Warehouse Builder and Lake Builder

A builder Mind works on the platform itself. The Warehouse Builder builds facts, dimensions, views and transformations for you. The Lake Builder imports source tables into the Lake, and manages connectors, syncs and load settings. Use a builder when you want a Mind that makes changes on the platform, and you want to decide which of them go through.

Create a builder Mind

Select Add Mind in the Minds list.
Under Mind Kind, select Warehouse Builder or Lake Builder. Each kind is listed only if you may create that kind of Mind.
Enter a Name.
Select Create Mind.

A builder has no Owner Role field and no sources to link, because it sees every Lake and Warehouse table itself, deployed or not. Instead of the role picker, the form shows the note Owned by the admin role · runs as the messaging user · scheduling stays manual:

Owned by the admin role. Every builder Mind belongs to the admin role, whoever created it.
Runs as the messaging user. A builder works as the person who messages it, with that person's permissions.
Scheduling stays manual. The builder never switches a schedule on for what it builds. A transformation or workflow it builds arrives with its schedule off, and a person turns the schedule on in the Warehouse or Lake screens.

What is fixed on a builder Mind

Query Identity is locked to Execute as User, with the reason Lake Builder Minds always run as the messaging user. for a Lake Builder, or Warehouse Builder Minds always run as the messaging user. for a Warehouse Builder.
Owner Role appears disabled in its settings, with the note Lake Builder Minds are owned by the admin role. or Warehouse Builder Minds are owned by the admin role.
Permission Groups do not appear.
Sources shows This Mind sees every Lake table; no sources need to be linked. for a Lake Builder, or This Mind sees every Lake and Warehouse table; no sources need to be linked. for a Warehouse Builder.
Benchmarks shows Benchmarks are for analytical Minds. To test an analytical Mind instead, see Test a Mind with benchmarks.
The kind is fixed. A builder Mind cannot become another kind, and a duplicate keeps the original kind: a Lake Builder Mind can only be duplicated as a Lake Builder Mind. The duplicate form shows the same owner note instead of an Owner Role picker.

In a builder chat

Type @ to tag a person: the menu heading reads Tag a person.
Type /tag-object to tag tables or transformations for the message you are sending.
The Warehouse Builder can design and build a semantic model inside its chat, in rounds. See Model Builder.
When the Lake Builder hands custom connector work to the connector Mind, the work continues in the connector's own thread, and the result appears as Report from the connector Mind.

Choose how changes are approved

Each chat with a builder Mind has a change acceptance mode. The mode decides which changes wait for your approval.

Mode	What happens	Permission needed
Manual	Every change waits for your approval.	None
Auto-accept	Changes apply automatically; drops and deletes still ask.	Add/Modify Warehouse Objects (Lake Builder: Add/Modify Lake Objects)
Unrestricted	Everything runs without asking, including drops and deletes.	Remove Warehouse Objects (Lake Builder: Remove Lake Objects)

To change the mode:

Open a chat with the builder Mind.
Select the mode chip in the message box toolbar, or press Alt+G. The tooltip reads Change acceptance mode.
Select a mode. A mode you may not use is greyed out, and hovering it shows what it needs, such as Requires the Warehouse modify permission. Anyone who can send messages in the chat can set Manual.

The picker notes Applies to tool calls evaluated after the change. Approvals already waiting stay pending. The requirement follows the mind kind: a Warehouse right never unlocks a Lake Builder chat, and a Lake right never unlocks a Warehouse Builder chat. A new chat starts in the Mind's default mode.

Selecting Unrestricted opens Enable Unrestricted mode?. Confirm with Enable Unrestricted mode. While the mode is on, a stripe over the message box reads Unrestricted mode: destructive warehouse changes run without approval, with a Switch to Auto-accept button.

Warning

In Unrestricted mode, drops, deletes, truncates and other destructive actions run without asking, in this chat and in every swarm agent it spawns. Use it only while you are watching the build.

Approve or reject a change

When a change is held for approval, an approval card appears in the chat and the chat shows Approval pending; sends are blocked until you decide.

Select Approve to let the change run, or Reject.
To reject, write an optional reason the builder reads, then confirm.

An approved change runs as you, the approver, with your permissions.
Changes cannot be approved from an impersonated session.

The cards, their buttons and their states are described on Change approval in a builder chat.

Settings

Setting	What it does	Default
Default change acceptance (AI Config tab)	The mode a new chat starts in: Manual (Every change is proposed and waits for approval.) or Auto-accept (Changes apply automatically; destructive actions still ask.).	Auto-accept
Can Mind Preview Source Data (Settings tab, Lake Builder group)	Lets the Mind read sample rows from a source table. Columns marked with a PII domain are excluded, so their values are never shown to the model.	On
Force Mind to Assign PII Domains to lake tables (Settings tab, Lake Builder group)	The Mind assigns PII domains wherever it detects personal data. When off, it only sets a domain when you ask for it directly.	On
Allow Excel / CSV uploads (Settings tab)	Lets people attach .xlsx, .csv and .tsv files in chats.	Off for a new builder

Unrestricted is never a stored default. The note under Default change acceptance reads Unrestricted mode can only be switched on per chat, by users with the Warehouse remove permission. (a Lake Builder shows the Lake remove permission).

Permissions

To do this	You need
See, create, edit, duplicate or delete a Warehouse Builder Mind	The admin role
See a Lake Builder Mind	View Lake Objects
Create, edit, duplicate or delete a Lake Builder Mind	Add/Modify Lake Objects, plus the Mind permission for the action, such as Add Mind or Edit Mind
Use Auto-accept in a chat	Add/Modify Warehouse Objects (Lake Builder: Add/Modify Lake Objects)
Use Unrestricted	Remove Warehouse Objects (Lake Builder: Remove Lake Objects)
Approve a destructive change	Add/Modify Warehouse Objects (Lake Builder: Add/Modify Lake Objects)

A builder runs as the person who messages it, so it can change only what you may change. Nobody without the admin role sees a Warehouse Builder Mind, whatever else they hold. Managing a Lake Builder Mind without Add/Modify Lake Objects is refused with Only Lake Administrators can manage Lake Builder Minds. A new builder Mind starts unpublished: View Lake Objects holders reach a Lake Builder once it is published, and the admin role reaches it either way. For the full list, see Who can do what with Minds.

Limits

While you are viewing the platform as another user, a builder cannot run SQL: its queries are refused with SQL execution is disabled while impersonating another user; exit the view to run queries. Changes cannot be approved from that session either.
A swarm child chat does not set its own mode: the chip shows Set on the root chat of this swarm, and a change is refused with Change acceptance mode is controlled by the root chat.
A task on a builder watches only workflows of its own kind: a Lake Builder task lists Lake workflows, and a Warehouse Builder task lists Warehouse workflows. See Scheduled Tasks.

Questions, answered

Who can see a builder Mind?

A Warehouse Builder Mind is visible to the admin role only. Nobody else can see it, whatever their other permissions. A Lake Builder Mind is visible to the admin role and to holders of View Lake Objects once it is published; managing one also needs Add/Modify Lake Objects.

Does the builder change things without asking?

That is what the mode decides. In Manual, every change waits for your approval. In Auto-accept, ordinary changes apply by themselves, but drops and deletes still ask. Only in Unrestricted does everything run without asking.

Why can't I choose Unrestricted?

It needs Remove Warehouse Objects, or Remove Lake Objects for a Lake Builder. Hover the greyed-out option to read Requires the Warehouse remove permission (or the Lake version), and ask your administrator if you do not hold it.

Whose permissions does the builder use?

The person who messages it. A builder runs as the messaging user, so it can change only what that person may change.

Who runs a change after I approve it?

You do. An approved change runs as the approver, with the approver's permissions. Changes cannot be approved from an impersonated session.

Can the Lake Builder see personal data in my sources?

It reads sample rows from a source table only while Can Mind Preview Source Data is on. Columns marked with a PII domain are excluded, so their values are never shown to the model. With Force Mind to Assign PII Domains to lake tables on, it also assigns PII domains to lake tables wherever it detects personal data.

Can I change a builder Mind's kind later?

No. The kind is fixed when the Mind is created, and a duplicate keeps it: a Lake Builder Mind can only be duplicated as a Lake Builder Mind.

Why can't I link sources to a builder Mind?

A builder does not need linked sources. It sees the tables it works with on its own, deployed or not, so the Sources tab shows This Mind sees every Lake table; no sources need to be linked. for a Lake Builder, or This Mind sees every Lake and Warehouse table; no sources need to be linked. for a Warehouse Builder.

What does "scheduling stays manual" mean?

The builder never switches a schedule on for what it builds. A transformation or workflow it builds arrives with its schedule off; a person turns the schedule on in the Warehouse or Lake screens.