---
search:
  tags:
    - imports-management
    - POST
seo:
  description: >-
    Executes a dry-run to preview exactly what will happen… Reference for the
    POST /imports-management/{importId}/dry-run endpoint in the Leadtime Public
    API API.
sidebar:
  badge: POST
  label: Preview import results without persisting data
title: Preview import results without persisting data
type: openapi-operation
---
Executes a dry-run to preview exactly what will happen when the import is executed, without making any changes to the database.

**What this does:**
The dry-run performs a complete simulation of the import process:
- Validates all field mappings and data types
- Processes every row in the CSV file
- Attempts to find existing records using lookup fields
- Determines which entities will be created, updated, or skipped
- Identifies validation errors and data quality issues
- Returns detailed results for each entity type
- **Does NOT persist any data** - completely safe to run multiple times

**Why use dry-run?**
- **Verify mappings**: Ensure CSV columns are correctly mapped to entity fields
- **Check data quality**: Identify rows with missing required fields, invalid values, or format issues
- **Estimate impact**: See how many records will be created vs updated before execution
- **Debug issues**: Get detailed error messages explaining why certain rows will be skipped
- **Validate lookup fields**: Confirm that custom lookup fields correctly identify existing records

**What is returned:**
- **Summary Statistics**: Total rows, counts of entities that will be created/updated/skipped, error count
- **Detailed Results**: For each mapping type (Employee, Project, etc.), lists of:
  - `toCreate`: New entities that will be created
  - `toUpdate`: Existing entities that will be updated (with old and new values)
  - `ignored`: Rows that will be skipped (with reasons)
- **Error Details**: List of all rows with errors, including row index, data, and error message

**Best Practice:**
Always run a dry-run after configuring mappings and before executing the import. This helps you:
1. Catch mapping errors early
2. Fix data quality issues in your CSV
3. Understand the import impact
4. Avoid accidentally creating duplicates or updating wrong records

<Operation source="api-reference" id="importsmanagementcontroller-dryrun" />