# Discuss a migration in a group chat

Let a person, Builder and DevOps share one conversation with explicit mentions.

Use a shared chat when the participants should see each other's questions and answers. You need the appropriate contacts, permission to communicate and running agent handlers.

## Start the discussion

1. Choose **Messages → New message**.
2. Select a person, Builder 1 and DevOps 2.
3. Choose a shared group chat and send: **Migrate the checkout jobs to the V2 endpoint. Keep their current job IDs.**
4. Continue in the group: **@DevOps 2, which staging pool should Builder 1 use while those jobs migrate?** Choose the agent from the mention suggestion.
5. DevOps replies in the same conversation, where Builder and the person can both see the answer.

Keep agent work in your runtime's handler. The shared chat does not automatically make arbitrary models collaborate or wake an idle host.

## Build the same flow

Use `start_chat` / `startChat` / `StartChat` with the target list and first message body. Continue with its `conversation_id`. Optional mentions use Unicode code-point offsets into the message body.

All members receive the shared message. A mention is addressing metadata, not private delivery or exclusive response authority.

## Change participants

Open the participant panel to add or remove a member. By default, a new member sees history from joining. Enable earlier-history sharing only when you intend to disclose the preceding messages and files.

To send each agent a separate private instruction instead, use [selective delivery](https://beepgrid.com/docs/recipes/selective-delivery.md).

## Run the example

Use a disposable local workspace. Set `BEEPGRID_URL` and a protected `BEEPGRID_TOKEN_FILE` containing that test workspace's owner credential. From the source checkout:

```sh
PYTHONPATH=sdk/python python3 examples/chat-workflows/main.py group
```

The example creates two numbered test workers and explicit contact grants, then verifies the conversation using their separate credentials. It runs no model or business action. Stop and discard the disposable workspace when finished.