ADR-016: CODI Rust Implementation Architecture (v4) - Part 1: Human Narrative
Document Specification Block
Document: ADR-016-v4-codi-rust-implementation
Version: 1.0.0
Purpose: Define the architecture for transforming CODI from bash scripts to a unified Rust binary
Audience: Developers, DevOps Engineers, CODITECT Users, AI Agents
Date Created: 2025-08-29
Date Modified: 2025-08-29
Date Released: DRAFT
QA Reviewed: Pending
Status: DRAFT
Table of Contents
- 1. Document Information
- 2. Purpose of this ADR
- 3. User Story Context
- 4. Executive Summary
- 5. Visual Overview
- 6. Background & Problem
- 7. Decision
- 8. Consequences
- 9. References & Standards
- 10. Review & Approval
1. Document Information
| Field | Value |
|---|---|
| ADR Number | ADR-016 |
| Title | CODI Rust Implementation Architecture |
| Status | Draft |
| Date Created | 2025-08-29 |
| Last Modified | 2025-08-29 |
| Version | 1.0.0 |
| Decision Makers | Platform Architect, Lead Developer, DevOps Lead |
| Stakeholders | All CODITECT developers, AI agents, Operations team |
2. Purpose of this ADR
This ADR serves dual purposes:
- For Humans 👥: Explains how CODI evolves from a collection of bash scripts into a powerful, unified Rust binary that makes CODITECT development feel like having a supercharged assistant
- For AI Agents 🤖: Provides complete implementation blueprints for building a production-ready Rust CLI with integrated monitoring, MCP protocol support, and direct FoundationDB access
3. User Story Context
As a CODITECT developer,
I want a single, fast, reliable command-line tool that handles all my development needs,
So that I can focus on building features instead of managing scripts and tools.
📋 Acceptance Criteria:
- Single binary replaces 50+ bash scripts
- Commands execute 10x faster than bash
- Built-in monitoring without external dependencies
- Works offline with local caching
- Integrates seamlessly with AI agents via MCP
- Memory usage under 100MB
- Zero runtime dependencies
4. Executive Summary
🏢 For Business Stakeholders
Imagine upgrading from a Swiss Army knife made of rubber bands and paperclips to a precision-engineered multi-tool. That's what we're doing with CODI.
Currently, developers use dozens of separate bash scripts that are:
- Slow (each script starts a new process)
- Fragile (depend on system utilities)
- Hard to maintain (spread across multiple files)
- Difficult to test (bash testing is painful)
The new CODI is like upgrading from a flip phone to a smartphone - same basic functions, but infinitely more powerful and pleasant to use.
Business Value:
- 40% faster development cycles due to improved tooling
- 90% reduction in tooling issues reported by developers
- Zero external dependencies means it works everywhere
- Native AI integration enables next-generation development workflows
Key Decision: Transform CODI into a single Rust binary that's fast, reliable, and delightful to use.
💻 For Technical Readers
Technical Summary: CODI becomes a monolithic Rust binary using Tokio for async operations, embedded SQLite for local state, native notify for file watching, integrated MCP server/client, and direct FoundationDB bindings - all with zero runtime dependencies and sub-50ms response times.
5. Visual Overview
5.1 Current vs Future Architecture
5.2 Performance Comparison
5.3 Component Architecture
6. Background & Problem
6.1 Business Context
- Why this matters: Developer productivity is directly tied to tooling quality
- User impact: Every CODITECT developer uses CODI dozens of times daily
- Cost of inaction: Continued maintenance burden, poor performance, limited features
6.2 Technical Context
- Current state: 50+ bash scripts with various dependencies
- Limitations:
- Process startup overhead for each command
- Dependency on system utilities (jq, inotifywait, etc.)
- No shared state between commands
- Difficult to test and maintain
- No native Windows support
- Technical debt:
- Duplicate code across scripts
- Inconsistent error handling
- No proper logging infrastructure
6.3 Constraints
| Type | Constraint | Impact |
|---|---|---|
| ⏰ Time | 4 weeks development | Phased rollout required |
| 💰 Budget | Use existing team | No additional hires |
| 👥 Resources | 1-2 developers | Focus on core features first |
| 🔧 Technical | Maintain compatibility | Gradual migration path |
| 📜 Compliance | Proprietary license | Cannot use GPL dependencies |
7. Decision
7.1 Y-Statement Format
In the context of CODITECT developer tooling,
facing performance issues, maintenance burden, and limited extensibility,
we decided for a unified Rust binary with embedded components
and neglected maintaining separate scripts, using Python, or creating a Node.js tool,
to achieve 10x performance, zero dependencies, and native AI integration,
accepting upfront development time and Rust learning curve,
because long-term benefits far outweigh short-term costs and Rust provides the best combination of performance, safety, and deployment simplicity.
7.2 What We're Doing
We're creating a single Rust binary that:
- Replaces all bash scripts with native implementations
- Embeds SQLite for local state management
- Includes a web server for dashboards
- Implements MCP protocol for AI tool integration
- Connects directly to FoundationDB
- Compiles to a single static binary with no dependencies
7.3 Why This Approach
- Performance: Rust gives us C-level speed with memory safety
- Deployment: Single binary is trivial to install and update
- Reliability: No more "command not found" or version conflicts
- Extensibility: Easy to add new features without script proliferation
- Testing: Rust's testing framework is excellent
- Cross-platform: Compiles for Linux, macOS, and Windows
7.4 Alternatives Considered
Option A: Improve Bash Scripts
| Aspect | Details |
|---|---|
| Description | Refactor and optimize existing bash scripts |
| ✅ Pros | • No new technology • Incremental improvement • Lower initial effort |
| ❌ Cons | • Still slow • Still fragile • Limited features • Testing remains difficult |
| Rejection Reason | Doesn't solve fundamental performance and reliability issues |
Option B: Python Rewrite
| Aspect | Details |
|---|---|
| Description | Rewrite all scripts in Python |
| ✅ Pros | • Familiar language • Good libraries • Better testing |
| ❌ Cons | • Requires Python runtime • Slower than compiled • Deployment complexity • Version conflicts |
| Rejection Reason | Runtime dependency and performance not sufficient |
Option C: Node.js/TypeScript
| Aspect | Details |
|---|---|
| Description | Build tool in Node.js with TypeScript |
| ✅ Pros | • Same language as frontend • Good ecosystem • TypeScript safety |
| ❌ Cons | • Requires Node runtime • Large deployment size • Slower startup • Memory hungry |
| Rejection Reason | Runtime overhead and deployment complexity |
8. Consequences
8.1 Positive Outcomes
- ✅ 10x performance improvement - Commands execute in milliseconds
- ✅ Single binary deployment - Copy one file and you're done
- ✅ Native AI integration - Built-in MCP protocol support
- ✅ Improved reliability - No more missing dependencies
- ✅ Better testing - Comprehensive Rust test suite
- ✅ Cross-platform support - Works on Linux, macOS, Windows
- ✅ Reduced maintenance - One codebase instead of 50+ scripts
8.2 Negative Impacts
- ⚠️ Development time - 4 weeks of focused development
- ⚠️ Learning curve - Team needs to learn Rust basics
- ⚠️ Migration period - Both systems exist during transition
8.3 Risk Register
| Risk | Probability | Impact | Mitigation | Owner |
|---|---|---|---|---|
| Rust complexity delays delivery | Medium | High | Start with core commands, incremental delivery | Lead Dev |
| Users resist change | Low | Medium | Maintain compatibility layer during transition | DevOps |
| Binary size too large | Low | Low | Use release optimizations, strip symbols | Platform |
9. References & Standards
9.1 Related ADRs
- ADR-009: CODI Command Interface - This ADR extends the command interface with Rust implementation
- ADR-010: Dual Document Standard - Following the standard for this document
9.2 External Documentation
- Rust Book: Language reference
- Clap Documentation: CLI framework
- Tokio Documentation: Async runtime
- Model Context Protocol: MCP specification
9.3 Standards & Compliance
- Proprietary License: CODI is CODITECT's "magic sauce"
- No GPL Dependencies: Ensure all dependencies are MIT/Apache
- Security: Follow OWASP guidelines for CLI tools
10. Review & Approval
Approval Signatures
| Role | Name | Date | Signature |
|---|---|---|---|
| Technical Lead | _______ | _______ | ___________ |
| Product Owner | _______ | _______ | ___________ |
| Security Review | _______ | _______ | ___________ |
| Architecture Board | _______ | _______ | ___________ |
Review History
| Version | Date | Reviewer | Status | Comments |
|---|---|---|---|---|
| 0.1 | 2025-08-29 | _______ | DRAFT | Initial draft |
QA Review: See ADR-016-v4-codi-rust-implementation-QA-REVIEW.md Technical Implementation: See Part 2