Preview import results without persisting data

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:

Catch mapping errors early
Fix data quality issues in your CSV
Understand the import impact
Avoid accidentally creating duplicates or updating wrong records

POST/imports-management/{importId}/dry-run

Authorization

AuthorizationOAuth2 access token · headerrequired

Scopes:api:write

AuthorizationBearer token (JWT) · headerrequired

Path parameters

importIdstringrequired

Unique identifier of the import

Query parameters

fieldsToReturnstring

Comma-separated list of top-level response fields to return. Overrides the endpoint compact default unless responseShape=full is used.

responseShapestring

Advanced override. Omit for the endpoint compact default. Use full only when you need the complete endpoint response, including nested fields that are not selectable with fieldsToReturn.

Allowed:compactfull

Header parameters

LT-Response-Shapestring

Advanced override. Set to full only when you need the complete endpoint response, including nested fields that are not selectable with fieldsToReturn.

Allowed:full

Responses

200Dry-run completed successfully

dryRunbooleanrequired

Always true for dry-run operations. Indicates this is a preview simulation, not an actual execution.

errorsany[]required

List of all rows that will be skipped due to errors, including row index, the data from that row, and the specific error message explaining why it will be skipped. Use this to identify and fix data quality issues before execution.

mappingsany[]required

Detailed results for each entity type mapping. Each result includes lists of entities that will be created (toCreate), updated (toUpdate with old/new values), and skipped (ignored with reasons). Use this to understand exactly what will happen for each entity type.

summaryobjectrequired

Summary statistics aggregating results across all mappings. Provides quick overview of total rows, create/update/skip counts, and error count.

Show properties

errorsnumberrequired

Number of rows that have validation errors. These are included in willSkip but counted separately to highlight data quality issues. Check the errors array for detailed error messages.

totalRowsnumberrequired

Total number of rows that were processed during the dry-run or execution

willCreatenumberrequired

Number of new entities that will be created (for dry-run) or were created (for execution). These are rows where no matching existing record was found using the lookup fields.

willSkipnumberrequired

Number of rows that will be skipped (for dry-run) or were skipped (for execution). These rows had validation errors, missing required fields, or other issues that prevented processing.

willUpdatenumberrequired

Number of existing entities that will be updated (for dry-run) or were updated (for execution). These are rows where a matching existing record was found using the lookup fields.

400Import has no mappings or invalid state

401Unauthorized - Invalid or missing authentication token

403Forbidden - Insufficient API scopes or permissions

404Import not found

Request

curl -X POST "https://leadtime.app/api/public/imports-management/d2ee76e3-95d7-4b98-8d5d-98dc1fb79364/dry-run" \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN"

const response = await fetch("https://leadtime.app/api/public/imports-management/d2ee76e3-95d7-4b98-8d5d-98dc1fb79364/dry-run", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_ACCESS_TOKEN"
  }
});

import requests

response = requests.post(
    "https://leadtime.app/api/public/imports-management/d2ee76e3-95d7-4b98-8d5d-98dc1fb79364/dry-run",
    headers={
        "Authorization": "Bearer YOUR_ACCESS_TOKEN"
    },
)

Response

{
  "dryRun": true,
  "errors": [
    null
  ],
  "mappings": [
    null
  ],
  "summary": {
    "errors": 5,
    "totalRows": 150,
    "willCreate": 100,
    "willSkip": 10,
    "willUpdate": 40
  }
}