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

# Retrieve an invoice

GET https://api.trygrant.com/v1/invoices/{id}

Fetches an invoice by its ID, including line items.

Reference: https://docs.trygrant.com/api-reference/grant-events-api/invoices/get

## Authentication

- `Authorization` header (bearer token, required) — API key obtained from the Grant dashboard

## Servers

- `https://api.trygrant.com` (Production, default)
- `http://localhost:8787` (Local development)

## Request

### Path parameters

- `id` (string, required)

## Response

### 200

Invoice found

- `success` (boolean, required)
- `invoice` (Invoice, required)
- `request_id` (string, required)

## Errors

### 401 Unauthorized Error

Unauthorized

- `success` (boolean, required)
- `error` (ErrorResponseError, required)
- `request_id` (string, optional) — Request ID for tracing

### 404 Not Found Error

Invoice not found

- `success` (boolean, required)
- `error` (ErrorResponseError, required)
- `request_id` (string, optional) — Request ID for tracing

### 500 Internal Server Error

Internal server error

- `success` (boolean, required)
- `error` (ErrorResponseError, required)
- `request_id` (string, optional) — Request ID for tracing

## Types

### Invoice

- `id` (string, required)
- `customer_id` (string, required, nullable)
- `subscription_id` (string, required, nullable)
- `status` (enum, required)
  - Allowed values: `draft`, `open`, `paid`, `void`, `uncollectible`
- `currency` (string, required)
- `collection_method` (enum, required)
  - Allowed values: `charge_automatically`, `send_invoice`
- `invoice_number` (string, required, nullable)
- `public_invoice_url` (string, required, nullable)
- `due_date` (string, required, nullable)
- `days_until_due` (integer, required, nullable)
- `description` (string, required, nullable)
- `customer_memo` (string, required, nullable)
- `footer` (string, required, nullable)
- `subtotal_cents` (integer, required)
- `discount_cents` (integer, required)
- `tax_cents` (integer, required)
- `total_cents` (integer, required)
- `finalized_at` (string, required, nullable)
- `paid_at` (string, required, nullable)
- `period_start` (string, required, nullable)
- `period_end` (string, required, nullable)
- `line_items` (list of InvoiceLineItem, required)
- `created_at` (string, required)
- `updated_at` (string, required)

### ErrorResponseError

- `code` (string, required)
- `message` (string, required)
- `details` (any, optional)

### InvoiceLineItem

- `id` (string, required)
- `description` (string, required, nullable)
- `quantity` (integer, required)
- `unit_amount_cents` (integer, required)
- `tax_amount_cents` (integer, required)
- `total_amount_cents` (integer, required)
- `period_start` (string, required, nullable)
- `period_end` (string, required, nullable)
- `created_at` (string, required)
- `updated_at` (string, required)

## Examples

**Response**

```json
{
  "success": true,
  "invoice": {
    "id": "cm5x9z8nv0000h85r7l9p2k1m",
    "customer_id": "cm5x9z8nv0001h85r7l9p2k2m",
    "subscription_id": null,
    "status": "draft",
    "currency": "usd",
    "collection_method": "send_invoice",
    "invoice_number": "INV-0001",
    "public_invoice_url": "https://www.trygrant.com/invoices/abc123",
    "due_date": null,
    "days_until_due": null,
    "description": null,
    "customer_memo": null,
    "footer": null,
    "subtotal_cents": 0,
    "discount_cents": 0,
    "tax_cents": 0,
    "total_cents": 0,
    "finalized_at": null,
    "paid_at": null,
    "period_start": null,
    "period_end": null,
    "line_items": [
      {
        "id": "cm5x9z8nv0000h85r7l9p2k1m",
        "description": "API calls — Feb 2024",
        "quantity": 1,
        "unit_amount_cents": 5000,
        "tax_amount_cents": 0,
        "total_amount_cents": 5000,
        "period_start": null,
        "period_end": null,
        "created_at": "2024-01-15T10:30:00.000Z",
        "updated_at": "2024-01-15T10:30:00.000Z"
      }
    ],
    "created_at": "2024-01-15T10:30:00.000Z",
    "updated_at": "2024-01-15T10:30:00.000Z"
  },
  "request_id": "req_abc123"
}
```

**SDK Code**

```python
import requests

url = "https://api.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m"

headers = {"Authorization": "Bearer <token>"}

response = requests.get(url, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m';
const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

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"
	"net/http"
	"io"
)

func main() {

	url := "https://api.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("Authorization", "Bearer <token>")

	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.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m")

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

request = Net::HTTP::Get.new(url)
request["Authorization"] = 'Bearer <token>'

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.get("https://api.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m")
  .header("Authorization", "Bearer <token>")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://api.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m', [
  'headers' => [
    'Authorization' => 'Bearer <token>',
  ],
]);

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

```csharp
using RestSharp;

var client = new RestClient("https://api.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m");
var request = new RestRequest(Method.GET);
request.AddHeader("Authorization", "Bearer <token>");
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Authorization": "Bearer <token>"]

let request = NSMutableURLRequest(url: NSURL(string: "https://api.trygrant.com/v1/invoices/cm5x9z8nv0000h85r7l9p2k1m")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "GET"
request.allHTTPHeaderFields = headers

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()
```

> API documentation for Grant — billing infrastructure for usage-based pricing