# Character Substitution (StringMaskGenerator)

The [Character Substitution](/app/generation/generators/generator-reference/character-substitution.md) generator performs a random character replacement that preserves formatting (spaces, capitalization, and punctuation).

Characters are replaced with other characters from within the same Unicode Block.

## Link object structure <a href="#generator-api-character-substitution-link-object" id="generator-api-character-substitution-link-object"></a>

The Character Substitution generator is implicitly consistent. You cannot configure consistency or differential privacy. There is no generator-specific configuration.

```json
{
  "schema": "string",
  "table": "string",
  "column": "string",
  "path": "string",  //JSON fields only
  "dataType": "string",  //MongoDB, Amazon DynamoDB, and JSON fields only
  "metadata": {
    "generatorId": "StringMaskGenerator",
    "encryptionProcessor": "x-on", //To use configured Structural data encryption
    "customValueProcessor": "string" //If custom value processor applied
  }
}
```

## Example replacement <a href="#generator-api-character-substitution-replacement" id="generator-api-character-substitution-replacement"></a>

The following example replacement assigns the Character Substitution generator to a column.

```json
{
  "name": "age",
  "schema": "public",
  "table": "users",
  "links": [
    {
      "schema": "public",
      "table": "users",
      "column": "age",
      "metadata": {
        "generatorId": "StringMaskGenerator"
      }
    }
  ]
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.tonic.ai/app/api/quick-start-guide/tonic-api-generator-assignment/generator-api-reference/generator-api-ref-character-substitution.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.