# Duplicate Template

Duplicate a template. This page documents the OpenSend-owned API contract for `POST /templates/{id}/duplicate`.

`POST /templates/{id}/duplicate`

## Authentication

Use an OpenSend API key in the Authorization header. Dashboard session cookies are not API credentials for public API clients.

```http
Authorization: Bearer os_YOUR_API_KEY
```

## When to use it

Template routes manage stored email templates. Published templates can be used by sends and broadcasts; draft and preview behavior depends on the renderer metadata stored with the template. Create a copy that can be edited independently from the source template.

## Parameters

Path parameters identify the tenant-scoped resource. JSON body fields are validated by the route before any database write.

## Request example

```json
{
  "name": "Welcome",
  "subject": "Welcome to OpenSend",
  "html": "<p>Hello {{name}}</p>"
}
```

## Response

Successful responses return JSON scoped to the authenticated tenant. A representative response shape is:

```json
{
  "id": "template_123",
  "name": "Welcome",
  "status": "draft"
}
```

## Errors

OpenSend returns structured errors for missing authentication, validation failures, not-found resources, quota/rate-limit conditions, and unexpected server failures. Treat `404` as either missing or not owned by the caller.

## Self-hosting notes

Self-hosted deployments can use the same path on their own `OPENSEND_BASE_URL`. Run migrations before deploying code that expects new fields, and keep API keys in a secrets manager instead of committing them to source control.