Massachusetts employer? AI training for your team can be up to 100% reimbursed. See the MA grant
Synaptic Labs
Book a call Take the assessmentAssessment
← All plugins

Nexus Obsidian plugin

Nexus: an Obsidian plugin for AI chat with your notes

Nexus is a plugin you install inside Obsidian, the note-taking app. It adds AI chat to your vault so you can ask about existing notes, work with them, and check answers against your sources.

Ask about a note Nexus on GitHub

The problem

A vault can hold the note you need while leaving you unsure where a decision or explanation lives. Opening files one by one interrupts the question you were trying to answer. A useful assistant should work from the notes you choose and leave you able to check its answer against them.

The solution

We built Nexus to let you ask questions about your existing notes through chat inside Obsidian. Name a note you know, ask a focused question, and compare the answer with the source. The chat can use vault tools for context when the chosen model and request support them.

How it works

  1. Start with a note you know

    Pick an existing note by title and a detail you want to understand or check. That gives you a source to compare with the answer.

  2. Ask in Nexus Chat

    Open Nexus Chat from the ribbon or Command palette and ask one focused question about the named note.

  3. Use the available vault context

    Depending on the model and request, Nexus can use vault tools to find relevant material. Read the answer as a starting point, not a replacement for the note.

  4. Check the answer

    Open the named note and compare it with the answer. Retrieval and citations vary, so confirm the detail you plan to use.

Use Nexus in your app

New to plugins? Read the beginner guide. Install Nexus from Obsidian Community plugins on desktop, configure a provider and model, and ask about an existing note you know. Check the answer against the note. Set up MCP or CLI separately if you want an external coding agent to access vault tools.

Begin in Obsidian desktop native chat; external MCP and CLI connections are optional desktop features.

Set it up

  1. Download Obsidian if needed, and open a vault with a few notes you know.

    Download Obsidian ↗

  2. Open Settings, turn on community plugins, then Community plugins and Browse.

  3. Search for Nexus. Choose Install, then Enable.

  4. In Settings > Nexus > Providers, configure a supported provider and model or local runtime.

    API keys and billing guide →

  5. Open Nexus Chat from the ribbon or Command palette > Nexus: Open Nexus Chat. Ask about one existing, named note and compare the answer with that note.

First use

Ask about one note you know

Paste into Nexus Chat inside Obsidian after configuring a provider.

What does my note titled [your note title] say about [a topic in that note]?

What to expect

Compare the answer with the named note. Retrieval or citations may vary with the configured provider and tools.

Your review

Open the note yourself. A chosen cloud provider receives the prompt and vault content included in the request.

API keys and provider billing

An API key is a private credential from an AI provider account. An Obsidian plugin uses it to request a cloud service. A ChatGPT or Claude app subscription does not pay for separate API use. Check the provider’s current free tier, billing, and usage limits before sending vault content.

For native Nexus chat, the five providers covered here are OpenAI, Anthropic, Google AI (Gemini), Groq, and OpenRouter. OpenRouter is our preferred starting point for compatible language models. Nexus also has separate local-runtime options that do not need one of these cloud keys.

Choose your provider, review billing if needed, create a key in its official account site, then enter it in Settings > Nexus > Providers. Keep the key out of notes and chats. Choose a model from the provider you configured, then ask about a test note.

Official key guides

Billing help

Frequently asked questions

Do I need ChatGPT or another AI provider?

Native chat needs a configured provider or local runtime. Some options require an API key, an authenticated CLI, or a running local model. Choose the option that fits your access and privacy needs.

Does my vault stay entirely on my device?

Vault files stay in Obsidian, but a chosen cloud AI provider receives your prompt and any vault content included for that request. A local model option can keep inference on your machine.

Does Nexus give an external assistant my whole vault?

External MCP and CLI access are separate desktop setups. Review those connection instructions and the tool permissions before connecting an agent; installing Nexus for native chat alone does not create a direct ordinary ChatGPT vault connection.

Will it always find and cite the right note?

No. Retrieval and citations depend on the configured model and tools. Ask about a note you can name, then open that note to check the answer.

Can I use it on mobile?

Native chat has experimental mobile support. External MCP, the local CLI bridge, and local semantic search are desktop paths.