Social media post checker API

Paste your post, pick the networks and say what media you attach. The checker shows, per network, what would stop the post from publishing and what would make it look worse, using the same rules PostBoost checks before it sends a post.

• Endpoint: POST https://postboost.co/app/api/tools/social-media-post-checker (operationId checkPost)
• Web tool: postboost.co/tools/social-media-post-checker
• Token: optional (limits)
• MCP: tool check-post on https://postboost.co/mcp/tools

Request

Field	Type	Default	Description
text	string	""	The post text, up to 10,000 characters; 5,000 without an API token.
networks	array of string		The networks to check the post for.
media	object		The attached media, all of one type. Omit for a text-only post.

Call it

curl

curl -X POST https://postboost.co/app/api/tools/social-media-post-checker \
  -H 'Content-Type: application/json' \
  -d '{"text":"Big news: https://postboost.co #launch","networks":["x","instagram"]}'

Python

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

with ApiClient(Configuration()) as client:
    api = FreeToolsApi(client)
    result = api.check_post(FreeToolCheckPostRequest.from_dict({"text": "Big news: https://postboost.co #launch", "networks": ["x", "instagram"]}))
    print(result.to_dict())

Node.js

import { FreeToolsApi } from 'postboost';

const api = new FreeToolsApi();
const { body } = await api.checkPost({ text: "Big news: https://postboost.co #launch", networks: ["x", "instagram"] });
console.log(body);

PHP

use PostBoostClient\Api\FreeToolsApi;
use PostBoostClient\Model\FreeToolCheckPostRequest;

$api = new FreeToolsApi(new GuzzleHttp\Client());
$result = $api->checkPost(new FreeToolCheckPostRequest(['text' => "Big news: https://postboost.co #launch", 'networks' => ["x", "instagram"]]));
echo $result;

Go

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

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

var request postboost.FreeToolCheckPostRequest
if err := json.Unmarshal([]byte(`{"text":"Big news: https://postboost.co #launch","networks":["x","instagram"]}`), &request); err != nil {
    panic(err)
}

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

Ruby

require 'postboost'

api = PostBoost::FreeToolsApi.new
result = api.check_post(PostBoost::FreeToolCheckPostRequest.new({ text: "Big news: https://postboost.co #launch", networks: ["x", "instagram"] }))
puts result.to_hash

Java

import com.postboost.ApiClient;
import com.postboost.api.FreeToolsApi;
import com.postboost.model.FreeToolCheckPostRequest;
import com.postboost.model.FreeToolCheckPostResponse;

FreeToolsApi api = new FreeToolsApi(new ApiClient());
FreeToolCheckPostRequest request = FreeToolCheckPostRequest.fromJson("{\"text\":\"Big news: https://postboost.co #launch\",\"networks\":[\"x\",\"instagram\"]}");
FreeToolCheckPostResponse result = api.checkPost(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<FreeToolCheckPostRequest>(@"{""text"":""Big news: https://postboost.co #launch"",""networks"":[""x"",""instagram""]}");
var result = await api.CheckPostAsync(request);
Console.WriteLine(result.ToJson());

Rust

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

let config = Configuration::new();
let request: FreeToolCheckPostRequest = serde_json::from_str(r##"{"text":"Big news: https://postboost.co #launch","networks":["x","instagram"]}"##)?;
let result = free_tools_api::check_post(&config, request).await?;
println!("{:?}", result);

CLI

echo '{"text":"Big news: https://postboost.co #launch","networks":["x","instagram"]}' | ./postboost-cli --content-type application/json checkPost -

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

Response

{
    "networks": [
        {
            "key": "x",
            "label": "X (Twitter) post",
            "ok": true,
            "count": 41,
            "limit": 280,
            "errors": [],
            "warnings": []
        },
        {
            "key": "instagram",
            "label": "Instagram caption",
            "ok": false,
            "count": 38,
            "limit": 2200,
            "errors": [
                {
                    "code": "media_required",
                    "message": "Add media: posts here need an image or a video to publish."
                }
            ],
            "warnings": [
                {
                    "code": "link_not_clickable",
                    "message": "Links in the text are not clickable here; point people to the link in your bio or a Story link sticker."
                }
            ]
        }
    ]
}

With MCP

Connect https://postboost.co/mcp/tools (setup) and ask, for example: Check a post against each network's publishing rules with the PostBoost check-post 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.