Nexus-SDLC

AI-powered Software Development Lifecycle orchestration

Design multi-agent workflows on a visual canvas · Dispatch tasks to the right AI tier · Ship with human-in-the-loop approvals

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What Is Nexus?

Nexus treats your entire SDLC as a directed graph of stages. Each stage is handled by an AI agent at the right cost tier — cheap fast models for boilerplate, powerful reasoning models for architecture and security. Think n8n, but for engineering teams running AI agents.

Input ──► Design ──► Implement ──► Test ──► Security Audit ──► Human Approval ──► Ship
           │            │            │              │                  │
         Senior       Mid         Junior          Senior         You decide

Key capabilities

• Visual workflow canvas built on ReactFlow — drag, connect, branch
• Tiered agent routing — automatically dispatches each stage to Junior / Mid / Senior based on complexity
• Human-in-the-loop — pause any stage, review agent output, approve or redirect
• Real-time streaming — SSE-based live output from every agent
• Cost tracking — per-run token spend broken down by tier
• Full audit trail — blame graph, decision log, cost log persisted to disk and Postgres

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Agent Tiers

Tier	Default Models	Token Budget	Cost	Use Cases
Junior	gpt-4o-mini, ollama/llama3:8b	2 048	1×	Unit tests, boilerplate, CSS/HTML
Mid	gemini-1.5-flash, mistral-large	8 192	5×	API dev, docs, standard bugfixes
Senior	claude-sonnet-4-6, gpt-4o	32 768	25×	Architecture, security audits, complex debug

Models are fully configurable. Point any tier at any LiteLLM-compatible model including local Ollama.

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Built-in Workflow Templates

Template	Stages	Best For
indie_hacker	Design → Build → QA → Ship	MVPs in a single Senior pass
security_first_dev	Plan → Implement → SAST → Review → Deploy	Security-sensitive codebases
refactor_expert	Analyze → Refactor → Regression QA → Approve	Legacy code cleanup
testing	Spec → Generate Tests → Validate → Report	Boosting test coverage

Custom templates are plain YAML — drop them in nexus/core/workflow/templates/ and they appear in the UI automatically.

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Architecture

nexus-sdlc/
├── nexus/                    # Backend (Python)
│   ├── api/                  # FastAPI — REST + SSE endpoints
│   │   └── routes/           #   workflows · agents · approvals · audit
│   ├── core/
│   │   ├── agents/           # Tiers, roles, perspectives
│   │   ├── workflow/         # LangGraph engine + YAML template loader
│   │   ├── tools/            # GitHub, sandbox, security, Slack
│   │   ├── human_loop/       # Approval queue & directive steering
│   │   ├── consensus/        # Multi-agent voting board
│   │   └── logging/          # Audit trail, blame graph, cost logger
│   ├── db/                   # SQLAlchemy async (Postgres)
│   └── cache/                # Redis client (SSE streaming)
└── ui/                       # Frontend (Next.js 14 + TypeScript)
    └── app/
        ├── components/
        │   ├── canvas/       # ReactFlow workflow designer
        │   ├── dashboard/    # Execution, audit, approvals, cost monitor
        │   └── hub/          # Template browser & YAML editor
        ├── store/            # Zustand state
        └── types/            # Shared TypeScript types

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Quick Start

Prerequisites

• Python 3.11+
• Node.js 18+
• Docker & Docker Compose

1. Clone & configure

git clone https://github.com/zer0dayf/nexus-sdlc.git
cd nexus-sdlc
cp .env.example .env
# Fill in at least one LLM provider key

2. Start infrastructure

docker-compose up -d postgres redis

3. Backend

python -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate
pip install -e ".[dev]"
uvicorn nexus.api.main:app --reload --port 8000

API: http://localhost:8000 · Docs: http://localhost:8000/docs

4. Frontend

cd ui
npm install
npm run dev

Open http://localhost:3000

Graceful degradation: Postgres and Redis are optional. Without them Nexus runs in memory-only mode — perfect for local testing.

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Configuration

Copy .env.example → .env and fill in your values.

# LLM Providers — at least one required
OPENAI_API_KEY=sk-...
ANTHROPIC_API_KEY=sk-ant-...
GOOGLE_API_KEY=...

# Infrastructure
DATABASE_URL=postgresql+asyncpg://nexus:nexus@localhost:5432/nexus
REDIS_URL=redis://localhost:6379/0

# Integrations (all optional)
GITHUB_TOKEN=ghp_...
SLACK_BOT_TOKEN=xoxb-...
SLACK_CHANNEL_ID=C...
SNYK_TOKEN=...
SONARQUBE_URL=http://localhost:9000
SONARQUBE_TOKEN=...

# App
NEXUS_ENV=development
NEXUS_SECRET_KEY=change-me-in-production
NEXUS_LOG_LEVEL=INFO

Production checklist

• Set NEXUS_ENV=production (enables strict CORS)
• Generate a strong secret: openssl rand -hex 32
• Replace the default Postgres password (nexus) with a secret manager value
• Set allow_origins to your actual domain in nexus/api/main.py

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Development

# Tests
pytest

# Lint & format
ruff check . --fix && ruff format .

# Type check
mypy nexus/

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Roadmap

See ROADMAP.md for planned features including:

• Google Search, Tavily, and Exa action nodes
• GitHub Actions trigger & await
• Slack async approvals
• Parallel stage execution
• Dynamic tier escalation
• Cost budgets per run
• RBAC & SSO

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Star History

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License

MIT © zer0dayf