What is lookml-fields?

A reference guide to LookML field types, the building blocks used to describe and calculate data in Looker. It explains dimensions, measures, filters, parameters, and how their SQL settings work.

Use it when modeling data in LookML or deciding how a field should describe, filter, group, or calculate results.

It helps choose the right field type and understand how LookML definitions become database queries.

lookml-fields — Skill for Claude Code by looker-open-source

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add looker-open-source/looker-skills --skill lookml-fields

Clone the repo

git clone --depth 1 https://github.com/looker-open-source/looker-skills

Made for: Claude Code.

Or install looker-skills, the plugin that ships this one along with the rest of its 23 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/looker-open-source/looker-skills/lookml-fields/github.svg)](https://agentmods.dev/skills/looker-open-source/looker-skills/lookml-fields)

Your own site

<a href="https://agentmods.dev/skills/looker-open-source/looker-skills/lookml-fields"><img src="https://agentmods.dev/badge/skills/looker-open-source/looker-skills/lookml-fields/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/looker-open-source/looker-skills/lookml-fields"><img src="https://agentmods.dev/badge/skills/looker-open-source/looker-skills/lookml-fields.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,338 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00046	$0.01338
Opus 5	$0.00023	$0.00669
Sonnet 5	$0.00009	$0.00268
Haiku 4.5	$0.00005	$0.00134

Measured 10d ago against content hash e921d0b18c87, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

lookml-fields scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/lookml-fields/SKILL.md · 118 lines

How it starts

The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Instructions

1. Field Types Overview

LookML fields are the building blocks of your data model. Each type serves a specific purpose in generating SQL.

Field Type	Purpose	SQL Generation Phase
Dimension	Describes data (attributes). Groups results.	`SELECT` and `GROUP BY` clause.
Measure	Aggregates data (metrics). Calculates results.	`SELECT` clause (with aggregation).
Filter	Restricts data based on conditions.	`WHERE` or `HAVING` clause (via templated filters).
Parameter	Captures user input for dynamic logic.	None directly (injects values into other fields).
Dimension Group	Generates time-based dimensions (`type: time`) or calculates date diffs/durations (`type: duration`).	`SELECT` and `GROUP BY` clause (multiple columns).

2. The Role of `sql` Parameter

The sql parameter behaves differently strictly based on the field type.

Dimensions: The "What"

Role: Defines the raw transformation of the column before any aggregation.
SQL Context: The expression is placed directly into the GROUP BY clause.
Input: Can reference table columns (${TABLE}.col), other dimensions (${dim}), or raw SQL functions.

Example:

dimension: full_name {
  sql: CONCAT(${first_name}, ' ', ${last_name}) ;;
}
-- Generates: CONCAT(table.first_name, ' ', table.last_name)

Measures: The "How Much"

Role: Defines the value to be aggregated or the calculation involving other aggregates.
SQL Context: Puts the expression inside the aggregation function (e.g., SUM(sql)), or as a standalone calculation for type: number.
Input:
- For type: sum/avg/min/max: References dimensions or columns.
- For type: number: References other measures.
- For type: count: sql is ignored (always COUNT(*) or COUNT(primary_key)).

Example:

measure: total_profit {
  type: sum
  sql: ${sale_price} - ${cost} ;; 
}
-- Generates: SUM(sale_price - cost)

Read the full file on GitHub · 118 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

10d ago First seen · 118 lines · 46 tokens per session scan A e921d0b18c87

Subscribe to this mod's changes

lookml-fields is a skill published in the GitHub repository looker-open-source/looker-skills (28 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 46 tokens to every session and 1,338 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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