monthletMove, Rename, and Delete Notes from an AI Agent over MCP
As of 1.2.0, Claude Code and other agents get 28 operations on your notes over MCP: move, rename, partial edits, tags, attachments, cells, and delete.
Blog
Posts about building monthlet. Written in Japanese first, then translated here.
What's new in monthlet 1.2.1
monthlet 1.2.1 adds model switching from the chat box, formatting buttons for Markdown editing, and performance improvements for large vaults.
Spreadsheets and Tables in a Notes App: Which to Use
Tables in a monthlet note sort, filter, and total columns. Spreadsheet documents add formulas with 312 functions, multiple sheets, formatting, and Excel or CSV import.
What's new in monthlet 1.2.0, and an updated roadmap
monthlet 1.2.0 adds more operations for external agents, including deletion and spreadsheet editing, along with a set of fixes. This post also covers the updated roadmap through early 2027.
Token estimates and confirmation before sending
monthlet can estimate how many input tokens a request will use before you send it, and pause for confirmation when the estimate goes over a threshold you set.
Notes App with a Calendar View and Daily Notes
monthlet's calendar view lists notes under the dates written in their title or body, with times and due dates. Turn on Daily Notes to keep one note per day.
Closed beta participants wanted for monthlet AI
monthlet AI lets you use AI by signing in instead of supplying your own API key. We are running an invite-only closed beta from early November through December 31, with up to 15 participants.
What's new in monthlet 1.1.0
monthlet 1.1.0 adds text color and underline, collapsible headings, inline note links, image pasting with search over text in images, Word export, a global capture window, kanban boards, and task due dates.
Running Claude Code in Four Parallel Lanes
How monthlet's development is split into four lanes of Claude Code sessions, with one repository per lane, a single source of truth for each kind of information, and a queue that keeps each lane moving without waiting for approval.
Asking about screenshots and PDFs
How to attach images, PDFs, and text files to a monthlet chat, how PDFs are sent depending on the connected AI, and where attached files end up in your vault.
Feature walkthrough videos are now on the official website
The monthlet website now has a page collecting 21 short videos that show how each feature works, grouped into five topics.
Interactive Notes: Sliders, Math, Flowcharts, Mind Maps
Place sliders, status badges, calculation fields, LaTeX formulas, flowcharts, and mind maps in a note from chat. They still display after export to HTML or PDF.
Folder galleries and pinned tabs
From version 1.0.0, a folder in the sidebar can be opened as a gallery of cards, and tabs can be pinned so they come back the next time you open the app. Image and PDF files can also show thumbnails.
Website updates and upcoming releases
Three new pages on the monthlet website — help, components, and the roadmap — plus how updates will be shipped from here.
Cards and columns in AI-built notes
From 1.0.0, monthlet's AI groups related content into cards and splits side-by-side material into two or three columns when it builds a note. It can also set a small number of visual options such as card fills, spacing, and eyebrow headings.
monthlet 1.0.0 released
monthlet 1.0.0 is out for macOS and Windows. Alongside bug fixes and interface adjustments, the release adds the option to register your own OpenAI-compatible endpoint as the AI connection.
Import an Obsidian Vault: Wikilinks, Images, Frontmatter
Import up to 5,000 Obsidian Markdown notes in one pass. Folders, [[wikilinks]], images, callouts, and frontmatter convert locally with no AI calls.
How monthlet tests AI responses (eval)
monthlet writes and edits notes through AI tool calls. This is a look at the scoring harness we added for those calls in August, and more importantly at what it does not measure.
How to Add a Chart to a Note, Linked to a Spreadsheet
Ask in chat and a chart is placed in your note, from bar and line to pie and radar, 11 types. Link it to a sheet range and it recalculates when the sheet is saved.
Editing Notes Together with AI
monthlet lets you write notes through AI chat and then edit them by hand. This article explains the three editing modes that make both kinds of editing possible in a single note.
Deciding how a note looks with themes
monthlet separates a note's structure from its appearance. Blocks carry meaning, and a theme decides how that meaning is displayed — across presets, folders, individual notes, and exported HTML.
Save Reusable AI Prompts as Slash Commands
Save instructions you send the AI often as skills and call them with / in chat. Text, date, and note variables fill in the parts that change each time.
Organize Notes with Tags: AI Suggestions and Filters
Add tags by hand or from AI suggestions, filter with #tag and -#tag, rename or merge a tag across every note, and color tags for the note map.
One Month After Release and the Road Ahead
A look back at monthlet's first month since the beta release, the numbers behind it, and the product roadmap through 2027.
The architecture of monthlet
How monthlet is built internally — the three layers inside a single note file, the process split in the app, and the options that were ruled out to keep every note a single .html file.
Meeting Notes and Weekly Review Templates in a Notes App
Use the Meeting notes or Weekly review template by asking in chat. Share what happened and the AI fills in the headings, decisions table, and to-do list.
Notes App with a Graph View: Link Notes and See Backlinks
Link notes by hand or from chat. Each note lists what links to it, and the note map draws your vault as a graph where well-linked notes appear larger.
Connecting Google Calendar
From version 0.14.0, monthlet can read and create Google Calendar events. Imported events become notes rather than entries in monthlet's calendar view.
Connecting to Google Sheets
From version 0.12.2, monthlet can read Google Sheets — either by asking about a sheet directly in Chat, or by importing sheets into a monthlet spreadsheet document.
Notes MCP Server: Read and Write Notes from Claude Code
Claude Code and other agents can search, read, and write notes in your monthlet vault over MCP. Writes go through the app and stay in version history.
monthlet now supports MCP — connecting external MCP servers
monthlet can now connect to MCP servers you register yourself, so you decide which external tools the AI in chat can use. This post walks through setup, confirmation prompts, lifecycle, and known limitations.
If You Are Not Sure How Something Works, Ask the AI — How Help Works in monthlet
monthlet ships a built-in help page and lets you ask usage questions directly in the AI chat, which answers from knowledge data bundled with the app. Version 0.12.0 also adds a way to report a chat response that did not work.
Syncing your vault with cloud storage
Because a monthlet vault is a plain folder of HTML files, you can keep it in sync across Macs with the cloud storage you already use. Here is how to set it up and what to watch out for.
Note history, and what comes next
Notes and spreadsheets now keep their earlier states, so you can go back to any of them — plus what is planned after this.
Introducing monthlet, an AI note-taking app
The first post — what monthlet does, why it is being built, and where the name comes from.