A real-time translation layer between your source code and its business value — right inside VS Code.

Rosetta Bridge reads the same code two ways and lets you choose the audience with a toggle:

Plain (Vibe Coder) channel — a jargon-free, plain-English walkthrough for non-technical founders: what the code does, how data flows, and where the cost/safety risks hide.
Executive channel — a business-impact briefing for tech leads: executive summary, ROI, risk/security, and ready-to-paste bullets for Slack, Jira, or a PR.

It runs on your existing GitHub Copilot seat (including Copilot Free) with zero configuration and zero hosting cost.

The Signal Station

The sidebar is a decoding station, not a chat box. You hoist a channel (Plain or Executive), drop in an intercepted selection, and watch it decode as it streams — then copy the transmission out.

State	What you see
Idle	A channel legend explaining the two modes.
Decoding	The intercepted source, a signal tether, and text decoding live behind a blinking station cursor.
Decoded	Structured Markdown, ready to Copy Transmission.
Signal lost	A clear station notice (no model, no selection, no staged changes, not a repo).

The whole accent system re-colors when you switch channels (teal for Plain, amber for Executive). The UI is fully theme-aware across VS Code light, dark, and high-contrast themes.

Usage

Translate a selection — select code (or place your cursor in any file), then run Rosetta Bridge: Translate Selection from the Command Palette or the editor right-click menu. With no selection, the whole file is captured.
Summarize staged changes — stage some changes (git add …), then run Rosetta Bridge: Summarize Git Staged Changes. This reads git diff --cached and always frames it for stakeholders (Executive channel).
Switch channels — click CH·1 PLAIN or CH·2 EXEC in the sidebar.
Copy — hit Copy Transmission and paste into Slack, Jira, a PR, or an investor update.

Output streams into the Rosetta Bridge view in the Activity Bar.

Commands

Command	ID
Rosetta Bridge: Translate Selection	`rosettaBridge.translateSelection`
Rosetta Bridge: Summarize Git Staged Changes	`rosettaBridge.summarizeStagedChanges`

Settings

Setting	Default	Notes
`rosettaBridge.provider`	`vscode-lm`	LLM provider. Only `vscode-lm` is implemented in this release; `openai`, `anthropic`, and `ollama` are listed for forward-compatibility and fall back to `vscode-lm`.
`rosettaBridge.defaultMode`	`vibeCoder`	The channel selected when the panel opens (`vibeCoder` or `executive`).

Requirements

VS Code ^1.90.0
An active GitHub Copilot session (the free tier works). Rosetta Bridge uses the native vscode.lm API, so no API keys are required.

Architecture

A thin activation layer wires the commands and sidebar view to a small, testable core:

Command / Webview action
        │
        ▼
  Orchestrator (extension.ts)          capture selection or git diff → pick channel → build messages
        │
        ▼
  ProviderRegistry ─▶ LLMProvider ─▶ VSCodeLMProvider (vscode.lm)   [extensible: OpenAI/Anthropic/Ollama drop in here]
        │  async-iterable text chunks
        ▼
  SidebarViewProvider ──postMessage──▶ Signal Station webview (markdown-it, re-rendered per chunk)

src/core/ — pure, unit-tested logic: prompt templates, mode→prompt mapping, selection capture, git diff --cached classification.
src/providers/ — the LLMProvider interface, the vscode.lm implementation, and the registry. New providers implement one streaming method.
src/webview/ — the sidebar view provider (message bridge, CSP + nonce) and the vanilla-TS Signal Station UI.

Product truth lives in PRODUCT.md; the visual system is documented in DESIGN.md.

Development

npm install
npm run compile        # build the extension + webview bundles (esbuild)
npm run watch          # rebuild on change
npm run lint
npm run test:unit      # fast mocha unit tests (core logic, no VS Code host)
npm test               # integration tests via @vscode/test-electron

Then press F5 in VS Code to launch the Extension Development Host with Rosetta Bridge loaded.

Design preview

The webview can be rendered outside VS Code for visual review:

node scripts/preview.mjs   # generate preview pages for every state × theme
node scripts/shoot.mjs     # screenshot them with Playwright's isolated Chromium → .preview/shots/

Roadmap

v1.1 — BYOK OpenAI/Anthropic providers (keys via vscode.SecretStorage), local Ollama support, cost/compliance warning detector, and custom prompt templates.