code: def index():
      content = request.get_json(force=True)
      if not content or not "X" in content:
          abort(400)
      X = np.array(content["X"])
      num_atoms = X.shape[0]
      x0 = X[:, 1:]
      a0 = X[:, :1]
  
      res = webapp.model.grad_one(x0, a0)
      res = res.reshape((num_atoms, 3))
  
      return flask.jsonify({"grad": res.tolist()}), 200
  
imports: import numpy
  from flask import request, abort, Flask
  import flask
label_desc: Use image node_id 2 for calling a global function with example usage: index() and returns: flask,  int