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Sending RFQs

After your customer selects an Offering, the next step is to send a Request for Quote (RFQ) to the PFI in order to initiate the transaction. The Offering provided an estimate, but the Quote will provide a formal offer based on the financial transaction the customer is requesting as well as the payment methods provided.

Create the RFQ

An RFQ is a structured tbDEX message that specifies the details of the transaction your customer wishes to make. It includes information about the Offering, payment methods, and any required verifiable credentials (VCs).

To create the message, construct an RFQ passing metadata and data:

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metadata

The metadata properties identify the DIDs of the sender (your customer), the recipient (the PFI), and the version of the tbDEX protocol you're using:

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data

The data properties contain the specifics of the transaction, such as the id of the Offering you're requesting the Quote for, payment methods, and credentials:

• offeringId - The unique identifier of the PFI's Offering the customer is interested in
• payin - How the customer intends to pay the PFI
  • kind - Type of payment method e.g. BTC_ADDRESS, DEBIT_CARD, MOMO_MPESA
  • amount - Total amount of currency the customer wants to pay in exchange for payout currency
  • paymentDetails - The exact details of the payment method. As this information is sensitive, the SDK will convert these details into salted hashes
• payout - How the customer wishes to receive the payout from the PFI
  • kind - Type of payment method e.g. BTC_ADDRESS, BANK_ACCOUNT, MOMO_MPESA
  • paymentDetails - The exact details of the payment method. As this information is sensitive, the SDK will convert these details into salted hashes
• claims - The VCs that satisfy the requirements of the Offer. As this information is sensitive, the SDK will convert these details into salted hashes

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Verify RFQ Data

Before sending the RFQ to the PFI, you can verify that the data within the RFQ satisfies the Offering's requirements.

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This will throw an error for any of the following:

• data.offeringId doesn't match the provided Offering's id
• data.payin.amount exceeds the provided Offering's max units allowed or is below the Offering's min units allowed
• data.payin.kind does not match the provided Offering's payin kinds
• data.payout.kind does not match the provided Offering's payout kinds
• data.payin.paymentDetails doesn't satisfy the Offering's requiredPaymentDetails
• data.payout.paymentDetails doesn't satisfy the Offering's requiredPaymentDetails
• data.claims does not contain JWTs for VCs that match the Offering's requiredClaims

Example error output

Error: offering does not support rfq's payinMethod kind. (rfq) BTC_ADDRESS was not found in: [BANK_ACCOUNT] (offering)

Sign the RFQ

Signing the RFQ ensures its authenticity. You can do so with the customer's Bearer DID:

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Send RFQ to PFI

Use TbdexHttpClient to send the RFQ to the PFI. If no error is thrown, the RFQ has been successfully sent to the PFI and an exchange has been created. This exchange serves as a thread of messages between your application and the PFI regarding this transaction.

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The next message written to the exchange will be a Quote from the PFI. You'll need to poll the PFI to receive the Quote and all other messages within the exchange, unless you provide an replyTo callback when sending the RFQ.

Optional Callback

If your wallet application has a deployed server, you can provide a callback when sending the RFQ. Callbacks are fully qualified URIs (DID or URL) that can be provided to the PFI via the optional replyTo property.

If replyTo is provided, the PFI will send all new messages of the exchange to the supplied URI. This URI is scoped to each exchange, allowing you to specify a different URI per exchange if desired.

No Callback

If a callback is not provided, you'll need to poll the PFI to receive the Quote and all other messages within the exchange.

Callback as a URL

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Callback as a DID

To provide your wallet application's DID as the replyTo property, it must have a service type of tbdex.

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To use your DID as the replyTo, you'll provide its uri.

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