fx vs ShogunAI: Features, Pricing & Which Is Better (2026)
A side-by-side comparison of fx and ShogunAI — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.
fx
Vercel Labs
Vercel Labs' tiny open-source coding agent — a ~6 MB native CLI written in Zig, built for speed, embeddability and Unix-style ergonomics.
Key features
- Tiny Native Binary: The whole agent ships as a roughly 6 MB executable designed for instant installation and for embedding in resource-constrained environments and agent sandboxes.
- Instant Time to Prompt: fx cold starts in about 10 microseconds and performs no unnecessary work or I/O before accepting user input, which matters for programmatic invocation.
- Minimal Memory Footprint: A single-digit-megabyte memory baseline lets you pack many concurrent instances onto one machine.
- Shell-Like Ergonomics: Scroll history is preserved by default and output is deliberately sparse, so the CLI composes like a Unix tool instead of taking over the terminal.
- Context Efficiency: A minimal system prompt and tool surface reduce token spend and improve time-to-first-token performance.
- WebAssembly Builds: Optimal fx.wasm builds from the Zig toolchain shrink the binary further and make the network stack pluggable, enabling the in-browser demo.
- Model and Provider Agnostic: Works with local models, LLM gateways, direct provider API access or existing subscriptions rather than locking you to one vendor.
- Extensible Small Core: Capabilities are added through skills, plugins and MCPs, following a Unix-like philosophy of a small core with composable extensions.
Best for
- Sandboxed Agent Execution: Ship a full coding agent inside a container or sandbox where a large runtime would not fit.
- Embedding in Larger Systems: Use fx as the agent harness inside your own product or internal platform rather than building a loop from scratch.
- CI and Scripted Automation: Invoke a coding agent from pipelines and scripts where fast cold starts and quiet output matter more than an interactive UI.
- Agent Harness Research: Experiment with system prompt and tool design on a deliberately minimal, readable Apache-2.0 codebase.
- Local-Model Coding: Run agentic coding against a locally hosted model without any dependency on a specific cloud provider.
- Browser-Based Demos and Playgrounds: Compile to WebAssembly and run the agent client-side with networking delegated to browser fetch.
ShogunAI
ShogunAI
A local-first macOS memory and execution assistant that remembers your workday on-device and finishes work inside the tools you already use.
Key features
- On-Device Memory Layer: Captures mail, meetings, documents and screen context locally and indexes them into an encrypted store on your Mac, with no cloud copy by default.
- Contextual Recall with Sources: Answers plain-language questions across Mail, chat, docs and calendar from a single search, attaching the source and timestamp to every hit so answers can be checked.
- Execution Layer with Three Autonomy Levels: Reversible work runs automatically, drafts wait for review, and anything leaving your Mac stops for explicit approval — with every action logged as what ran, on what evidence, and what left the device.
- Inline Draft at the Caret: Press Option and ShogunAI reads the field around your cursor plus the memory behind it, then writes the continuation directly in the app you are already typing in as a local write you send yourself.
- Meeting Minutes, Not Recordings: Transcribes a meeting as it starts and on completion writes a summary, the decisions made and the commitments it heard, filing next actions into your work state with one tap; audio is never written to disk.
- Two-Way Live Translation: Set the language you speak and the language they speak — their speech reaches you in yours and yours reaches them in theirs, with only text retained afterwards.
- Daily Brief: Assembles what moved overnight, what is still open and what you promised someone before the day starts, rather than on request.
- Shared Memory Across Models and Agents: The same structured state of people, projects, commitments and open loops reaches Claude, Cursor, ChatGPT and anything driven over MCP, CLI or REST, so no session starts cold.
Best for
- Eliminating Cold Starts: Stop re-pasting last week's decisions and open threads at the beginning of every model session — every assistant starts from the same live memory of your work.
- Closing Open Loops: Surface the follow-up that is due today, draft the reply with the correct file attached, and hold it for approval before it reaches the recipient.
- Meeting Follow-Through: Turn a call into decisions, commitments and filed next actions automatically instead of re-listening to a recording.
- Answering 'What Did We Decide?': Recall a specific decision from a Notion brief or Gmail thread weeks later, with the source and time attached so it can be verified.
- Privacy-Constrained Work: Run an assistant over sensitive client or company context on machines where a cloud-indexed copy of the workday is not acceptable.
- Cross-Language Collaboration: Hold live meetings with counterparts in another language and keep only the translated text afterwards.
- Consultant and Founder Context Switching: Keep separate projects, people and commitments straight across many concurrent engagements without manual note discipline.