API: APIs

Document Type

Code: API
Name: APIs
Domain: Technology & Data

Abstract

This specification defines the APIs document type within the BSpec 1.0 Universal Business Specification Standard. It establishes normative requirements, structured templates, and implementation guidance for organizations documenting apis within the technology-data domain. This specification enables systematic, machine-readable documentation that supports strategic planning, operational execution, and organizational alignment.

Purpose and Scope

The APIs document defines systematic approaches to designing, implementing, and managing application programming interfaces that enable business capabilities through effective integration, developer experience, and scalable service delivery. It establishes API frameworks that ensure security, performance, and strategic alignment.

Document Metadata Schema

yaml

---
id: API-{api-name}
title: "API — {API Name}"
type: API
status: Draft|Review|Approved|Active|Deprecated
version: 1.0.0
owner: API-Team|API-Owner
stakeholders: [api-team, development-team, security-team, api-consumers]
domain: technology
priority: Critical|High|Medium|Low
scope: api-development
horizon: tactical
visibility: internal

depends_on: [SYS-*, DAT-*, SEC-*, ARC-*]
enables: [PER-*, QUA-*, INT-*, DEV-*]

api_type: REST|GraphQL|gRPC|WebSocket|Webhook
api_audience: Internal|Partner|Public
api_maturity: Alpha|Beta|Stable|Deprecated
protocol: HTTP|HTTPS|WebSocket|gRPC

success_criteria:
  - "API delivers consistent and reliable functionality"
  - "API provides excellent developer experience"
  - "API meets performance and security requirements"
  - "API enables effective system integration"

assumptions:
  - "API requirements are clearly defined and validated"
  - "Consumer needs and use cases are understood"
  - "Security and compliance requirements are established"

constraints: [Technology and security constraints]
standards: [API design and development standards]
review_cycle: monthly
---

Content Structure Template

markdown

# API — {API Name}

## Executive Summary
**Purpose:** {Brief description of API purpose and capabilities}
**Type:** {REST|GraphQL|gRPC|WebSocket|Webhook}
**Audience:** {Internal|Partner|Public}
**Maturity:** {Alpha|Beta|Stable|Deprecated}

## API Overview

### Business Purpose
- **Business Function:** {Business capability provided by API}
- **Value Proposition:** {Value delivered to API consumers}
- **Use Cases:** {Primary use cases and scenarios}
- **Target Consumers:** {Who will use this API}

### Technical Overview
    ```yaml
    api_profile:
      protocol: {HTTP|HTTPS|WebSocket|gRPC}
      style: {REST|GraphQL|RPC}
      data_format: {JSON|XML|Protocol Buffers}
      base_url: {Base URL or endpoint}
    
      authentication:
        method: {API Key|OAuth 2.0|JWT|mTLS}
        authorization: {Scopes or permissions model}
    ```

### API Scope and Boundaries
- **Functional Scope:** {What the API covers and excludes}
- **Data Scope:** {What data is exposed through the API}
- **Consumer Scope:** {Who can access the API}
- **Rate Limits:** {Usage limitations and quotas}

## API Design

### Resource Model
    ```yaml
    resources:
      primary:
        - resource: {Resource name}
          description: {Resource description}
          operations: [obtain, POST, PUT, DELETE]
          relationships: [related_resource1, related_resource2]
    
      supporting:
        - resource: {Supporting resource}
          purpose: {Supporting function}
          operations: [operation_list]
    ```

### Endpoint Specification
| Method | Endpoint | Description | Request | Response | Status Codes |
|--------|----------|-------------|---------|----------|--------------|
| {HTTP Method} | {/resource/path} | {Operation description} | {Request format} | {Response format} | {200, 400, 404, 500} |

### Data Models
    ```yaml
    data_models:
      {ModelName}:
        description: {Model description}
        properties:
          - name: {property_name}
            type: {string|integer|boolean|array|object}
            required: {true|false}
            description: {Property description}
            validation: {Validation rules}
    
        example:
          {property_name}: {example_value}
    ```

## API Documentation

### OpenAPI Specification
    ```yaml
    openapi: 3.0.3
    info:
      title: {API Title}
      description: {API Description}
      version: {API Version}
      contact:
        name: {Contact name}
        email: {[email protected]}
    
    servers:
      - url: {API Base URL}
        description: {Environment description}
    ```

### Request/Response Examples
    ```yaml
    examples:
      create_resource:
        request:
          method: POST
          endpoint: /resources
          headers:
            Authorization: Bearer {token}
            Content-Type: application/json
          body: |
            {
              "name": "Example Resource",
              "description": "Resource description"
            }
    
        response:
          status: 201
          headers:
            Location: /resources/123
          body: |
            {
              "id": 123,
              "name": "Example Resource",
              "created_at": "2023-01-01T00:00:00Z"
            }
    ```

### Error Handling
- **Error Format:** {Consistent error response structure}
- **Error Codes:** {Application-specific error codes}
- **Error Messages:** {User-friendly error messages}
- **Error Recovery:** {Guidelines for error handling and recovery}

## Security and Authentication

### Authentication Mechanisms
    ```yaml
    authentication:
      api_key:
        location: {Header|Query Parameter}
        name: {X-API-Key}
        description: {API key authentication}
    
      oauth2:
        flows: [authorization_code, client_credentials]
        scopes:
          - scope: {read:resources}
            description: {Scope description}
    ```

### Authorization Model
- **Permission Model:** {RBAC|ABAC|Scope-based}
- **Resource Access:** {Who can access what resources}
- **Operation Authorization:** {Who can perform what operations}
- **Data Filtering:** {Row and column level security}

### Security Controls
    ```yaml
    security:
      transport_security:
        tls_version: {TLS 1.2+}
        certificate_validation: {Certificate requirements}
    
      api_security:
        rate_limiting: {Request rate limits}
        input_validation: {Request validation rules}
        output_filtering: {Response data filtering}
    
      monitoring:
        access_logging: {API access logging}
        security_monitoring: {Threat detection}
    ```

## Performance and Scalability

### Performance Characteristics
    ```yaml
    performance:
      response_times:
        typical: {Typical response time}
        p95: {95th percentile response time}
        sla: {Response time SLA}
    
      throughput:
        requests_per_second: {RPS capacity}
        concurrent_connections: {Concurrent connection limit}
    
      data_transfer:
        request_size_limit: {Maximum request size}
        response_size_typical: {Typical response size}
    ```

### Scalability Design
- **Horizontal Scaling:** {How API scales horizontally}
- **Caching Strategy:** {Response caching approach}
- **Load Balancing:** {Load distribution strategy}
- **Performance Optimization:** {Query optimization, data pagination}

### Rate Limiting
    ```yaml
    rate_limits:
      anonymous:
        requests_per_hour: {Rate limit}
        burst_capacity: {Burst allowance}
    
      authenticated:
        requests_per_hour: {Higher rate limit}
        burst_capacity: {Burst allowance}
    
      premium:
        requests_per_hour: {Premium rate limit}
        burst_capacity: {Premium burst}
    ```

## API Lifecycle Management

### Versioning Strategy
    ```yaml
    versioning:
      strategy: {URL Path|Header|Query Parameter}
      current_version: {Current version}
      supported_versions: [v1, v2, v3]
    
      deprecation_policy:
        notice_period: {Advance notice period}
        support_period: {Version support duration}
        migration_support: {Migration assistance}
    ```

### Change Management
- **Breaking Changes:** {How breaking changes are handled}
- **Non-breaking Changes:** {Backward compatible change process}
- **Communication:** {How changes are communicated to consumers}
- **Migration Support:** {Support for API consumer migration}

### API Governance
    ```yaml
    governance:
      design_standards: {API design standards and guidelines}
      review_process: {API review and approval process}
      quality_gates: {Quality criteria for API approval}
    
      consumer_management:
        onboarding: {Consumer onboarding process}
        support: {Consumer support model}
        feedback: {Consumer feedback collection}
    ```

## Monitoring and Analytics

### API Monitoring
    ```yaml
    monitoring:
      availability:
        uptime_monitoring: {API availability monitoring}
        health_checks: {Health check endpoints}
    
      performance:
        response_time_monitoring: {Performance tracking}
        error_rate_monitoring: {Error rate tracking}
    
      security:
        access_monitoring: {Access pattern monitoring}
        threat_detection: {Security threat detection}
    ```

### Usage Analytics
- **Consumer Analytics:** {API consumer usage patterns}
- **Endpoint Analytics:** {Popular endpoints and usage trends}
- **Performance Analytics:** {Performance trends and optimization opportunities}
- **Error Analytics:** {Error pattern analysis}

### SLA Monitoring
    ```yaml
    sla_metrics:
      availability:
        target: {99.9%}
        measurement: {Uptime monitoring}
    
      performance:
        response_time: {Response time SLA}
        throughput: {Throughput guarantees}
    
      support:
        response_time: {Support response time}
        resolution_time: {Issue resolution time}
    ```

## Consumer Experience

### Developer Experience
- **Documentation Quality:** {Comprehensive and clear documentation}
- **Interactive Documentation:** {API explorer and testing tools}
- **Code Examples:** {SDKs and code samples}
- **Sandbox Environment:** {Testing and development environment}

### Consumer Onboarding
    ```yaml
    onboarding:
      registration:
        process: {Consumer registration process}
        approval: {Approval workflow}
    
      getting_started:
        quick_start_guide: {Quick start documentation}
        tutorials: {Step-by-step tutorials}
        sample_applications: {Example implementations}
    ```

### Support Model
- **Documentation:** {Self-service documentation and guides}
- **Community Support:** {Developer forums and community}
- **Direct Support:** {Support channels and SLAs}
- **Status Page:** {API status and incident communication}

## Business Continuity

### Availability Requirements
- **Uptime Target:** {99.9%, 99.99%, etc.}
- **Maintenance Windows:** {Planned maintenance schedule}
- **Incident Response:** {Incident response procedures}

### Disaster Recovery
    ```yaml
    disaster_recovery:
      backup_apis: {Backup API endpoints}
      failover_procedures: {Failover process}
      data_recovery: {Data backup and recovery}
    
      testing:
        frequency: {DR testing schedule}
        procedures: {Testing procedures}
    ```

## Future Evolution

### API Roadmap
    ```yaml
    roadmap:
      current_release:
        features: [feature1, feature2]
        timeline: {Current release timeline}
    
      future_releases:
        - version: {Future version}
          features: [planned_feature1, planned_feature2]
          timeline: {Planned timeline}
    ```

### Technology Evolution
- **Technology Upgrades:** {Planned technology improvements}
- **Standard Adoption:** {New standards and protocols}
- **Consumer Feedback Integration:** {How consumer feedback drives evolution}

## Validation
*Evidence that API delivers consistent functionality, provides excellent developer experience, and enables effective integration*

## Quality Standards

### Bronze Level (Minimum Viable)
- [ ] Basic API specification with core endpoints
- [ ] Simple authentication and basic documentation
- [ ] Basic error handling and response formats
- [ ] All required metadata fields completed

### Silver Level (Investment Ready)
- [ ] Comprehensive API design with full OpenAPI specification
- [ ] Robust security, authentication, and authorization
- [ ] Detailed documentation with examples and testing tools
- [ ] Performance monitoring and basic analytics

### Gold Level (Operational Excellence)
- [ ] Advanced API design with optimal developer experience
- [ ] Sophisticated analytics, monitoring, and consumer insights
- [ ] Comprehensive lifecycle management and governance
- [ ] Strategic API evolution with ecosystem thinking

## Common Pitfalls

1. **Poor API design**: Inconsistent naming, resource modeling, and error handling
2. **Inadequate security**: Weak authentication, authorization, or input validation
3. **Poor documentation**: Incomplete, outdated, or unclear API documentation
4. **Version management issues**: Poor versioning strategy and change management

## Success Patterns

1. **API-first development**: APIs designed before implementation with clear contracts and strong producer-consumer collaboration
2. **Developer-centric design**: APIs designed for excellent developer experience with comprehensive tooling and support
3. **Data-driven evolution**: API evolution driven by usage analytics and consumer feedback with continuous improvement
4. **Security by design**: Comprehensive security framework with defense-in-depth and continuous monitoring

## Relationship Guidelines

### Typical Dependencies
- **SYS (Systems)**: System architecture drives API design and integration patterns
- **DAT (Data Models)**: Data models inform API resource design and data structures
- **SEC (Security)**: Security requirements drive API authentication and authorization design
- **ARC (Architecture)**: Architecture patterns inform API design and implementation approach

### Typical Enablements
- **PER (Performance Specification)**: API performance drives overall system performance achievement
- **QUA (Quality Specification)**: API quality standards drive overall integration quality
- **INT (Integration)**: API design enables system integration and interoperability
- **DEV (Development)**: API standards enable development consistency and practices

## Document Relationships

This document type commonly relates to:

- **Depends on**: SYS (Systems), DAT (Data Models), SEC (Security), ARC (Architecture)
- **Enables**: PER (Performance Specification), QUA (Quality Specification), INT (Integration), DEV (Development)
- **Informs**: Integration strategy, development standards, security architecture
- **Guides**: Implementation decisions, testing strategies, documentation standards

## Validation Checklist

- [ ] Executive summary with clear purpose, type, audience, and maturity level
- [ ] API overview with business purpose, technical overview, and scope boundaries
- [ ] API design with resource model, endpoint specifications, and data models
- [ ] API documentation with OpenAPI specification, examples, and error handling
- [ ] Security and authentication with mechanisms, authorization model, and security controls
- [ ] Performance and scalability with characteristics, design, and rate limiting
- [ ] API lifecycle management with versioning, change management, and governance
- [ ] Monitoring and analytics with monitoring framework, usage analytics, and SLA tracking
- [ ] Consumer experience with developer experience, onboarding, and support model
- [ ] Business continuity with availability requirements and disaster recovery procedures
- [ ] Future evolution with roadmap and technology evolution planning
- [ ] Validation evidence of API effectiveness, developer experience, and integration enablement

---

## Related Documents

- [Back to Document Types](/docs/document-types)
- [Domain: Technology & Data](/docs/domains/technology-data)
- [Full Specification](/spec/v1-0-0)

API: APIs ​

Abstract ​

Purpose and Scope ​

Document Metadata Schema ​

Content Structure Template ​

API: APIs

Abstract

Purpose and Scope

Document Metadata Schema

Content Structure Template