> For the complete documentation index, see [llms.txt](/llms.txt).
[◆ miniwebtool /api](/)
[Tools](/tools/) [Docs](/docs/) [Reference](/v1/docs) [Pricing](/#pricing) [Log in](/dashboard/login/) [Start free](/billing/checkout/?plan=free)
- [Home](/)
- ›
- [Tools](/tools/)
- ›
- [Text](/tools/#text)
- ›
- Text Case Converter API

# Text Case Converter API

text 1 credits / call v2026-04-22
Convert text to uppercase, lowercase, title, sentence, camel, snake, kebab, and related cases.
Use this endpoint to add Text Case Converter to your app, site, workflow, or agent without rebuilding formulas, validation, examples, and docs.
Prefer the browser version? [Open the Text Case Converter on miniwebtool.com](https://miniwebtool.com/lowercase-uppercase-letters/).
[Start free — get a key →](/billing/checkout/?plan=free) 1,000 credits · no card · 30 seconds
What this saves
Skip a custom implementation, validation rules, examples, OpenAPI shape, billing checks, and support copy for this utility.
Where it fits
Product forms, calculator pages, finance content, education flows, support tools, automations, and agent actions.
How to evaluate
Inspect the required fields, try the hosted playground, then copy cURL, Python, or Node code into your integration.

### Endpoint

```text
POST https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run
```

### Request body

Field
Type
Req.
`text`
`str`
✓
`conversion`
upper | lower | title | sentence | alternating | inverse | camel | pascal | snake | kebab | constant | dot
`str`
—

### Cost & access

- 1 credit per successful call.
- Starts on: Free.
- Max payload: 65536 bytes.
- Privacy mode:`no_body_logs`
- Available on: free, starter, pro, business, scale

### Response envelope

```text
{
  "request_id": "01K...",
  "tool": "lowercase-uppercase-letters",
  "tool_version": "2026-04-22",
  "credits_used": 1,
  "result": {... }
}
```

### Try it

API key *
Stored only in this browser tab. Playground test key is prefilled and only works on this page. [Get a live key →](/billing/checkout/?plan=free)
text (str) * hello world from MiniWebtool
conversion (str) upper lower title sentence alternating inverse camel pascal snake kebab constant dot
upper | lower | title | sentence | alternating | inverse | camel | pascal | snake | kebab | constant | dot
Send request →
Response copy body
This endpoint starts on Free
Your key is valid, but its current plan cannot call`lowercase-uppercase-letters`. Upgrade to Free or higher to run this tool.
[Start Free →](/billing/checkout/?plan=free) [Compare plans](/#pricing)

```text

```

Response headers

```text

```

### Code examples

cURL Python JavaScript PHP Ruby Go Java
copy

```text
curl -X POST https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"text":"hello world from MiniWebtool","conversion":"kebab"}'
```

copy

```text
import requests

resp = requests.post(
    'https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run',
    headers={'Authorization': 'Bearer mwt_live_YOUR_KEY'},
    json={'text': 'hello world from MiniWebtool', 'conversion': 'kebab'},
)
resp.raise_for_status()
print(resp.json())
```

copy

```text
const resp = await fetch(
  'https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run',
  {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer mwt_live_YOUR_KEY',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({"text":"hello world from MiniWebtool","conversion":"kebab"}),
  }
);
const data = await resp.json();
console.log(data);
```

copy

```text
<?php
$ch = curl_init('https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer mwt_live_YOUR_KEY',
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode([
    'text' => 'hello world from MiniWebtool',
    'conversion' => 'kebab'
]),
]);
$resp = curl_exec($ch);
curl_close($ch);
print_r(json_decode($resp, true));
```

copy

```text
require 'net/http'
require 'json'
require 'uri'

uri = URI('https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = (uri.scheme == 'https')

req = Net::HTTP::Post.new(uri)
req['Authorization'] = 'Bearer mwt_live_YOUR_KEY'
req['Content-Type'] = 'application/json'
req.body = {
  'text' => 'hello world from MiniWebtool',
  'conversion' => 'kebab'
}.to_json

resp = http.request(req)
puts JSON.parse(resp.body).inspect
```

copy

```text
package main

import (
  "bytes"
  "encoding/json"
  "fmt"
  "io"
  "net/http"
)

func main() {
  body, _:= json.Marshal(map[string]interface{}{
    "text": "hello world from MiniWebtool",
    "conversion": "kebab",
  })
  req, _:= http.NewRequest("POST", "https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run", bytes.NewReader(body))
  req.Header.Set("Authorization", "Bearer mwt_live_YOUR_KEY")
  req.Header.Set("Content-Type", "application/json")

  resp, err:= http.DefaultClient.Do(req)
  if err!= nil { panic(err) }
  defer resp.Body.Close()
  out, _:= io.ReadAll(resp.Body)
  fmt.Println(string(out))
}
```

copy

```text
import java.net.URI;
import java.net.http.*;

var client = HttpClient.newHttpClient();
var req = HttpRequest.newBuilder()
.uri(URI.create("https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run"))
.header("Authorization", "Bearer mwt_live_YOUR_KEY")
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString("{\"text\":\"hello world from MiniWebtool\",\"conversion\":\"kebab\"}"))
.build();

var resp = client.send(req, HttpResponse.BodyHandlers.ofString());
System.out.println(resp.body());
```

## How to call Text Case Converter

- 1 Get an API key
[Get an API key](/billing/checkout/?plan=free). Sign up free for a bearer token. 1,000 credits/month, no card.
- 2 Assemble the JSON body
Required fields:`text`,. See the Request body table below for the full schema.
- 3 POST to`https://api.miniwebtool.com/v1/tools/lowercase-uppercase-letters/run`
Headers:`Authorization: Bearer <key>`and`Content-Type: application/json`. Copy-paste snippets in 7 languages are under Code examples.
- 4 Parse the response
Envelope:`{request_id, tool, tool_version, credits_used, result}`. The typed output lives in`result`.

## Frequently asked

What does the Text Case Converter API do? ▾
Convert text to uppercase, lowercase, title, sentence, camel, snake, kebab, and related cases. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.
How much does one call to Text Case Converter cost? ▾
1 credit per successful call. Failed calls (validation errors, 5xx) don't bill.
What parameters does the Text Case Converter API require? ▾
Required fields: text. Full schema at /v1/openapi.json.
Is the Text Case Converter API deterministic? ▾
Yes — same input, same output, forever. Tool version 2026-04-22; output shape is stable within a major version.
Can an AI agent call the Text Case Converter API? ▾
Yes. Connect to https://api.miniwebtool.com/v1/mcp over the Model Context Protocol. The agent discovers `lowercase-uppercase-letters` with its JSON Schema automatically, so the model can plan while MiniWebtool handles the exact tool result.
What format does the API return? ▾
JSON with a stable envelope: `{request_id, tool, tool_version, credits_used, result}`. Errors are RFC 7807 `application/problem+json`.

## Use from an AI agent

Every endpoint on this site is also exposed via the [Model Context Protocol](/docs/#mcp) at`https://api.miniwebtool.com/v1/mcp`. Claude, Cursor, and any MCP-capable agent can discover this tool (`lowercase-uppercase-letters`) and its JSON Schema automatically — no client codegen.

```text
# List tools the agent can call
curl -s https://api.miniwebtool.com/v1/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' \
 | jq '.result.tools[] | select(.name=="lowercase-uppercase-letters")'
```

## Related text tools

[
Remove Accent
Remove accents and combining marks from Unicode text.
](/tools/remove-accent/) [
Word Counter
Count words, characters, sentences, paragraphs, reading/speaking time, top word…
](/tools/word-counter/) [
Character Counter
Count characters, letters, digits, whitespace, and punctuation.
](/tools/character-counter/) [
Line Counter
Count total / non-empty / empty lines and longest-line length.
](/tools/line-counter/)
© 2026 miniwebtool. API is a separate product from the consumer site. [Terms](https://miniwebtool.com/about/terms-and-disclaimer/#api-terms) [Privacy](https://miniwebtool.com/about/privacy/#api-privacy) [consumer site →](https://miniwebtool.com)