A VS Code extension that classifies Move smart-contract code using a
local CodeBERT + LoRA model (trained as part of an MSc thesis), and then
asks Claude for a concrete fix when the classifier flags a real issue.
Architecture
VS Code Extension (TS)
│ POST /classify (localhost only)
▼
Local FastAPI server (Python) ← auto-spawned on activation
│ CodeBERT + LoRA
▼
{label, confidence}
│ if label != "Perfect":
▼
Anthropic API (your key, your billing)
▼
Fix suggestion shown in a side panel (with Apply Fix button)
Setup
Install dependencies:
cd extension && npm install && npm run compile
cd ../server && python -m venv .venv && source .venv/bin/activate && pip install -r requirements.txt
Open the extension/ folder in VS Code and press F5 to launch an
Extension Development Host.
In the host window, set your Anthropic API key in
Settings → Extensions → NiceMove → Anthropic API Key.
Open a .move file, select code (or none for the whole file), and run
Move: Diagnose Selection (Cmd+Alt+M / Ctrl+Alt+M).
Features
Inline diagnostics — predictions appear as squiggles in the editor and
entries in the Problems tab.
Multi-label diagnostics — when the classifier is uncertain, the second-most
likely prediction is shown as a hint alongside the primary diagnosis.
Quick Fix lightbulb — every diagnostic carries a Fix … with Claude
code action; trigger it with Cmd+..
Streaming Claude output — the side panel streams tokens as Claude
generates them.
Apply Fix inline — after Claude suggests a fix, click "Apply Fix" in the
panel to patch the code directly in the editor.
Status bar indicator — shows ✓ NiceMove when idle, a spinner while
classifying, and ⚠ NiceMove when issues are detected.
Workspace scan — run Move: Scan All Move Files from the command palette
to classify every .move file in the workspace at once.
Classification cache — unchanged code is not re-classified, making
repeated diagnoses instant.
OOD guard — a Move-likeness heuristic suppresses predictions on
non-Move snippets so the model's over-confidence on out-of-distribution
input does not surface as false diagnostics.
Auto-classify on save(opt-in) — set
moveClassifier.classifyOnSave to true to refresh diagnostics every time
a .move file is saved.
Settings
Key
Default
Description
moveClassifier.anthropicApiKey
""
Your Anthropic API key. Required for fix suggestions.
moveClassifier.claudeModel
claude-sonnet-4-5
Claude model used for fix suggestions.
moveClassifier.serverUrl
http://127.0.0.1:8765
Local classifier server URL.
moveClassifier.confidenceThreshold
0.6
Below this, the prediction is treated as uncertain.
moveClassifier.autoSpawnServer
true
Launch the FastAPI server on activation.
moveClassifier.classifyOnSave
false
Auto-classify Move files on save.
moveClassifier.pythonPath
""
Python interpreter (auto-detected if empty).
Packaging
To produce a .vsix for sideloading or marketplace upload:
cd extension
npx @vscode/vsce package --no-yarn
Privacy
The classifier server binds to 127.0.0.1 only.
Your code is sent to the local server (in-process) and, only when an issue
is detected, to api.anthropic.com using your API key.
The extension does not send telemetry, analytics, or code anywhere else.
We never see your code or your key.
Billing
You bring your own Anthropic API key. You are billed by Anthropic directly
based on your usage of their API. The maintainers of this extension do not
process payments and do not see your key or your invoices.
