examples of how to use the quasar api to pin files via http endpoints and ethereum smart contracts

quasar.js

const quasarUrl = 'http://quasar.yourdomain.com' // wherever you are hosting the server

// tell quasar to listen for pin events from a smart contract at contractAddress
async function addStorageContract(contractAddress) {
  return await fetch(`${quasarUrl}/api/v0/contracts`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({ contractAddress })
  })
}

// get a list of storage contracts that quasar is listening to for pin events
async function getStorageContracts() {
  const response = await fetch(`${quasarUrl}/api/v0/contracts`, {
    method: 'GET'
  })
  return await response.json()
}

// quasar optimistically pins your dag, then returns a hash for you to pass to a storage contract
// if the storage contract is registered with quasar, the pin is confirmed
// if the pin is never confirmed, quasar removes it after a week
async function dagPut(dag) {
  const response = await fetch(`${quasarUrl}/api/v0/dag/put`, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify(dag)
  })
  const hash = await response.text() 
  storageContract.invokePinMethod(hash)
  return hash
}

// same as above, but files instead of dags
async function addFile(file) {
  const response = await fetch(`${quasarUrl}/api/v0/files/add`, {
    method: 'POST',
    headers: {
      'Content-Type': 'multipart/form-data',
    },
    file
  })
  const hash = await response.text()
  storageContract.invokePinMethod(hash)
  return hash
}