Google Vault matter portfolio board with case brief intake

Build me an internal app my legal ops team opens every day to run our Google Vault matters end to end, so we stop clicking through the Vault console one matter at a time. The landing surface has to show the whole portfolio at a glance, not a search box.

The main page is a portfolio board of every matter. Load matters with List Matters, covering both open and closed states, and give me a state filter (open, closed, all) plus a text search over matter names. Each row shows the matter name, its state, how many holds it has, and how many custodians are covered across those holds. Get the hold count with List Holds for that matter, and the custodian count by calling List Hold Accounts for each hold and counting the distinct accounts. Fetch those counts in parallel per matter and cache them so the board stays fast, with a visible refresh control. Clicking a row opens the matter detail page.

The matter detail page loads the matter with Get Matter and shows four sections: holds (List Holds, with each hold's name and the data source it covers), held accounts (List Hold Accounts per hold, showing custodian email addresses grouped by hold), saved queries (List Saved Queries), and exports (List Exports, showing name and status).

From the detail page I need buttons for: create a hold (Create Hold, with a picker for the data source and the custodian emails), add custodians (Add Held Accounts), remove custodians (Remove Held Accounts), rename the matter or edit its description (Update Matter), close the matter (Close Matter) and reopen it (Reopen Matter), and manage who can see it (Add Matter Permissions and Remove Matter Permissions, listing current collaborators and letting me add or remove one by email). Every action refreshes the affected section in place and surfaces the Vault error message when a call is rejected, for example when the matter is in a state that does not allow the change.

Add an "Open matter from case brief" button at the top of the board that kicks off a background agent. I paste a plain English description of the case with the custodian email addresses and the legal team members who need access, and the agent handles the whole opening: create the matter with Create Matter, filling in a clear name, a description summarizing the dispute, and the region; create one hold per data source with Create Hold, named after that source; add the custodians to each hold with Add Held Accounts; and grant the legal team access with Add Matter Permissions.

Then the agent writes a matter opening memo. It creates a document with Create Document titled after the matter, and fills it in with Batch Update Document: the matter name and Vault matter ID, the date opened, a summary of the dispute taken from my brief, the list of custodians, the data sources placed on hold with their hold names, who was granted access, and any data source it deliberately did not hold along with the reason. The agent links that document back onto the matter inside the app, so the matter detail page shows an Opening memo link at the top and I never have to hunt for it.

Two rules the app and the agent must always respect. First, Gemini data supports search and export only and cannot be placed on hold, so never attempt a Gemini hold: leave Gemini out of the hold data source picker, and when a brief asks to preserve Gemini activity, the agent skips the hold and records in the memo that Gemini data is available for search and export but cannot be held. Second, a matter must be closed before it can be deleted, so only offer delete on a closed matter and prompt me to close it first if I try from an open one.

Persist per matter inside the app: the opening memo document link and title, the date the matter was opened through the app, and the status of the most recent case brief run (running, finished, failed) with a short log of what the agent created. Show the running state on the board so I can see an opening in progress, and show the finished memo link on both the board row and the matter detail page. Follow Vault pagination when listing matters, holds, accounts, saved queries, and exports so nothing is silently cut off at the first page.