The problem Like a lot of developers, I live in several surfaces at once: an editor, a terminal, notes, task lists, and an AI assistant. Each one is fine on its own. Together, they’re awful at one thing: keeping a single, trustworthy slice of project context in sync. I was tired of: Re-explaining the same background to Claude Copy-pasting chunks of notes or repo context “Knowing” something lived in some doc or ticket, but not being able to pull the exact passage when I needed it I wanted one local place for workspace + knowledge, but I also wanted that data everywhere on my Mac—not trapped in a single app. DeepThink is a local-first workspace for macOS: projects, notes, tasks, reminders, and a personal knowledge base, with a native SwiftUI UI so you can actually browse and edit your data like a real app. On top of that, it ships: An MCP server so MCP-capable clients can read and update what the app manages A deepthink CLI for terminal workflows Hybrid RAG (keyword + semantic retrieval) so assistants can attach tight excerpts instead of whole directories Persistence is on your machine (SwiftData plus on-disk markdown and embeddings under ~/DeepThink/). The goal isn’t “another notes app”—it’s one workspace that other tools can see and reuse through MCP and CLI, with a GUI when you want to think in screens instead of prompts. MCP is the difference between “my data lives in an app” and “my data is a capability my editor and agents can call.” If your assistant can query your workspace the same way your UI does, you stop treating AI as a separate silo and start treating it as another client over the same source of truth. The CLI covers the cases where you’re not in an MCP-aware client at all: scripts, SSH-ish flows, quick captures, or “just give me context for this query” from the shell. Together, they’re how I get local data onto the rest of my machine without turning copy-paste into a second job. Dumping large folders into Claude “works” until it doesn’t: you burn tokens, dilute signal, and the model still might miss the one paragraph that mattered. DeepThink uses hybrid retrieval: BM25-style keyword search plus semantic search (on Apple’s embedding stack via NLEmbedding). In practice that means: Exact symbols, filenames, and rare terms still surface via lexical matching Paraphrases and “I can’t remember the wording” queries still surface via semantic matching You can ground the assistant on the passages you mean, not the whole haystack That’s the same underlying idea as good RAG in production systems: retrieve narrow, generate broad. Conversational AI routes through Anthropic’s Claude CLI (claude login) alongside that retrieval layer. The point isn’t to replace your editor; it’s to make workspace-aware conversations cheap enough to use all day because you’re not re-sending the world on every turn. There’s also a /deepthink command path in the workflow so common actions stay fast once you’re set up. You might care if you: Want local-first control over notes, tasks, and knowledge Use Claude and want MCP as the bridge into a real workspace Prefer native macOS UI for browsing and editing, not only chat You probably don’t need this if you’re happy with a single SaaS silo and don’t care about local storage or MCP integration. Try: try-deepthink.vercel.app Repo: deepthink Mac app: v1.0.0 release (Full install and troubleshooting are on that release page.) Feedback and PRs are welcome, especially on MCP, retrieval, and the CLI.