FuseSearch

Multi-source search aggregation tool that unifies retrieval across diverse data sources — Confluence, MCP servers, local files, and more — using AI-powered search and response synthesis through a single query interface.

Installation

pip install fusesearch

With all optional dependencies (MCP server, local embeddings, OpenAI):

pip install fusesearch[all]

Quick Start

make build
make start
make index    # index docs from data/docs
make search "your query"

How It Works

Query → Embed → Vector Search  ─┐
                                ├→ RRF Fusion → Rerank (optional) → Results
                Keyword Search ─┘

Embedding Providers

FuseSearch supports three embedding providers. Each uses a separate Qdrant collection due to different vector dimensions.

	Local (default)	OpenAI	Ollama
Model	all-MiniLM-L6-v2 (384 dims)	text-embedding-3-small (1536 dims)	nomic-embed-text (768 dims)
Quality	Good for general English	Better for nuanced/complex queries	Good, varies by model
Cost	Free	~$0.02 per 1M tokens	Free
Privacy	Data stays local	Data sent to OpenAI	Data stays local
Offline	Yes	No	Yes

Local (default)

Uses sentence-transformers. Runs entirely on your machine, no API key needed.

OpenAI

Uses OpenAI's API. Higher quality embeddings but requires an API key.

To use OpenAI embeddings, add to your .env:

FUSESEARCH_EMBEDDER=openai
OPENAI_API_KEY=sk-...

Or pass via CLI:

fusesearch --embedder openai index data/docs
fusesearch --embedder openai search "your query"

Rate limits: OpenAI Tier 1 accounts have a 40k tokens-per-minute limit on embeddings. FuseSearch retries automatically on rate limit errors, but initial indexing of large document sets will be slow. Higher tiers (auto-upgrade as you spend) increase this significantly. See OpenAI rate limits.

Ollama

Uses Ollama to run embedding models locally. No API key needed.

1. Install from ollama.com
2. Pull an embedding model: ollama pull nomic-embed-text

FUSESEARCH_EMBEDDER=ollama

Or pass via CLI:

fusesearch --embedder ollama index data/docs
fusesearch --embedder ollama search "your query"

Docker: When running FuseSearch in Docker with Ollama on the host, set OLLAMA_HOST so the container can reach it:

OLLAMA_HOST=http://host.docker.internal:11434

Other Ollama embedding models: bge-m3, mxbai-embed-large, snowflake-arctic-embed. Configure with:

OLLAMA_EMBED_MODEL=bge-m3

Reranking

Reranking uses a cross-encoder model to rescore search results after retrieval. The cross-encoder evaluates each (query, document) pair directly, producing more accurate relevance scores than initial retrieval alone.

When enabled, FuseSearch overfetches 3x candidates from hybrid search, then reranks down to the requested limit.

Usage

Per-request via CLI flag or API parameter:

fusesearch search "your query" --rerank

curl -X POST http://localhost:8000/search \
  -H "Content-Type: application/json" \
  -d '{"query": "your query", "rerank": true}'

Or enable globally via environment variable:

FUSESEARCH_RERANK=true

Configuration

Variable	Default	Description
FUSESEARCH_RERANK	false	Enable reranking globally
FUSESEARCH_RERANKER	local	Reranker provider
FUSESEARCH_RERANK_MODEL	cross-encoder/ms-marco-MiniLM-L-6-v2	Cross-encoder model

The reranker is independent of the embedding provider — it works on raw text, not vectors. You can use FUSESEARCH_EMBEDDER=openai with FUSESEARCH_RERANK=true. The local reranker requires the [local] extra (sentence-transformers).

Ask (LLM Synthesis)

The ask command searches your indexed documents and uses an LLM to synthesize an answer with citations. This is optional — search works without any LLM provider installed.

Usage

fusesearch ask "What is Drupal?"

curl -X POST http://localhost:8000/ask \
  -H "Content-Type: application/json" \
  -d '{"query": "What is Drupal?"}'

LLM Providers

Provider	Model	Extra	Cost
Anthropic	claude-sonnet-4-20250514	[anthropic]	Pay-as-you-go API
OpenAI	gpt-4o-mini	[openai]	Pay-as-you-go API
Ollama	llama3.2	[ollama]	Free (runs locally)

Anthropic

Requires a separate API key (a Claude Pro/Team subscription does not include API access).

1. Create an account at console.anthropic.com
2. Add billing under Settings > Billing (pay-as-you-go)
3. Create a key under Settings > API Keys

FUSESEARCH_LLM=anthropic
ANTHROPIC_API_KEY=sk-ant-...

OpenAI

If you already have an API key for OpenAI embeddings, the same key works here.

1. Go to platform.openai.com/api-keys
2. Create a new secret key

FUSESEARCH_LLM=openai
OPENAI_API_KEY=sk-...

Ollama

No API key needed. Runs entirely on your machine.

1. Install from ollama.com
2. Pull a model: ollama pull llama3.2

FUSESEARCH_LLM=ollama

If FUSESEARCH_LLM is not set, FuseSearch auto-detects the first installed provider. If none are installed, ask returns a clear error — search continues to work normally.

MCP Server

The fusesearch-mcp Docker service exposes a streamable HTTP endpoint on port 8001. Tools: search (hybrid search), count (indexed chunks).

Claude Code

claude mcp add fusesearch http://localhost:8001/mcp --transport http

Claude Desktop

Option 1: Connectors UI (recommended)

In Claude Desktop, go to Settings > Connectors > Add custom connector and enter https://localhost:8001/mcp.

Option 2: Config file with mcp-remote bridge (local dev)

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "fusesearch": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "http://localhost:8001/mcp", "--allow-http"]
    }
  }
}

Requires Node.js >= 18. --allow-http is required for plain HTTP (not needed for HTTPS).