3.6 KiB
3.6 KiB
Incoming Sarafu
When users exchange CIC <> National Currency we have to manually send them Mpesa or CIC. We would like to automate this.
Solution
Configure - using our own system AfricasTalking API to automatically send Sarafu / Mpesa based on rules:
Incoming Sarafu Rules - MPESA out
- white list The chama (group accounts only but eventually anyone) must only be able to cash out - using the exchange option to an Agent account
- amount The max cash out is the minimum of (30,000 Sarafu, half their balance, their total amount of outward trade volume to other users (standard transactions)
- time They can only cash out once per month
- rate The Sarafu (and their community) to Mpesa rate should be calculated as follows:
- CIC_supply_b: Get the total CIC supply off blockchain - the amount of CIC_burn
- total_reserve_b: Get the total reserve off blockchain - the amount of cash_out we've gotten (in USD)
- CIC_burn_amount = whatever they have sent to exhange
The Reserve (xDAI) pulled out
const reserveOut_xDAI = total_reserve_b * (Math.pow(1 + (-1 * CIC_burn) / CIC_supply_b, 1 / trr) - 1);
- Mpesa_out = reserveOut_xDAI USD => KSH rate
- reserve_given = reserve_out - CIC_created*fee (0.02) (this is given to the user)
- Simulate as if done on blockchain .... new_cic_supply_b = cic_supply_b - CIC_burn
- Simulate as if done on blockchain .... new_total_reserve_b = total_reserve_b - reserveOut_xDAI
Outgoing Sarafu Rules - MPESA In
- white list Only users sending via paybill receive Sarafu. Non users receive a invitation to join Sarafu sms (alert to admins there was a donation).
- amount The max sarafu out is 20,000 Sarafu per user, KYC_limit max, supply_max
- time No limit
- rate The Mpesa to Sarafu (and their community) rate should be calculated as follows:
- CIC_supply_b: Get the total CIC supply off blockchain + the amount of CIC_given
- total_reserve_b: Get the total reserve off blockchain + the amount of cash_in we've gotten (in USD)
- cash_in_amount = Mpesa_in KSH -> USD rate (what is the current USD <> KSH rate)
The amount cashed in = cash_in_amount
const CIC_Created = cic_supply_b * (Math.pow(1 + cash_in_amount / total_reserve_b, trr) - 1);
- CIC_given = CIC_Created - CIC_created*fee (0.02)
- Simulate as if done on blockchain .... new_cic_supply_b = cic_supply_b + CIC_given
- Simulate as if done on blockchain .... new_total_reserve_b = total_reserve_b + cash_in_amount
Security
- Balance alerts: On both Mpesa and CIC balances: The paybill from which Sarafu is sent needs to send a sms and email alert when low
- Failure alerts: If the API session fails an sms and email alert should be sent
- Reject on not enough Mpesa balance: If there is not enough Mpesa (on incoming Sarafu) the transaction should be rejected and an email sent to admin along with a SMS to admin and user (Sarafu should not be taken from user). (message should be visible also on mgmt platform txn view and user view and admin view).
- Reject on not enough Sarafu balance: If there is not enough Sarafu (on incoming Mpesa) the transaction should be rejected and an email sent to admin along with a SMS to admin and user (Mpesa should not be taken from user). (message should be visible also on mgmt platform txn view and user view and admin view).
Variables
- The account from which Sarafu is sent should be a Agent account
- The cash-out rules for a chama (minimum and time limit)
- Alert balance levels
- Fees: Mpesa to Sarafu
- Fees: Sarafu to Mpesa