---
title: "Add production traces to a dataset"
description: "Map production trace evidence into schema-enforced dataset rows for review and regression testing."
sidebar:
  label: "Add production traces"
seo:
  title: "Add Production Traces to a Dataset | Judgment How-to"
  description: "Select a production trace, map its fields into a dataset example, and verify the saved trace-backed row."
---

Use this guide after a production trace reveals a failure, edge case, or useful
success. You will save the trace as a schema-enforced row that remains available
for calibration and regression testing.

## Prerequisites

- A completed production trace in the target project
- An existing non-legacy dataset, or permission to create one
- A dataset schema that includes one `trace` field, unless the target dataset
  is still an empty draft

If you have not localized the failure yet, follow [Investigate a failed
trace](/documentation/monitoring/trace-investigation) first.

## Add the trace

1. ### Select the evidence

    Open **Logs > Traces**. Select one or more traces in the table and
    choose **Add to Dataset** from the selection bar.

    For one open trace, use **Add to Dataset** in the trace header or overflow
    menu.

2. ### Choose the dataset

    Select an existing dataset. To start a new collection, choose **Create New
    Dataset**, enter a name, and continue with the new draft selected.

    Legacy datasets do not appear because they are read-only.

3. ### Map trace fields into the row

    Map source trace fields to the dataset fields. A defined schema fixes the
    target names and types. For an empty draft, the mapping defines the schema
    when you save the first trace.

    The **LLM Eval** mapping is a useful starting point for `input` and
    `actual_output`. Add fields for expected output, labels, or context only
    when the dataset schema declares them.

    The trace pointer is filled automatically and appears in the preview. Do
    not map the trace ID into an ordinary string field.

4. ### Review and save

    Inspect **Example Preview**. Confirm that the values, field names, and types
    match the target schema, then select **Done**.

    Judgment creates one example per selected trace, preserves the source trace
    link, and creates a new dataset version for the batch.

## Verify the saved evidence

Open the dataset from the success message or from **Datasets**. Confirm that:

- The latest version contains the new row.
- The mapped input, output, and context fields match the source trace.
- The trace field contains the source trace ID and opens the saved trace
  evidence.

The production case is now durable test input rather than only a row in a
moving time window.

## Troubleshooting

- If the dataset is missing from the picker, it may be a read-only legacy
  dataset.
- If **Done** is disabled, select a dataset and resolve empty, duplicate, or
  type-incompatible target fields.
- If the preview is still loading, wait before saving an empty draft. Judgment
  uses the preview values to infer its field types.
- If the schema needs another field after its first example, create a new
  dataset with the intended schema and add the trace there.
- If the saved trace does not contain the evidence you expected, return to the
  production trace and verify its span boundaries before treating it as a
  regression case.

## Next step

[Turn the production failure into a regression
test](/documentation/tests/regression-cases).