Migrate from Looker
Convert your LookML views, explores, and models into governed Malloy semantic models
Your LookML is years of encoded business logic — dimension definitions, measure formulas, join relationships, and the curation decisions behind them. Credible reads it as prior art and rebuilds the analytical domain as governed Malloy: the same metrics — validated to the row wherever a connection allows — plus the context an AI agent needs to answer the questions your explores couldn't.
LookML's UI patterns, Liquid templating, and performance-only constructs are identified and deliberately left behind.
What Credible Reads
The agent inventories your LookML project — manifest, model, view, and explore files — resolving manifest constants as it goes. Give it the .lkml files and it has what it needs; it can also work from dashboards and other unstructured context when that's all you have. How far validation goes depends on what else it can reach:
- LookML + live data — with a warehouse connection (and, optionally, the Looker API), LookML supplies the business context and the data validates each proposal against live results.
- LookML only — with no connection, LookML is the sole source of context and each proposal is flagged unvalidated until data confirms it.
What Comes Across
The everyday modeling carries over. Here's how the bigger pieces land — and where they get better:
| In Looker | In Credible |
|---|---|
| Views & explores | Malloy sources, joins folded in; import/export and the explores manifest curate what's exposed |
| Dimensions & measures (filtered, ratio, time) | The everyday building blocks, carried over |
| Persistent & native derived tables (PDTs) | Pipelined queries and query-as-source — the same transformation, minus the PDT build schedules, datagroups, and cascading rebuilds |
access_grant, model & explore permissions | Fine-grained access control, defined in the model and versioned in Git, enforced on every surface |
description: and labels | #(doc) / #(index) tags, indexed by the AI Analytics Engine so an agent can find the right field and use it correctly |
| Dashboards & Looks | Rebuilt as data apps or notebooks — interactive, and not capped at Looker's tile set |
| Liquid SQL templating | Real typed Malloy expressions — no SQL string-templating to write or debug |
| Drill fields, HTML, viz styling | Dropped as Looker-specific; genuine logic (e.g. thresholds) is kept |
The Migration Flow
Read
Inventory every .lkml file, categorize it, and extract source and join candidates with prior-art notes. The explore/view split collapses into a single Malloy source: joins move from the explore into the source, and relationship: many_to_one becomes join_one.
Translate
Extract field-level proposals from each view — dimensions and measures with a lookml provenance — and convert derived tables and struct/UNNEST joins. Apply the keep / skip / flag triage: keep aggregation formulas, join cardinality, and CASE logic; skip drill_fields, html:/Liquid, and PDT optimization keys; flag 50-line SQL dimensions and synthetic primary keys.
Enrich
Rewrite each LookML description: into a #(doc) tag that tells an agent what the field means and how to use it, #(index) the categorical dimensions, and map LookML visibility (hidden, fields exclusions, required_access_grants) to Malloy access modifiers and access control.
Validate
Confirm numeric parity and produce a coverage report — what was modeled, renamed, rearchitected, deferred, or skipped, and why.
What Credible Handles
- Liquid and HTML —
{% … %}templating andhtml:conditional formatting are stripped; their intent is noted, and re-created as a renderer annotation only if it belongs in the model. - Persistent derived tables — classified as transformation, aggregation, or performance-only. Perf-only PDTs are skipped in favor of querying the base table directly; real transformations become query-based sources.
- Refinements (
+view) — consolidated into one definition rather than layered, so there's a single source of truth per field. - Synthetic keys — a
primary_keybuilt fromconcat()orgenerate_uuid()is flagged so you can confirm the real grain instead of baking in a workaround.
Proving Parity
Two channels, used together:
- Looker API — run the original explore through the API and compare. This requires the service account to satisfy the explore's
required_access_grants, or restricted explores return 404 — so the agent preflights access first. - SQL against the same warehouse — run equivalent SQL directly against the warehouse the LookML reads and diff it against the Malloy result. This is the channel that validates the numbers in practice, with or without API access.
Before & After
A LookML view and explore:
view: orders {
sql_table_name: sales.orders ;;
dimension: order_id {
primary_key: yes
type: number
sql: ${TABLE}.order_id ;;
}
dimension: status {
label: "Order Status"
description: "Current fulfillment status of the order"
type: string
sql: ${TABLE}.order_status ;;
}
dimension: order_size {
type: string
sql: CASE
WHEN ${TABLE}.amount >= 100 THEN 'large'
WHEN ${TABLE}.amount >= 20 THEN 'medium'
ELSE 'small'
END ;;
}
dimension_group: created {
type: time
timeframes: [date, week, month, year]
sql: ${TABLE}.created_at ;;
}
measure: order_count {
type: count
drill_fields: [order_id, status, created_date] # dropped — UI only
}
measure: total_revenue {
label: "Total Revenue"
description: "Total revenue in USD"
type: sum
sql: ${TABLE}.amount ;;
value_format_name: usd
}
measure: cancelled_orders {
type: count
filters: [status: "cancelled"]
}
measure: cancellation_rate {
type: number
sql: 1.0 * ${cancelled_orders} / NULLIF(${order_count}, 0) * 100 ;;
value_format_name: percent_1
html: {% if value > 10 %}<span style="color:red">{{ rendered_value }}</span>{% endif %} ;;
}
}
explore: orders {
join: customers {
type: left_outer
sql_on: ${orders.customer_id} = ${customers.customer_id} ;;
relationship: many_to_one
}
}The same domain in Malloy — one source, joins folded in, Liquid and drill fields dropped:
source: orders is conn.table('sales.orders') extend {
primary_key: order_id
join_one: customers is conn.table('sales.customers') on customer_id
dimension:
#(doc) Current fulfillment status of the order
#(index)
status is order_status
#(doc) Order size bucket derived from amount
order_size is
pick 'large' when amount >= 100
pick 'medium' when amount >= 20
else 'small'
#(doc) Date the order was placed
created_date is created_at::date
measure:
#(doc) Number of orders
order_count is count()
#(doc) Total revenue in USD
# currency
total_revenue is sum(amount)
#(doc) Orders that were cancelled
cancelled_orders is count() { where: status = 'cancelled' }
#(doc) Percentage of orders that were cancelled
# percent
cancellation_rate is cancelled_orders / order_count * 100
view:
#(doc) Monthly revenue trend with order counts
monthly_revenue is {
group_by: created_date.month
aggregate: total_revenue, order_count
}
}The type: time dimension group becomes a single date dimension you truncate with .month/.year in a view — no enumerated timeframe list. drill_fields, the Liquid html: block, and value_format_name have no field-level model equivalent: drilling is implicit in Malloy, and formatting moves to # currency/# percent render tags.
More than a reformat. Off LookML, the model is AI-discoverable through the AI Analytics Engine, composes into questions your explores couldn't answer, and is open code you own rather than logic locked in Looker. See what you gain →