Skip to main content

CODITECT Standard: Technical Design Documents (TDDs)

Standard ID: CODITECT-STANDARD-TDD Version: 1.0.0 Status: Active Created: 2025-12-22 Author: AZ1.AI INC Architecture Team Compliance: Mandatory for all TDDs

1. Purpose​

This standard defines the requirements for creating Technical Design Documents (TDDs) within the CODITECT ecosystem. TDDs provide implementation-level detail for developers to build software systems.

2. Scope​

This standard applies to:

  • All TDDs in internal/architecture/ or docs/technical/
  • Implementation specifications
  • Algorithm designs
  • Data structure specifications
  • Integration specifications

3. TDD Definition​

A Technical Design Document (TDD) describes implementation-level details for building a system. It translates the SDD's architecture into actionable specifications:

  • Data structures and algorithms
  • Function signatures and contracts
  • Error handling patterns
  • Configuration specifications
  • Integration protocols
  • Performance optimizations

4. When to Create a TDD​

4.1 Create TDD For​

TriggerExample
Complex algorithmsBinary search, routing algorithms
Custom data structuresPriority queues, caches
Integration protocolsWebSocket handshake, OAuth flow
Performance-critical codeHot paths, batch processing
Cross-platform implementationsPlatform-specific code

4.2 SDD vs TDD​

DocumentPurposeAudienceDetail Level
SDDDescribe architectureArchitectsSystem/component
TDDDescribe implementationDevelopersCode/algorithm

5. Naming Convention​

5.1 File Naming Format​

{SYSTEM-NAME}-TDD.md

Examples:

  • CODITECT-CORE-TDD.md
  • INSTALLATION-SYSTEM-TDD.md
  • BINARY-LOCATOR-TDD.md

5.2 Document ID Format​

AZ1-TDD-{DOMAIN}-{NUMBER}

Examples:

  • AZ1-TDD-CORE-001
  • AZ1-TDD-INSTALL-001

6. TDD Structure​

6.1 Required Sections​

Every TDD MUST contain:

  1. Overview - Purpose and scope
  2. Technical Architecture - Component interactions
  3. Data Structures - Types and schemas
  4. Algorithms - Core logic with pseudocode
  5. APIs and Interfaces - Function signatures
  6. Error Handling - Error types and recovery
  7. Configuration - Environment and settings
  8. Testing Strategy - Test approach

6.2 Optional Sections​

  • Performance considerations
  • Security implementation
  • Migration procedures
  • Monitoring and observability
  • Debugging guide

6.3 Template Reference​

Use template: CODITECT-CORE-STANDARDS/TEMPLATES/TDD-TEMPLATE.md

7. Content Requirements​

7.1 Data Structures​

Document with:

  • Type definitions (TypeScript/Python/Rust)
  • Field descriptions
  • Validation rules
  • Example instances
interface User {
  id: string;           // UUID v4
  email: string;        // Valid email, unique
  createdAt: Date;      // ISO 8601 timestamp
  metadata?: UserMeta;  // Optional profile data
}

7.2 Algorithms​

Document with:

  • Purpose and use case
  • Pseudocode or flowchart
  • Time/space complexity
  • Edge cases
Algorithm: FindBinaryPath
Input: platform (string), arch (string)
Output: path (string) or Error

1. searchPaths = getSearchPaths(platform)
2. FOR each path IN searchPaths:
     3. binaryPath = join(path, getBinaryName(platform))
     4. IF exists(binaryPath):
          RETURN binaryPath
5. RETURN Error("Binary not found")

Complexity: O(n) where n = number of search paths

7.3 APIs and Interfaces​

Document with:

  • Function signature
  • Parameter descriptions
  • Return type
  • Error conditions
  • Usage example
/**
 * Locate platform-specific binary
 * @param platform - Target OS ('darwin', 'linux', 'win32')
 * @param arch - CPU architecture ('x64', 'arm64')
 * @returns Absolute path to binary
 * @throws BinaryNotFoundError if binary not installed
 * @example
 * const path = getBinaryPath('darwin', 'arm64');
 * // Returns: '/usr/local/bin/coditect'
 */
function getBinaryPath(platform: string, arch: string): string;

8. Code Examples​

8.1 Requirements​

  • Use actual language syntax (not pseudocode for examples)
  • Include imports and dependencies
  • Show complete, runnable examples
  • Add comments for complex logic

8.2 Language Preference​

LanguageUse For
TypeScriptNode.js, frontend, npm packages
PythonScripts, AI/ML, automation
RustPerformance-critical, CLI tools
SQLDatabase queries and schemas
BashShell scripts, CI/CD

9. Error Handling Specification​

9.1 Error Types​

Document error categories:

Error TypeDescriptionRecovery
ValidationErrorInvalid inputReturn 400, show message
NotFoundErrorResource missingReturn 404
SystemErrorInternal failureLog, return 500, alert

9.2 Error Propagation​

Document error flow:

Component A ──[Error]──► Component B ──[Wrapped]──► API Response
                              │
                              ▼
                           Logging

10. Relationship to Other Documents​

10.1 Document Hierarchy​

Software Design (SDD)
    │
    ▼
Technical Design (TDD) ◄── YOU ARE HERE
    │
    ▼
Implementation (Code)
    │
    ▼
Tests (Unit/Integration)

10.2 Cross-References​

TDDs should reference:

  • Parent SDD for architecture context
  • Related ADRs for decisions
  • Test specifications
  • API documentation

11. Versioning​

11.1 Version Format​

MAJOR.MINOR.PATCH
Change TypeVersion Bump
Breaking API changeMAJOR
New algorithm/functionMINOR
Bug fix or clarificationPATCH

11.2 Change Log​

Every TDD must include a changelog:

VersionDateAuthorChanges
1.1.02025-12-22{Name}Added retry logic
1.0.02025-12-01{Name}Initial version

12. Storage Location​

TypeLocation
Core systemsinternal/architecture/system-design/
Subsystemsinternal/architecture/{subsystem}/
Distributiondistribution/*/technical-docs/

13. Review Process​

13.1 Before Publishing​

  • All required sections complete
  • Data structures fully specified
  • Algorithms documented with complexity
  • Error handling comprehensive
  • Code examples tested
  • Cross-references valid

13.2 Maintenance​

  • Update when implementation changes
  • Review with major releases
  • Archive superseded versions
DocumentPurpose
TDD-TEMPLATE.mdTDD template
CODITECT-STANDARD-SDD.mdSoftware design standard
CODITECT-STANDARD-ADR.mdADR standard

Last Updated: 2025-12-22 Review Schedule: Quarterly Owner: Architecture Team, AZ1.AI INC