Invoice Ninja provides a REST based API, click here to see the full list of methods available.

To access the API you first need to create a token using the “Tokens” page under “Advanced Settings”.


Replace ninja.dev with https://app.invoiceninja.com to access a hosted account.

Reading Data

Here’s an example of reading the list of clients using cURL from the command line.

curl -X GET ninja.dev/api/v1/clients -H "X-Ninja-Token: TOKEN"

For invoices, quotes, tasks and payments simply change the object type.

curl -X GET ninja.dev/api/v1/invoices -H "X-Ninja-Token: TOKEN"

You can search clients by their email address or id number and invoices by their invoice number.

curl -X GET ninja.dev/api/v1/clients?email=<value> -H "X-Ninja-Token: TOKEN"
curl -X GET ninja.dev/api/v1/clients?id_number=<value> -H "X-Ninja-Token: TOKEN"
curl -X GET ninja.dev/api/v1/invoices?invoice_number=<value> -H "X-Ninja-Token: TOKEN"

To load a single record specify the Id in the URL.

curl -X GET ninja.dev/api/v1/invoices/1 -H "X-Ninja-Token: TOKEN"

You can specify additional relationships to load using the include parameter.

curl -X GET ninja.dev/api/v1/clients/1?include=invoices.invitations -H "X-Ninja-Token: TOKEN"

You can download a PDF using the following URL

curl -X GET ninja.dev/api/v1/download/1 -H "X-Ninja-Token: TOKEN"

Optional Settings

The following are optional query parameter settings:

  • serializer: Either array (the default) or JSON.
  • include: A comma-separated list of nested relationships to include.
  • client_id: If set the results will be filtered by the client.
  • page: The page number of results to return when the results are paginated.
  • per_page: The number of results to return per page.
  • updated_at: Timestamp used as a filter to only show recently updated records.

Creating Data


Add -H "X-Requested-With: XMLHttpRequest" to see validation errors in the response.

Here’s an example of creating a client. Note that email address is a property of the client’s contact not the client itself.

curl -X POST ninja.dev/api/v1/clients -H "Content-Type:application/json"
  -d '{"name":"Client","contact":{"email":"[email protected]"}}' -H "X-Ninja-Token: TOKEN"

You can also update a client by specifying a value for ‘id’. Next, here’s an example of creating an invoice.

curl -X POST ninja.dev/api/v1/invoices -H "Content-Type:application/json"
  -d '{"client_id":"1", "invoice_items":[{"product_key": "ITEM", "notes":"Test", "cost":10, "qty":1}]}'
  -H "X-Ninja-Token: TOKEN"

If the product_key is set and matches an existing record the product fields will be auto-populated. If the email field is set then we’ll search for a matching client. If no matches are found a new client will be created.


The following options are available when creating an invoice.

  • email_invoice: Email the invoice to the client.
  • auto_bill: Attempt to auto-bill the invoice using stored payment methods or credits.
  • paid: Create a payment for the defined amount.

Updating Data


When updating a client it’s important to include the contact ids.

curl -X PUT ninja.dev/api/v1/clients/1 -H "Content-Type:application/json"
  -d '{"name":"test", "contacts":[{"id": 1, "first_name": "test"}]}'
  -H "X-Ninja-Token: TOKEN"

Emailing Invoices

To email an invoice use the email_invoice command passing the id of the invoice.

curl -X POST ninja.dev/api/v1/email_invoice -d '{"id":1}'
  -H "Content-Type:application/json" -H "X-Ninja-Token: TOKEN"


You can use subscriptions to have Invoice Ninja POST newly created records to a third-party application. To enable this feature you need to manually add a record to the subscriptions table. To determine the event_id find the associated EVENT_CREATE_ value from app/Constants.php.