You can read Private & Public bins using the Read API.

Root
https://api.jsonbin.io/v3
Route (READ a specific Bin)
/b/<BIN_ID>
Route (READ a specific Bin Version)
/b/<BIN_ID>/<BIN_VERSION>
Route (READ the latest Record of a Bin)
/b/<BIN_ID>/latest        # Will always return the last Updated record
Request Type
GET
Request Headers
Header Value Required
X-Master-Key <YOUR_API_KEY> No
X-Master-Key

X-Master-Key needs to be passed in-order to Read a Private bin. In-order to get the key, you need to sign-up and navigate to API Keys page.

Basic Code Samples
curl -v\
  -H "X-Master-key: <YOUR_API_KEY>" \
  --request GET \
    https://api.jsonbin.io/v3/b/<BIN_ID>/<BIN_VERSION | latest>
let req = new XMLHttpRequest();

req.onreadystatechange = () => {
  if (req.readyState == XMLHttpRequest.DONE) {
    console.log(req.responseText);
  }
};

req.open("GET", "https://api.jsonbin.io/v3/b/<BIN_ID>/<BIN_VERSION | latest>", true);
req.setRequestHeader("X-Master-Key", "<YOUR_API_KEY>");
req.send();
import requests
url = 'https://api.jsonbin.io/v3/b/<BIN_ID>/<BIN_VERSION | latest>'
headers = {
  'X-Master-Key': '<YOUR_API_KEY>'
}

req = requests.get(url, json=None, headers=headers)
print(req.text)
require 'net/http'
require 'json'

uri = URI("https://api.jsonbin.io/v3/b/<BIN_ID>/<BIN_VERSION | latest>")
res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) do |http|
  req = Net::HTTP::Post.new(uri)
  req['X-Master-Key'] = '<YOUR_API_KEY>'

  http.request()
end

puts res.body
Request Response
Success
200
{
  "record": {
    "sample": "Hello World"
  },
  "metadata": {
    "id": "<BIN_ID>",
    "private": true
  }
}
Error
400, 401, 403
{
  "message": "<ERROR_MESSAGE>"
}
Status Code Error Message
400 Bad Request
Invalid Bin Id provided
404 Not Found
Bin not found or it doesn't belong to your account
403 Not Found
Bins not associated to any user are now blocked. Contact the admin at https://jsonbin.io/contact for further info
401 Unauthorised
You need to pass X-Master-Key in the header to read a private bin
401 Unauthorised
X-Master-Key is invalid or the bin doesn't belong to your account
401 Unauthorised
Bin not associated to any user account
400 Bad Request
Bin version is invalid
403 Forbidden
Requests exhausted. Buy additional requests at https://jsonbin.io/pricing
404 Not Found
Bin version not found