Swap tokens

import { TronWeb } from 'tronweb'

const tronWeb = new TronWeb({ fullHost: 'https://api.trongrid.io' }) // sandbox: https://nile.trongrid.io
const sign = (tx) => tronWeb.trx.sign(tx, process.env.USER_PRIVATE_KEY)
const base = { chain: 'tron', mode: 'sunswap_swap', environment: 'live' }

const intent = {
  user_address: 'TXyz...',
  token_in: 'TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t', // USDT
  token_out: 'TToken...',
  amount_in: '10000000',   // base units of token_in
  slippage_bps: 100,       // 1%
  recipient: 'TXyz...',    // must equal user_address
}

let state = await call('/chain_relayers/portal/estimate', { ...base, payload: intent })

while (state.nextAction !== 'done') {
  if (state.nextAction === 'wait') {
    await new Promise((resolve) => setTimeout(resolve, 2000))
  } else {
    // 1. Build the current stage
    const draft = await call('/chain_relayers/portal/construct-tx', {
      ...base,
      payload: { session_id: state.sessionId },
    })

    // 2. Sign exactly what was returned, in order
    const payload = draft.stage === 'setup'
      ? {
          session_id: draft.sessionId,
          draft_id: draft.draftId,
          signed_txs: await Promise.all(
            draft.unsignedTxs.map(async (entry) => ({ id: entry.id, tx: await sign(entry.tx) })),
          ),
        }
      : { session_id: draft.sessionId, draft_id: draft.draftId, signed_tx: await sign(draft.unsignedTxs[0].tx) }

    // 3. Execute and wait for this stage to finish
    const run = await call('/chain_relayers/portal/execute', {
      ...base,
      idempotencyKey: draft.executeIdempotencyKey,
      payload,
    })
    const operation = await waitForOperation(run.operationId) // see Track status
    if (operation.status !== 'completed') throw new Error(`${draft.stage} ${operation.status}: ${operation.errorCode}`)
  }

  // 4. Ask what comes next
  state = await call('/chain_relayers/portal/estimate', {
    ...base,
    payload: { ...intent, session_id: state.sessionId },
  })
}