Your first session in VS Code

By the end of this tutorial, the Lemniscate extension is installed in your VS Code, connected to your organization’s gateway, and you have obtained an answer about code of your own.

This tutorial is the workstation step in the Install the complete code assistant path. It assumes the gateway services already respond. The workstation carries only the extension, and the extension knows only the gateway address: the inference engine is reached through the gateway alone (security white paper V3, section 3.1).

Lemniscate is not published on any marketplace or package registry. You install it from the signed archive the vendor provided.

1. Check the archive you received

Your contact sent you an archive and the accompanying fingerprint file. The exact names of these two files are given to you at delivery; the commands below refer to them as ARCHIVE and EMPREINTES, which you replace with what you received.

Move to the directory where you placed them, then:

sha256sum -c EMPREINTES

Expected result: one line per file checked, each ending with Réussi (OK in English). If a line says ÉCHEC, stop here: the archive is incomplete or altered. Ask your contact for another one before going further.

2. Extract the archive and locate the extension

mkdir -p ~/lemniscate
tar -xzf ARCHIVE -C ~/lemniscate
find ~/lemniscate -name 'lemniscate-*.vsix'

Expected result: the last command prints a single path, that of the VS Code extension package. The archive also contains the JetBrains plugin and the terminal; this tutorial does not use them.

3. Install the extension in VS Code

VSIX=$(find ~/lemniscate -name 'lemniscate-*.vsix' | head -n 1)
code --install-extension "$VSIX"

Expected result: the terminal prints Extension 'lemniscate-<version>.vsix' was successfully installed. Reopen VS Code: a Lemniscate icon appears in the activity bar, on the side.

4. Pin the version you just installed

VS Code updates extensions on its own. This extension comes from a file, not from a marketplace: left active, that mechanism can replace the version you installed. Turn it off.

Open the command palette, run Preferences: Open User Settings (JSON), and add this entry:

{
  "extensions.autoUpdate": false
}

Expected result: the entry appears in your settings.json and VS Code accepts it without underlining it. The installed version stays in place until you install the next archive yourself.

5. Declare your organization’s gateway

Open the Lemniscate panel: the icon in the VS Code activity bar. Since no model is declared yet, the panel shows the welcome screen, opened on the Gateway tab.

In Gateway address, enter the address you were given, as is, and in Account key, your account key. Click Test.

Expected result: a line reports the number of models found and their names. These are the models the gateway serves. If the gateway does not respond or rejects the key, the line says what to correct: the test writes nothing, so you can run it again after each correction.

Confirm with Use.

Expected result: below the input area, the model selector lists the models the gateway serves.

6. Ask your first question about your code

Open one of your projects in VS Code, then a file you know well. Select about thirty lines in it, a whole function rather than a fragment. Press Ctrl+L (Cmd+L on macOS), write your question in the input area, and confirm:

Que fait ce code, et quels cas d'entrée ne sont pas traités ?

Expected result: the selected code appears as a context block above your question, and the answer names your own functions, variables and files. The model read your code instead of producing a generality.

What you have obtained

An extension installed from a file you checked yourself, exchanges with the model that all go through your organization’s gateway, and a conversation whose context is the code you selected.

Lemniscate builds no index of the source code. The repository is explored on demand, and no derived, persistent copy of your code exists (security white paper V3, sections 3.2 and 11.3).

Next steps

• Delegate a task to a subagent: hand part of the work to a secondary agent, once this first session is working.
• The lifecycle of an agentic session: what happens when the agent modifies code and runs commands.
• VS Code extension: the settings and commands exposed by the extension.
• Where the data goes: what travels between the workstation, the gateway and the engine, and what does not leave your perimeter.

The VS Code welcome screen also offers a four-step guided walkthrough, Get started with Lemniscate, shipped with the extension and usable without Internet: it covers what you just did and goes on to completion, code modification and conversation. Its steps are checked off as you complete them.