---
phase: design
title: System Design & Architecture
description: Define the technical architecture, components, and data models
---

# System Design & Architecture

## Architecture Overview
**What is the high-level system structure?**

- Include a mermaid diagram that captures the main components and their relationships.
  ```mermaid
  graph TD
    User -->|memory search --table| CLI[CLI Command Parser]
    CLI --> SearchCmd[memorySearchCommand]
    SearchCmd --> MemorySvc[@ai-devkit/memory search]
    SearchCmd --> Formatter{Output Mode}
    Formatter -->|default| JsonOut[JSON Printer]
    Formatter -->|--table| TableOut[ui.table Renderer]
  ```
- Key components and their responsibilities
  - `packages/cli/src/commands/memory.ts`: parse `--table` and select output mode.
  - `@ai-devkit/memory` search command: unchanged data retrieval path.
  - `packages/cli/src/util/terminal-ui.ts`: table rendering utility for human-readable output.
- Technology stack choices and rationale
  - Reuse existing Commander option parsing.
  - Reuse existing table renderer to avoid introducing new formatting dependencies.

## Data Models
**What data do we need to manage?**

- Core entities and their relationships
  - `SearchKnowledgeResult` contains `results[]` with memory item metadata.
  - Table projection maps each result row to `{ id, title, scope }`.
- Data schemas/structures
  - No persistence or schema changes required.
  - Output-only projection is applied in CLI layer.
- Data flow between components
  - CLI options -> memory search execution -> format selection -> JSON or table output.

## API Design
**How do components communicate?**

- External APIs (if applicable)
  - None added.
- Internal interfaces
  - Extend CLI search command options with `table?: boolean`.
  - Keep `memorySearchCommand(options)` unchanged.
- Request/response formats
  - Existing command:
    - `npx ai-devkit@latest memory search --query "<query>" [--tags "..."] [--scope "..."] [--limit N]`
  - New table mode:
    - `npx ai-devkit@latest memory search --query "<query>" --table`
  - Table output columns:
    - `id`
    - `title`
    - `scope`
  - Empty result behavior:
    - Print a clear warning message (no table rows) and return success exit code (`0`).
- Authentication/authorization approach
  - No change.

## Component Breakdown
**What are the major building blocks?**

- Frontend components (if applicable)
  - Terminal-only output, no GUI.
- Backend services/modules
  - `registerMemoryCommand` search action branch for output selection.
  - Mapper utility (inline or helper) that extracts row fields from search results.
- Database/storage layer
  - No changes.
- Third-party integrations
  - No new integrations.

## Design Decisions
**Why did we choose this approach?**

- Key architectural decisions and trade-offs
  - Keep JSON as default to avoid breaking scripts.
  - Add opt-in table mode via a simple boolean flag.
  - Restrict table fields to `id`, `title`, `scope` to maximize scanability.
  - Truncate very long `title` values in table mode with ellipsis for terminal readability.
- Alternatives considered
  - `--format table|json` (more flexible but larger surface area for this request).
  - Replacing default output with table (rejected due to compatibility risk).
- Patterns and principles applied
  - Backward-compatible extension.
  - Presentation concern kept at CLI boundary, not in memory service layer.

## Non-Functional Requirements
**How should the system perform?**

- Performance targets
  - No measurable regression versus current search execution.
- Scalability considerations
  - Table rendering should remain usable for current capped `--limit` range.
- Security requirements
  - No security model changes; output formatting only.
- Reliability/availability needs
  - Table mode should gracefully handle empty result sets and undefined optional fields.
  - For narrow terminals, title truncation preserves legibility without changing underlying data.
