The Fiscal Information Exchange (iFIX) platform is an open-source solution designed to standardize and streamline the exchange of fiscal data among various government agencies, funding bodies, and implementing organizations. Built on the DIGIT platform, iFIX facilitates real-time, seamless communication of financial information, enhancing transparency, efficiency, and accountability in public finance management.

Key Architecture Highlights

• Distributed Reference Data Management: Each department or agency can host its own instance of the iFIX platform, maintaining autonomy over its fiscal data while adhering to standardized protocols for data exchange. This distributed approach ensures that departments manage their own data, reducing bottlenecks and enhancing data accuracy.

• Microservices-Based Architecture: Leveraging a microservices design, iFIX ensures that each component operates independently, promoting scalability, flexibility, and ease of maintenance. This modular approach allows for the seamless addition or modification of services without disrupting the entire system.

• Seamless Integration with External Systems: The platform employs adapters to connect with various external agency systems, facilitating the smooth transmission and reception of fiscal data. These adapters ensure compatibility with existing systems, minimizing the need for extensive overhauls.

• Enhanced Security and Reliability: iFIX incorporates multiple layers of security—ensuring data integrity, authentication, and secure data transmission—while its redundant design and failover mechanisms guarantee continuous operation in mission-critical environments.

• Flexible Deployment Options: Whether deployed on-premises, within a private cloud, or via a hybrid model, iFIX is designed to meet various infrastructure and performance requirements. This flexibility allows organizations to choose deployment strategies that align with their technical capabilities and policy requirements.

Multi-Layer Architecture

iFIX adopts a multi-layered, distributed architecture pattern, ensuring flexibility, maintainability, and scalability. Each layer comprises a set of microservices with specific roles and responsibilities, facilitating independent deployment, maintenance, and updates. This design enhances interoperability and allows for parallel development and testing.

Advantages of the Layered Architecture:

• Flexibility and Maintainability: Components can be updated or replaced independently, reducing system downtime and simplifying maintenance.

• Scalability: Each layer can be scaled independently to accommodate increasing loads or additional functionalities.

• Reusability: Components can be reused across different applications, promoting consistency and reducing development time.

• Parallel Development: Teams can work on different layers simultaneously, accelerating development and deployment cycles.

• Security: Different security levels can be configured for each layer, enhancing overall system security.

• Independent Testing: Components can be tested independently, ensuring robustness and reliability before integration.

This multi-layer architecture ensures that iFIX serves as a robust and adaptable platform for modernizing public finance management, aligning with strategic goals of transparency, efficiency, and accountability.

The Fiscal Information Exchange (iFIX) platform employs a hexagonal architecture, also known as the Ports and Adapters pattern, to facilitate seamless and standardized fiscal data exchange among various government entities. This architectural approach ensures that the core business logic remains isolated from external systems and technologies, enhancing flexibility and maintainability.

Key Components of iFIX Architecture

1. DIGIT Exchange

2. Program Service

3. Adapters

DIGIT Exchange

DIGIT Exchange acts as the secure and trusted bridge between independently deployed systems that need to communicate fiscal data. It ensures data integrity, non-repudiation, and secure transmission between producers (like program services) and consumers (like IFMS or auditing tools).

Core Responsibilities:

• Message Authentication & Signing: Ensures that all outgoing and incoming messages are cryptographically signed and verified, preventing tampering and ensuring authenticity.

• Event Publishing: Each successfully exchanged message is logged as an event. These events are published to Kafka and pushed to Elasticsearch to support operational dashboards and real-time monitoring.

• Interoperability Backbone: DIGIT Exchange makes it possible for different organizations or departments to operate independent systems while still collaborating and sharing data securely.

• Audit Trail & Observability: Tracks and stores the flow of all messages to enable full traceability and debugging capabilities across the exchange network.

Program Service

The Program Service is the domain-specific core service within iFIX that manages fiscal operations — including sanctions, allocations, and disbursements — under defined financial programs.

Key Features & Responsibilities:

• Program Definition: Allows administrators to define “programs” — logical boundaries for budget and fund flow such as health campaigns, infrastructure projects, or welfare schemes.

• Transaction Management: Each fiscal transaction (e.g., allocation or disbursement) is linked to a program and governed by its lifecycle.

• Validation & Business Rules: All incoming messages from the adapter are validated against business rules. This ensures that transactions are complete, legitimate, and follow the proper hierarchy of approval.

• Interaction with DIGIT Exchange: Valid messages are forwarded to DIGIT Exchange for further routing to external financial systems (e.g., IFMS). Invalid messages are rejected with precise error codes.

• State Management: Maintains records of program-wise amounts sanctioned, allocated, committed, and available for disbursement — enabling accurate fiscal control and audit readiness.

Adapters

Adapters are the integration glue of the iFIX ecosystem. They decouple the internal working of iFIX from the unique data formats, protocols, and workflows of external systems.

There are two types of adapters:

1. Producer Adapter: Sits on the side of a department or donor system that generates fiscal data.

2. Consumer Adapter: Placed at the system which is the recipient of fiscal data (e.g., an IFMS or treasury system).

Core Functions & Advantages:

• Data Transformation & Mapping: Converts messages between iFIX’s standardized fiscal event format and the target system’s native format (e.g., XML, JSON, SOAP). This ensures seamless compatibility regardless of the external system’s design.

• System-Agnostic Integration: Adapters can be easily configured or extended to integrate iFIX with any kind of system, including legacy platforms, ERP solutions, MIS dashboards, or financial gateways.

• Validation & Enrichment: Adapters can enrich messages (e.g., attaching metadata) or perform pre-validation before sending data to core services or external endpoints.

• Reusability & Portability: Once an adapter is built for a particular system (like a state’s IFMS), it can be reused across other programs or departments, accelerating rollouts.

• Loose Coupling: Adapters ensure that changes in external systems do not impact the core iFIX services, enabling independent evolution and easier upgrades.

Sequence Diagram

Overview

The DIGIT Exchange Service is a robust data interchange platform designed to facilitate the seamless and secure exchange of digital information between two endpoints. Built with a fixed schema for headers and dynamic messaging capabilities, this service ensures reliable communication while prioritizing data integrity and confidentiality.

Dependencies

DIGIT-exchange can implement any service if it has the same request structure as the program.

• Program Service

API Specifications

Base Path: /digit-exchange/

API Contract Link

API spec YAML is here. Click below to view it in Swagger Editor.

Swagger Editor

APIs

curl -L \
  --request POST \
  --url '/digit-exchange/v1/exchange/EXCHANGE_TYPE' \
  --header 'Content-Type: application/json' \
  --data '{
    "signature": "TgE1hcA2E+YPMdPGz4vveKQpR0x+pgzRTlet52qh63Kekr71vWWScXqaRFtQW64uRFZGBUhHYYZQ2y6LffwnNOOQhhssaThhqVBhXNEwX9i75SNYXi5XSJVDYzSyHrhF20HW6RE9mAVWdc80i7d+FXlh+b/U+fnj+SrZ2s6Xd0WUZvU29LgqeUpyznlWLu1mDdJxNZavsDLWmxjTnknqBjDvwSc35WhFDhXDA2lWmm8YpZ1Y6TBmvvtVS7mAOTnhFy9sdCbrLcfXk5QWIsdzlvPqlkvdwEf30OZ6ewb680Aj3hO2OT5LCv7iLyz7C7srnB9lJT5gXiw+eSnktPXlDA==",
    "header": {
      "message_id": "123",
      "message_ts": "text",
      "action": "create",
      "sender_id": "program@https://spp.example.org",
      "sender_uri": "https://spp.example.org/{namespace}/callback/on-create",
      "receiver_id": "program@https://pymts.example.org",
      "is_msg_encrypted": true
    },
    "message": "{\"location_code\":\"pg.citya\",\"name\":\"Test 1\",\"start_date\":0,\"end_date\":0,\"client_host_url\":\"https://unified-dev.digit.org\",\"function_code\":\"string\",\"administration_code\":\"string\",\"recipient_segment_code\":\"string\",\"economic_segment_code\":\"string\",\"source_of_fund_code\":\"string\",\"target_segment_code\":\"string\",\"currency_code\":\"string\",\"locale_code\":\"string\",\"status\":{\"status_code\":\"RECEIVED\",\"status_message\":\"string\"}}"
  }'

{
  "errors": [
    {
      "code": "text",
      "message": "text"
    }
  ]
}

Exchange Flow

Data Model

DB Schema Diagram

Web Sequence Diagrams

Sequence of exchange between two environments

Exchange Service example of an exchange

Overview

The Program Service is constructed using iFIX specifications and serves as an extensive platform aimed at simplifying program creation, sanction management, fund allocation, and disbursement execution. It equips organizations with essential tools to effectively oversee available funds and guarantee transparent and accountable distribution to designated beneficiaries.

Functional Overview

Funds Summary

1. IFMS adapter manages funds summary based on the head of accounts and SSU codes. It creates sanctions for each head of accounts and SSU details based on ULB tenant ID.

2. Three types of transactions can be received from the JIT VA API -

   • Initial Allotment - A new sanction will be created only if AllotmentTxnType is Initial Allotment.

   • Additional allotment - For this type of transaction it will update the amount of existing sanction.

   • Allotment withdrawal - It deducts the transaction amount from the sanction for this type of transaction.

Payment Instructions

• When a bill is approved this service creates payment using the expense service.

• Some consumers keep listening to the payment create Kafka topic and generate payment instructions (PI) using payment and bill details and post the PI to the IFMS system using JIT API.

• A new PI will be generated when enough funds are available for any head of accounts for that tenantId.

• Before posting the PI there were multiple enrichments like bank account details, org and individual details, etc.

• After creating the PI it deducts the available balance from the funds summary.

• If a PI is created for any payment then the user can not generate a PI again till the PI fails.

• It keeps a log of each status call of PI and saves it in the DB

Program Service takes care of Program, Sanction, Allocation and Disbursement using the standardized exchange interface.

iFIX API Specification

Implemented API Specifications

Base Path: /program-service/

API Contract Link

APIs

Data Model

DB Schema

Web Sequence Diagrams

Program

Sanction

Allocation

Disbursal