> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.modernfi.com/api-reference/transactions/create/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.modernfi.com/_mcp/server.

# Create Transaction

POST https://api.modernfi.com/digital-banking/v1/accounts/{account_id}/transactions
Content-Type: application/json

Reference: https://docs.modernfi.com/api-reference/transactions/create

## Authentication

- `Authorization` header (bearer token, required) — Bearer authentication of the form `Bearer <token>`, where token is your auth token.

## Servers

- `https://api.modernfi.com` (Production, default)
- `https://api.uat.modernfi.com` (UAT)
- `http://localhost:8000` (Local)

## Request

### Path parameters

- `account_id` (DigitalBankingV1AccountsAccountIdTransactionsPostParametersAccountId, required)

### Query parameters

- `id_type` (enum, optional, nullable) — Type of the account id. Must be 'institution' or 'None'.
  - Allowed values: `INSTITUTION`

### Headers

- `idempotency-key` (string, required)

### Body (application/json)

This endpoint expects a CreateTransactionRequest.

- `amount` (string, required) — Transaction amount. If negative, the transaction type will be Debit instead of Credit.
- `transacted_at` (string, required) — The datetime when the transaction occurred. Must be timezone-aware and cannot be in the future. Backdating is restricted to the current calendar month and to the last 7 days. Transactions submitted after the allocation cutoff on the last day of the month will have their effective date adjusted to the 1st of the following month.
- `description` (string, optional, nullable)
- `institution_transaction_id` (string, optional, nullable)
- `submitted_by` (string, optional, nullable) — The user who initiated the transaction.

## Response

### 201

Successful Response

- `id` (string, required)
- `account_id` (string, required)
- `institution_id` (string, required)
- `amount` (string, required)
- `transacted_at` (string, required)
- `transaction_status` (enum, required)
  - Allowed values: `PENDING`, `POSTED`, `CANCELLED`
- `is_interest_payment` (boolean, required)
- `transaction_type` (enum, required)
  - Allowed values: `CREDIT`, `DEBIT`
- `description` (string, optional, nullable)
- `posted_at` (string, optional, nullable)
- `institution_transaction_id` (string, optional, nullable)

## Errors

### 400 Bad Request Error

Bad Request - Invalid input or validation error

- `detail` (list of map from string to any, required)

### 401 Unauthorized Error

Unauthenticated - Invalid or missing authentication credentials

- `detail` (string, required)

### 403 Forbidden Error

Unauthorized - Insufficient permissions to access resource

- `detail` (string, required)

### 422 Unprocessable Entity Error

Validation Error

- `detail` (list of ValidationError, optional)

### 500 Internal Server Error

Internal Server Error

- `detail` (string, required)

## Types

### DigitalBankingV1AccountsAccountIdTransactionsPostParametersAccountId

### ValidationError

- `loc` (list of ValidationErrorLocItems, required)
- `msg` (string, required)
- `type` (string, required)
- `input` (any, optional)
- `ctx` (ValidationErrorCtx, optional)

### ValidationErrorLocItems

### ValidationErrorCtx

## Examples

**Request**

```json
{
  "amount": "string",
  "transacted_at": "2024-01-15T09:30:00Z"
}
```

**Response**

```json
{
  "id": "string",
  "account_id": "string",
  "institution_id": "string",
  "amount": "string",
  "transacted_at": "string",
  "transaction_status": "PENDING",
  "is_interest_payment": true,
  "transaction_type": "CREDIT",
  "description": "string",
  "posted_at": "string",
  "institution_transaction_id": "string"
}
```

**SDK Code**

```python
import requests

url = "https://api.modernfi.com/digital-banking/v1/accounts/string/transactions"

payload = {
    "amount": "string",
    "transacted_at": "2024-01-15T09:30:00Z"
}
headers = {
    "idempotency-key": "idempotency-key",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.json())
```

```javascript
const url = 'https://api.modernfi.com/digital-banking/v1/accounts/string/transactions';
const options = {
  method: 'POST',
  headers: {
    'idempotency-key': 'idempotency-key',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json'
  },
  body: '{"amount":"string","transacted_at":"2024-01-15T09:30:00Z"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

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

func main() {

	url := "https://api.modernfi.com/digital-banking/v1/accounts/string/transactions"

	payload := strings.NewReader("{\n  \"amount\": \"string\",\n  \"transacted_at\": \"2024-01-15T09:30:00Z\"\n}")

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

	req.Header.Add("idempotency-key", "idempotency-key")
	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(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.modernfi.com/digital-banking/v1/accounts/string/transactions")

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

request = Net::HTTP::Post.new(url)
request["idempotency-key"] = 'idempotency-key'
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"amount\": \"string\",\n  \"transacted_at\": \"2024-01-15T09:30:00Z\"\n}"

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

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.modernfi.com/digital-banking/v1/accounts/string/transactions")
  .header("idempotency-key", "idempotency-key")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"amount\": \"string\",\n  \"transacted_at\": \"2024-01-15T09:30:00Z\"\n}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.modernfi.com/digital-banking/v1/accounts/string/transactions', [
  'body' => '{
  "amount": "string",
  "transacted_at": "2024-01-15T09:30:00Z"
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
    'idempotency-key' => 'idempotency-key',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.modernfi.com/digital-banking/v1/accounts/string/transactions");
var request = new RestRequest(Method.POST);
request.AddHeader("idempotency-key", "idempotency-key");
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"amount\": \"string\",\n  \"transacted_at\": \"2024-01-15T09:30:00Z\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "idempotency-key": "idempotency-key",
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [
  "amount": "string",
  "transacted_at": "2024-01-15T09:30:00Z"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.modernfi.com/digital-banking/v1/accounts/string/transactions")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```