Sheets: a spreadsheet where a column runs one of your agents

.github/workflows/kits.yml

@@ -0,0 +1,34 @@
+# Build every kit app on every PR.
+#
+# Nothing built these before, and a broken kit only showed up at image bake — where the failure is
+# a docker layer, not a diff. An undefined JSX identifier does not even fail there: it is a
+# runtime error, so it ships. This is the cheapest place to catch both.
+name: kits
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        kit: [slides, sheets]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      # Not `npm ci` at the repo root: install-kits.sh cds into each app and resolves against that
+      # app's own lockfile, so hoisting here would test a tree the image never has.
+      - run: npm ci
+        working-directory: kits/${{ matrix.kit }}/app
+      - run: npm test --if-present
+        working-directory: kits/${{ matrix.kit }}/app
+      - run: npm run build
+        working-directory: kits/${{ matrix.kit }}/app
+      - name: dist exists
+        run: test -d kits/${{ matrix.kit }}/app/dist

kits.json

@@ -13,6 +13,7 @@
     "so adding a kit does not mean editing this file beyond one line."
   ],
   "kits": [
-    { "name": "slides", "include": true }
+    { "name": "slides", "include": true },
+    { "name": "sheets", "include": true }
   ]
 }

kits/sheets/CREDITS.md

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+# Credits
+
+## Templates
+
+The starting sheets in `templates/templates.json` are original to this kit.
+
+## Components
+
+The grid, the conversation surface, the dialogs and the HarnessRouter transport come from
+**[reifyui](https://www.npmjs.com/package/reifyui)** (MIT), which is where they live so that a
+second kit does not start a second copy of them.
+
+## Spreadsheet export
+
+`.xlsx` export uses **[SheetJS](https://sheetjs.com/)** (`xlsx`, Apache-2.0), loaded only when
+someone actually exports one.

kits/sheets/README.md

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+# Sheets
+
+A spreadsheet where a column can be an agent. Rows are your data; an **agent column** runs one of
+your other agents once per row, builds its input from the columns to its left, and fills each cell
+with what that agent said and made.
+
+Launch it from **Starter Kits** in the HarnessRouter console. That provisions the Harness this app
+talks to; nothing else is deployed and nothing is configured.
+
+## How it works
+
+- **One session is one sheet.** The sheet list is this Harness's session list, and a sheet's
+  content is `sheet.json` in that session's workspace. There is no database.
+- **The app is served by the HarnessRouter image** at `/kits/sheets`, same-origin with the
+  console, which is why it needs no API key and no login of its own.
+- **Column order is execution order.** An agent column may only read columns earlier in the sheet,
+  which makes the column list a valid running order by construction — there is no graph to sort
+  and no cycle to handle.
+- **The run happens in your browser tab.** There is no workflow engine in this deployment, so the
+  page is the orchestrator: it walks the cells in dependency order with a concurrency limit you
+  choose. Cells already started finish if you leave; nothing new starts, and the page says so
+  before you press Run.
+- **Each cell is its own conversation.** One session per cell, titled for its column and row, so
+  every result is a real conversation you can open in the console and read.
+- **Only the last run is kept.** Starting a run clears the cells it owns. The conversations are
+  never deleted — you drop the reference, not the work.
+
+## What's in the folder
+
+| Path | What |
+|---|---|
+| `kit.json` | The Harness this kit needs, and where its app is served |
+| `skills/sheet-design/` | The `sheet.json` contract and how to design columns — read before anything is written |
+| `templates/templates.json` | Starting points, including one with agent columns |
+| `app/` | The UI |
+
+## Working on the app
+
+```
+cd app
+npm install
+npm test          # the document rules and the run planner, no network needed
+npm run build
+```
+
+`src/lib` is deliberately free of React and of the network:
+
+| File | What |
+|---|---|
+| `model.js` | The document: ids, references, interpolation, and every way a sheet can be wrong |
+| `run.js` | `plan()` and the `Runner` — what would run, and the walk, over an injected dispatcher |
+| `cell.js` | The dispatcher: one cell, one turn |
+| `sh.js` | What "sheet" adds on top of `reifyui/harness` |
+
+`model.test.mjs` and `run.test.mjs` cover both. `skills/sheet-design/validate_sheet.py` is the
+agent-side twin of `model.js`'s `validate()`; if the two ever disagree, the app is right.

kits/sheets/app/.gitignore

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+public/

kits/sheets/app/index.html

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+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>Sheets</title>
+  </head>
+  <body><div id="root"></div><script type="module" src="/src/main.jsx"></script></body>
+</html>