Nexus

⚡ What is Nexus? (10-second pitch)¶

Nexus is a programmable filesystem for AI agents that combines:

• 📁 File Storage - Store and version files (local, S3, GCS)
• 🧠 Agent Memory - Agents remember and learn across sessions
• 🔒 Smart Permissions - Fine-grained access control (ReBAC/Zanzibar-style)
• 🔍 Semantic Search - Find anything with natural language
• 🚀 Zero→Production - Start local (pip install), scale without code changes

One API. Multiple backends. Built for AI agents.

Quick Start in 30 Seconds¶

# Install
pip install nexus-ai-fs

# Use it
import nexus

# Just works - no auth needed in embedded mode
nx = nexus.connect(config={"data_dir": "./nexus-data"})

# Write and read files
nx.write("/hello.txt", b"Hello, Nexus!")
content = nx.read("/hello.txt")
print(content.decode())  # "Hello, Nexus!"

# Install
pip install nexus-ai-fs

# Initialize workspace
nexus init ./my-project

# Use with server (see Server Mode tab)
export NEXUS_URL=http://localhost:2026
export NEXUS_API_KEY=your-key
nexus write /workspace/hello.txt "Hello from CLI!"
nexus cat /workspace/hello.txt

# Start server with authentication
nexus serve --host 0.0.0.0 --port 2026

# Connect from Python
import nexus
nx = nexus.connect(
    remote_url="http://localhost:2026",
    api_key="your-api-key"
)
nx.write("/workspace/hello.txt", b"Remote write!")

🎯 Is Nexus For Me?¶

Answer 2 quick questions to find your path:

1. What are you building?¶

2. What's your experience level?¶

Still not sure? Check out Why Nexus? for detailed comparisons with S3, Vector DBs, and traditional filesystems.

How It Works¶

%%{init: {'theme':'base', 'themeVariables': { 'primaryColor':'#e3f2fd','primaryTextColor':'#1a237e','primaryBorderColor':'#5C6BC0','lineColor':'#AB47BC','secondaryColor':'#fce4ec','tertiaryColor':'#fff3e0','fontSize':'14px'}}}%%
graph TB
    subgraph agents[" 🤖 AI Agents "]
        agent1["Agent A<br/>(GPT-4)"]
        agent2["Agent B<br/>(Claude)"]
        agent3["Agent C<br/>(Custom)"]
    end

    subgraph vfs[" 📁 Nexus Virtual File System "]
        api["Unified VFS API<br/>read() write() list() search()"]
        memory["💾 Memory API<br/>Persistent learning & context"]
        rebac["🔒 ReBAC Permissions<br/>Backend-aware object types"]
        version["📦 Versioning<br/>Snapshots & time-travel"]
        router["Smart Router<br/>Path → Backend + Object Type"]
    end

    subgraph backends[" 💾 Storage & Data Backends "]
        subgraph storage[" File Storage "]
            local["Local Filesystem<br/>object: file"]
            gcs["Cloud Storage<br/>object: file"]
        end
        subgraph data[" Data Sources "]
            postgres["PostgreSQL<br/>object: postgres:table/row"]
            redis["Redis<br/>object: redis:instance/key"]
            mongo["MongoDB<br/>object: mongo:collection/doc"]
        end
    end

    agent1 -.->|"write('/workspace/data.json')"| api
    agent2 -.->|"read('/db/public/users')"| api
    agent3 -.->|"memory.store('learned_fact')"| memory

    api --> rebac
    memory --> rebac
    rebac <-->|"Check with object type"| router
    rebac -->|"✓ Allowed"| version
    version --> router

    router -->|"File operations"| local
    router -->|"File operations"| gcs
    router -->|"Queries as files"| postgres
    router -->|"KV as files"| redis
    router -->|"Documents as files"| mongo

    style agents fill:#e3f2fd,stroke:#5C6BC0,stroke-width:2px,color:#1a237e
    style vfs fill:#f3e5f5,stroke:#AB47BC,stroke-width:2px,color:#4a148c
    style backends fill:#fff3e0,stroke:#FF7043,stroke-width:2px,color:#e65100
    style storage fill:#e8f5e9,stroke:#4CAF50,stroke-width:1px
    style data fill:#e1f5fe,stroke:#0288D1,stroke-width:1px
    style api fill:#5C6BC0,stroke:#3949AB,stroke-width:2px,color:#fff
    style memory fill:#AB47BC,stroke:#7B1FA2,stroke-width:2px,color:#fff
    style rebac fill:#EC407A,stroke:#C2185B,stroke-width:2px,color:#fff
    style version fill:#66BB6A,stroke:#388E3C,stroke-width:2px,color:#fff
    style router fill:#42A5F5,stroke:#1976D2,stroke-width:2px,color:#fff

Backend Abstraction:

Nexus presents everything as files to users, while backends provide appropriate object types for permission control:

• File Storage (Local, GCS, S3): Standard file objects
• Databases (PostgreSQL, Redis, MongoDB): Backend-specific objects (tables, keys, documents)
• Unified Interface: All accessed through the same VFS API (read/write/list)
• Fine-Grained Permissions: ReBAC uses backend-appropriate object types (e.g., grant access to a PostgreSQL schema vs. individual rows)

🧠 Core Concepts¶

New to Nexus? Start here to understand how it works:

🎓 Choose Your Learning Path¶

Progressive learning from beginner to advanced. Pick based on your use case and experience level.

🌱 Beginner Paths (5-15 minutes)¶

🚀 Intermediate Paths (15-25 minutes)¶

⚙️ Advanced Paths (25-30+ minutes)¶

Not sure where to start? Use the Is Nexus For Me? quiz above to find your recommended path.

What Makes Nexus Different?¶

For AI Agent Developers¶

Why AI Developers Choose Nexus:

• 🤖 Multi-Agent Native: Built-in workspace sharing and collaboration for CrewAI, LangGraph teams
• 🧠 Memory + Storage Combined: Not just embeddings—full agent memory with automatic consolidation
• 🔄 Event-Driven Automation: Workflows trigger automatically when agents write files (no manual event firing)
• 🗄️ Unified Data Access: Access files, databases (PostgreSQL/Redis/MongoDB), and vectors through one API
• 🔒 Production-Ready Security: Fine-grained ReBAC permissions with multi-tenancy out of the box
• 📚 LLM-Powered Intelligence: Ask questions about stored documents, get AI answers with citations
• ⚡ Framework Integrations: First-class support for CrewAI, LangGraph, Claude SDK, OpenAI Agents, Google ADK

🆘 Need Help?¶