Templates

Templates let you define reusable email layouts with placeholder variables. Store your HTML once, then send personalized emails by passing different data each time.

Note

The RelayPost dashboard uses a separate internal GraphQL API. This documentation covers the public REST API for external integrations.

Create a template

POST /api/v1/templates

cURL

curl -X POST https://relaypost.dev/api/v1/templates \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "name": "Order Confirmation",
    "subject": "Your order #{{orderNumber}}",
    "html": "<h1>Thanks, {{customerName}}!</h1><p>Your order #{{orderNumber}} totaling {{total}} has been confirmed.</p>",
    "text": "Thanks, {{customerName}}! Your order #{{orderNumber}} totaling {{total}} has been confirmed."
  }'

JavaScript

const response = await fetch("https://relaypost.dev/api/v1/templates", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "Authorization": "Bearer YOUR_API_KEY",
  },
  body: JSON.stringify({
    name: "Order Confirmation",
    subject: "Your order #{{orderNumber}}",
    html: "<h1>Thanks, {{customerName}}!</h1><p>Your order #{{orderNumber}} totaling {{total}} has been confirmed.</p>",
    text: "Thanks, {{customerName}}! Your order #{{orderNumber}} totaling {{total}} has been confirmed.",
  }),
});

const result = await response.json();
console.log(result.data.id);

Python

import requests

response = requests.post(
    "https://relaypost.dev/api/v1/templates",
    headers={
        "Content-Type": "application/json",
        "Authorization": "Bearer YOUR_API_KEY",
    },
    json={
        "name": "Order Confirmation",
        "subject": "Your order #{{orderNumber}}",
        "html": "<h1>Thanks, {{customerName}}!</h1><p>Your order #{{orderNumber}} totaling {{total}} has been confirmed.</p>",
        "text": "Thanks, {{customerName}}! Your order #{{orderNumber}} totaling {{total}} has been confirmed.",
    },
)

result = response.json()
print(result["data"]["id"])

Request body

Field	Type	Required	Description
name	string	Yes	Template name
subject	string	Yes	Subject line (supports {{variables}})
html	string	No	HTML body (supports {{variables}})
text	string	No	Plain text body (supports {{variables}})

Response (201)

{
  "data": {
    "id": "tmpl_abc123",
    "name": "Order Confirmation",
    "subject": "Your order #{{orderNumber}}",
    "html_body": "<h1>Thanks, {{customerName}}!</h1><p>Your order #{{orderNumber}} totaling {{total}} has been confirmed.</p>",
    "text_body": "Thanks, {{customerName}}! Your order #{{orderNumber}} totaling {{total}} has been confirmed.",
    "variables": null,
    "is_active": true,
    "created_at": "2025-01-15T10:30:00.000Z",
    "updated_at": "2025-01-15T10:30:00.000Z"
  }
}

Send with a template

Reference the template by ID and pass the variable values using POST /api/v1/emails/send:

cURL

curl -X POST https://relaypost.dev/api/v1/emails/send \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "from": { "email": "[email protected]" },
    "to": [{ "email": "[email protected]" }],
    "subject": "Your order #1234",
    "template_id": "tmpl_abc123",
    "template_data": {
      "customerName": "Jane",
      "orderNumber": "1234",
      "total": "$49.99"
    }
  }'

JavaScript

const response = await fetch("https://relaypost.dev/api/v1/emails/send", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "Authorization": "Bearer YOUR_API_KEY",
  },
  body: JSON.stringify({
    from: { email: "[email protected]" },
    to: [{ email: "[email protected]" }],
    subject: "Your order #1234",
    template_id: "tmpl_abc123",
    template_data: {
      customerName: "Jane",
      orderNumber: "1234",
      total: "$49.99",
    },
  }),
});

const result = await response.json();
console.log(result.data.message_id);

Python

import requests

response = requests.post(
    "https://relaypost.dev/api/v1/emails/send",
    headers={
        "Content-Type": "application/json",
        "Authorization": "Bearer YOUR_API_KEY",
    },
    json={
        "from": {"email": "[email protected]"},
        "to": [{"email": "[email protected]"}],
        "subject": "Your order #1234",
        "template_id": "tmpl_abc123",
        "template_data": {
            "customerName": "Jane",
            "orderNumber": "1234",
            "total": "$49.99",
        },
    },
)

result = response.json()
print(result["data"]["message_id"])

Tip

template_data is a JSON object with key-value pairs. The keys should match the {{ variable }} placeholders in your template.

List templates

GET /api/v1/templates

cURL

curl "https://relaypost.dev/api/v1/templates?page=1&limit=20" \
  -H "Authorization: Bearer YOUR_API_KEY"

JavaScript

const response = await fetch(
  "https://relaypost.dev/api/v1/templates?page=1&limit=20",
  {
    headers: { "Authorization": "Bearer YOUR_API_KEY" },
  }
);

const result = await response.json();
console.log(result.data);

Python

import requests

response = requests.get(
    "https://relaypost.dev/api/v1/templates",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    params={"page": 1, "limit": 20},
)

result = response.json()
print(result["data"])

Query parameters

Parameter	Type	Default	Description
page	integer	1	Page number
limit	integer	20	Results per page (max 100)

Response (200)

{
  "data": [
    {
      "id": "tmpl_abc123",
      "name": "Order Confirmation",
      "subject": "Your order #{{orderNumber}}",
      "html_body": "...",
      "text_body": "...",
      "variables": null,
      "is_active": true,
      "created_at": "2025-01-15T10:30:00.000Z",
      "updated_at": "2025-01-15T10:30:00.000Z"
    }
  ],
  "pagination": {
    "page": 1,
    "limit": 20,
    "total_count": 5,
    "total_pages": 1
  }
}

Update a template

PUT /api/v1/templates/:id

Only include the fields you want to change — everything else stays the same.

cURL

curl -X PUT https://relaypost.dev/api/v1/templates/tmpl_abc123 \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "html": "<h1>Updated layout</h1><p>Hello {{customerName}}</p>"
  }'

JavaScript

const response = await fetch(
  "https://relaypost.dev/api/v1/templates/tmpl_abc123",
  {
    method: "PUT",
    headers: {
      "Content-Type": "application/json",
      "Authorization": "Bearer YOUR_API_KEY",
    },
    body: JSON.stringify({
      html: "<h1>Updated layout</h1><p>Hello {{customerName}}</p>",
    }),
  }
);

const result = await response.json();
console.log(result.data.updated_at);

Python

import requests

response = requests.put(
    "https://relaypost.dev/api/v1/templates/tmpl_abc123",
    headers={
        "Content-Type": "application/json",
        "Authorization": "Bearer YOUR_API_KEY",
    },
    json={
        "html": "<h1>Updated layout</h1><p>Hello {{customerName}}</p>",
    },
)

result = response.json()
print(result["data"]["updated_at"])

Request body

Field	Type	Required	Description
name	string	No	Updated template name
subject	string	No	Updated subject line
html	string	No	Updated HTML body
text	string	No	Updated plain text body

At least one field must be provided.

Response (200)

{
  "data": {
    "id": "tmpl_abc123",
    "name": "Order Confirmation",
    "subject": "Your order #{{orderNumber}}",
    "html_body": "<h1>Updated layout</h1><p>Hello {{customerName}}</p>",
    "text_body": "Thanks, {{customerName}}! Your order #{{orderNumber}} totaling {{total}} has been confirmed.",
    "variables": null,
    "is_active": true,
    "created_at": "2025-01-15T10:30:00.000Z",
    "updated_at": "2025-01-15T11:00:00.000Z"
  }
}

Errors

Status	Code	Description
400	VALIDATION_ERROR	No update fields provided or invalid values
404	NOT_FOUND	Template not found or belongs to another organization

Delete a template

DELETE /api/v1/templates/:id

cURL

curl -X DELETE https://relaypost.dev/api/v1/templates/tmpl_abc123 \
  -H "Authorization: Bearer YOUR_API_KEY"

JavaScript

const response = await fetch(
  "https://relaypost.dev/api/v1/templates/tmpl_abc123",
  {
    method: "DELETE",
    headers: { "Authorization": "Bearer YOUR_API_KEY" },
  }
);

const result = await response.json();
console.log(result.data);

Python

import requests

response = requests.delete(
    "https://relaypost.dev/api/v1/templates/tmpl_abc123",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
)

result = response.json()
print(result["data"])

Response (200)

{
  "data": {
    "id": "tmpl_abc123",
    "deleted": true
  }
}

Errors

Status	Code	Description
404	NOT_FOUND	Template not found or belongs to another organization