Composer mentions

When a user types @ in the message box, DioscHub can offer a list of your entities (a customer, an order, a document) and turn the chosen one into a reference the assistant understands. You supply the data; DioscHub renders the popover and wires the result into the message.

Register a provider

Give DioscHub a function that takes what the user typed after @ and returns the matching items:

import type { MentionItem } from '@dioschub/client';

diosc('mentionProvider', (needle: string): MentionItem[] => {
  return customerIndex
    .filter((c) => c.name.toLowerCase().includes(needle.toLowerCase()))
    .map((c) => ({
      id: c.id,        // the stable reference the assistant receives
      name: c.name,    // shown in the popover and on the chip
      kind: 'customer' // your category, prefixed into the reference
    }));
});

Pass null to remove the provider: diosc('mentionProvider', null).

Return synchronously

The provider must return its results synchronously. DioscHub calls it on every keystroke. Don’t await a network request inside it. Instead, fetch your data into a local index up front (on load, or as the user works) and filter that index in the provider. The filtering you do is authoritative; DioscHub shows exactly what you return.

What the user sees

1. The user types @cust in the message box.

2. DioscHub calls your provider with "cust" and renders a popover of what you return.

3. The user picks an item. It becomes a non-editable chip in the message. They can’t accidentally break the reference by editing the text.

4. On send, that chip is delivered to the assistant as a stable reference, not as display text.

The popover after typing @. Your provider’s results appear alongside the kit’s built-in mentions (like @file:); picking one inserts a chip.

How a mention reaches the assistant

A selected mention is serialized into the message as:

@[Display Name](kind:id)

The assistant receives the id, your stable, canonical reference, tagged with its kind. The display name is for the human; the id is what the model resolves against your tools. So a mention of “Acme Corp” arrives as something the assistant can pass straight to get_customer, not a name it has to guess at.

The MentionItem shape

Field	Required	Purpose
id	yes	The stable reference delivered to the assistant. Namespaced by you.
name	yes	The label shown in the popover and on the chip.
kind	yes	Your category for the entity; becomes the prefix in @[name](kind:id).

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Next: render the approval body your own way with a consensus view.