Step 1 — Metric

Documentation Index

Fetch the complete documentation index at: https://docs.galileo.ai/llms.txt

Use this file to discover all available pages before exploring further.

The first step asks: what should this metric measure? You can pick from a curated list of templates, or click Use custom prompt to write your own.

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Pick a metric

The Metric select is searchable. It includes trainable Galileo LLM-as-judge metrics available to your workspace, plus custom metrics and prompts your org created. The picker is organized into three groups:

• Galileo presets — built-in Galileo scorers that Luna Studio can train.
• Custom Galileo metrics — custom metrics already created in Galileo.
• Saved custom prompts — prompts previously authored in Luna Studio.

Metrics that exist but are not trainable yet can appear disabled with a “not trainable yet” suffix. Multimodal metrics are filtered out because Luna Studio trains text metrics today.

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Inspect a selected template

Once you pick a template, the form expands to show a read-only Metric details panel:

• Output type — the metric’s return shape (Boolean, Categorical etc.). See Output types.
• Step — the trace step the metric runs against (LLM span, Retriever, Agent span, or Trace).
• Input step — the input shape Luna Studio expects for training data, such as a single message, input / output pair, full trace, or full session.
• Prompt — the LLM-as-judge prompt the template uses, in a read-only textarea.

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Write a custom prompt

For metrics that don’t fit a template, click the dropdown’s Use custom prompt option (with a + icon). The form switches into editable mode. In custom mode, you fill in:

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Where to go next