# .NET client documentation ## Set up the client ### Prerequisites This documentation assumes you are using either [Microsoft Visual Studio](https://visualstudio.microsoft.com/) (Windows) or [Visual Studio Code with the C# extension](https://code.visualstudio.com/docs/languages/dotnet) (Windows, macOS, or Linux) and with the [NuGet Package Manager](https://www.nuget.org/). Refer to the [client changelog](https://github.com/alphagov/notifications-net-client/blob/main/CHANGELOG.md) for the version number and the latest updates. ### Install the client TheNotify client can be installed from [Nuget.org](https://www.nuget.org/packages/GovukNotify/). You can install the Notify client package using either the command line or Microsoft Visual Studio. #### **Use the dotnet command line interface** Go to your project directory and run the following in the command line to install the client package: ```shellscript dotnet add package GovukNotify ``` #### **Use Microsoft Visual Studio or Visual Studio Code with C# Extension** Use the [NuGet Package Manager](https://docs.microsoft.com/en-us/nuget/what-is-nuget) to install the `GovukNotify` client package in Visual Studio. You can use either the [console](https://docs.microsoft.com/en-us/nuget/tools/package-manager-console) or [the UI](https://docs.microsoft.com/en-us/nuget/tools/package-manager-ui). #### **Console** Run the following in the NuGet package manager console to install the client package: ```shellscript nuget install GovukNotify ``` #### **User Interface (UI)** Use the Package Manager UI to [search for and install the client package](https://docs.microsoft.com/en-us/nuget/tools/package-manager-ui#finding-and-installing-a-package). ### Create a new instance of the client Add this code to your application: ```csharp using Notify.Client; using Notify.Models; using Notify.Models.Responses; var client = new NotificationClient("https://api.notifynl.nl", apiKey); ``` To get an API key, [sign in to NotifyNL](https://admin.notifynl.nl/sign-in) and go to the **API integration** page. You can find more information in the [API keys](/misc/api-keys.md) section of this documentation. #### **Connect through a proxy (optional)** If you use a proxy, you must set the proxy configuration in the `web.config` file. Refer to the [Microsoft documentation on proxy configuration](https://docs.microsoft.com/en-us/dotnet/framework/network-programming/proxy-configuration) for more information. ```csharp using Notify.Client; using Notify.Models; using Notify.Models.Responses; using System.Net.Http; var httpClientWithProxy = new HttpClientWrapper(new HttpClient(...)); var client = new NotificationClient(httpClientWithProxy, apiKey); ``` ## Send a message You can use NotifyNL to send emails, text messages and letters. ### Bulk sending You cannot use a single API call to send messages in bulk. To send a batch of messages, use the API to loop over your recipient list, sending one message at a time to each recipient. Make sure you do not exceed our [rate limits](https://docs.notifications.service.gov.uk/net.html#rate-limits). ### Send a text message #### **Method** ```csharp SmsNotificationResponse response = client.SendSms( mobileNumber: "+447900900123", templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a", ); ``` #### **Arguments** **mobileNumber (required)** The phone number of the recipient of the text message. This can be a UK or international number. ```csharp string mobileNumber: "+447900900123"; ``` **templateId (required)** To find the template ID: 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Templates** page and select the relevant template. 3. Select **Copy template ID to clipboard**. For example: ```csharp string templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a"; ``` **personalisation (optional)** If a template has placeholder fields for personalised information such as name or reference number, you need to provide their values in a `Dictionary`. For example: ```csharp Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"} }; ``` You can leave out this argument if a template does not have any placeholder fields for personalised information. **reference (optional)** A unique identifier you can create if you need to. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address. For example: ```csharp string reference: "my reference"; ``` You can leave out this argument if you do not have a reference. **smsSenderId (optional)** A unique identifier of the sender of the text message notification. To find the text message sender: 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Settings** page. 3. In the **Text Messages** section, select **Manage** on the **Text Message sender** row. You can then either: * copy the sender ID that you want to use and paste it into the method * select **Change** to change the default sender that the service uses, and select **Save** For example: ```csharp string smsSenderId: "8e222534-7f05-4972-86e3-17c5d9f894e2"; ``` You can leave out this argument if your service only has one text message sender, or if you want to use the default sender. #### **Response** If the request to the client is successful, the client returns an `SmsNotificationResponse`: ```csharp public String id; public String reference; public String uri; public Template template; public SmsResponseContent; public class Template { public String id; public String uri; public Int32 version; } public class SmsResponseContent{ public string body; public string fromNumber; } ``` If you use the [test API key](/misc/api-keys.md#test), all your messages come back with a `delivered` status. All messages sent using the [team and guest list](/misc/api-keys.md#team-and-guest-list) or [live](/misc/api-keys.md#live) keys appear on your dashboard. #### **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors).
Error messageHow to fix
ValidationError (status code 400)
phone_number Too many digitsProvide a valid recipient phone number.
phone_number Not enough digitsProvide a valid recipient phone number.
phone_number Not a NL mobile numberProvide a valid Dutch recipient phone number.
phone_number Must not contain letters or symbolsProvide a valid recipient phone number.
phone_number Not a valid country prefixProvide a valid recipient phone number.
BadRequestError (status code 400)
sms_sender_id <sms_sender_id> does not exist in database for service idGo to your service Settings and copy a valid sms_sender_id. Check that the API key you are using and the sms_sender_id belong to the same service.
Cannot send to this recipient when service is in trial mode - see https://admin.notifynl.nl/trial-modeYour service cannot send this text message in trial mode. To fix, you need to request for your service to go live.
Cannot send to international mobile numbersSending to international mobile numbers is turned off for your service. You can change this in your service Settings.
### Send an email #### **Method** ```csharp EmailNotificationResponse response = client.SendEmail(emailAddress, templateId, personalisation, reference, emailReplyToId); ``` ```csharp client.SendEmail( emailAddress: "sender@something.com", templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a" ); ``` #### **Arguments** **emailAddress (required)** The email address of the recipient. For example: ```csharp string emailAddress: "sender@something.com"; ``` **templateId (required)** To find the template ID: 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Templates** page and select the relevant template. 3. Select **Copy template ID to clipboard**. For example: ```csharp string templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a"; ``` **personalisation (optional)** If a template has placeholder fields for personalised information such as name or reference number, you need to provide their values in a `Dictionary`. For example: ```csharp Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"}, // pass in a list and it will appear as bullet points in the message: {"required_documents", new List {"passport", "utility bill", "other id"}} }; ``` You can leave out this argument if a template does not have any placeholder fields for personalised information. Find out how to [reduce the risk of malicious content injection in placeholders](#reducing-the-risk-of-malicious-content-injection-in-placeholders). **reference (optional)** A unique identifier you can create if you need to. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address. For example: ```csharp string reference: "my reference"; ``` You can leave out this argument if you do not have a reference. **oneClickUnsubscribeURL (recommended)** If you send subscription emails you must let recipients opt out of receiving them. Read our Using Notify page for more information about [unsubscribe links](/using-notifynl/using-notifynl/unsubscribe-links.md). The one-click unsubscribe URL will be added to the headers of your email. Email clients will use it to add an unsubscribe button. ```csharp string oneClickUnsubscribeURL : "https://example.com/unsubscribe.html?opaque=123456789"; ``` The one-click unsubscribe URL must respond to an empty `POST` request by unsubscribing the user from your emails. You can include query parameters to help you identify the user. Your unsubscribe URL and response must comply with the guidance specified in [Section 3.1 of IETF RFC 8058](https://www.rfcreader.com/#rfc8058_line139). You can leave out this argument if the email being sent is not a subscription email. You must also add an unsubscribe link to the bottom of your email. The unsubscribe link at the bottom of your email should take the email recipient to a webpage where they can confirm that they want to unsubscribe. Find out how to add a link when you create a **New template** or **Edit** an email template. **emailReplyToId (optional)** This is an email address specified by you to receive replies from your users. You must add at least one reply-to email address before your service can go live. To add a reply-to email address: 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Settings** page. 3. In the **Email** section, select **Manage** on the **Reply-to email addresses** row. 4. Select **Add reply-to address**. 5. Enter the email address you want to use, and select **Add**. For example: ```csharp string emailReplyToId: "8e222534-7f05-4972-86e3-17c5d9f894e2"; ``` You can leave out this argument if your service only has one email reply-to address, or you want to use the default email address. #### **Response** If the request to the client is successful, the client returns an `EmailNotificationResponse`: ```csharp public String id; public String reference; public String oneClickUnsubscribeURL; public String uri; public Template template; public EmailResponseContent content; public class Template{ public String id; public String uri; public Int32 version; } public class EmailResponseContent{ public String fromEmail; public String body; public String subject; } ``` #### **Reducing the risk of malicious content injection in placeholders** Notify lets you [personalise messages](/using-notifynl/using-notifynl/personalisation.md) using placeholders. You can [format](/using-notifynl/using-notifynl/formatting-emails-and-letters.md) content or add links and urls into placeholders using Markdown. If you pass in information from untrusted sources (such as online forms) into your Notify template using personalisation, this may be used to add malicious content and links to notifications you send via Notify. The malicious content could be: * Markdown syntax intended to be rendered into HTML * a plain text URL which would be rendered into a clickable phishing link An example of how malicious content can be injected into Notify personalisation: **Template in Notify**: ```markdown Hello ((name)) ``` **Personalisation**: ```json {name: "Anne Example, now [click this evil link](https://malicious.link)"} ``` **Email will appear as**: ``` Dear Anne Example, now click this evil link ``` We recommend you sanitise all input from untrusted sources to prevent the injection of malicious content. You can use a backslash to escape [individual characters](https://www.markdownguide.org/basic-syntax/#characters-you-can-escape). The characters of most concern are those that could be used to add a URL link such as `[`, `]`, `(` or `)`. **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | -------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **ValidationError (status code 400)** | | | `email_address Not a valid email address` | Provide a valid recipient email address. | | `one_click_unsubscribe_url is not a valid https url` | Provide a valid https url for your unsubscribe link. | | **BadRequestError (status code 400)** | | | `email_reply_to_id does not exist in database for service id ` | Go to your service Settings and copy a valid `email_reply_to_id`. Double check that the API key you are using and the `email_reply_to_id` belong to the same service. | | `Emails cannot be longer than 2000000 bytes. Your message is bytes.` | Shorten your email message. | | `Cannot send to this recipient when service is in trial mode - see https://admin.notifynl.nl/trial-mode` | Your service cannot send this email in [trial mode](/using-notifynl/using-notifynl/trial-mode.md). To fix, you need to request for your service to go live. | ### Send a file by email To send a file by email, add a placeholder to the template then upload a file. The placeholder will contain a secure link to download the file. The links are unique and unguessable. GOV.UK Notify cannot access or decrypt your file. Your file will be available to download for a default period of 26 weeks (6 months). To help protect your files you can also: * ask recipients to confirm their email address before downloading * choose the length of time that a file is available to download #### **Add contact details to the file download page** 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Settings** page. 3. In the **Email** section, select **Manage** on the **Send files by email** row. 4. Enter the contact details you want to use, and select **Save**. #### **Add a placeholder to the template** 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Templates** page and select the relevant email template. 3. Select **Edit**. 4. Add a placeholder to the email template using double brackets. For example: “Download your file at: ((link\_to\_file))” Your email should also tell recipients how long the file will be available to download. #### **Upload your file** You can upload the following file types: * CSV (.csv) * image (.jpeg, .jpg, .png) * Microsoft Excel Spreadsheet (.xlsx) * Microsoft Word Document (.doc, .docx) * PDF (.pdf) * text (.json, .odt, .rtf, .txt) Your file must be smaller than 2MB. [Contact the NotifyNL team](https://admin.notifynl.nl/support) if you need to send other file types. 1. Convert the PDF to a `byte[]`. 2. Pass the `byte[]` to the personalisation argument. 3. Call the [sendEmail method](#send-an-email). For example: ```csharp byte[] documentContents = File.ReadAllBytes(""); Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"}, { "link_to_file", NotificationClient.PrepareUpload( documentContents: documentContents) } }; ``` #### **Set the filename** To do this you will need version 7.0.0 of the .NET client library, or a more recent version. You should provide a filename when you upload your file. The filename should tell the recipient what the file contains. A memorable filename can help the recipient to find the file again later. The filename must end with a file extension. For example, `.csv` for a CSV file. If you include the wrong file extension, recipients may not be able to open your file. If you do not provide a filename for your file, Notify will: * generate a random filename * try to add the correct file extension If Notify cannot add the correct file extension, recipients may not be able to open your file. ```csharp byte[] documentContents = File.ReadAllBytes(""); Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"}, { "link_to_file", NotificationClient.PrepareUpload( documentContents: documentContents, filename: "2023-12-25-daily-report.csv") } }; ``` #### **Ask recipients to confirm their email address before they can download the file** When a recipient clicks the link in the email you’ve sent them, they have to enter their email address. Only someone who knows the recipient’s email address can download the file. This security feature is turned on by default. #### **Turn off email address check (not recommended)** If you do not want to use this feature, you can turn it off on a file-by-file basis. To do this you will need version 6.1.0 of the .NET client library, or a more recent version. You should not turn this feature off if you send files that contain: * personally identifiable information * commercially sensitive information * information classified as ‘OFFICIAL’ or ‘OFFICIAL-SENSITIVE’ under the [Government Security Classifications](https://www.gov.uk/government/publications/government-security-classifications) policy To let the recipient download the file without confirming their email address, set the `confirmEmailBeforeDownload` flag to `false`. ```csharp byte[] documentContents = File.ReadAllBytes(""); Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"}, { "link_to_file", NotificationClient.PrepareUpload( documentContents: documentContents, confirmEmailBeforeDownload: false) } }; ``` #### **Choose the length of time that a file is available to download** Set the number of weeks you want the file to be available using the `retentionPeriod` parameter. To use this feature will need version 6.1.0 of the .NET client library, or a more recent version. You can choose any value between 1 week and 78 weeks. When deciding this, you should consider: * the need to protect the recipient’s personal information * whether the recipient will need to download the file again later If you do not choose a value, the file will be available for the default period of 26 weeks (6 months). Files sent before 12 April 2023 had a longer default period of 78 weeks (18 months). ```csharp byte[] documentContents = File.ReadAllBytes(""); Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"}, { "link_to_file", NotificationClient.PrepareUpload( documentContents: documentContents, confirmEmailBeforeDownload: true, retentionPeriod: "52 weeks") } }; ``` **Response** ```csharp public String id; public String reference; public String oneClickUnsubscribeURL; public String uri; public Template template; public EmailResponseContent content; public class Template{ public String id; public String uri; public Int32 version; } public class EmailResponseContent{ public String fromEmail; public String body; public String subject; } ``` **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **BadRequestError (status code 400)** | | | `Unsupported file type '(FILE TYPE)'. Supported types are: '(ALLOWED TYPES)'` | Wrong file type. You can only upload .csv, .doc, .docx, .jpeg, .jpg, .odt, .pdf, .png, .rtf, .txt or .xlsx files | | `filename cannot be longer than 100 characters` | Choose a shorter filename | | `filename must end with a file extension. For example, filename.csv` | Include the file extension in your filename | | `Unsupported value for retention_period '(PERIOD)'. Supported periods are from 1 to 78 weeks.` | Choose a period between 1 and 78 weeks | | `Unsupported value for confirm_email_before_download: '(VALUE)'. Use a boolean true or false value.` | Use either True or False | | `File did not pass the virus scan` | The file contains a virus | | `Send files by email has not been set up - add contact details for your service at https://admin.notifynl.nl/services/(SERVICE ID)/service-settings/send-files-by-email` | See how to [add contact details to the file download page](https://docs.notifications.service.gov.uk/java.html#add-contact-details-to-the-file-download-page) | | `Can only send a file by email` | Make sure you are using an email template | | **Client error (no status code)** | | | `ValueError('File is larger than 2MB')` | The file is too big. Files must be smaller than 2MB. | ### Send a letter When you add a new service it will start in [trial mode](/using-notifynl/using-notifynl/trial-mode.md). You can only send letters when your service is live. To send Notify a request to go live: 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Settings** page. 3. In the **Your service is in trial mode** section, select **request to go live**. **Method** ```csharp string templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a" Dictionary personalisation = new Dictionary { { "address_line_1", "The Occupier" }, // required { "address_line_2", "123 High Street" }, // required { "address_line_3", "SW14 6BF" }, // required ... // any other optional address lines, or personalisation fields found in your template }; string reference = "my reference" LetterNotificationResponse response = client.SendLetter(templateId, personalisation, reference); ``` **Arguments** **templateId (required)** To find the template ID: 1. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in). 2. Go to the **Templates** page and select the relevant template. 3. Select **Copy template ID to clipboard**. For example: ```csharp string templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a"; ``` **personalisation (required)** The personalisation argument always contains the following parameters for the letter recipient’s address: * `address_line_1` * `address_line_2` * `address_line_3` * `address_line_4` * `address_line_5` * `address_line_6` * `address_line_7` The address must have at least 3 lines. The last line needs to be a real UK postcode or the name of a country outside the UK. Notify checks for international addresses and will automatically charge you the correct postage. The `postcode` personalisation argument has been replaced. If your template still uses `postcode`, Notify will treat it as the last line of the address. Any other placeholder fields included in the letter template also count as required parameters. You need to provide their values in a `Dictionary`. For example: ```csharp Dictionary personalisation = new Dictionary { {"address_line_1", "The Occupier"}, {"address_line_2", "123 High Street"}, {"address_line_3", "Richmond upon Thames"}, {"address_line_4", "Middlesex"}, {"address_line_5", "SW14 6BF"}, {"first_name", "Amala"}, {"application_id", "4134325"}, // pass in a list and it will appear as bullet points in the letter: {"required_documents", new List {"passport", "utility bill", "other id"}} }; ``` **reference (optional)** A unique identifier you can create if you need to. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address. For example: ```csharp string reference: "my reference"; ``` You can leave out this argument if you do not have a reference. **Response** If the request to the client is successful, the client returns a `LetterNotificationResponse`: ```csharp public String id; public String reference; public String uri; public Template template; public string postage; public LetterResponseContent content; public class Template { public String id; public String uri; public Int32 version; } public class LetterResponseContent{ public string body; public string subject; } ``` **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ---------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **ValidationError (status code 400)** | | | `personalisation address_line_1 is a required property` | Ensure that your template has a field for the first line of the address, check [personalisation](/using-notifynl/using-notifynl/personalisation.md) for more information. | | `Must be a real NL postcode` | Ensure that the value for the last line of the address is a real NL postcode. | | `Must be a real address` | Provide a real recipient address. We do not accept letters for “no fixed abode” addresses, as those cannot be delivered. | | `Last line of address must be a real NL postcode or another country` | Ensure that the value for the last line of the address is a real NL postcode or the name of a country outside the NL. | | `The last line of a BFPO address must not be a country.` | The last line of a BFPO address must not be a country. | | `Address must be at least 3 lines` | Provide at least 3 lines of address. | | `Address must be no more than 7 lines` | Provide no more than 7 lines of address. | | `Address lines must not start with any of the following characters: @ ( ) = [ ] ” \ / , < >` | Change the start of an address line, so it doesn’t start with one of these characters. This is a requirement from our printing provider. | | `postage invalid. It must be either first, second or economy.` | Specify valid postage option. | | **BadRequestError (status code 400)** | | | `Cannot send letters when service is in trial mode - see https://admin.notifynl.nl/trial-mode` | Your service cannot send this letter in [trial mode](/using-notifynl/using-notifynl/trial-mode.md). | | `Service is not allowed to send letters` | Turn on sending letters in your service Settings on NotifyNL webpage | | `letter_contact_id does not exist in database for service id ` | Go to your service Settings and copy a valid `letter_contact_id`. Check that the API key you are using and the `letter_contact_id` belong to the same service. | | **BadRequestError (status code 403)** | | | `Cannot send letters with a team api key` | Use the correct type of [API key](/misc/api-keys.md). | ### Send a precompiled letter **Method** ```csharp LetterNotificationsResponse response = client.SendPrecompiledLetter( clientReference: "my reference", pdfContents: File.ReadAllBytes(""), postage: "first" ); ``` **Arguments** **clientReference (required)** A unique identifier you create. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address. ```csharp string reference = "my reference"; ``` **pdfContents (required for the SendPrecompiledLetter method)** The precompiled letter must be a PDF file which meets [the GOV.UK Notify letter specification](https://www.notifications.service.gov.uk/using-notify/guidance/letter-specification). The method sends the contents of the file to GOV.UK Notify. ```csharp byte[] pdfContents = File.ReadAllBytes(""); ``` **postage (optional)** You can choose first class, second class or economy mail postage for your precompiled letter. Set the value to `first` for first class, `second` for second class or `economy` for economy mail. If you do not pass in this argument, the postage will default to second class. ```csharp string postage = "first"; ``` **Response** If the request to the client is successful, the client returns a `LetterNotificationResponse` with the `id`, `reference` and `postage`: ```csharp public String id; public String reference; public String postage; public String uri; // null for this response public Template template; // null for this response public LetterResponseContent content; // null for this response ``` **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ---------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------- | | **ValidationError (status code 400)** | | | `reference is a required property` | Add a `reference` argument to the method call | | `postage invalid. It must be either first, second or economy.` | Change the value of `postage` argument in the method call to either `"first"`, `"second"` or `"economy"` | | **BadRequestError (status code 400)** | | | `Letter content is not a valid PDF` | PDF file format is required. | | `Cannot send letters when service is in trial mode - see https://admin.notifynl.nl/trial-mode` | Your service cannot send this precompiled letter in [trial mode](/using-notifynl/using-notifynl/trial-mode.md). | | **BadRequestError (status code 403)** | | | `Cannot send letters with a team api key` | Use the correct type of [API key](/misc/api-keys.md). | ## Get message data ### Get the data for one message You can only get the data for messages sent within the retention period. The default retention period is 7 days. **Method** ```csharp Notification notification = client.GetNotificationById(notificationId: "740e5834-3a29-46b4-9a6f-16142fde533a"); ``` **Arguments** **notificationId (required)** The ID of the notification. To find the notification ID, you can either: * check the response to the [original notification method call](https://docs.notifications.service.gov.uk/net.html#response) * [sign in to NotifyNL](https://admin.notifynl.nl/sign-in) and go to the **API integration** page ```csharp string notificationId = "740e5834-3a29-46b4-9a6f-16142fde533a"; ``` **Response** If the request to the client is successful, the client returns a `Notification`. ```csharp public String id; public String completedAt; public String createdAt; public String emailAddress; public String body; public String subject; public String line1; public String line2; public String line3; public String line4; public String line5; public String line6; public String line7; public String phoneNumber; public String postage; public String reference; public String sentAt; public String status; public Template template; public String type; public string createdByName; public bool isCostDataReady; public double costInPounds; public CostDetails costDetails; public class Template { public String id; public String uri; public Int32 version; } public class CostDetails { [JsonProperty("billable_sms_fragments")] public int? billableSmsFragments; [JsonProperty("international_rate_multiplier")] public double? internationalRateMultiplier; [JsonProperty("sms_rate")] public double? smsRate; [JsonProperty("billable_sheets_of_paper")] public int? billableSheetsOfPaper; public string postage; } ``` For more information, see the: * [email status descriptions](#email-status-descriptions) * [text message status descriptions](#text-message-status-descriptions) * [letter status descriptions](#letter-status-descriptions) * [precompiled letter status descriptions](#precompiled-letter-status-descriptions) **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | | **ValidationError (status code 400)** | | | `id is not a valid UUID` | Check the notification ID. | | **NoResultFound (status code 404)** | | | `No result found` | If it’s outside the retention period, you may no longer get the status of the message. The default retention period is 7 days. | ### Get the data for multiple messages This API call returns the data for multiple messages. You can get either the most recent messages, or get older messages by specifying a particular notification ID in the `olderThanId` argument. You can only get messages that are within your data retention period. The default data retention period is 7 days. It can be changed in your Service Settings. **Method** ```csharp NotificationList notifications = client.GetNotifications( templateType, status, reference, olderThanId, includeSpreadsheetUploads); ``` For example: ```csharp NotificationList notifications = client.GetNotifications( templateType: "sms" ); ``` **Arguments** You can leave out these arguments to ignore these filters. **templateType (optional)** You can filter by: * `email` * `sms` * `letter` **status (optional)** You can filter by each: * [email status](#email-status-descriptions) * [text message status](#text-message-status-descriptions) * [letter status](#letter-status-descriptions) * [precompiled letter status](#precompiled-letter-status-descriptions) You can leave out this argument to ignore this filter. **reference (optional)** A unique identifier you can create if you need to. This reference identifies a single unique notification or a batch of notifications. It must not contain any personal information such as name or postal address. For example: ```csharp string reference = "my reference"; ``` **olderThanId (optional)** Input the ID of a notification into this argument to return the next 250 received notifications older than the given ID. For example: ```csharp string olderThanId: "e194efd1-c34d-49c9-9915-e4267e01e92e"; ``` If you leave out this argument, the client returns the most recent 250 notifications. The client only returns notifications that are 7 days old or newer. If the notification specified in this argument is older than 7 days, the client returns an empty response. **includeSpreadsheetUploads (optional)** Specifies whether the response should include notifications which were sent by uploading a spreadsheet of recipients to Notify. ```csharp bool includeSpreadsheetUploads = true; ``` If you do not pass in this argument it defaults to `false`. **Response** If the request to the client is successful, the client returns a `NotificationList`. ```csharp public List notifications; public Link links; public class Link { public String current; public String next; } ``` **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- | | **ValidationError (status code 400)** | | | `status ‘elephant’ is not one of [cancelled, created, sending, sent, delivered, pending, failed, technical-failure, temporary-failure, permanent-failure, pending-virus-check, validation-failed, virus-scan-failed, returned-letter, accepted, received]` | Change the [status argument](https://docs.notifications.service.gov.uk/java.html#status-optional). | | `‘Apple’ is not one of [sms, email, letter]` | Change the [template\_type argument](https://docs.notifications.service.gov.uk/java.html#template-type-optional). | ### Email status descriptions | Status | Description | | ------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `created` | NotifyNL has placed the message in a queue, ready to be sent to the provider. It should only remain in this state for a few seconds. | | `sending` | NotifyNL has sent the message to the provider. The provider will try to deliver the message to the recipient for up to 72 hours. NotifyNL is waiting for delivery information. | | `delivered` | The message was successfully delivered. | | `permanent-failure` | The provider could not deliver the message because the email address was wrong. You should remove these email addresses from your database. | | `temporary-failure` | The provider could not deliver the message. This can happen when the recipient’s inbox is full or their anti-spam filter rejects your email. [Check your content does not look like spam](https://www.gov.uk/service-manual/design/sending-emails-and-text-messages#protect-your-users-from-spam-and-phishing) before you try to send the message again. | | `technical-failure` |

Your message was not sent because there was a problem between Notify and the provider.
You’ll have to try sending your messages again.

| ### Text message status descriptions | Status | Description | | ------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `created` | NotifyNL has placed the message in a queue, ready to be sent to the provider. It should only remain in this state for a few seconds. | | `sending` | NotifyNL has sent the message to the provider. The provider will try to deliver the message to the recipient for up to 72 hours. NotifyNL is waiting for delivery information. | | `pending` |

NotifyNL is waiting for more delivery information.
NotifyNL received a callback from the provider but the recipient’s device has not yet responded. Another callback from the provider determines the final status of the text message.

| | `sent` | The message was sent to an international number. The mobile networks in some countries do not provide any more delivery information. The NotifyNL website displays this status as 'Sent to an international number'. | | `delivered` | The message was successfully delivered. | | `permanent-failure` | The provider could not deliver the message. This can happen if the phone number was wrong or if the network operator rejects the message. If you’re sure that these phone numbers are correct, you should [contact NotifyNL support](https://admin.notifynl.nl/support). If not, you should remove them from your database. You’ll still be charged for text messages that cannot be delivered. | | `temporary-failure` | The provider could not deliver the message. This can happen when the recipient’s phone is off, has no signal, or their text message inbox is full. You can try to send the message again. You’ll still be charged for text messages to phones that are not accepting messages. | | `technical-failure` |

Your message was not sent because there was a problem between Notify and the provider.
You’ll have to try sending your messages again. You will not be charged for text messages that are affected by a technical failure.

| ### Letter status descriptions | Status | Description | | ------------------- | ----------------------------------------------------------------------------------- | | `accepted` | NotifyNL has sent the letter to the provider to be printed. | | `received` | The provider has printed and dispatched the letter. | | `cancelled` | Sending cancelled. The letter will not be printed or dispatched. | | `technical-failure` | NotifyNL had an unexpected error while sending the letter to our printing provider. | | `permanent-failure` | The provider cannot print the letter. Your letter will not be dispatched. | ### Precompiled letter status descriptions | Status | Description | | --------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `accepted` | NotifyNL has sent the letter to the provider to be printed. | | `received` | The provider has printed and dispatched the letter. | | `cancelled` | Sending cancelled. The letter will not be printed or dispatched. | | `pending-virus-check` | NotifyNL has not completed a virus scan of the precompiled letter file. | | `virus-scan-failed` | NotifyNL found a potential virus in the precompiled letter file. | | `validation-failed` | Content in the precompiled letter file is outside the printable area. See the [NotifyNL letter specification](https://admin.notifynl.nl/using-notify/guidance/letter-specification) for more information. | | `technical-failure` | NotifyNL had an unexpected error while sending the letter to our printing provider. | | `permanent-failure` | The provider cannot print the letter. Your letter will not be dispatched. | ### Get a PDF for a letter notification **Method** This returns the pdf contents of a letter notification. ```csharp byte[] pdfFile = client.GetPdfForLetter(notificationId: "740e5834-3a29-46b4-9a6f-16142fde533a"); ``` **Arguments** **notificationId (required)** The ID of the notification. To find the notification ID, you can either: * check the response to the [original notification method call](#get-the-data-for-one-message) * [sign in to NotifyNL](https://admin.notifynl.nl/sign-in) and go to the **API integration** page **Response** If the request to the client is successful, the client will return a `byte[]` object containing the raw PDF data. **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ---------------------------------------------------- | --------------------------------------------------------------------------- | | **ValidationError (status code 400)** | | | `id is not a valid UUID` | Check the notification ID. | | `Notification is not a letter` | Check that you are looking up the correct notification. | | **PDFNotReadyError (status code 400)** | | | `PDF not available yet, try again later` | Wait for the letter to finish processing. This usually takes a few seconds. | | **BadRequestError (status code 400)** | | | `File did not pass the virus scan` | You cannot retrieve the contents of a letter that contains a virus. | | `PDF not available for letters in technical-failure` | You cannot retrieve the contents of a letter in technical-failure. | | `Notification is not a letter` | Check that you are looking up the correct notification. | | **NoResultFound (status code 404)** | | | `No result found` | Check the notification ID. | ## Get a template ### Get a template by ID **Method** This returns the latest version of the template. ```csharp TemplateResponse response = client.GetTemplateById( templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a" ); ``` **Arguments** **templateId (required)** The ID of the template. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in) and go to the **Templates** page to find it. For example: ```csharp string templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a"; ``` **Response** If the request to the client is successful, the client returns a `TemplateResponse`. ```csharp public String id; public String name; public String type; public DateTime created_at; public DateTime? updated_at; public String created_by; public int version; public String body; public String subject; // null if an sms message public String letter_contact_block; // null if not a letter template or contact block not set for letter ``` **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ----------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- | | **NoResultFound (status code 404)** | | | `No Result Found` | Check your [template ID](https://docs.notifications.service.gov.uk/java.html#get-a-template-by-id-arguments-template-id-required). | ### Get a template by ID and version **Method** ```csharp TemplateResponse response = client.GetTemplateByIdAndVersion( templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a", version: 1 // integer required for version number ); ``` **Arguments** **templateId (required)** The ID of the template. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in) and go to the **Templates** page to find it. For example: ```csharp string templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a"; ``` **version (required)** The version number of the template. **Response** If the request to the client is successful, the client returns a `TemplateResponse`. ```csharp public String id; public String name; public String type; public DateTime created_at; public DateTime? updated_at; public String created_by; public int version; public String body; public String subject; // null if an sms message public String letter_contact_block; // null if not a letter template or contact block not set for letter ``` **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | ----------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- | | **NoResultFound (status code 404)** | | | `No Result Found` | Check your [template ID](https://docs.notifications.service.gov.uk/java.html#get-a-template-by-id-arguments-template-id-required). | ### Get all templates **Method** This returns the latest version of all templates. ```csharp TemplateList response = client.GetAllTemplates( templateType: "sms" // optional ); ``` **Arguments** **templateType (optional)** If left out, the method returns all templates. Otherwise you can filter by: * `email` * `sms` * `letter` **Response** If the request to the client is successful, the client returns a `TemplateList`. ```csharp List templates; ``` If no templates exist for a template type or there no templates for a service, the client returns a `TemplateList` with an empty `templates` list element: ```csharp List templates; // empty list of templates ``` ### Generate a preview template **Method** This generates a preview version of a template. ```csharp Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"} }; TemplatePreviewResponse response = client.GenerateTemplatePreview( templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a", personalisation: personalisation ); ``` The parameters in the personalisation argument must match the placeholder fields in the actual template. The API notification client ignores any extra fields in the method. **Arguments** **templateId (required)** The ID of the template. [Sign in to NotifyNL](https://admin.notifynl.nl/sign-in) and go to the **Templates** page to find it. For example: ```csharp string templateId: "f33517ff-2a88-4f6e-b855-c550268ce08a"; ``` **personalisation (required)** If a template has placeholder fields for personalised information such as name or reference number, you need to provide their values in a `Dictionary`. For example: ```csharp Dictionary personalisation = new Dictionary { {"first_name", "Amala"}, {"application_date", "1 January 2018 at 01:00PM"} }; ``` You can leave out this argument if a template does not have any placeholder fields for personalised information. **Response** If the request to the client is successful, you receive a `TemplatePreviewResponse` response. ```csharp public String id; public String type; public int version; public String body; public String subject; // null if a sms message ``` **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). | Error message | How to fix | | -------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- | | **BadRequestError (status code 400)** | | | `Missing personalisation: [PERSONALISATION FIELD]` | Check that the personalisation arguments in the method match the placeholder fields in the template. | | **NoResultFound (status code 404)** | | | `No Result Found` | Check your [template ID](https://docs.notifications.service.gov.uk/java.html#get-a-template-by-id-arguments-template-id-required). | ## Get received text messages This API call returns one page of up to 250 received text messages. You can get either the most recent messages, or get older messages by specifying a particular notification ID in the `olderThanId` argument. You can only get the data for messages that are 7 days old or newer. You can also set up [callbacks](/misc/callbacks.md) for received text messages. ### Enable received text messages To receive text messages: 1. Go to the **Text message settings** section of the **Settings** page. 2. Select **Change** on the **Receive text messages** row. ### Get a page of received text messages **Method** ```csharp ReceivedTextListResponse response = client.GetReceivedTexts(olderThanId: "e194efd1-c34d-49c9-9915-e4267e01e92e"); ``` **Arguments** **olderThanId (optional)** Input the ID of a notification into this argument to return the next 250 received notifications older than the given ID. For example: ``` olderThanId: "740e5834-3a29-46b4-9a6f-16142fde533a" ``` If you leave out the `olderThanId` argument, the client returns the most recent 250 notifications. The client only returns notifications that are 7 days old or newer. If the notification specified in this argument is older than 7 days, the client returns an empty `ReceivedTextListResponse` response. **Response** If the request to the client is successful, the client returns a `ReceivedTextListResponse` that returns all received text messages. ```csharp public List receivedTextList; public Link links; public class Link { public String current; public String next; } ``` ```csharp public String id; public String userNumber; public String createdAt; public String serviceId; public String notifyNumber; public String content; ``` If the notification specified in the `olderThanId` argument is older than 7 days, the client returns an empty `ReceivedTextListResponse` response. **Error codes** If the request is not successful, the client returns a `Notify.Exceptions.NotifyClientException` containing the relevant error code. To learn more about error structure, go to [Errors section](#errors). There are no errors specific to this endpoint, but you may encounter: * [various schema validation errors](#schema-validation-errors), for example when you forget to pass in an argument, or pass in an argument of a wrong type. * errors that are not related to generating a preview template, but instead are related to things like authentication and rate limits. You can find a list of these errors [in General errors](#general-errors) ## Errors ### Error handling If the request is not successful, the client will throw a `Notify.Exceptions.NotifyClientException`. The exceptions message attribute is a string consisting of: * a status code, for example `400` * an error type, for example `BadRequestError` * a message, for example `Mobile numbers can only include: 0 1 2 3 4 5 6 7 8 9 ( ) + -` You can use a regex match to get specific information out of the exception’s message attribute. An illustration of error handling: ```csharp try { var response = client.SendSms( mobileNumber, templateId ); } catch (NotifyClientException ex) { string pattern = """(?<=Status code )([0-9]+)"""; Regex r = new Regex(pattern, RegexOptions.IgnoreCase); Match match = r.Match(ex.Message); int statusCode = Int32.Parse(match.Value); if (statusCode >= 500) { //some retry logic goes here } else { Console.WriteLine(ex.Message); } } ``` The exception’s message attribute contains a `string`, for example: ``` Status code 403. Error: {"errors":[{"error":"AuthError","message":"Invalid token: API key not found"}],"status_code":403} , Exception: Status code 403. The following errors occured [ { "error": "AuthError", "message": "Invalid token: API key not found" } ] ``` Do not use the content of the messages in your code. These can sometimes change, which may affect your API integration. Use the status code or the error type instead, as these will not change. ### General errors You may encounter following errors when making requests to a number of NotifyNL’s API endpoints. | Error message | How to fix | | -------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- | | **BadRequestError (status code 400)** | | | `Cannot send to this recipient using a team-only API key.` | Use a live API key, or add recipient to `Guest list` (located in API Integration section) | | `Cannot send to this recipient when service is in trial mode – see https://admin.notifynl.nl/trial-mode` | You need to request for your service to go live before you can send messages to people outside your team. | | **BadRequestError (status code 403)** | | | `Error: Your system clock must be accurate to within 30 seconds` | Check your system clock | | `Invalid token: API key not found` | Use the correct API key. Refer to [API keys](/misc/api-keys.md) for more information | | **RateLimitError (status code 429)** | | | `Exceeded rate limit for key type of 3000/ requests per 60 seconds` | Refer to [API rate limits](https://docs.notifications.service.gov.uk/java.html#rate-limits) for more information | | **TooManyRequestsError (status code 429)** | | | `Exceeded send limits (: ) for today` | Refer to [service limits](/misc/limits.md#daily-limits) for the limit size | | **Exception (status code 500)** | | | `Internal server error` | Notify was unable to process the request, resend your notification. | ### Schema validation errors The following are a few examples of schema validation errors you may encounter when making a request to a Notify endpoint. | Error message | How to fix | | ---------------------------------------------------------------------------------------- | ------------------------------------------------------------------------- | | **ValidationError (status code 400)** | | | `template_id is a required property` | Provide the missing argument. | | `sms_sender_id is not a valid UUID` | Check the argument to make sure that it is valid for the given data type. | | `personalisation is not of type object` | Provide argument in the correct type. | | `reference is too long` | Provide a shorter string. | | `type is not one of [sms, email, letter]` | Make sure that the argument matches one of the items in the list. | | `Additional properties are not allowed ( was unexpected)` | Only provide allowed arguments for the endpoint. | ### Endpoint-specific errors In addition to the above, you may also encounter endpoint-specific errors, which are listed under each relevant API endpoint section. Find references for endpoint-specific errors in: * [send a message](#send-a-message) * [get message data](#get-message-data) * [get a template](#get-a-template) * [get received text messages](#get-received-text-messages) *** {% columns %} {% column %} {% content-ref url="/pages/zmjcVSa5Xe7QsTwT7Crx" %} [REST API documentation](/tech-documentation/rest-api-documentation.md) {% endcontent-ref %} {% content-ref url="/pages/gzLqwtaF4w08ZFqaZXmP" %} [Testing](/misc/testing.md) {% endcontent-ref %} {% content-ref url="/pages/eJ5Siv2htOqgwa3qWwtS" %} [API keys](/misc/api-keys.md) {% endcontent-ref %} {% endcolumn %} {% column %} {% content-ref url="/pages/1CI9M7KfQyF0y4yCEZT9" %} [Limits](/misc/limits.md) {% endcontent-ref %} {% content-ref url="/pages/Slz631l7ubYSloQijgE1" %} [Callbacks](/misc/callbacks.md) {% endcontent-ref %} {% content-ref url="/pages/tJqjLxiKW6ITgckwkFno" %} [API architecture](/misc/api-architecture.md) {% endcontent-ref %} {% endcolumn %} {% endcolumns %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.notifynl.nl/tech-documentation/dotnet.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.