request-transformer

The request-transformer plugin modifies requests before they reach the backend.

Overview

Phase: Access
Purpose: Transform request headers, query, body, and path
Behavior: Applies transformations before proxying

Configuration

{
  "pluginName": "request-transformer",
  "config": {
    "add": {
      "headers": ["X-Gateway: true"],
      "query": ["source=gateway"]
    },
    "set": {
      "headers": ["X-Forwarded-Proto: https"]
    },
    "remove": {
      "headers": ["X-Internal-*"]
    },
    "rename": {
      "headers": ["X-Old: X-New"]
    },
    "replace": {
      "path": "/api/v1/: /v2/"
    }
  }
}

Transformation Types

Usage Example

Template Variables

Use variables in transformations:

Variable	Description
`${request_id}`	Unique request ID
`${timestamp}`	Current timestamp
`${consumer.id}`	Consumer ID (if auth)
`${route.id}`	Matched route ID
`${service.id}`	Matched service ID

Example:

{
  "add": {
    "headers": ["X-Consumer-ID: ${consumer.id}"]
  }
}

Body Transformation

Transform JSON request body fields:

{
  "add": {
    "body": ["source: gateway"]
  },
  "remove": {
    "body": ["internal_field"]
  },
  "rename": {
    "body": ["oldName: newName"]
  }
}

Query Transformation

Add or modify query parameters:

{
  "add": {
    "query": ["api_version=2"]
  },
  "remove": {
    "query": ["debug"]
  }
}

Wildcard Patterns

Use * for pattern matching:

{
  "remove": {
    "headers": ["X-Internal-*", "X-Debug-*"]
  }
}

Removes all headers matching the pattern.

Regex Replacement

Use regex for complex replacements:

{
  "replace": {
    "headers": ["User-Agent: (.*): Gateway/$1"]
  }
}