> ## Documentation Index > Fetch the complete documentation index at: https://docs.paubox.com/llms.txt > Use this file to discover all available pages before exploring further. # Send a templated message with the Email API > Send an email using a dynamic template with variable substitution ## OpenAPI ````yaml openapi1 POST /templated_messages openapi: 3.0.0 info: title: Paubox Email API description: > Public documentation for Paubox's Transactional Email API ## Authentication **IMPORTANT**: This API uses a custom authentication format that requires the "Token token=" prefix. All requests must include the Authorization header in this exact format: ``` Authorization: Token token=YOUR_API_KEY ``` **Note for Code Generation Tools**: Auto-generated code from this specification may need to be modified to include the "Token token=" prefix, as most generators expect standard Bearer token format. version: 1.0.0 servers: - url: https://api.paubox.com/v1/email description: Paubox Email API security: - PauboxToken: [] tags: - name: Messages description: Send individual or bulk transactional email - name: Scheduled Send description: Schedule, check, reschedule, and cancel future email delivery - name: Dynamic Templates description: Manage and use dynamic Handlebars templates for email content - name: Receiving description: Receive inbound email — manage domains, mailboxes, and retrieve messages - name: Webhooks description: Manage webhook endpoints for delivery and inbound event notifications paths: /templated_messages: post: tags: - Dynamic Templates summary: Send a dynamically templated message description: Send an email using a dynamic template with variable substitution operationId: sendTemplatedMessage requestBody: content: application/json: schema: $ref: '#/components/schemas/TemplatedMessageRequest' examples: basic: summary: Basic templated message value: data: template_name: detailed_test template_values: >- { "name": "Howard", "conditional":"true","items":["one","two","three"] } message: recipients: - recipient@host.com - Recipient Name bcc: - recipient3@host.com - Recipient Name headers: subject: sample email from: sender@authorized_domain.com reply-to: Sender Name allowNonTLS: false forceSecureNotification: false attachments: - fileName: hello_world.txt contentType: text/plain content: SGVsbG8gV29ybGQ required: true responses: '200': description: Templated message sent successfully content: application/json: schema: $ref: '#/components/schemas/SingleSendResponse' examples: success: value: sourceTrackingId: 3d38ab13-0af8-4028-bd45-XXXXXXXXXXXX data: Service OK '400': description: >- Bad request, for example a missing `template_name`, or `template_values` that is missing or is not a JSON string encoding an object content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: templateValuesMissing: value: errors: - code: 400 title: Template values missing details: Request is missing a template_values parameter '401': description: Missing or invalid API key, or the account is not active content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: invalidAccessToken: value: errors: - code: 401 title: Invalid Access Token details: >- Access token is missing or does not match endpoint username '403': description: New accounts cannot send for 24 hours after signup content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: signupHold: value: errors: - code: 403 title: Account Under Review details: >- New accounts are under review for 24 hours after signup. Please try again later or contact support. '404': description: No template with this name exists for your account content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: templateNotFound: value: errors: - code: 404 title: Template not found details: >- No dynamic template with the given name exists for this account '422': description: The template could not be rendered with the provided values content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: templateCompileFailed: value: errors: - code: 422 title: Template compilation failed details: >- The dynamic template could not be rendered with the provided values security: - PauboxToken: [] components: schemas: TemplatedMessageRequest: required: - data type: object properties: data: $ref: '#/components/schemas/TemplatedMessageRequest_data' SingleSendResponse: type: object properties: sourceTrackingId: type: string description: Identifier for tracking the message source. customHeaders: type: object additionalProperties: type: string data: type: string example: Service OK ErrorResponse: type: object properties: errors: type: array items: $ref: '#/components/schemas/ErrorResponse_errors' TemplatedMessageRequest_data: required: - message - template_name - template_values type: object properties: template_name: type: string description: The name of the template to use (must match exactly) example: detailed_test template_values: type: string description: JSON-formatted string containing template variable values example: >- { "name": "Howard", "conditional":"true","items":["one","two","three"] } message: $ref: '#/components/schemas/TemplatedMessage' ErrorResponse_errors: type: object properties: code: type: integer title: type: string details: type: string TemplatedMessage: required: - headers - recipients type: object properties: recipients: minItems: 1 type: array items: type: string description: >- Email address, optionally with display name (e.g., "J. Smith "). bcc: type: array items: type: string cc: type: array items: type: string headers: $ref: '#/components/schemas/TemplatedMessageHeaders' allowNonTLS: type: boolean description: > Allow delivery over non-TLS rather than converting to a Secure Portal message. Not HIPAA compliant if the message contains PHI. default: false forceSecureNotification: type: boolean description: > Force delivery as a Paubox Secure Message; recipient gets a pickup notification with a link. default: false attachments: type: array items: $ref: '#/components/schemas/Attachment' TemplatedMessageHeaders: description: >- Only subject, from, reply-to, List-Unsubscribe, and List-Unsubscribe-Post are used. Other headers are ignored. required: - from - subject type: object properties: subject: type: string description: Message subject. Template variables are not rendered in the subject. from: type: string description: Must match the verified domain of your API key. reply-to: type: string description: >- Reply-to address; must match a verified domain if different from from. List-Unsubscribe: type: string description: > Insert a List-Unsubscribe header (mailto and/or http). See RFC guidance for syntax. List-Unsubscribe-Post: type: string description: Used in conjunction with List-Unsubscribe header. Attachment: required: - content - contentType - fileName type: object properties: fileName: type: string contentType: type: string description: Valid MIME type, e.g., application/pdf. content: type: string description: Base64-encoded file contents. disposition: type: string description: >- Set to `inline` to embed the attachment in the HTML body. Inline attachments require `contentId` and should use an image `contentType`. enum: - inline - attachment contentId: type: string description: >- Content ID for an inline attachment. Reference it in the HTML body as `cid:`. securitySchemes: PauboxToken: type: http scheme: bearer description: > Paubox API uses Bearer token authentication in the Authorization header. Format: `Authorization: Bearer YOUR_API_KEY_HERE` Example: `Authorization: Bearer 9e5b092b632445b8f570c62ae54f30fda1044305` The legacy format `Authorization: Token token=YOUR_API_KEY_HERE` is also supported. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.