Block Studio¶

Block Studio is where you write, run, review and certify blocks.

Open it¶

In the left rail, click Blocks.

With a block selected in the sidebar, Block Studio opens that block.
With nothing selected, it shows Create DQL blocks with three ways to start:

Card	Button	Use it to
Ask AI	Describe block	Describe what you need; AI drafts it from your blocks, models and metrics.
Import SQL	Start import	Turn existing SQL into drafts. See Import SQL.
Build manually	Open builder	Build a semantic block from metrics, dimensions, time grain and filters.

Under Manual options you also find Blank SQL block (Create) and Semantic block (Build).

You can also click New block at any time. The New Block dialog asks for the type (SQL Block or Semantic Block), who it is for (Shared with the team or Private to me), a Block Name, a Domain and an optional Folder. Click Create Block.

SQL block or semantic block¶

A SQL block runs SQL you write against dbt models or warehouse tables.
A semantic block asks for metrics and dimensions from the semantic layer, so you do not write joins. Use it when the metric is already defined in dbt.

The block page¶

When you open a block, you see its overview:

the name, a status badge such as Draft or Certified, the domain and the owner;
for a certified block, the certification receipt under the name;
Last run, Rows, Used in and Tests;
Outputs, Parameters, the DQL source, tests and lineage.

Buttons on the overview: Open in builder and Run.

The toolbar at the top has:

Button	Does
New block	Starts another block.
Ask AI / Modify with AI	Has AI draft or change the block.
Run	Runs the block and shows the rows in Results.
Save draft	Saves your changes as a draft. Never certifies.
Certify / Re-certify	Runs the certification checks. See Save and certify.
Delete	Deletes a saved block.

Switch between Visual Builder and DQL Source to edit the block in a form or as text. Context opens a panel with the block's context.

The tabs at the bottom are Results, Run inputs, Lineage, History and Metadata.

Edit and save¶

Click Open in builder (or switch to DQL Source).
Change the query, the chart or the details. In the visual builder, the Details box holds Block name, Domain, Owner, Tags, Folder and Description.
Click Run to check the rows.
Click Save draft.

Saving a certified block does not change the certified version: your edit is saved as a separate draft beside it until you certify it.

Add tests¶

In the visual builder, use the Tests box ("Assertions checked on every run and required for certification"). In DQL source:

tests {
  assert row_count > 0
}

Fill in the details that help Ask¶

Ask and your AI agents find blocks by what they say about themselves. In the Metadata tab or the DQL source, set:

a plain description of what the block answers,
grain: what one row is, such as customer or day,
outputs: the columns it returns,
llmContext: a short note for AI about when to use the block.

Certification records these as warnings when they are missing.

From the terminal¶

zlens new block "Revenue by segment" --domain finance --owner you@example.com

This writes a draft block under blocks/ (or domains/finance/blocks/ if your project has domain folders) and prints its path. Open it in Block Studio to run and certify it.