---
title: "XProcess"
slug: "xprocess"
updated: 2026-06-09T15:55:29Z
published: 2026-06-09T15:55:29Z
canonical: "docs.datajet.app/xprocess"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.datajet.app/llms.txt
> Use this file to discover all available pages before exploring further.

# XProcess

Calls out to a 3rd party process - for example, PScript will run a python script.

| Key | Value(s) | Description |
| --- | --- | --- |
| method | "XProcess" |  |
| name | "NameOfExternalProcessor" | Available Processes: - NDJSONProc.exe - PScript.exe - KaggleDownload.exe - DJFScanProc.exe - {TODO} |
| wait | true/false | If true, script will wait for XProcess to return before continuing. |
| param{} | { "script": "ScriptPathAndFileName", "inFile":"InputPathAndFileName", "outFile": "OutputPathAndFileName", "params":[ "param1: value1", "param2: value2" "param3: value3" "..." ] } | - "script" - the path and name of the script to execute. Root location is DataJet bin folder. Best practise is to store scripts in "plugins" folder - "inFile" - input file to the process. Input file, if produced by DataJet, is usually generated using the Export method. Passed in as sys.argv[2] - "outFile" - output file path. Passed in as sys.argv[3]. Best practise is to output to a subfolder in Data Sources and use the %DATAPATH% variable. NOTE: %OUTPUT% system variable is NOT resolved by XProcess and so cannot be used. - "params":[] - output file path. Passed in as sys.argv[4]...sys.argv[N] |
| project | "ActiveProjectName" |  |
|  |  |  |

## Overview

XProcess allows external data processing to be added to scripts - i.e., data processing that takes place outside of the core datajet server. When used in conjunction with a programming language like python, this provides a simple but powerful way of extending the core Datajet functionality.

A call to XProcess generally uses these principles:

1. Export data from Datajet (for example, Export into file)
2. Use external process to:
  1. Open data file and process
  2. Create output file
3. Import Output file back into Datajet

#### Exporting Data

Data can be exported in the following ways:

- Using one of the export methods (e.g., Export, ExportIntoWorkbook)
- Export to file from an analytical process (e.g., [AnalyseSegments](/v1/docs/analysesegments), [Overlap](/v1/docs/overlap), [IProfile](/v1/docs/iprofile)...etc)

#### Processing

The most common process to use is python:

```json
{
  "method": "XProcess",
  "name": "PScript",
  "wait": true,
  "param": {
    "language": "python",
    "script": "%PLUGINS%analyse-segments-top-and-bottom.py",
    "inFile": "%DATAPATH%AnalyseSegments/AS_composite_index_full.csv",
    "outFile": "%DATAPATH%AnalyseSegments/",
    "params": [
      "interleaved: true",
      "sort_type: Index",
      "output_type: ITO",
      "topFileName: TableC_TopN",
      "bottomFileName: TableD_BottomN",
      "thresholds: I 1.2, T 500, O 50",
      "create_suffix: false"
    ]
  },
  "description": "PScript - Analyse Segments Top & Bottom Targets",
  "project": "AnalyseSegments"
}
```

Sample processing within python script:

```json

#Write errors to filename in sys.argv[1]
err_file = sys.argv[1]

...

# Get input file and output location from command line arguments
input_file = sys.argv[2]
output_location = sys.argv[3]

# Parse parameters from sys.argv[4] to sys.argv[10]
for i in range(4, min(11, len(sys.argv))):
    param = sys.argv[i]
```

#### Output File Format

Output format can be whatever is required by the XProcess script. The following outputs can be easily imported back into datajet:

- Excel - use [CreateTableFromWorkbook](/v1/docs/createtablefromworkbook) - use this if the file format generated by XProcess is unknown.
- Delimited File - use [CreateTableFromFile](/v1/docs/createtablefromfile) - use this if the field format generated by XProcess is known, or have the XProcess script also generate an excel definition file
- Direct from file - use CreateFieldsFromFile - NOTE: be very cautious using this method as it can lead to unbalanced tables.

#### Importing Data

Data can be imported in the following ways:

- Into a new table - using CreateTableFromFile, CreateTableFromWorkbook etc
- Into an existing table using CreateFieldsFromFile

#### Debugging

If XProcess returns with success, but the process has failed, first look in the engine server log to see if any unhandled errors have been reported:

![](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/image-1754061184336.png)

If errors are being correctly written by the process to the error file contained in sys.argv[1] then errors will be reported back in script editor

## Configuring a server to use XProcess

## Examples

### Python

#### JSON

```json
{
  "method": "XProcess",
  "name": "PScript",
  "wait": true,
  "param": {
    "script": "%PLUGINS%dmetaphone.py",
    "inFile": "%DATAPATH%%SFIELD%.txt",
    "outFile": "%DATAPATH%%SFIELD%_metaphone.txt",
    "params": []
  },
  "project": "#project#"
}
```

```json
{
  "method": "XProcess",
  "name": "PScript",
  "wait": true,
  "param": {
    "language": "python",
    "script": "%PLUGINS%external_process.py",   
    "inFile": "%DATAPATH%nationwide/nwi/dj_source/allant_individual_A_ACX.txt",
    "outFile": "%DATAPATH%nationwide/nwi/dj_source/amp_footprint.txt",
    "params": []
  },
  "project": "Nationwide-NWI-B"
}
```

#### Sample Python Script (*.py)

For full details of implementing XProcess, look in the plugins folders for examples.

```python
errFile = ""

try:
    errFile = sys.argv[1]
    # ... (your main code goes here) ...

except:
    try:
        if errFile != "":
            eFile = open(errFile, 'w')
            eFile.write("Regression Failed\n")
            eFile.close()
    except:
        pass  # Silently fail if we can't even write the error file
```