Files

Create file upload

Starts a direct upload of a PDF: returns a URL to PUT the PDF to, straight to Finta’s file storage, and the file_id the PDF becomes. Use it where a multipart request isn’t practical, such as an AI agent connected through the MCP that runs curl from its terminal. Requires API access: Manage and Taxes: Manage.

Send the file’s filename, its size in bytes, and its MD5 checksum in base64. Then PUT the file’s bytes to url with every header in headers, before expires_at (10 minutes):

curl --fail -X PUT --upload-file return.pdf \
  -H "Content-Type: application/pdf" \
  -H "Content-MD5: <checksum>" \
  -H "Content-Disposition: <Content-Disposition from headers>" \
  "<url>"

Storage accepts only bytes that match size and checksum, so a URL can’t be used to store a different file, and each call returns a new URL and file. The PDF check happens when a tax upload attaches the file: a file with no content yet, or one that is not a PDF, is refused then with invalid_file. Like a file from Create file, it attaches once and is deleted if nothing attaches it within 24 hours of this call.

POST

file_uploads

Create file upload

curl --request POST \
  --url https://app.finta.com/api/v1/file_uploads \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "filename": "2025 Form 1120.pdf",
  "size": 482113,
  "checksum": "r8Hq2wJ5bNf0uYk3cX7d1A=="
}
'

import requests

url = "https://app.finta.com/api/v1/file_uploads"

payload = {
    "filename": "2025 Form 1120.pdf",
    "size": 482113,
    "checksum": "r8Hq2wJ5bNf0uYk3cX7d1A=="
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    filename: '2025 Form 1120.pdf',
    size: 482113,
    checksum: 'r8Hq2wJ5bNf0uYk3cX7d1A=='
  })
};

fetch('https://app.finta.com/api/v1/file_uploads', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://app.finta.com/api/v1/file_uploads",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'filename' => '2025 Form 1120.pdf',
    'size' => 482113,
    'checksum' => 'r8Hq2wJ5bNf0uYk3cX7d1A=='
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://app.finta.com/api/v1/file_uploads"

	payload := strings.NewReader("{\n  \"filename\": \"2025 Form 1120.pdf\",\n  \"size\": 482113,\n  \"checksum\": \"r8Hq2wJ5bNf0uYk3cX7d1A==\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://app.finta.com/api/v1/file_uploads")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"filename\": \"2025 Form 1120.pdf\",\n  \"size\": 482113,\n  \"checksum\": \"r8Hq2wJ5bNf0uYk3cX7d1A==\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.finta.com/api/v1/file_uploads")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"filename\": \"2025 Form 1120.pdf\",\n  \"size\": 482113,\n  \"checksum\": \"r8Hq2wJ5bNf0uYk3cX7d1A==\"\n}"

response = http.request(request)
puts response.read_body

{
  "object": "file_upload",
  "file_id": "<string>",
  "url": "<string>",
  "method": "PUT",
  "headers": {},
  "expires_at": 123
}

Authorizations

Authorization

string

header

required

API key prefixed with finta_

Body

application/json

filename

string

required

The PDF's file name, kept and shown on the Taxes page.

Minimum string length: 1

size

integer

required

The file's length in bytes, such as from wc -c < return.pdf.

Required range: 1 <= x <= 5368709120

checksum

string

required

The file's MD5 digest in base64, such as from openssl md5 -binary return.pdf | base64.

Pattern: ^[A-Za-z0-9+/]{22}==$

Response

The upload URL and the file it becomes.

object

enum<string>

required

Available options:

file_upload

file_id

string

required

The file the PDF becomes once it is PUT to url. Pass it to a tax upload.

Pattern: ^file_[A-Za-z0-9]+$

url

string<uri>

required

Signed storage URL to PUT the PDF's bytes to. Treat it as a secret.

method

enum<string>

required

Available options:

PUT

headers

object

required

Headers to send with the PUT, exactly as given (Content-Type, Content-MD5 and Content-Disposition).

Show child attributes

expires_at

integer

required

Unix seconds after which url stops working, 10 minutes after the call. The file itself can be attached for 24 hours.

Create file upload

curl --request POST \
  --url https://app.finta.com/api/v1/file_uploads \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "filename": "2025 Form 1120.pdf",
  "size": 482113,
  "checksum": "r8Hq2wJ5bNf0uYk3cX7d1A=="
}
'

import requests

url = "https://app.finta.com/api/v1/file_uploads"

payload = {
    "filename": "2025 Form 1120.pdf",
    "size": 482113,
    "checksum": "r8Hq2wJ5bNf0uYk3cX7d1A=="
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    filename: '2025 Form 1120.pdf',
    size: 482113,
    checksum: 'r8Hq2wJ5bNf0uYk3cX7d1A=='
  })
};

fetch('https://app.finta.com/api/v1/file_uploads', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://app.finta.com/api/v1/file_uploads",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'filename' => '2025 Form 1120.pdf',
    'size' => 482113,
    'checksum' => 'r8Hq2wJ5bNf0uYk3cX7d1A=='
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://app.finta.com/api/v1/file_uploads"

	payload := strings.NewReader("{\n  \"filename\": \"2025 Form 1120.pdf\",\n  \"size\": 482113,\n  \"checksum\": \"r8Hq2wJ5bNf0uYk3cX7d1A==\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://app.finta.com/api/v1/file_uploads")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"filename\": \"2025 Form 1120.pdf\",\n  \"size\": 482113,\n  \"checksum\": \"r8Hq2wJ5bNf0uYk3cX7d1A==\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.finta.com/api/v1/file_uploads")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"filename\": \"2025 Form 1120.pdf\",\n  \"size\": 482113,\n  \"checksum\": \"r8Hq2wJ5bNf0uYk3cX7d1A==\"\n}"

response = http.request(request)
puts response.read_body

{
  "object": "file_upload",
  "file_id": "<string>",
  "url": "<string>",
  "method": "PUT",
  "headers": {},
  "expires_at": 123
}

API Reference

Taxes

Files

Company

Team

Categories

Rules

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Integrations

Aggregations

Transactions

Forms

Journal Entries

Invoices

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Reports

Feedback

Tax Credits

Create file upload

Authorizations

Body

Response