API Framework

Description

API Framework is a layered API application framework designed to provide a structured foundation for building maintainable, scalable, and extensible web services.

The framework separates framework capabilities, application capabilities, resource management, request processing, policy enforcement, and runtime execution into clearly defined architectural layers. It provides standardized request handling, response generation, execution pipelines, reusable utility services, and runtime orchestration while maintaining strict ownership boundaries between framework and application components.

The framework supports:

• API request routing
• Request processing
• Response generation
• Policy-driven execution
• Authentication and authorization pipelines
• Rate limiting and validation policies
• Runtime lifecycle management
• Reusable infrastructure services

The architecture is organized into four primary layers:

• Data — Framework and application resources.
• Essential — Reusable framework capabilities and infrastructure.
• Operational — Application-specific business capabilities and policies.
• Run — Runtime initialization, execution, and request processing.

This separation enables developers to focus on application behavior while relying on a consistent framework foundation for API processing, security, policy enforcement, utility services, and runtime coordination.

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Purpose

API Framework exists to provide a consistent, maintainable, and extensible architecture for building API-driven applications while establishing clear boundaries between framework responsibilities and application responsibilities.

Objectives

• Establish clear separation of concerns.
• Standardize API request and response processing.
• Distinguish framework-owned and application-owned resources.
• Provide reusable infrastructure and utility capabilities.
• Centralize policy enforcement and access control.
• Simplify application development through a structured architecture.
• Improve maintainability and scalability.
• Enable controlled application extensibility.
• Protect internal framework implementation details.
• Encourage consistent API design and execution patterns.

Design Principles

Layered Architecture

Each architectural layer is responsible for a specific concern and communicates through clearly defined boundaries.

Ownership Separation

Framework-owned capabilities remain separate from application-owned capabilities to prevent implementation leakage and architectural drift.

Extensibility

Applications extend the framework through approved extension surfaces without modifying framework internals.

Reusability

Common functionality is implemented once and reused throughout both framework and application layers.

Encapsulation

Internal framework implementation details remain hidden behind stable interfaces.

Policy-Driven Execution

Request processing and business operations are governed through dedicated execution pipelines and policy enforcement mechanisms.

Consistency

Request handling, response generation, execution patterns, and resource management follow standardized conventions throughout the framework.

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Architecture

High-Level Structure

source
├── data
├── essential
├── operational
└── run

The architecture is organized into four primary layers that collectively provide resource management, reusable framework capabilities, application capabilities, policy enforcement, and runtime execution.

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Data Layer

The Data Layer stores all framework-owned and application-owned resources.

source/data
├── framework
│   ├── metadata
│   └── glossary
└── application
    ├── metadata
    └── glossary

Responsibilities

• Store framework metadata and configuration resources.
• Store framework glossary and terminology resources.
• Store application metadata and configuration resources.
• Store application glossary and terminology resources.
• Provide centralized resource ownership boundaries.

Ownership

Area	Owner
data/framework	Framework
data/application	Application

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Essential Layer

The Essential Layer contains reusable framework capabilities, infrastructure services, request processing capabilities, and shared functionality.

source/essential
├── exchange
├── hidden
└── visible

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Essential Exchange

Provides the framework API interaction model.

exchange
├── router
├── request
├── response
└── imperative

Responsibilities

• API request routing.
• Request processing.
• Response generation.
• Imperative execution.
• Framework-level API orchestration.

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Essential Hidden

Contains internal framework capabilities that are not intended for application consumption.

hidden
└── service
    └── management

Management

Framework runtime management capabilities.

management
├── initialize
├── lifecycle
├── config
├── monitor
└── cleaner

Initialize

Responsible for framework and runtime initialization.

Lifecycle

Responsible for:

• Startup
• Shutdown
• Restart operations

Config

Responsible for runtime configuration management.

Monitor

Responsible for runtime health and operational monitoring.

Cleaner

Responsible for maintenance and cleanup operations.

Responsibilities

• Runtime initialization.
• Lifecycle management.
• Runtime configuration.
• Monitoring and observability.
• Maintenance operations.

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Essential Visible

Contains reusable framework capabilities available to applications.

visible
└── service
    └── helper

Available helper capabilities include:

retriever
status
log
progress
filesystem
datetime
marker
key
hash
cipher
codec

Responsibilities

• Resource retrieval.
• Status reporting.
• Structured logging.
• Progress tracking.
• Filesystem operations.
• Date and time utilities.
• Identifier generation.
• Key generation.
• Hash calculation and comparison.
• Encryption and decryption.
• Encoding and decoding.

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Operational Layer

The Operational Layer contains all application-specific behavior, business capabilities, and policy definitions.

source/operational
├── exchange
├── pipeline
└── service

This is the primary application development area.

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Operational Exchange

Provides the application API interaction model.

exchange
├── router
├── request
├── response
└── imperative

Responsibilities

• Application request routing.
• Application request processing.
• Application response generation.
• Imperative execution.
• Application-level API orchestration.

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Operational Pipeline

Contains application-defined policy execution capabilities.

pipeline
└── policy
    ├── validation
    └── ratelimit

Validation

Responsible for request validation policies.

Examples:

• Schema validation
• Payload validation
• Business rule validation

Rate Limit

Responsible for request throttling and usage control.

Examples:

• Client limits
• Endpoint limits
• Resource protection

Responsibilities

• Request validation.
• Request throttling.
• Policy definition.
• Application-specific execution controls.

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Operational Service

Contains application-specific business capabilities.

service
└── [service]
    └── [feature]

Example:

service
├── user
│   ├── create
│   └── delete
├── customer
│   └── register
└── invoice
    └── generate

Feature structure:

service
└── user
    └── create
        ├── function.go
        └── function-data.json

Responsibilities

• Implement business rules.
• Manage application workflows.
• Execute domain-specific operations.
• Consume reusable framework capabilities.

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Runtime Layer

The Runtime Layer initializes, secures, coordinates, and executes API requests.

source/run
├── exchange
├── pipeline
└── main

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Runtime Exchange

Receives incoming requests and dispatches execution.

exchange
├── router
├── request
├── response
└── imperative

Responsibilities

• Runtime request handling.
• Request dispatching.
• Response delivery.
• Execution coordination.

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Runtime Pipeline

Provides execution-time access control and policy enforcement.

pipeline
├── access
└── policy

Access

Access control pipeline.

access
├── authentication
└── authorization

Authentication

Verifies the identity of the request originator.

Examples:

• API Keys
• JWT Tokens
• Session Authentication

Authorization

Determines whether authenticated entities can access requested resources.

Examples:

• Role-based access control
• Permission-based access control
• Scope validation

Policy

Responsible for runtime policy enforcement.

policy
└── enforce.go

Responsibilities:

• Execute policy decisions.
• Enforce validation outcomes.
• Enforce access decisions.
• Coordinate runtime controls.

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Runtime Main

Application bootstrap and startup.

main
└── main.go

Responsibilities

• Framework initialization.
• Application initialization.
• Runtime startup.
• Lifecycle coordination.
• API server bootstrap.

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Request Lifecycle

The framework follows a layered request processing model.

Client Request
      │
      ▼
Runtime Exchange
      │
      ▼
Access Pipeline
(Authentication / Authorization)
      │
      ▼
Policy Enforcement
      │
      ▼
Application Exchange
      │
      ▼
Application Policies
(Validation / Rate Limiting)
      │
      ▼
Application Service
      │
      ▼
Framework Services
      │
      ▼
Resource Layer
      │
      ▼
Response

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Ownership Model

Layer	Owner	Responsibility
data/framework	Framework	Framework resources
data/application	Application	Application resources
essential	Framework	Reusable framework capabilities
operational	Application	Business capabilities and policies
run	Framework	Runtime execution and enforcement

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Extension Surface

Applications are expected to extend the framework through the following locations:

source/data/application
source/operational

Applications should consume reusable framework capabilities from:

source/essential/visible

Applications should not directly depend on:

source/essential/hidden

as these components are considered internal framework implementation details and may change without notice.