> ## Documentation Index
> Fetch the complete documentation index at: https://docs.leadlex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Personalize Email

> Generate a personalized email draft for a specific contact, optionally based on a template

<Warning>
  This endpoint consumes 2 AI credits per call. If the workspace balance is insufficient, the API returns `402 insufficient_credits`.
</Warning>

## Request

### Headers

```
Authorization: Bearer wbk_your_api_key_here
Content-Type: application/json
```

<ParamField header="Idempotency-Key" type="string">
  Optional UUID for retry deduplication.
</ParamField>

### Body Parameters

<ParamField body="contact_id" type="string" required>
  UUID of the contact the email is for.
</ParamField>

<ParamField body="intent" type="string" required>
  High-level purpose of the email, in natural language. Examples: `"schedule an intro call"`, `"follow up on proposal"`, `"check-in after six weeks of silence"`.
</ParamField>

<ParamField body="template" type="string">
  Optional template body. Merge tokens (`{{first_name}}`, `{{company}}`) are resolved and the output is personalized around the template's voice.
</ParamField>

<ParamField body="tone" type="string" default="professional">
  One of `professional`, `warm`, `formal`, `casual`.
</ParamField>

<ParamField body="length" type="string" default="medium">
  `short` (\~50 words), `medium` (\~120 words), or `long` (\~250 words).
</ParamField>

<ParamField body="language" type="string" default="en">
  ISO 639-1 language code.
</ParamField>

## Response

<ResponseField name="data" type="object">
  <Expandable title="properties">
    <ResponseField name="subject" type="string">Suggested subject line</ResponseField>
    <ResponseField name="body_text" type="string">Plain-text email body</ResponseField>
    <ResponseField name="body_html" type="string">HTML-formatted body</ResponseField>
    <ResponseField name="personalization_notes" type="array">Bullet list of what was tailored (e.g. "Referenced recent Series B announcement")</ResponseField>
    <ResponseField name="reading_time_seconds" type="integer">Estimated time to read</ResponseField>
    <ResponseField name="credits_remaining" type="integer">Balance after this call</ResponseField>
  </Expandable>
</ResponseField>

Responses include `X-RateLimit-Limit`, `X-RateLimit-Remaining`, `X-RateLimit-Reset`, and `X-Request-ID`.

<CodeGroup>
  ```bash cURL theme={null}
  curl -X POST \
    https://data.leadlex.com/functions/v1/api-gateway/v1/lexi/personalize-email \
    -H "Authorization: Bearer wbk_your_api_key_here" \
    -H "Content-Type: application/json" \
    -d '{
      "contact_id": "123e4567-e89b-12d3-a456-426614174000",
      "intent": "follow up on proposal",
      "tone": "warm"
    }'
  ```

  ```python Python theme={null}
  import requests

  API_KEY = "wbk_your_api_key_here"
  BASE_URL = "https://data.leadlex.com/functions/v1/api-gateway"

  r = requests.post(
      f"{BASE_URL}/v1/lexi/personalize-email",
      headers={
          "Authorization": f"Bearer {API_KEY}",
          "Content-Type": "application/json",
      },
      json={
          "contact_id": "123e4567-e89b-12d3-a456-426614174000",
          "intent": "follow up on proposal",
          "tone": "warm",
      },
  )
  print(r.json()["data"]["subject"])
  ```

  ```javascript JavaScript theme={null}
  const res = await fetch(
    'https://data.leadlex.com/functions/v1/api-gateway/v1/lexi/personalize-email',
    {
      method: 'POST',
      headers: {
        'Authorization': 'Bearer wbk_your_api_key_here',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        contact_id: '123e4567-e89b-12d3-a456-426614174000',
        intent: 'follow up on proposal',
      }),
    }
  );
  const { data } = await res.json();
  console.log(data.subject, data.body_text);
  ```
</CodeGroup>

### Example Response

```json theme={null}
{
  "data": {
    "subject": "Quick follow-up on the Series B engagement proposal",
    "body_text": "Hi Jane,\n\nHope the week has been smooth on your end. Wanted to circle back on the flat-fee engagement proposal we shared last Tuesday and see if anything could use another pass or clarification before you share internally...",
    "body_html": "<p>Hi Jane,</p><p>Hope the week has been smooth on your end. Wanted to circle back on the flat-fee engagement proposal we shared last Tuesday and see if anything could use another pass or clarification before you share internally...</p>",
    "personalization_notes": [
      "Referenced the proposal date from the last email thread",
      "Used warm tone aligned with prior correspondence"
    ],
    "reading_time_seconds": 28,
    "credits_remaining": 4840
  }
}
```

## Errors

| Status | Code                       | Description                           |
| ------ | -------------------------- | ------------------------------------- |
| 400    | `validation_error`         | Missing `contact_id` or `intent`      |
| 401    | `invalid_key`              | Invalid or expired API key            |
| 402    | `insufficient_credits`     | Workspace credit balance is exhausted |
| 403    | `insufficient_permissions` | Missing `write:ai` permission         |
| 404    | `not_found`                | Contact not found                     |
| 429    | `rate_limited`             | Rate limit exceeded                   |