Closed beta participants wanted for monthlet AI

monthlet is a note app where you write and grow notes through AI chat. Each note is a single ordinary HTML file that also opens in a browser.

At the moment, using AI in monthlet requires you to obtain an API key from an API provider yourself and configure it in the app. monthlet AI is a service that lets you use AI by simply signing in to monthlet, without preparing your own API key, and we are preparing it for general release. Ahead of that release, we would like to run an invite-only closed beta from early November through December 31. There are up to 15 places, and there is no cost to participate. As a thank you, participants who keep sending reports will be able to use monthlet AI free for six months after the general release.

Purpose of the closed beta

With monthlet AI, instead of configuring an API key, you sign in to a monthlet.ai account with your email address and a six-digit code sent to it.

Exchanges with the AI pass through monthlet.ai servers and are sent on to Anthropic. Notes are still saved as files on your own machine and are not stored on monthlet’s servers. The contents of the requests sent to the AI and the AI’s responses are not kept on the server either; the only thing recorded is how much AI usage has taken place. Anything you send with the app’s “Report what didn’t work” button is stored as a report.

How the feature gets used in everyday note-writing, and where people get stuck, is not something we can learn from testing on our own machines. We also need to understand token consumption in real use cases. Before the general release, we want a small group to use it for real, then improve the feature and fix bugs based on that feedback.

What we would like you to try

There is no special way you need to use it. The three things we most want to see are:

The flow from signing in to asking the AI for something and actually creating a note
How it feels to ask the AI to create or revise notes as you normally would, through to getting the result
Whether the AI usage limit that applies during the beta is set at an appropriate level for how people actually work (that is, whether it runs out too quickly)

We welcome any feedback: things you notice, things that concern you, things you think should be improved. Send reports through the Discord channel for participants, the app’s “Report what didn’t work” button, a reply to the invitation email, or a DM to monthlet’s X account (@monthlet).

During the beta we expect roughly one report per week. If something behaves differently from what you expected, tell us what you did and what happened. For requests to add or improve features, we want to know specifically what situation you were in and what gave you trouble. Other impressions and feedback are welcome too. Brief reports are fine in all cases.

Thank-you offer

Participants who meet the following conditions will be able to use monthlet AI free for six months after the general release.

This applies to everyone who sends at least 10 valid reports during the beta period and answers both of the surveys we send during the period. What counts as one report is explained in the guide for participants.

We would be glad if you wrote about taking part on a blog or social media, but this is optional and is not part of the conditions for the thank-you offer. If you do write about it, the guide explains how to describe the beta.

Period and number of participants

Period: early November 2026 through December 31
Participants: up to 15
Cost: free
Where to send reports: the Discord channel for participants, the in-app report, a reply to the invitation email, or a DM on X

If you are selected, we will send you an invitation email explaining how to get started. The invitation is tied to the email address you apply with, so please sign in with that address when using monthlet AI.

The beta ends on December 31. Your notes stay on your own machine. If you configure your own API key, you can keep using AI as before.

What we ask of you

Use it at least once a week
Send us what you notice through Discord, the in-app report, email, or a DM on X (ideally about once a week)
We will send a short survey of no more than five questions in early December and at the end of December. Please answer both

If you stop using it during the beta period, there is no need to report that.

How to apply

Applications are accepted through the form below. The deadline is October 31.

(Updated October 25, 2026) We have extended the deadline to November 7 (end of day, Japan time). We will still email results in early November.

Apply for the monthlet AI closed beta

The form asks about the following:

The note app you usually use
What you want to do with monthlet (one or two lines)
Whether you can send us what you notice about once a week
The computer you use (an Apple Silicon Mac, or Windows)
Where you live

If more than 15 people apply, we will select participants based on the information in the form. Those selected will receive an invitation email in early November. If you are not selected this time, we will let you know first when the general release happens.

Residents of the EU, EEA, UK, and Switzerland are not eligible for this beta.

You can take part on either the Mac or the Windows version.

Try monthlet

monthlet runs on macOS (Apple Silicon) and Windows. The Windows version is available from the Microsoft Store. Enter your own AI API key and you can use all of the features.