Show HN: Local Motion – Use Cursor Agents and Chat with a Local LLM

Local Motion turns a local coding agent on and off for VS Code and Cursor. It chooses a compatible local model for your Mac, loads it when you need it, and frees the memory when you do not.

• Gives you one local-agent switch: turn on, connect Cursor, free memory.
• Chooses a compatible local coding model for this Mac.
• Reuses the installed model when possible, so turning it on again is quick.
• Keeps every downloaded model on disk and switches between them on demand, so you can run a maximum-size model normally and a lighter one when the Mac is busy.
• Connects Cursor automatically when running inside Cursor — model stays on this Mac, Cursor relays chats through its servers — without writing Cursor private state.
• Frees the loaded model from memory immediately when you are done.
• Keeps the runtime bound to 127.0.0.1

.

• Profiles your Mac for architecture, memory, and model storage space.
• Sizes the model memory budget at 80% of unified memory, pegged to the Apple Silicon Metal wired-memory limit (the real ceiling for GPU-resident GGUF weights), and estimates load cost at 1.1x file size plus explicit KV-cache and server overheads.
• Fits the context window to the machine: the localMotion.contextTokens

setting is a ceiling, and every model start uses the largest context the memory budget affords under it. - Never blocks a start on current free memory. macOS reclaims cache and compresses idle apps on demand, and Local Motion reports an honest out-of-memory explanation if llama-server

genuinely cannot load. - Searches Hugging Face GGUF repositories and ranks compatible quantizations only when setup or advanced model controls need them.

• Downloads model files with resumable streaming.
• Finds or installs llama-server

through Homebrew. - Starts llama-server

and a stable loopback OpenAI-compatible proxy.Connect Cursor to Local Agent

starts the tunnel that makes the proxy reachable by Cursor's backend. In real VS Code no tunnel starts and thevscode.lm

path stays fully local. - Registers the running model with the VS Code Language Model API, with the provider's manage action opening the local-agent switch.

• macOS.
• VS Code or Cursor compatible with VS Code ^1.105.0

. - Homebrew, when llama-server

is not already available onPATH

,/opt/homebrew/bin

, or/usr/local/bin

; Local Motion uses it to installllama.cpp

. - Enough free disk and unified memory for the selected GGUF file.

• Localhost port 41434

available for the Cursor-facing proxy, or setlocalMotion.proxyPort

to another port. If the preferred port is occupied, Local Motion falls back to an ephemeral port and shows updated setup values. cloudflared

for the Cursor connection; when you connect Cursor, Local Motion installs it through Homebrew on demand, or setlocalMotion.cursorTunnelUrl

to a public HTTPS tunnel URL you manage.

• Install Local Motion.
• Local Motion opens the local-agent switch once on first startup.
• Click Turn On Local Agent

.

The setup panel also exposes advanced model controls, but the default path does not require choosing a repository, model size, or quantization.

When a local model is already running, Local Motion: Connect Cursor to Local Agent

runs the Cursor handoff directly from the command palette. If a size-valid installed model is stopped, the command starts it first; then it verifies the endpoint, copies the setup block, and opens Cursor Models settings.

Turn On Local Agent

may install llama.cpp

through Homebrew and download the best compatible GGUF quantizations for this Mac. The default setup is a two-model pack: Max: Qwen3-Coder-30B-A3B and Mini: Gemma 4 26B A4B. Local Motion preinstalls both when they fit, then starts the selected model. It does not silently downgrade the one-click setup to older Qwen2.5 models; choose those explicitly from Advanced when needed. Set localMotion.runAutomagicalSetupOnFirstStartup

to true

only if you want that install/download to start automatically on first startup.

The ladder is maintained from a live ranking; see README/Notes/model-selection.md and npm run models:check

/ npm run models:refresh

.

If setup fails or is cancelled, run Local Motion: Repair Local Agent

.

Run Local Motion: Free Memory

to unload the local model immediately.

The setup panel shows Max and Mini as first-class choices with their selected quantization, download size, and estimated runtime memory. Select either model and use the main button to start, switch, or install the pack if it is not downloaded yet. The current model stops, the selected one starts, and it becomes the model that Turn On Local Agent

starts next time.

Max and Mini are replaceable slots. Paste a Hugging Face GGUF repository into either row and click Replace

; Local Motion validates the best compatible Q4+ quantization, downloads it into that slot, and restarts the model only when that slot was already running.

Run Local Motion: Diagnose Setup

for a read-only status check of the installed model file, local runtime, proxy verification, copied Cursor values, and the remaining Cursor picker verification step.

After Cursor setup succeeds once, Local Motion can restart the installed model automatically on future editor startups without down a new model, opening the setup panel, opening Cursor settings, or replacing the clipboard. The Cursor tunnel still starts only when you run Connect Cursor to Local Agent

. Tunnel URLs can rotate across handoffs, so the setup panel marks previously copied Cursor values stale when the active Base URL changes. Disable localMotion.resumeAutomagicalSetupOnStartup

to turn automatic local model restart off.

For advanced manual control:

• Load a Hugging Face GGUF repository.
• Pick a quantization marked Compatible

. - Click Install and Turn On

; Local Motion installs the quantization and starts the local model. UseConnect Cursor to Local Agent

when you want Cursor chat to use it.

Connect Cursor to Local Agent

verifies GET /v1/models

through the Cursor-facing tunnel with the current session key, copies the full setup block, opens Cursor Settings (in plain VS Code, the filtered settings editor instead), and leaves one-click copy controls visible for:

• OpenAI API Key: the current session key
• Override OpenAI Base URL: the active public Cursor tunnel Base URL
• Add Custom Model: the active Local Motion model ID
• Full setup block

In Cursor's API Keys section, turn on OpenAI API Key after pasting the session key. A saved key with that provider toggle off makes Cursor reject the selected custom model before it sends any request. See the custom-model validation debugging guide.

Cursor does not expose a stable extension API for mutating its native model picker or private settings. Local Motion deliberately does not write Cursor SQLite databases, secure storage, settings.json

, or other private application state.

Known Cursor limit (confirmed 2026-07-01): Cursor routes every custom-model request through its own cloud backend, which refuses private addresses with Provider returned error: Access to private networks is forbidden

. A http://127.0.0.1:41434/v1

Base URL therefore cannot work in Cursor's native chat, in any build. The proven workaround is a public HTTPS tunnel (cloudflared or ngrok) in front of the Local Motion proxy — with the tradeoff that prompts then transit Cursor's backend and the tunnel, so the Cursor path is "local compute", not "fully private". Anyone with the tunnel URL and current session key can reach the proxy while the tunnel is up, and Cursor's Zero Data Retention does not apply to custom keys. Full failure analysis, fix matrix, and setup steps: Cursor private-network block guide. The fully local path (vscode.lm

provider) works in real VS Code only; Cursor does not implement the VS Code Language Model API.

Cursor's OpenAI Base URL override is global in Cursor settings and may not apply to every Cursor surface. Custom API keys officially power chat models only — Tab autocomplete, Apply, and Auto never use the custom endpoint, and Agent mode is best-effort. Treat setup as proven only for the Cursor surface you manually test, such as Cmd+L

chat. Do not assume Agent, Composer, Inline Edit, or Tab autocomplete use the tunnel until verified in your Cursor build.

Local Motion keeps the loopback proxy stable by preferring http://127.0.0.1:41434/v1

, but Cursor must use the active public tunnel Base URL shown by Connect Cursor to Local Agent

. If that URL changes, the setup panel marks previously copied Cursor values stale and offers Copy Updated Setup

.

Local Motion binds its runtime services to 127.0.0.1

. Model files are stored in the extension global storage directory, outside the workspace. VS Code Language Model API requests stay on loopback. Cursor requests use local compute but transit Cursor's backend and the configured tunnel before reaching the Local Motion proxy. Requests sent to the proxy are sanitized before forwarding to llama-server

.

npm install
npm run check
npm run lint
npm test
npm run package

The CI

GitHub Actions workflow runs the same deterministic gate on pull requests and pushes: install, typecheck, lint, test, and package.

Optional local runtime smoke proof:

npm run smoke:local-runtime

This downloads the default compatible GGUF when it is not already cached, starts llama-server

, verifies the Cursor-facing proxy, and sends one local chat completion.

Open this folder in VS Code or Cursor, run the Extension Development Host, and execute Local Motion: Open Local Agent

.

Found a defect or have an idea worth trying? Start with CONTRIBUTING.md. Do not put a vulnerability, session key, or private prompt in an issue; use the private reporting path in SECURITY.md.

Local Motion publishes to the Visual Studio Marketplace with vsce

.

Local package proof:

npm run check
npm run lint
npm test
npm run package

Manual Marketplace publish:

VSCE_PAT=<token> npx vsce publish -p "$VSCE_PAT"

GitHub Actions publish:

• Create or verify the Visual Studio Marketplace publisher ID from package.json

. - Add a repository secret named VSCE_PAT

with MarketplaceManage

scope. - Run the Publish VS Code Extension

workflow manually.

Microsoft recommends moving automated publishing to Entra ID before global Azure DevOps Personal Access Tokens retire on December 1, 2026.

See Local Native LLM Extensions for VS Code and Cursor on macOS for the sidecar architecture field guide.

source & further reading

github.com — original article