Access ceiling and limits
A chat never reaches a chat that may do more than it may, and fixed limits cap how many messages, stops and new chats one turn and one computer can make.
Where in StudioStudio → Chats
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Two rules keep chats that work together in check. The access ceiling stops a chat from using another chat to do more than it may itself. Fixed limits stop a chat from flooding other chats or starting chats without end. Neither is a setting, and what you do in a chat yourself never counts toward them.
The access ceiling
A chat cannot send a message to a chat that may do more than it may. Studio compares the two chats on:
- How much they may change: read only, then workspace write, then full access.
- Whether they skip approval prompts: a chat that skips them counts as wider than one that does not.
A message to a wider chat is refused and nothing is sent. A message to an equal or narrower chat goes through. The check runs when the message is sent and again just before the receiving chat acts on it, so widening a chat in between does not get a message through.
Studio compares what each chat really runs with, not only what its access control shows:
| Agent | Counted as |
|---|---|
| Claude Code, Codex, Cursor | Full access |
| Devin, Grok | The chat's access level; read only in Plan or Ask mode |
So a Devin chat in workspace write cannot message a Claude Code chat, while two Claude Code or Codex chats can always message each other.
The same rule applies to starting a chat. A new chat can never have more access than the chat that starts it, and a chat below full access that does not run Orchestra cannot start a chat with Orchestra on, because Orchestra agents run with the access their role names.
Reading another chat, listing chats, waiting for a reply and stopping a chat are not limited by the ceiling.
Limits for one turn
These count what one turn of the agent (from your message until it finishes) can do:
| Action | Limit |
|---|---|
| Messages sent | 24 |
| Messages to the same chat | 6 |
| Chats stopped | 3 (a stop that found nothing running does not count) |
| Chats started | 4 |
| Replies waited for at a time | 1 |
| Orchestra proposals | 5 |
| Chats in one list | 60, newest activity first |
Limits across the computer
These count over a rolling hour and survive a restart of Studio:
| Limit | Value |
|---|---|
| Chats started on this computer | 20 per hour |
| Messages one chat receives from other chats | 30 per hour, from all chats together |
| Chain of started chats | A chat you start can start chats, and so can the chats it starts. A chat two levels down cannot start more. |
When a limit is reached, the action is refused and nothing is sent, started or charged. For the hourly limits, the agent is told roughly how many minutes until a slot frees.
An open Orchestra proposal counts toward a limit of 5 per chat. Starting a proposal yourself does not count toward the chats-started limits.
Message and brief sizes
| Text | Limit |
|---|---|
| A message to another chat, or a started chat's first message | 4,000 characters |
| A started chat's title | 120 characters |
| An Orchestra proposal's brief | 4,000 characters |
| A wait for a reply | 15 minutes |
Note
These rules apply to chats on the same computer only. A chat cannot reach chats on another device at all.