Contributing

twinny is developed at github.com/twinnydotdev/twinny under the MIT licence. Contributions are welcome; for anything beyond a small fix, open an issue describing the change first so the design can be discussed. Pull requests go to the development branch.

Building and running

Requirements: Node.js 18 or newer, npm, and VS Code.

git clone https://github.com/twinnydotdev/twinny.git
cd twinny
npm install
npm run build        # or: npm run watch

Open the folder in VS Code and press F5 to launch an Extension Development Host with twinny loaded from the source. The webview is a React app bundled alongside the extension; npm run watch rebuilds both on change.

Other scripts:

Script	What it does
npm run lint / npm run lint:fix	ESLint over src
npm test	Builds, lints, then runs the test suite in a headless VS Code. On Linux without a display, run it as xvfb-run npm test
npm run node	Runs the twinny-node P2P command line from the build
npm run vscode:package	Builds a .vsix

Building a VSIX

npm install
npm run vscode:package

produces twinny-<version>.vsix in the folder, installable with Extensions: Install from VSIX….

Layout

src/
  index.ts              extension entry: commands, providers, wiring
  common/               shared by extension and webview: constants, types,
                        provider validation and discovery (pure, unit-tested)
  extension/
    chat/               chat service, context builder, mentions, history
    completion/         FIM provider, templates, parser, LSP and recent-edit context
    edit/               inline edit: diff regions, CodeLens, code actions, tests
    embeddings/         indexer, chunker, LanceDB store, hybrid search, reranker
    inference/          provider-agnostic adapters (HTTP, hosted SDKs) and errors
    p2p/                gateway, host, runtime for paired devices
    providers/          provider store, manager, probe, first-run setup
    review/             code review, git helpers, commit messages
    templates/          Handlebars templates and defaults
    terminal/           command writer, error fixer, shell-integration history
    webview/            sidebar and panel hosts, file handling
  node/                 the twinny-node command line
  p2p/                  the peer-to-peer protocol, pairing and identity (no vscode imports)
  webview/              the React sidebar: chat, providers, devices, embeddings, review
  test/suite/           tests, run inside VS Code

Two conventions worth knowing:

• Code in src/common, src/p2p and most of src/extension/* that does not import vscode is pure and has direct unit tests. Keep new logic there where you can, and keep the VS Code-facing layer thin.
• The webview and the extension talk through a typed message protocol in src/common/messaging. Add a message type there before using it on either side.

Adding a provider preset

1. Add the provider id to API_PROVIDERS in src/common/constants/providers.ts and a display name to PROVIDER_DISPLAY_NAMES.
2. If it is an OpenAI-compatible local server, add it to OPEN_AI_COMPATIBLE_PROVIDERS and give it endpoint defaults in src/common/provider-validation.ts; add it to LOCAL_SERVER_PROVIDERS in provider-discovery.ts if first-run discovery should probe it.
3. If it is a hosted API, add it to HOSTED_PROVIDERS (and CHAT_ONLY_PROVIDERS if it has no completions endpoint) and wire the SDK in src/extension/inference/adapters/hosted.ts.
4. Add a preset in src/webview/providers/presets.tsx and a preset-<id> blurb in each locale under src/webview/assets/locales/.
5. Add a case to src/test/suite/inference.test.ts.

Adding a FIM template

Add the format to FIM_TEMPLATE_FORMAT and a stop-word list in src/common/constants/models.ts, a render function and a model-name hint in src/extension/completion/fim-templates.ts, and a test in fim-templates.test.ts.

Translations

The sidebar’s strings live in src/webview/assets/locales/<locale>.json. To add a language, copy en.json, translate, and add the locale to the twinny.locale enum in package.json. To fix a translation, edit the file.

This documentation lives in twinnydotdev/twinny-docs, an Astro Starlight site; pages are Markdown under src/content/docs/, with the Chinese translation under zh-cn/. npm run dev previews it.

Reporting bugs

Open an issue with the twinny version, VS Code version, server and model, and the relevant lines from the Twinny output channel at Debug level. Keys are redacted from the log automatically.