Localsynapse

What is Localsynapse?

Localsynapse is a Windows desktop application that provides AI-powered local search for files and email. It indexes documents and email using hybrid full-text (BM25) and semantic (local AI embeddings) search, and exposes a built-in MCP server so AI assistants like Claude can query the index and read structured file contents—all on your own machine, without sending data to the cloud.

How to use Localsynapse?

Download the latest installer from the GitHub Releases page and run it. Indexing and search happen automatically; the built-in MCP server is ready for your AI assistant to connect.

Key features of Localsynapse

• Hybrid search combining BM25 and local AI embeddings, with strong Korean/English support.
• Reads PDF, Word, PowerPoint, Hangul (HWP), CSV, Markdown, and plain text.
• Faithful Excel reading: cell coordinates, merged ranges, correct types, up to 25 MB.
• Local email search across .eml, .msg, .mbox, and exported mailbox JSON.
• Built-in MCP server for AI assistants with local, source-attributed access.
• All indexing, search, and embedding run locally; files never leave your device.

Use cases of Localsynapse

• Find documents and emails by keyword or meaning without an internet connection.
• Let an AI assistant read and summarize your spreadsheets, preserving structure and cell references.
• Search across email and file attachments together using sender, subject, or body text.
• Complete privacy—no data is sent externally, suitable for confidential information.

FAQ from Localsynapse

How does Localsynapse differ from cloud-based search tools?

Localsynapse performs all indexing, search, and AI embedding locally on your Windows machine. No file contents or search queries are sent to any external service, ensuring complete data privacy.

What file formats does Localsynapse support?

It supports PDF, Word, PowerPoint, Hangul (HWP), CSV, Markdown, plain text, and Excel (faithful structured reading up to 25 MB). For email it reads .eml, .msg, .mbox, and exported mailbox JSON.

What are the system requirements?

Localsynapse is a Windows-only application. It requires no additional runtime dependencies; all local AI models and components are bundled with the installer.

How does the MCP server work?

A built-in MCP (Model Context Protocol) server lets AI assistants like Claude connect directly to your local index. The server provides search results and structured views of your files (including spreadsheets with cell coordinates) with source attribution.

Where is my data stored?

Indexes, embeddings, and all content stay entirely on your local machine. No data is transmitted over the network.