Fork a tool

A fork is your own copy of a tool’s source. Use it when the change is too large for a patch: a new page, a new server route, or changes in many parts of the tool. You keep the tool’s server and its API, and change what you need.

The steps below use Kanban. The same steps work for the other tools. For a complete example with screenshots, see Task board.

Tool	Repository	Package
Kanban	claude-code-kanban	`claude-code-kanban`
Marketplace	claude-code-marketplace	`claude-code-marketplace`
Cost	claude-code-cost	`claude-code-cost`
Memory Diagnoser	claude-code-memory	`claude-code-memory-explorer`

1. Clone the version your hub runs

Clone the repository and check out the tag of the version that your hub runs. Make a branch for your change:

git clone https://github.com/NikiforovAll/claude-code-kanban kanban-fork
cd kanban-fork
git checkout -b my-board v4.31.1
npm install

The hub does not run npm install for you. Run it again after each change to package.json.

Run npm start once to make sure that the tool works alone. A fork must work with no hub too.

2. Pick the id

Decide if the fork replaces the built-in tool or runs next to it:

You want	`id`	The built-in tool
The fork in place of the tool	The built-in id, for example `kanban`	Does not run
The fork and the tool, each in its own tab	A new id, for example `kanban-next`	Runs as before

A fork next to the original is the safer start: the original keeps working, and you can compare the two.

3. Change the manifest

Edit hub-app.json in the fork. For a fork next to the original, change these fields:

{
  "manifest": 1,
  "id": "kanban-next",
  "name": "Task Board",
  "icon": "layout-dashboard",
  "run": { "entry": "server.js", "defaultPort": 4545 }
}

id is the id that you picked in step 2.
run.defaultPort must be a port that no other tool uses. The port is the tool’s origin in the browser, so the fork starts with empty localStorage.
Keep publishes, provides and actions only for what the fork still does. See What the built-in tool gives.

See The app manifest for all the fields.

4. Change the code

Each tool is an Express server in server.js with a page in public/. There is no build step.

The page. public/index.html, public/app.js and public/style.css. Kanban, Cost and Memory Diagnoser mark the parts of these files with #region comments, for example rg "#region" public/app.js.
The hub connection. The HUB_INTEGRATION region in public/app.js connects to the hub with the SDK. A new page loads /vendor/claude-hub-sdk.js as the first element in <body> and calls ClaudeHub.connect().
The server API. The page reads its data from the server, for example GET /api/sessions in Kanban. A new page can use the same routes.

Do not edit public/vendor/claude-hub-sdk.js. Under the hub, the hub serves its own SDK at that path. The file in the repository is used only when the tool runs alone.

5. Add it to the hub

Add the fork to the apps list in config.json. Put it first, so that it is the first tab (Alt+1):

{
  "apps": [
    { "id": "kanban-next", "path": "C:/dev/kanban-fork" },
    { "id": "kanban" }
  ]
}

To replace Kanban, use "id": "kanban" in the entry and in hub-app.json, and remove the second entry.

Restart the hub. The startup log shows where the fork runs from, and each capability that two tools declare:

kanban-next runs from C:\dev\kanban-fork
kanban and kanban-next both declare capability "terminal"; kanban-next has it. Disable one of them.

6. Work on the fork

A change in public/. Reload the hub page.
A change in the server. Restart the hub. The hub starts the tool once and does not watch its files.
Logs. The hub prints the tool’s output with the id in front, for example [kanban-next].

What the built-in tool gives

When the fork replaces a built-in tool, the hub and the other tools lose what the fork does not keep. Kanban gives:

What	Manifest	Without it
The project list	`provides.projects`	`Ctrl+Alt+P` has no projects
The embedded terminal	`provides.terminal`	No tool has a terminal
The open session	`publishes: ["session.changed"]`	An app that subscribes to `session.changed` gets nothing

The other built-in tools handle actions: Cost handles session.cost, Marketplace handles project.plugins, and Memory Diagnoser handles project.memory. A fork that replaces one of them must handle the same action, or the buttons that call it in other tools go away. See The built-in tools.

A fork next to the original can leave these to the original. Only the first tool in tab order gets a capability. See One tool per capability.

Things to know

Upgrades. To get a new version of the tool, merge its tag into your branch, for example git fetch --tags and git merge v4.32.0. Keep your changes in new files where you can, so the merge has fewer conflicts.
The SDK. Under the hub, the fork always runs the hub’s SDK, not the copy in its public/vendor. See The SDK.
A tool that does a different job. When the fork keeps little of the original, write a new app.