Whispering Text Transformer

Local server compatible with OpenAI API for text transformations in Whispering.

Quick start

# Node
npm install && npm start

# Bun
bun install && bun server.js
# or with script
bun run bs

The server will run at http://localhost:3000 by default.

Custom port

You can configure the port using the PORT environment variable:

# Node
PORT=8080 npm start

# Bun
PORT=8080 bun server.js

Available transformations

Transformation	Description	Example
lowercase	Converts to lowercase	"HELLO WORLD" → "hello world"
uppercase	Converts to uppercase	"hello world" → "HELLO WORLD"
capitalize	First letter uppercase, rest lowercase	"HELLO WORLD" → "Hello world"
capitalize-words	Capitalizes each word	"hello world" → "Hello World"
remove-spaces	Removes all spaces	"hello world" → "helloworld"
trim	Removes leading and trailing spaces	" hello " → "hello"
trim-trailing-newlines	Removes only trailing line breaks	"hello\n\n" → "hello"
reverse	Reverses the text	"hello" → "olleh"
remove-punctuation	Removes commas, periods and semicolons	"Hello, world." → "Hello world"
all-remove-punctuation	Removes all punctuation marks	"Hello, world!" → "Hello world"
remove-trailing-period	Removes the trailing period	"Hello world." → "Hello world"
decapitalize	Lowercases the first letter	"Hello world" → "hello world"
final	Removes trailing line breaks and period + decapitalizes	"Hello world.\n" → "hello world"

Whispering setup

Don't have Whispering yet? Check the repo for installation instructions.

1. Create transformation: Transformations > Create Transformation > Prompt Transform step
2. Configure provider:
   • Provider: Custom
   • Base URL: http://localhost:3000/v1
   • Model: transformation name (e.g. final)
   • API Key: any value
3. Prompts:
   • System Prompt: empty
   • User Prompt: {{input}}

Testing

# Manual
curl http://localhost:3000/health
curl http://localhost:3000/v1/models
curl -X POST http://localhost:3000/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{"model": "final", "messages": [{"role": "user", "content": "Hello world."}]}'

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Part of the Whispering ecosystem.