A Holochain app for collaborative spreadsheets, built by Lightning Rod Labs and called Calcy inside the repository. Real-time collaboration is delivered by Holochain's syn library.

The project is in active development: its last code push was on 2026-09-08 and its latest release, v0.10.6, is dated 2026-05-13.

What Holochain version does it use?

The project's manifests specify the Holochain Development Kit (HDK) version 0.6.0.

How do I install or run it?

Enter the nix shell, run npm install, then npm run package to build the calcy.webhapp, which you install in the Holochain Launcher.

Can I run multiple agents?

Running npm start launches a network of two agents with their UIs, and npm run network bootstraps a custom network, for example with AGENTS=3.

It is packaged as a web hApp that is installed in the Holochain Launcher desktop app.

What changed in version 0.10.6?

The release adds the ability to import from CSV and improves responsiveness in large spreadsheets.

Project · spreadsheet

Calcy

Name: Calcy
Author: lightningrodlabs

a collaborative spreadsheet appSpreadsheet for Holochain

Explore this project All projects

How you run it: In Moss
Holochain version: 0.6.0
Activity: active
Checked: 29 October 2026

What is Calcy and does it work?

Calcy is a Holochain app for collaborative spreadsheets, with its latest release, v0.10.6, dated 2026-05-13 and its last code push on 2026-09-08. We read its README and the v0.10.6 release notes to confirm what it is and that it is actively maintained.

Calcy is a Holochain app for collaborative spreadsheets, made by Lightning Rod Labs. Inside the repository the project is called Calcy. It gives agents real-time collaboration, delivered by syn, Holochain's library for shared state. The project is actively developed: the latest release, v0.10.6, was published on 2026-05-13, and the last code push was on 2026-09-08.

The code is a Holochain app (hApp). Its manifests use the Holochain Development Kit (HDK) version 0.6.0, and the user interface uses the Holochain client library version 0.20.2. The software is MIT-licensed, as noted in the LICENSE file in the README, and is packaged as a web hApp so it can be installed in the Holochain Launcher.

To run it yourself, the README documents building a packaged calcy.webhapp and installing it through the Holochain Launcher, plus local development and test commands that run inside a nix shell. The v0.10.6 release notes list the ability to import from CSV and responsiveness improvements for large spreadsheets.

How to get it

In Moss

Enter the nix shell and install dependencies: run nix develop, then npm install.
Build and package the web hApp: run npm run package.
Install the resulting calcy.webhapp from the workdir folder in the Holochain Launcher.

Source: https://raw.githubusercontent.com/lightningrodlabs/sweet/HEAD/README.md

Questions people ask

What is Calcy?: A Holochain app for collaborative spreadsheets, built by Lightning Rod Labs and called Calcy inside the repository. Real-time collaboration is delivered by Holochain's syn library. source
Does it work?: The project is in active development: its last code push was on 2026-09-08 and its latest release, v0.10.6, is dated 2026-05-13. source
What Holochain version does it use?: The project's manifests specify the Holochain Development Kit (HDK) version 0.6.0. source
How do I install or run it?: Enter the nix shell, run npm install, then npm run package to build the calcy.webhapp, which you install in the Holochain Launcher. source
Can I run multiple agents?: Running npm start launches a network of two agents with their UIs, and npm run network bootstraps a custom network, for example with AGENTS=3. source
Where does it run?: It is packaged as a web hApp that is installed in the Holochain Launcher desktop app. source
What changed in version 0.10.6?: The release adds the ability to import from CSV and improves responsiveness in large spreadsheets. source

From 3 public sources, checked 13 September 2026.

Try Calcy

Code on GitHubOpen on GitHub ↗Last change 16 October 2026.
Releasev0.4.0Pre-release, published 16 October 2026.
In Moss's tool library (Moss 0.16)lightningrodlabs.org/weave-tool-curation/0.16/curations-0.16.json ↗

Details & sources

Source: lightningrodlabs/sweet

Evidence

Release: github.com/lightningrodlabs/sweet/releases/tag/v0.4.0shipped in a release · seen since 20 October 2026 · github.release@1
Last change: api.github.com/repos/lightningrodlabs/sweetlisted by a third party · seen since 20 October 2026 · github.repository@1
Activity: github.com/lightningrodlabs/sweet/releases/tag/v0.4.0shipped in a release · seen since 20 October 2026 · liveness@1
Moss: lightningrodlabs.org/weave-tool-curation/0.16/curations-0.16.jsonlisted by a third party · seen since 20 October 2026 · moss.listed@1

Compatibility

hdk: 0.6.0 · Cargo.toml @ cbcbd56
hdi: 0.7.0 · Cargo.toml @ cbcbd56
holochain-client: 0.20.2 · ui/package.json @ cbcbd56
happ.yaml: present · workdir/happ.yaml @ cbcbd56
web-happ.yaml: present · workdir/web-happ.yaml @ cbcbd56

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