Promptly V0.6.2 BackendPart1 UpdateLog

# 📝 Promptly v0.6.2 — Backend Part-1 Update Summary

This update introduces the **first half of the Backend v0.6.2 upgrade**, focusing on the foundation of the new **Spec System**, backend versioning, and multi-agent integration.

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## ✅ 1. Added: Spec System Database Tables
Two new tables were added to support **Backend_TechSpec_v0.7**, enabling versioning, compilation, and future best-of-N workflows.

### New Tables
- specs
- compiled_prompts

### Purpose
- Spec Versioning
- Store compiled prompts independently
- Support future features: diff, iteration, repair, best-of-N

This makes Spec a first-class backend entity of Promptly.

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## ✅ 2. Added: /api/specs Route (RESTful + Versioning)

Endpoints implemented:

- GET /api/specs
- POST /api/specs
- GET /api/specs/:id
- PATCH /api/specs/:id
- POST /api/specs/:id/compile

This formalizes the Spec System API.

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## ✅ 3. Added: Spec Compiler (compileSpecToPrompt)

Implements:

- systemRole
- userGoal
- requirements
- constraints
- architecture
- outputFormat
- explanation

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## ✅ 4. Added: openaiClient.js (Unified LLM JSON Layer)

Ensures:
- strict JSON output
- unified interface for Agents A/B/C
- reusable for scoring/iteration/repair

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## ✅ 5. Added: llmAgents.js (Agents A/B/C Integrated)

Roles:
- Agent A → broad questions
- Agent B → choice questions
- Agent C → spec + compiled prompt

All outputs validated via Zod.

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## ✅ 6. Added: specs.js (Complete Route Module)

Implements full logic for Spec System.

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## ✅ 7. Updated: server.js (Mounted Specs Route)

Backend now supports:

Auth  
Docs  
Share  
Question Sessions  
⭐ Spec System (new)