A product by OPENXEL

Never start from a blank reply.

henna writes the first draft. You select the message you need to answer, press a key, and the reply is already there — in your own words' shape, waiting to be corrected rather than composed. You read every word before it goes anywhere.

How to get it Why it works this way Runs in Chrome. Free — bring your own API key.

The story

The hard part of a reply is the first sentence

You open your inbox and most of what is there needs two lines back. None of it is difficult. Somebody wants a date confirmed, somebody wants to know if you saw the file, somebody is following up politely on a thing you have already decided.

What is expensive is starting. The cursor sits in an empty box. You type a greeting and stop, because the next sentence needs the shape of the whole reply and you have not built it yet. So the message goes back to the pile, and you answer it tomorrow with an apology at the top.

henna exists for that gap and nothing else. It reads the message you highlighted and writes the obvious version of the reply — the greeting, the acknowledgement, the structure, the sign-off. Not because those parts are clever, but because they are the parts that stop you.

Then it stops and hands the draft to you. henna does not fill your composer and it does not press Send. It puts the draft on your clipboard, and you paste it in yourself.

That step is the whole design. An assistant that types straight into your composer is one distracted moment away from sending something you did not read. Copying is a small friction that guarantees a person saw the words — and it is why henna can be useful without needing to be trusted.

The same discipline runs through the draft itself. Where a reply would need a fact henna cannot know — a date, a price, an amount — it writes [date] rather than something plausible. A confident wrong number in an email you send is worse than an empty box, and a tool that produces one has cost you more than it saved.

How it works

Four steps, about ten seconds

No new inbox to learn, no account to create, no rules to configure. henna appears where you already are and gets out of the way.

Select

Highlight the text of the email you need to answer, in whatever webmail you already use.

Invoke

Press the shortcut, right-click and choose Draft a reply, or click the toolbar icon.

⌘ ⇧ E · Ctrl ⇧ E

Read

A panel opens beside your selection and the draft streams in. Change the tone, add an instruction, or regenerate.

Copy & send

Press Copy, click your reply box, paste. henna never types into the composer and never presses Send.

Where it works

Any webmail, because it reads your selection

henna does not know what Gmail's page looks like, and that is the point. It reads the text you highlighted, so there is nothing to configure per site and nothing to break when one of them ships a redesign.

Mail

Gmail, Outlook, Zoho, Proton

Any webmail in a browser tab. Also Superhuman, HEY, and whatever you move to next.

Work

Support desks and shared inboxes

Zendesk, Freshdesk, Intercom — anywhere a message you need to answer is rendered as selectable text.

Anywhere

A forwarded email in a document

Pasted into Notion, a Google Doc, a text file. If you can select it, henna can draft a reply to it.

Steering

Tell it what to say, in two layers

Both are optional. With neither set you get a straight reply to what was written.

Settings · every draft

A standing instruction

The things that are always true. Sign off as Satish. Never commit to a date or a price. British spelling. Set it once; it applies to everything henna drafts until you change it.

The panel · this draft

A this-reply instruction

What is true right now. Say yes, and that I'll send the figures on Friday. Where the two disagree, the one you typed in the panel wins.

Three deliberate limits

What henna will not do

Each of these is a decision, not a missing feature.

Boundary

It will not send

henna never types into your composer and never presses Send. You place the text yourself, every time. That step is the point, not an omission: it keeps a person between a model and a real recipient.

Facts

It will not invent a fact

Asked to confirm a date, a price or an amount it cannot know, henna writes [date] or [amount] for you to fill in. A reply that quietly fabricates a delivery date is worse than no draft at all.

Nothing collected

It will not phone home

No analytics, no telemetry, no account, no henna server. There is nothing on our side to collect anything with.

Privacy

Where your text actually goes

To exactly one company: the AI provider you chose and configured with your own API key. henna has no server, so we could not read your email if we wanted to.

your browser
     │
     │  the text you selected + henna's prompt
     │  (only when you press the shortcut)
     ▼
the one provider you chose
     Google Gemini · Anthropic Claude · OpenAI
     using your API key, under your account


     ✕  no henna server            ✕  no analytics
     ✕  no account or sign-in      ✕  no page content or URLs
     ✕  no browsing history        ✕  no third parties

Your API key is stored in your own browser profile using chrome.storage.local. It is deliberately not put in chrome.storage.sync, so it is never replicated through your Google account or to your other devices. It is not encrypted — anything with access to your Chrome profile can read it, which is worth knowing before you paste in a shared team key.

Read the full privacy policy →

Permissions

Nothing is requested when you install

Most extensions that read pages ask for access to every site up front. henna asks for none, and requests each access later, in context, at the moment it is actually needed.

Access	When it is asked for	What happens if you refuse
The current tab	Never asked. Chrome grants it for that page when you press the shortcut, use the menu item, or click the icon — and it ends when you leave the page.	—
Your AI provider	When you save your API key, naming the one host it will contact.	Nothing is saved, and no request is made.
All sites	Only if you switch on the optional ✦ button, which has to watch for a selection on any page.	The button stays off. Everything else works.

Getting started

How to get henna, and how to set it up

About a minute, once. There is no account to create and no subscription — henna talks to your own AI provider account with your own key.

1	Install henna in Chrome. The install prompt asks for no site access at all.
2	Settings opens by itself, because nothing works before a key is entered.
3	Choose a provider — Google, Anthropic or OpenAI. The page links straight to where you create the key.
4	Paste the key and save. Chrome asks permission to reach that one company's servers.
5	Select an email, press `⌘⇧E`, and copy the draft.

If you cannot find it

Not showing up when you search the Chrome Web Store?

That is expected. henna is published as an unlisted release, which means it does not appear in search results or on a public listing page — it is installed from a direct link.

Email tech@openxel.com and we will send you the link. If you would rather not set up an API key yourself, say so in the same message and someone will walk you through it, or get on a call and do it with you.

Tell us which browser you are using and which AI provider you would prefer, and the reply will have the right instructions in it.

What a key costs

A free key is enough to try henna. Google's free tier allows a limited number of requests per day per model, and one draft is one request — enough to see whether henna is for you, not enough to lean on. Adding billing to your provider account lifts it. henna itself is free and always will be; the only money involved is what your AI provider charges you directly.