withMutationJSON.js

// wrapper

import { graphql } from 'react-apollo';
import gql from 'graphql-tag';

export default function withMutation(name) {
  return graphql(gql`
    mutation ${name}($vars: JSON) {
      ${name}(vars: $vars)
    }
  `, {
    props: ({ownProps, mutate}) => ({
      [name]: vars => {
        return mutate({ 
          variables: { vars },
        });
      }
    }),
  });
  
}

// component

import { withMutation } from 'withMutation.js';

const MyComponent extends Component {
  fetchMetaData() {
    this.props.getMetaData({url: this.props.url}) /* get url from somewhere */
      .then(result => {/* do something with the result */})
      .catch(error => {/* do something with the error */})
  },
  render() {
    return (/* render component here */)
  }
}

export default withMutation('getMetaData')(MyComponent);

// schema

const schema = [`
type Mutation {
  getMetaData(
    vars: JSON
  ) : JSON
}
`];

// resolver

const rootResolvers = {
  Mutation: {
    getMetaData(root, { vars: { url } }, context) {
      const data = ... // make some kind of API call
      return data;
    },
  },
};