obsidian_ollama/README.md

Ollama Chat Plugin for Obsidian

A plugin that integrates Ollama with Obsidian to create a chat interface that can access your vault content.

Features

• Chat with Ollama models directly in Obsidian
• Vault context search — the assistant can reference your notes
• Tool integration — create files based on chat responses
• Streaming responses
• Semantic response cache — repeated or similar queries are answered instantly without hitting the model (requires ChromaDB)
• Customisable model, URL, and cache settings

Installation

1. Install the plugin via Obsidian's community plugins
2. Make sure you have Ollama installed and running

Setup

Required

1. Install Ollama: Follow the instructions at ollama.ai
2. Start Ollama: ollama serve
3. Pull a chat model: ollama pull llama3 (or any other model you prefer)

Optional — Semantic Cache

The semantic cache stores responses in a local ChromaDB vector database. When you ask a question that is semantically similar to one already cached, the stored answer is returned immediately instead of calling the model.

1. Install ChromaDB:

   pip install chromadb
   

2. Start ChromaDB:

   chroma run --host localhost --port 8000
   

3. Pull an embedding model (used to generate vectors for cache lookups):

   ollama pull nomic-embed-text
   

4. Enable the cache in the plugin settings and configure the ChromaDB URL.

Configuration

Open Settings → Ollama Chat to configure the plugin.

Setting	Default	Description
Ollama URL	http://localhost:11434	Base URL of your Ollama instance
Model	llama3	Model used for chat responses
Enable Semantic Cache	Off	Cache responses for fast repeated queries
ChromaDB URL	http://localhost:8000	URL of your running ChromaDB instance
Cache Embedding Model	nomic-embed-text	Ollama model used to generate cache embeddings
Cache Similarity Threshold	0.85	Minimum cosine similarity (0–1) for a cache hit — higher values require closer matches
Clear Semantic Cache	—	Button to wipe all cached responses from ChromaDB

Usage

1. Click the ribbon icon to open the chat view
2. Type your message in the input box
3. Press Enter or click Send to send your message
4. Press Shift+Enter to insert a line break
5. Click New Chat to start a fresh conversation

Semantic Cache Behaviour

• The cache is bypassed when tool calls are involved (e.g. file creation), since those requests have side effects.
• Responses are stored against the last user message in the conversation. If a new query is sufficiently similar (above the configured threshold), the cached response is returned.
• Re-asking the same question updates the existing cache entry rather than creating a duplicate.
• Use the Clear Semantic Cache button in settings to remove all stored responses (for example after switching embedding models).

Supported Models

Any model supported by Ollama should work, including:

• llama3
• llama2
• mistral
• codellama
• and many more — see ollama.com/library

Development

npm install
npm run build
npm test

Troubleshooting

Symptom	Likely cause	Fix
Cannot connect to Ollama	Ollama is not running	Run ollama serve
Model not found	Model not pulled	Run ollama pull <model>
Semantic cache unavailable (notice shown)	ChromaDB is not running, or the ChromaDB URL is wrong	Start ChromaDB (chroma run) and verify the URL in settings
Cache always misses	Similarity threshold is too high, or the embedding model was changed	Lower the threshold or click Clear Semantic Cache and let the cache rebuild
Slow first response after enabling cache	Embedding model not yet pulled	Run ollama pull nomic-embed-text (or the model you configured)
Permission issues	Vault write permissions	Check that your Obsidian vault has proper write permissions

License

MIT