: lambda a, b: a * b,
ast.Div: lambda a, b: a / b,
ast.Mod: lambda a, b: a % b,
ast.Pow: lambda a, b: a ** b,
ast.FloorDiv: lambda a, b: a // b,
}[type(node.op)](left, right)
if isinstance(node, ast.Call) and isinstance(node.func, ast.Name):
func_name = node.func.id
if func_name not in allowed_funcs:
raise ValueError(f"Function '{func_name}' not allowed")
args = [eval_node(arg) for arg in node.args]
return allowed_funcs[func_name](*args)
if isinstance(node, ast.Name) and node.id in allowed_names:
return allowed_names[node.id]
raise ValueError("Unsupported expression")
tree = ast.parse(expr, mode='eval')
return str(eval_node(tree))
def http_get(url: str) -> str:
try:
r = requests.get(url, timeout=10)
r.raise_for_status()
title = re.search(r"<title[^>]*>(.*?)</title>", r.text or "", flags=re.I|re.S)
t = title.group(1).strip() if title else "(no title)"
preview = re.sub(r"\s+", " ", (r.text or ""))[:300]
return f"title: {t}\npreview: {preview}"
except Exception as e:
return f"http_get error: {e}"
TOOLS = {
"calculator": {
"schema": {"type": "object", "properties": {"input": {"type": "string"}}, "required": ["input"]},
"run": lambda arg: safe_calc_eval(arg),
},
"http_get": {
"schema": {"type": "object", "properties": {"input": {"type": "string", "format": "uri"}}, "required": ["input"]},
"run": lambda url: http_get(url),
},
"time": {
"schema": {"type": "object", "properties": {"input": {"type": "string"}}, "required": []},
"run": lambda _=None: __import__("datetime").datetime.now().isoformat(),
},
}
_DYNAMIC: Dict[str, Dict[str, Any]] = {}
@app.get("/health")
def health() -> Dict[str, Any]:
REQUESTS.labels(route="health").inc()
return {"status": "ok", "port": PORT, "dynamic_tools": list(_DYNAMIC.keys())}
@app.get("/tools")
def list_tools() -> Dict[str, Any]:
REQUESTS.labels(route="tools").inc()
combined = {name: {"schema": meta["schema"]} for name, meta in TOOLS.items()}
combined.update({name: {"schema": meta.get("schema", {})} for name, meta in _DYNAMIC.items()})
return combined
@app.post("/call")
async def call(req: Request) -> JSONResponse:
with LATENCY.labels(route="call").time():
REQUESTS.labels(route="call").inc()
body = await req.json()
tool = str(body.get("tool", "")).strip()
inp = body.get("input", "")
if tool in TOOLS:
try:
out = TOOLS[tool]["run"](inp)
return JSONResponse(status_code=200, content={"tool": tool, "output": out})
except Exception as e:
return JSONResponse(status_code=500, content={"error": str(e)})
if tool in _DYNAMIC:
meta = _DYNAMIC[tool]
kind = meta.get("type")
if kind == "gorilla":
# Forward to Gorilla bridge; expects dict input
base = meta.get("base", "http://127.0.0.1:8089")
try:
payload = inp if isinstance(inp, dict) else {"prompt": str(inp)}
r = requests.post(f"{base}/gorilla/completions", json=payload, timeout=30)
return JSONResponse(status_code=r.status_code, content=r.json())
except Exception as e:
return JSONResponse(status_code=502, content={"error": f"gorilla error: {e}"})
if kind == "http":
base = meta.get("base", "")
path = meta.get("path", "/")
method = str(meta.get("method", "POST")).upper()
url = (base.rstrip("/") + path) if base else path
try:
if method == "POST":
r = requests.post(url, json=inp if isinstance(inp, dict) else {"input": inp}, timeout=30)
else:
r = requests.get(url, timeout=30)
content = r.json() if r.headers.get("content-type", "").startswith("application/json") else {"text": r.text}
return JSONResponse(status_code=r.status_code, content=content)
except Exception as e:
return JSONResponse(status_code=502, content={"error": f"http tool error: {e}"})
return JSONResponse(status_code=400, content={"error": f"unsupported dynamic tool type: {kind}"})
return JSONResponse(status_code=400, content={"error": f"unknown tool: {tool}"})
@app.post("/register_tool")
async def register_tool(req: Request) -> JSONResponse:
REQUESTS.labels(route="register").inc()
body = await req.json()
name = str(body.get("name", "")).strip()
if not name:
return JSONResponse(status_code=400, content={"error": "missing name"})
_DYNAMIC[name] = {
"type": body.get("type"),
"schema": body.get("schema", {}),
"base": body.get("base", ""),
}
return JSONResponse(status_code=200, content={"registered": name})
# Prometheus metrics
metrics_app = make_asgi_app()
app.mount("/metrics", metrics_app)
if __name__ == "__main__":
uvicorn.run(app, host="0.0.0.0", port=PORT)
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