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# Send a rendered email from a standalone runtime

POST https://api.runtype.com/v1/runtime/email/send
Content-Type: application/json

Hosted fulfillment of the runtime EmailSender seam. Accepts a fully RENDERED message (no template strings) and dispatches it through the platform email path with the managed-send-from-domain gate evaluated against the authenticated account. Requires a Runtype API key with the RUNTIME:EXECUTE scope (FLOWS:EXECUTE also accepted). Requires an Enterprise plan: ineligible accounts receive 403 (code `BYOC_PLAN_REQUIRED`).

Reference: https://docs.runtype.com/api-reference/runtype-api/self-hosting/send-a-rendered-email-from-a-standalone-runtime

## Authentication

- `Authorization` header (bearer token, required) — API key or Clerk session token

## Servers

- `https://api.runtype.com` (Production, default)
- `https://api.runtype-staging.com` (Staging)

## Request

### Body (application/json)

This endpoint expects an object.

- `subject` (string, required)
- `to` (list of string, required)
- `attachments` (list of V1RuntimeEmailSendPostRequestBodyContentApplicationJsonSchemaAttachmentsItems, optional)
- `bcc` (list of string, optional)
- `cc` (list of string, optional)
- `from` (string, optional)
- `html` (string, optional)
- `managedLocalPart` (string, optional) — Managed sender local part. Must be an identity the account owns: its user id, `virtual`, or an owned `flow_`/`agent_` id; anything else is refused. Defaults to the caller's user id.
- `rawFrom` (string, optional)
- `replyTo` (string, optional)
- `text` (string, optional)

## Response

### 200

Email dispatched

- `from` (string, required)
- `id` (string, required)
- `to` (list of string, required)

## Errors

### 400 Bad Request Error

Invalid request, or a custom sender without a custom email provider key

- `error` (string, required)
- `code` (enum, optional)
  - Allowed values: `managed_domain_custom_sender`, `platform_credit_exhausted`, `platform_email_unconfigured`, `custom_sender_key_missing`, `provider_error`

### 401 Unauthorized Error

Unauthorized

- `error` (string, required)
- `code` (enum, optional)
  - Allowed values: `managed_domain_custom_sender`, `platform_credit_exhausted`, `platform_email_unconfigured`, `custom_sender_key_missing`, `provider_error`

### 402 Payment Required Error

Platform key spend credit exhausted, or monthly spend limit exceeded

- `error` (string, required)
- `code` (string, optional)
- `message` (string, optional)

### 403 Forbidden Error

Not an API key, missing RUNTIME:EXECUTE scope, custom sender on the managed domain, or the account is not on an Enterprise plan (code `BYOC_PLAN_REQUIRED`)

- `error` (string, required)
- `code` (string, optional)
- `message` (string, optional)

### 429 Too Many Requests Error

Daily execution limit or rate limit exceeded

- `error` (string, required)
- `code` (string, optional) — Stable error code. `insufficient_scope` marks an API key that lacks a scope this request needs.
- `details` (list of ErrorDetailsItems, optional)
- `requiredScopes` (list of string, optional) — On `insufficient_scope`: every API key scope this request needs.

### 500 Internal Server Error

Internal server error

- `error` (string, required)
- `code` (enum, optional)
  - Allowed values: `managed_domain_custom_sender`, `platform_credit_exhausted`, `platform_email_unconfigured`, `custom_sender_key_missing`, `provider_error`

### 502 Bad Gateway Error

Upstream email provider error

- `error` (string, required)
- `code` (enum, optional)
  - Allowed values: `managed_domain_custom_sender`, `platform_credit_exhausted`, `platform_email_unconfigured`, `custom_sender_key_missing`, `provider_error`

### 503 Service Unavailable Error

Platform email sending is not configured

- `error` (string, required)
- `code` (enum, optional)
  - Allowed values: `managed_domain_custom_sender`, `platform_credit_exhausted`, `platform_email_unconfigured`, `custom_sender_key_missing`, `provider_error`

## Types

### V1RuntimeEmailSendPostRequestBodyContentApplicationJsonSchemaAttachmentsItems

- `content` (string, required)
- `filename` (string, required)
- `contentType` (string, optional)

### ErrorDetailsItems

- `message` (string, required)
- `code` (string, optional) — Stable Runtype validation code (e.g. MISSING_REQUIRED_FIELD, INVALID_ENUM).
- `path` (string, optional) — Dotted JSON path to the offending field.
- `suggestion` (string, optional) — Actionable hint (allowed values, accepted range, …).

## Examples

**Request**

```json
{
  "subject": "string",
  "to": [
    "string"
  ]
}
```

**Response**

```json
{
  "from": "string",
  "id": "string",
  "to": [
    "string"
  ]
}
```

**SDK Code**

```python
import requests

url = "https://api.runtype.com/v1/runtime/email/send"

payload = {
    "subject": "string",
    "to": ["string"]
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.runtype.com/v1/runtime/email/send';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"subject":"string","to":["string"]}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.runtype.com/v1/runtime/email/send"

	payload := strings.NewReader("{\n  \"subject\": \"string\",\n  \"to\": [\n    \"string\"\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.runtype.com/v1/runtime/email/send")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"subject\": \"string\",\n  \"to\": [\n    \"string\"\n  ]\n}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.runtype.com/v1/runtime/email/send")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"subject\": \"string\",\n  \"to\": [\n    \"string\"\n  ]\n}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.runtype.com/v1/runtime/email/send', [
  'body' => '{
  "subject": "string",
  "to": [
    "string"
  ]
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.runtype.com/v1/runtime/email/send");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"subject\": \"string\",\n  \"to\": [\n    \"string\"\n  ]\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = [
  "subject": "string",
  "to": ["string"]
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.runtype.com/v1/runtime/email/send")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```