text: 
  // this file was generated by ./scripts/generate-web-api
  import exec from './_exec'
  import validate from './_validate'
  
  export default function channelshistory(params, callback) {
    let ns = 'channels.history'
    let err = validate(ns, params)
    if (err) {
      callback(err)
    }
    else {
      exec(ns, params, callback)
    }
  }
  