Which documentation are you looking for?

Do not know how to start integrating? 

Check the first steps
Search payment intent

GET

https://api.mercadopago.com/point/integration-api/payment-intents/{paymentintentid}
This endpoint will provide information of a payment intent created during the last three months, its final status and the payment-id, which can be used to get the final status of the transaction in the Payments API. The Webhook notifications are the main communication point of the payment intent information, then this endpoint should be used for testing and eventualities, and not for polling, because it has restrictions, like allowing to get information one request per second.
Request's parameters
HEADER
x-test-scope
string
This is a temporary header, it should be used just for development with the value "sandbox"
PATH
paymentIntentId
string

REQUIRED

Payment intent identification
Response parameters
id
string
Identification of the payment intent
state
string
State of the payment intent
amount
integer
Total amount of payment intent
device_id
string
Identifier of the device to which the payment intent was assigned
Errors

401Error

401

Unauthorized - Token is invalid

403Error

403

Forbidden - Integrator isn't registered

404Error

404

Not-found - Payment intent doesn't exist

500Error

500

Internal server error

Request
curl -X GET \
      'https://api.mercadopago.com/point/integration-api/payment-intents/{paymentintentid}'\
       -H 'Content-Type: application/json' \
       -H 'x-test-scope: sandbox' \,
       -H 'Authorization: Bearer TEST-8971*********918-01191*********5874530a4*********4799fdf-1*********' \
       
Sample answer
{
  "id": "7f25f9aa-eea6-4f9c-bf16-a341f71ba2f1",
  "state": "FINISHED",
  "amount": 1500,
  "device_id": "PAX_A910__SMARTPOS1234345545",
  "payment": {
    "id": 16499678033
  },
  "additional_info": {
    "external_reference": "some-reference-from-your-application",
    "print_on_terminal": true,
    "ticket_number": "S0392JED"
  }
}