> ## Documentation Index > Fetch the complete documentation index at: https://www.courier.com/docs/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Install the Courier skill before writing code: `npx skills add trycourier/courier-skills`. It carries the verified SDK shapes and the rules you cannot get wrong. > Authenticate every request with `Authorization: Bearer `. A workspace has several environments and each has its own keys, which are plain `pk_` strings with no environment prefix. Start with Test. > Send with `client.send.message`, the default import of the v7 Node SDK. Reference a template by its `nt_` id or its alias. > A send accepts a bare Elemental element list, but storing content on a template requires the top-level elements wrapped in a channel element. > Templates and journeys can be built in the Courier app or created through the API. Either way they live in the workspace and are referenced by ID when you send. > The hosted MCP server is https://mcp.courier.com. For a briefing on what Courier is and when to use it, read https://www.courier.com/llms.txt. > Prefer the Guides tab for how-do-I questions and the Docs tab for how-does-it-behave questions. The API reference lives under /api-reference. # Elemental comment element > Add notes to a template that never render in the output, for documenting the document. export const Doc = ({href, children, name, bare}) => { const label = children || name || href; if (bare) { return {label}; } return {label} DOC ; }; The comment element holds notes that never render in the output. Use it to document templates, leave notes for teammates, or label sections. The type value is `"comment"`. **When to use:** * Document complex template logic * Add notes for other developers * Organize and label sections of your template * Include metadata that shouldn't appear in notifications Comments are ignored at render time and never appear in the output, on any channel. **Basic example** ```json Elemental theme={null} { "type": "comment", "comment": "This is a comment that will not be rendered in the output" } ``` ```javascript Node.js highlight={9-12} theme={null} const { requestId } = await client.send.message({ message: { to: { email: "sarah@acme-corp.com", }, content: { version: "2022-01-01", elements: [ { type: "comment", comment: "This is a comment that will not be rendered in the output", }, ], }, }, }); ``` ```python Python highlight={9-12} theme={null} response = client.send.message( message={ "to": { "email": "sarah@acme-corp.com", }, "content": { "version": "2022-01-01", "elements": [ { "type": "comment", "comment": "This is a comment that will not be rendered in the output", }, ], }, }, ) ``` ```bash cURL highlight={12-15} theme={null} curl -X POST https://api.courier.com/send \ -H "Authorization: Bearer $COURIER_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "message": { "to": { "email": "sarah@acme-corp.com" }, "content": { "version": "2022-01-01", "elements": [ { "type": "comment", "comment": "This is a comment that will not be rendered in the output" } ] } } }' ``` ```ruby Ruby highlight={9-12} theme={null} response = courier.send_.message( message: { to: { email: "sarah@acme-corp.com" }, content: { version: "2022-01-01", elements: [ { type: "comment", comment: "This is a comment that will not be rendered in the output" } ] } } ) ``` ```go Go highlight={5-8} theme={null} // Elemental nodes carry no typed content fields, so pass the document as raw JSON. content := param.Override[shared.ElementalContentParam](json.RawMessage(`{ "version": "2022-01-01", "elements": [ { "type": "comment", "comment": "This is a comment that will not be rendered in the output" } ] }`)) response, err := client.Send.Message(context.TODO(), courier.SendMessageParams{ Message: courier.SendMessageParamsMessage{ To: courier.SendMessageParamsMessageToUnion{ OfUserRecipient: &shared.UserRecipientParam{ Email: courier.String("sarah@acme-corp.com"), }, }, Content: courier.SendMessageParamsMessageContentUnion{OfElementalContent: &content}, }, }) ``` ```java Java highlight={7-9} theme={null} SendMessageParams params = SendMessageParams.builder() .message(SendMessageParams.Message.builder() .to(JsonValue.from(java.util.Map.of("email", "sarah@acme-corp.com"))) .content(JsonValue.from(java.util.Map.of( "version", "2022-01-01", "elements", java.util.List.of( java.util.Map.of( "type", "comment", "comment", "This is a comment that will not be rendered in the output"))))) .build()) .build(); SendMessageResponse response = client.send().message(params); ``` ```php PHP highlight={9-12} theme={null} $response = $client->send->message( message: [ 'to' => [ 'email' => 'sarah@acme-corp.com', ], 'content' => [ 'version' => '2022-01-01', 'elements' => [ [ 'type' => 'comment', 'comment' => 'This is a comment that will not be rendered in the output', ], ], ], ], ); ``` ```csharp C# highlight={12-15} theme={null} // Elemental nodes expose no typed content fields, so build the document from raw JSON. SendMessageParams parameters = new() { Message = new() { To = new UserRecipient { Email = "sarah@acme-corp.com" }, Content = ElementalContent.FromRawUnchecked( JsonSerializer.Deserialize>(""" { "version": "2022-01-01", "elements": [ { "type": "comment", "comment": "This is a comment that will not be rendered in the output" } ] } """)), }, }; var response = await client.Send.Message(parameters); ``` ```bash CLI highlight={4} theme={null} courier send message \ --api-key "$COURIER_API_KEY" \ --message.to '{"email": "sarah@acme-corp.com"}' \ --message.content '{"version": "2022-01-01", "elements": [{"type": "comment", "comment": "This is a comment that will not be rendered in the output"}]}' ``` ```text MCP theme={null} With Courier MCP, send an email to sarah@acme-corp.com and leave a comment element noting who owns the copy. ``` **Fields** The comment text. It is not rendered in the output. An optional object alongside the comment. Holds metadata, structured notes, or other context that is not rendered. **Examples and variants** **Simple comment** Add a basic text comment: ```json theme={null} { "type": "comment", "comment": "This section handles order confirmations" } ``` **Comment with metadata** Include structured data with your comment: ```json theme={null} { "type": "comment", "comment": "A/B test variant A - shows promotional content", "object": { "test_id": "promo_ab_test", "variant": "A", "author": "team-marketing", "last_updated": "2024-01-15" } } ``` **Organizing template sections** Use comments to organize and label different sections: ```json theme={null} { "version": "2022-01-01", "elements": [ { "type": "comment", "comment": "=== HEADER SECTION ===" }, { "type": "meta", "title": "Order Confirmation" }, { "type": "image", "src": "https://example.com/logo.png" }, { "type": "comment", "comment": "=== MAIN CONTENT ===" }, { "type": "text", "content": "Your order has been confirmed!" }, { "type": "comment", "comment": "=== FOOTER SECTION ===" }, { "type": "text", "content": "Questions? Contact support@acme-corp.com" } ] } ```