X thread maker API

Paste an article, a newsletter or a long idea and get a ready thread for X, Threads, Bluesky or Mastodon: split at paragraphs and sentences, numbered 1/n if you like, each post within the network's limit.

• Endpoint: POST https://postboost.co/app/api/tools/x-thread-maker (operationId splitThread)
• Web tool: postboost.co/tools/x-thread-maker
• Token: optional (limits)
• MCP: tool split-thread on https://postboost.co/mcp/tools

Request

Field	Type	Default	Description
text	string	""	The long text, up to 10,000 characters. A line with only --- forces a new post.
network	string: x, threads, bluesky, mastodon	"x"
numbering	boolean	false	End each post with " k/n".

Call it

curl

curl -X POST https://postboost.co/app/api/tools/x-thread-maker \
  -H 'Content-Type: application/json' \
  -d '{"text":"Short one.\n\nShort two.\n---\nSecond post.","numbering":true}'

Python

from postboost import ApiClient, Configuration
from postboost.api.free_tools_api import FreeToolsApi
from postboost.models import FreeToolSplitThreadRequest

with ApiClient(Configuration()) as client:
    api = FreeToolsApi(client)
    result = api.split_thread(FreeToolSplitThreadRequest.from_dict({"text": "Short one.\n\nShort two.\n---\nSecond post.", "numbering": True}))
    print(result.to_dict())

Node.js

import { FreeToolsApi } from 'postboost';

const api = new FreeToolsApi();
const { body } = await api.splitThread({ text: "Short one.\n\nShort two.\n---\nSecond post.", numbering: true });
console.log(body);

PHP

use PostBoostClient\Api\FreeToolsApi;
use PostBoostClient\Model\FreeToolSplitThreadRequest;

$api = new FreeToolsApi(new GuzzleHttp\Client());
$result = $api->splitThread(new FreeToolSplitThreadRequest(['text' => "Short one.\n\nShort two.\n---\nSecond post.", 'numbering' => true]));
echo $result;

Go

import (
    "context"
    "encoding/json"
    "fmt"

    postboost "github.com/postboost-co/postboost-go"
)

var request postboost.FreeToolSplitThreadRequest
if err := json.Unmarshal([]byte(`{"text":"Short one.\n\nShort two.\n---\nSecond post.","numbering":true}`), &request); err != nil {
    panic(err)
}

client := postboost.NewAPIClient(postboost.NewConfiguration())
result, _, err := client.FreeToolsAPI.SplitThread(context.Background()).FreeToolSplitThreadRequest(request).Execute()
fmt.Println(result, err)

Ruby

require 'postboost'

api = PostBoost::FreeToolsApi.new
result = api.split_thread(PostBoost::FreeToolSplitThreadRequest.new({ text: "Short one.\n\nShort two.\n---\nSecond post.", numbering: true }))
puts result.to_hash

Java

import com.postboost.ApiClient;
import com.postboost.api.FreeToolsApi;
import com.postboost.model.FreeToolSplitThreadRequest;
import com.postboost.model.FreeToolSplitThreadResponse;

FreeToolsApi api = new FreeToolsApi(new ApiClient());
FreeToolSplitThreadRequest request = FreeToolSplitThreadRequest.fromJson("{\"text\":\"Short one.\\n\\nShort two.\\n---\\nSecond post.\",\"numbering\":true}");
FreeToolSplitThreadResponse result = api.splitThread(request);
System.out.println(result.toJson());

C#

using Newtonsoft.Json;
using PostBoost.Client.Api;
using PostBoost.Client.Client;
using PostBoost.Client.Model;

var api = new FreeToolsApi(new Configuration());
var request = JsonConvert.DeserializeObject<FreeToolSplitThreadRequest>(@"{""text"":""Short one.\n\nShort two.\n---\nSecond post."",""numbering"":true}");
var result = await api.SplitThreadAsync(request);
Console.WriteLine(result.ToJson());

Rust

use postboost::apis::configuration::Configuration;
use postboost::apis::free_tools_api;
use postboost::models::FreeToolSplitThreadRequest;

let config = Configuration::new();
let request: FreeToolSplitThreadRequest = serde_json::from_str(r##"{"text":"Short one.\n\nShort two.\n---\nSecond post.","numbering":true}"##)?;
let result = free_tools_api::split_thread(&config, request).await?;
println!("{:?}", result);

CLI

echo '{"text":"Short one.\n\nShort two.\n---\nSecond post.","numbering":true}' | ./postboost-cli --content-type application/json splitThread -

With a token, send Authorization: Bearer YOUR_API_TOKEN as a default header (how, per SDK).

Response

{
    "limit": 280,
    "posts": [
        {
            "text": "Short one.\n\nShort two. 1/2",
            "count": 26
        },
        {
            "text": "Second post. 2/2",
            "count": 16
        }
    ]
}

With MCP

Connect https://postboost.co/mcp/tools (setup) and ask, for example: Split long text into a thread with the PostBoost split-thread tool.

Errors

Status	When
401	The Authorization header holds an invalid token. Leave it out to call as a guest.
413	The JSON body is larger than 128 KB.
422	A field is invalid; the body lists the errors per field.
429	A limit is reached; see limits.