Getting started

This guide takes you from a clone of the repository to a file with your own records in it. The Use page gives the short version. Nendo is a research prototype. Read Status before you rely on it.

Requirements

You need	Detail
Windows x64	Nendo runs on Windows only. There is no ARM64 build.
WebView2 Evergreen runtime	The app draws its interface in WebView2. Most Windows 11 computers already have it.
.NET SDK	The version pinned in global.json (10.0.204, later feature bands are accepted).
Node.js 22.12 or later	Declared under engines in src/Nendo.Workbench/package.json. The build uses npm.
PowerShell 7	The build and test scripts are .ps1 files run with pwsh.
NSIS	Only to package the installer (makensis on your PATH). Where winget is disabled, the portable NuGet package NSIS-Tool works too, put on PATH for the build shell only; architecture.md has the steps.

There is no download, no signed installer and no automatic update. You build the installer yourself.

Build from source

1. Clone the repository and run the full test gate:

   git clone https://github.com/ThomasRohde/nendo
   cd nendo
   pwsh ./tools/Test-Production.ps1

   The gate restores the Workbench packages with npm ci, builds the Workbench, builds the .NET solution and runs the tests. It takes about a minute after the first restore. The Workbench is the web interface that the desktop app bundles, so it is built first. Some tests open real windows and use the clipboard, so run the gate in an unlocked desktop session: on a locked or headless session they fail without any defect in Nendo.

2. Publish the app and package the installer:

   pwsh ./tools/Publish-NendoPayload.ps1
   pwsh ./tools/Build-NendoInstaller.ps1

   The result is artifacts/installer/Nendo-Setup.exe, an unsigned per-user installer.

Install

Run artifacts/installer/Nendo-Setup.exe. The installer is unsigned, so Windows can warn before it runs. The installer writes to your user profile under Programs\Nendo and needs no administrator rights. Running a newer installer upgrades that installation in place.

The installer also:

• registers the .nendo file type with its own document icon, so a double-click opens a file in Nendo;
• adds New › Nendo application to the Explorer context menu;
• adds Nendo to the Start menu and to Windows’ installed apps, where you uninstall it.

Uninstall removes the files the installer put there. It keeps your .nendo files and the settings stored on this computer.

Open or create a file

A .nendo file is one application: its record types, records, screens and history. See Files and data for what it holds.

To	Do this
Create a file from Explorer	Right-click in a folder and choose New › Nendo application. Explorer names the file; Nendo creates a real empty file and opens it.
Create a file in the app	On the start screen, choose Create Nendo file. With a file already open, choose Close file from the file menu first; New file is available only when no file is open.
Start the same application again	With a file open, choose New empty copy… from the file menu, or the name the application gives it, such as New planner…. The new file has the record types, screens and views, and only the records the application keeps in new files. See Files and data.
Open a file you have	Double-click it in Explorer, choose Open Nendo file on the start screen, or choose Open file… from the file menu.
Open a recent file	The start screen lists up to four recent files. Right-click Nendo’s taskbar button for the same list.
Drag a file in	Drop one .nendo file on the window. Nendo opens one file at a time and refuses a drop of several.
Get back to a file that is already open	Open it again any of these ways. Each file has its own window, and Nendo brings that window forward, from the notification area if it was closed there, instead of opening the file a second time.

Keep the file in a local folder. Nendo warns when a file is in a folder that OneDrive, Dropbox or Google Drive syncs, and does not support writable use there.

There is no Save command. Nendo saves each successful edit as you make it.

Closing the window does not close the file. Nendo stays in the notification area with the file open. Use Close file in the file menu, or choose Exit Nendo from the notification area icon’s menu.

An empty file is a working application

A new file has no record types, no records and no screens, and it is valid. Nendo never adds sample data or screens on its own. The Data area says This file is ready and offers Create record type.

Studio

Studio is the part of Nendo that the host provides for every file. No file content can remove it or hide it. It has five areas, listed under Studio in the navigation.

Area	What it shows	What you can do there
Data	Each record type as a table, with a record editor. A record type kept as a tree opens as an outline, with a switch to the table.	Add, edit and delete records; click a column’s name to sort by it, drag its edge to resize it, or use its pencil to rename the field; filter and search; open Show retired data. In an outline, open and close records and move one with Move up, Move down, Indent and Outdent, or Alt, Shift and an arrow key.
Structure	Record types and their fields.	Add field, Rename, Rename record type, Edit choices, make a field required or optional, Make unique, Number automatically, retire and reactivate. Each change opens a proposal for you to review.
Surfaces	The screens the file defines and what each one is bound to.	Read screen definitions and their diagnostics.
History	Every saved change, in order, with its lane and its reversibility.	View changes on an entry, and Compensate where Nendo can reverse it.
Health	Whether the file is ready for editing, read-only or in recovery, and the last integrity check.	Create and restore backups, export readable data, re-inspect the file, and approve automatic actions on this computer.

Three more items sit beside Studio in the navigation. Use opens the screens the file defines (lists, boards, calendars, record pages); it has nothing to show until the file has screens. Under it the navigation lists the file’s front page, its views and its record types, each with an icon, so you can go straight to one. Agent controls agent access. Help is built in and works with no file open.

The places you keep open are tabs across the top of the window, and each tab has its own Back and Forward. Ctrl T or + opens a new tab on the screen you are on, Ctrl W closes one and Ctrl Tab moves to the next. Ctrl-click or middle-click anything in the navigation to open it in a new tab. Under the tabs, the address row shows where you are, and the box at its right end (Ctrl K) goes anywhere or runs a command. The theme (System, Light or Dark) is at the right end of the status bar.

Your first record type and records, by hand

You do not need an agent for this.

1. In Data, choose Create record type.
2. Enter a name for the record type, for example Book. First field starts as Name; keep it or change it. This first field is required short text.
3. Choose Preview record type. Nendo builds a proposal and shows the review: What changes lists each operation, What this builds describes the file as it will be.
4. Choose Accept changes. The record type now exists. Reject leaves the file unchanged.
5. Choose Add Book, enter a name and choose Add. The record is saved.
6. To change a value, double-click a cell in the table, edit it and press Enter.

To add more fields, open Structure, select the record type and choose Add field. The field types are Short text, Long text, Markdown text, Choice, Whole number, Rating on a scale, Decimal, Yes / No, Date, Date and time with timezone, UUID and Reference to another record. A new field is optional, so existing records stay valid. It goes through the same review as the record type.

This split is the rule for the whole product. A change to records (the data lane) saves at once and adds one entry to History. A change to the shape of the application (record types, fields, screens) is a proposal: a set of typed operations that Nendo validates on a private copy of the file and shows you before anything changes. The concepts guide explains both lanes.

Every record type gets its table and record editor in Studio. Other screens, such as a board or a calendar, come from a proposal. In practice an agent writes most of them.

Connect an agent

Nendo has no built-in agent. A coding agent such as Claude Code or Codex connects to the open file over MCP at http://127.0.0.1:41763/mcp (each further file keeps a port of its own), after you turn agent access on in the Agent area and choose a level: Off, Inspect, Edit data, Shape app or Unattended. There is no key or password, so any program on this computer can connect at the level you chose; set access to Off when no agent is working. The registrations in a clone of this repository point at port 41766, the port the author’s planner file keeps, so on your computer register the address Agent → Connection shows. The agent writes proposals, and you accept them in Nendo. The agents guide covers the access levels, the connection commands and what an agent can and cannot do.

Try Nendo Station

Nendo Station is a demonstration file: a fictional orbital habitat with nine record types (Modules, Systems, Components, Feeds, Readings, Incidents, Maintenance, Experiments, Crew), about 500 records and every kind of screen Nendo draws. It is in the repository at workspace/Nendo Station.nendo.

To look around, open the file. It starts on the Station status front page. The file has automatic actions, so editing stays off until you choose Approve automatic actions under Health. Reading works without it.

The Systems Lens schematic is a custom view, a screen of Components, and the file carries its code as it was when the file was last updated. To bring the view up to the repository’s version, pick extensions/systems-lens/nendo-package.json in Studio › Surfaces › Custom views › Import package… and accept the proposal. See Custom views.

To keep the tracked file unchanged, open it and use Duplicate… from the file menu, then work in the copy. A copy asks for the approval of automatic actions again.

The file is an output. tools/Build-NendoStation.mjs authors it from an empty file over MCP, one stage at a time:

node tools/Build-NendoStation.mjs --list    # the stages, in order
node tools/Build-NendoStation.mjs           # the first stage not yet applied

To rebuild it, create an empty file in Nendo, turn agent access on at a level that lets an agent shape the app, and run the script once for each stage. Each schema, behaviour and screen stage becomes a proposal that you accept in Nendo; the script never accepts one. The data stages write records directly. The readings-csv stage writes artifacts/station/readings.csv, which you import into Readings with Import CSV… and the Nendo CSV profile. The lens-in-file stage puts the Systems Lens code into the file from extensions/systems-lens/. The script dates the data relative to the day you build it.

Next

• Concepts for the terms this guide uses.
• Screens for what a file can show in Use.
• Files and data for CSV, history, copies and recovery.