5.8 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:
Variables
- blockchain_CIC_Supply = the total supply of the CIC on the blockchain
- blockchain_CIC_reserve = the total reserve (xDAI) of the CIC on the blockchain
- trr = the connector weight on blockchain converter between supply and reserve
- FLoat CIC: THe amount of CIC supply we have in our master wallet
- FLoat Mpesa: THe amount of Mpesa supply we have in our PayBill account
- total_CIC_sent = the total amount of CIC that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
- total_CIC_Reserve_Sent = the total amount of Reserve (xDAI) that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
- total_CIC_recieved = the total amount of CIC that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
- total_CIC_Reserve_recieved = the total amount of Reserve (xDAI) that has been sent to users from our Float account - this needs to be updated for each conversion and when clearing
- CIC_supply_b: blockchain_CIC_Supply - total_CIC_sent + total_CIC_recieved = this simulates/tracks the changes to the blockchain
- CIC_reserve_b: blockchain_CIC_reserve - total_CIC_Reserve_Sent + total_CIC_Reserve_recieved = this simulates/tracks the changes to the blockchain
- CIC_excahnge_amount = the amount of CIC they user has sent to exhange
- Mpesa_excahnge_amount = the amount of MPesa the user has sent to exhange
- Rate: USD -> KSH
- Rate: KSH -> USD
- The account to which CIC are sent should be a Agent account
- The cash-out rules for a chama (minimum and time limit)
- Alert balance levels
- Fees: Sarafu to Mpesa FeeCC2M = 2%
- Fees: Sarafu to Mpesa FeeM2CC = 2%
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
- mpesa given The amount of Mpesa given should be calculated as follows:
The Reserve (xDAI) pulled out
reserveOut_xDAI = CIC_reserve_b * (Math.pow(1 + (-1 * CIC_excahnge_amount) / CIC_supply_b, 1 / trr) - 1) --> this should be calculated as it is done on contract
- Mpesa_out = reserveOut_xDAI USD => KSH rate
- Mpesa_given = Mpesa_out - Mpesa_out*S22M (fee) this is the amount of Mpesa sent to the user
- Update CIC variables on database:
- total_CIC_recieved+= CIC_excahnge_amount
- total_CIC_Reserve_Sent+= 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
- Mpesa_excahnge_amount The amount of CIC given should be calculated as follows:
- reserveIn_xDAI = Mpesa_excahnge_amount KSH => USD rate
The amount cashed in = cash_in_amount
CIC_Created = CIC_supply_b * (Math.pow(1 + reserveIn_xDAI / CIC_reserve_b, trr) - 1) --> this should be calculated as it is done on contract
- CIC_given = CIC_Created - CIC_created*FeeM2CC ()
- 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
- Update CIC variables on database:
- total_CIC_sent+= CIC_excahnge_amount
- total_CIC_Reserve_recieved+= reserveIn_xDAI
Exchange Rate
When dislaying the SPOT price or excahnge rate to a user we should use the following formula:
Exchange Price = CIC_reserve_b / (CIC_supply_b * trr)
User Interface
-
When a user chooses to ``Redeem```:
- They should enter the amount (limited to the max in their balance)
- They should get a confirmation Based on the above equations:
- The user should be asked you will revice Mpesa_given for CIC_excahnge_amount: Please type your PIN to confirm
- The user should get a Mpesa responce for recieving the Mpesa
-
When a user chooses to ``Contribute```:
- They should enter the amount of Mpesa they wish to contribute
- They should get a confirmation:
- Based on the above equations:
- The user should be asked you will revice CIC_given for Mpesa_excahnge_amount: Please type your PIN to confirm
- They will then get instructions on USSD as well as a SMS on how to send Mpesa or Bonga boints to our Lipa na Mpesa
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).