Building the MW-JSON Standard

Interoperability in the African fintech landscape is notoriously difficult. In Malawi, connecting a modern digital wallet to a legacy banking system often meant writing custom integration layers for every single partner.

This is why I built the MW-JSON Standard.

The Problem with Custom Integrations

When building malawi-pay-standard, we noticed a pattern:

1. Bank A uses XML/SOAP.
2. Telco B uses a proprietary REST API.
3. Startup C uses GraphQL.

Every new connection scaled at $O(n^2)$ complexity.

// The old way: A tangled mess of custom parsers
func HandlePayment(provider string, payload []byte) error {
    switch provider {
    case "bank_a":
        return parseSOAP(payload)
    case "telco_b":
        return parseREST(payload)
    default:
        return ErrUnknownProvider
    }
}

The Solution: A Unified Protocol

MW-JSON provides a single, strongly-typed JSON schema for all financial transactions in the region. It handles currency conversion, KYC metadata, and asynchronous callbacks natively.

The goal wasn't to replace existing APIs, but to provide a translation layer that everyone could agree on.

Key Features

• Deterministic: Exactly-once semantics via idempotent transaction IDs.
• Fast: Built in Go, the translation layer adds less than 2ms of overhead.
• Secure: Native support for asymmetric payload signing.

Check out the GitHub repository to see the full specification.