Choose your AI: signing in to Claude, Codex, or both

Status (2026-09-18): shipped in Hydrogen 1.0.436 to 1.0.443 (insiders). Live today: no AI sign-in in setup, the Choose your AI dialog on first landing, sign in or an API key for Claude Code and Codex, Install then sign in for Kimi Code and Antigravity, Grok as coming soon, Manage AIs in the Adom menu, AI accounts in the profile menu, the Welcome tab's live Your AIs line, and the /agents/* control API (a port of Kyle's macOS engine, one contract on both platforms). Verified on a fresh Windows machine: setup ended with no Claude step, the dialog opened, and a Claude sign-in from it completed through the browser. Not yet shipped: the dot on a signed-out AI button and the Your AIs section in the VS Code AI menu (the next adom-vscode release), the one nudge on a signed-out button, the usage widget link, and the hydrogen-ai-accounts skill. The pictures below were mockups drawn before the build; the real dialog matches them closely (rows instead of two big cards, per Kyle's macOS design).

1.0.441 to 1.0.443 fixed the first landing on a box that already has an AI signed in. From 1.0.439 the check died on a settings lookup (the cloud flag had no Settings entry, so reading it threw) before it ever asked the catalog, so a fresh account never recorded or asked about its AIs; only boxes recorded on 1.0.437 or 1.0.438 looked fine. Two more guards came with it: a workspace that does not answer the install probe right after a relaunch is reported as not answering (the check retries) instead of every AI reading as not installed, and the check writes its trail to the Hydrogen log ([ai-accounts] lines: setup state, catalog verdict, what it recorded). Verified on arav-rog: 1.0.443 recorded Claude silently with no dialog.

Hydrogen works with Claude Code and Codex today, yet setup still stops and makes every new user sign in to Claude before they can see Hydrogen at all. A Codex user pays that price for nothing, and everyone waits longer to reach the app. This plan takes AI sign-in out of setup, asks once when the user first lands, lets them pick Claude, Codex, both, or more, and then stops asking. It also gives them obvious ways back when they want to add another AI later.

What changes in setup

The Adom sign-in stays in setup: Hydrogen needs it to build the workspace.

The first time Hydrogen opens

As soon as VS Code finishes loading, one dialog appears over the VS Code pane. Everything around it stays visible, so the user knows they are already in Hydrogen.

• Two main cards, Claude Code and Codex, each with Sign in and Use an API key.
• More AIs below them. Antigravity and Kimi Code install and sign in the same way. Grok is shown as coming soon (see the open decisions).
• I'll do this later closes the dialog with nothing signed in. Continue lights up once any AI is signed in.
• The footer names the ways back, so skipping never feels like a dead end.

Signing in

Sign in runs the AI's own sign-in. Its page opens in the user's browser, and the card waits until the user approves. When a site shows a code, the card shows the same code. Use an API key takes a key instead, for Claude, Codex and Kimi.

When Hydrogen stops asking

• One AI signed in counts as done. The dialog never opens on its own again.
• Skipped with nothing signed in: exactly one more nudge. The first time the user clicks an AI button that is not signed in, that AI's sign-in card opens instead of a thread that cannot work. After that, nothing appears on its own.
• The answer follows the user. It is saved with their Hydrogen settings, so a second machine does not ask again.
• Never at every start. No reminder is tied to launching Hydrogen.

Getting back to it

One dialog, reachable from every place a user would look. In manage mode it shows who is signed in, lets them switch account or sign out, and installs more AIs. Its only button is Close.

The AI menu in VS Code

The AI menu at the right of the VS Code title bar is where people already look for AIs. It gains a Your AIs section at the top, with each AI's state and Manage AIs.

A signed-out AI button

A signed-out AI's button in the VS Code title bar carries a small dot, and its hover card says so.

Clicking it opens that one AI's sign-in card rather than an empty thread:

The profile menu

Click your avatar, then AI accounts. The row shows at a glance who is signed in.

The Adom menu

Manage AIs sits at the top of the Adom menu, above Settings.

The Welcome tab

The Welcome tab stops promising Claude. It lists Your AIs, with Sign in on any AI that is not signed in and Manage AIs beside the heading. The Welcome tab itself reopens from the Adom menu.

The usage widgets

When a usage widget has no sign-in to read, its message becomes a link to the same card.

Your AI

Your AI can open the dialog for you ("open the AI sign-in") through Hydrogen's control API, and read which AIs are signed in before it suggests a thread.

For your AI and for developers

The routes follow the design Kyle already built for the Mac version, so both platforms share one contract:

A hydrogen-ai-accounts skill would replace the current hydrogen-claude-auth skill.

Where this comes from

Kyle already solved most of this in Hydrogen for macOS (adom-inc/hydrogen-macos):

• Its first-run intro plays three sample prompts, one each for Claude, Codex and Kimi, and asks for no AI sign-in.
• Set Up Agent Harnesses is a card overlay over the VS Code pane listing Claude Code, Codex, Kimi Code and Antigravity, with live installed and signed-in state. Each signs in through its own command-line tool: a browser link, a device code, token paste, or an API key.
• Skip or Continue is recorded once per install, and a manage mode reopens the same cards.

This plan brings that design to Windows and adds the parts it leaves open: the one-nudge rule, the dot on signed-out buttons, and a way back from every menu a user already knows.

Open decisions

1. Grok. Hydrogen has no Grok editor integration today; it exists only as a dock app. The recommendation is to leave Grok out of the dialog, or show it as coming soon, until a real sign-in path exists.
2. One implementation. Port Kyle's backend and panel so macOS and Windows share one code path, with Kyle reviewing the Windows port.
3. Names. Kyle's panel says "Agent Harnesses". The recommendation is "Your AIs" in the interface, the words users know.
4. The dialog on first landing. Recommended: shown automatically once. The alternative is to show it only when the user first clicks an AI button.

How it would be tested

On a fresh Windows machine, before release:

• A new install with no AI sign-in reaches Hydrogen without a sign-in step.
• A Codex-only user, a Claude-only user, a user with both, and a user who skips everything.
• The one nudge fires exactly once, on the first click of a signed-out AI button.
• Every way back opens the dialog: AI menu, dot, profile menu, Adom menu, Welcome tab, usage widget, control API.