YAAST — Yet Another AI Summary Tool

A VS Code / Cursor extension for navigating unfamiliar codebases

YAAST puts an AI-generated headline above every function, method, and class — and a file-level overview at the top of every file. Headers are inline, hover-on-demand, persisted to disk, and only regenerate when the underlying code changes.

There are a lot of AI summary tools. This one happens to be useful for navigating code rather than chatting about it.

Install

Grab the latest yaast.vsix from Releases.

Cursor:

cursor --install-extension /path/to/yaast.vsix

VS Code:

code --install-extension /path/to/yaast.vsix

Or in either editor: Extensions sidebar → ⋯ menu → "Install from VSIX…".

After install, run Cmd+Shift+P → "Semantic Fold Mode: Set Anthropic API Key" and paste your sk-ant-... key. It's stored in the OS keychain via SecretStorage — never written to disk in plaintext, never synced.

You'll need an API key from console.anthropic.com.

How to use it

1. Open any code file. You'll see deterministic headers (function buildIndex, etc.) above each symbol, plus a top-of-file CodeLens: ✨ Generate summaries for this file (N). Click it.
2. One batched API call summarizes everything. Land in ~5–10s.
3. The 📘 banner at the top of the file shows the file's headline. Hover the banner (in the leading whitespace) for the full overview — purpose, main features, regenerate link.
4. Each function gets a ⟪ AI headline ⟫ inline. Hover the inline text for the full card — purpose, methods used, techniques, risks, confidence.
5. Edit a function. Only that function marks itself out-of-date. The class containing it stays fresh (we hash containers on their skeleton, not their full body). Click the inline lens to regenerate just that one.

What's good about it

• Ambient, not on-demand. Summaries are already there when you open a file.
• Persistent. Every summary lives on disk, keyed by content hash. Reopen the file later, no re-spend.
• Selective regeneration. Editing one function only invalidates that function. The page-level "regenerate" button only re-summarizes stale items.
• Batched. Up to 30 symbols per API call. ~50% input-token saving vs. one-by-one. Cap configurable.
• Native to the editor. Built on VS Code's symbol/folding/decoration/codelens APIs. No webviews, no chat panel.

What it's not (yet)

• Not a chatbot. Doesn't answer questions about your code.
• Not perfect. AI summaries can be confidently wrong. The Confidence: low/medium/high field helps, but it's also AI-generated.
• Not for secret code. Source goes to Anthropic. Don't point it at code you can't share with a third party. (A local-Ollama provider is stubbed for the future.)
• Not yet for non-developers. Lives only in VS Code / Cursor. The summary engine could power a web UI for non-IDE readers, but that's not built.

Settings

Setting	Default	Notes
semanticFoldMode.enabled	true	Master toggle.
semanticFoldMode.provider	cloud	cloud (Anthropic), static (no AI), vscode-lm and local are stubs.
semanticFoldMode.cloud.model	claude-haiku-4-5	Any Claude model id (claude-sonnet-4-6, claude-opus-4-7, etc.)
semanticFoldMode.cloud.batchSize	30	Max symbols per batched call.
semanticFoldMode.cloud.maxBatchInputChars	60000	Char budget per batch. Splits if exceeded.
semanticFoldMode.autoFoldOnOpen	true	Auto-collapse function bodies on open.
semanticFoldMode.includeKinds	["Function","Method","Class"]	Symbol kinds to summarize.
semanticFoldMode.concurrency	3	Max in-flight summary calls.

Costs

Default provider is Claude Haiku 4.5. Rough numbers:

• ~$0.02 per file with 30 functions in a single batched call.
• Disk cache means each unique chunk of code is paid for at most once.
• Editing one function regenerates only that function (~$0.001), not the page.

Development

git clone https://github.com/claycantrell/YAAST
cd YAAST
npm install
npm run build           # bundle into dist/extension.js
npm test                # integration test (downloads VS Code on first run)
# F5 in VS Code/Cursor to launch the Extension Development Host

To package and install locally:

npm run install:cursor  # builds .vsix and installs into Cursor
npm run package         # just builds the .vsix without installing

Releasing

Tag-driven via GitHub Actions. Bump version in package.json, then:

git tag v0.1.1
git push --tags

The workflow at .github/workflows/release.yml builds and attaches yaast.vsix to a new GitHub Release.

License

MIT