> ## 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.

# Merge Contacts

> Merge one or more duplicate contacts into a primary record

## Request

Merges fold the duplicates into the primary contact. The primary keeps its UUID; duplicate UUIDs are retired. Non-empty fields on the primary are preserved; missing fields are filled from the duplicates in order. Notes, activities, tasks, emails, documents, and list memberships are re-homed to the primary.

### Headers

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

<ParamField header="Idempotency-Key" type="string">
  Strongly recommended. Same key returns the same result within 24 hours.
</ParamField>

### Body Parameters

<ParamField body="primary_id" type="string" required>
  UUID of the contact that will remain after the merge.
</ParamField>

<ParamField body="duplicate_ids" type="array" required>
  UUIDs of contacts to merge into the primary. Maximum 20 per request.
</ParamField>

<ParamField body="overwrite" type="boolean" default="false">
  When `true`, non-empty fields on the primary can be overwritten by duplicate values. Defaults to fill-only behavior.
</ParamField>

<ParamField body="dry_run" type="boolean" default="false">
  When `true`, the API returns a preview of the merge without making changes.
</ParamField>

## Response

<ResponseField name="data" type="object">
  <Expandable title="properties">
    <ResponseField name="primary" type="object">The resulting contact object after the merge</ResponseField>
    <ResponseField name="merged_ids" type="array">UUIDs of the duplicates that were retired</ResponseField>
    <ResponseField name="fields_populated" type="array">Field names that were filled from duplicates</ResponseField>
    <ResponseField name="counts" type="object">`{ notes, activities, tasks, emails, documents, list_memberships }` moved to the primary</ResponseField>
  </Expandable>
</ResponseField>

Responses include `X-RateLimit-Limit`, `X-RateLimit-Remaining`, `X-RateLimit-Reset`, and `X-Request-ID`. Each merged duplicate emits a `contact.merged` webhook event.

<CodeGroup>
  ```bash cURL theme={null}
  curl -X POST \
    https://data.leadlex.com/functions/v1/api-gateway/v1/contacts/merge \
    -H "Authorization: Bearer wbk_your_api_key_here" \
    -H "Content-Type: application/json" \
    -d '{
      "primary_id": "123e4567-e89b-12d3-a456-426614174000",
      "duplicate_ids": ["456e7890-a1b2-34c5-d678-901234567890"]
    }'
  ```

  ```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/contacts/merge",
      headers={
          "Authorization": f"Bearer {API_KEY}",
          "Content-Type": "application/json",
      },
      json={
          "primary_id": "123e4567-e89b-12d3-a456-426614174000",
          "duplicate_ids": ["456e7890-a1b2-34c5-d678-901234567890"],
      },
  )
  print(r.json()["data"])
  ```

  ```javascript JavaScript theme={null}
  const res = await fetch(
    'https://data.leadlex.com/functions/v1/api-gateway/v1/contacts/merge',
    {
      method: 'POST',
      headers: {
        'Authorization': 'Bearer wbk_your_api_key_here',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        primary_id: '123e4567-e89b-12d3-a456-426614174000',
        duplicate_ids: ['456e7890-a1b2-34c5-d678-901234567890'],
      }),
    }
  );
  const { data } = await res.json();
  console.log(data);
  ```
</CodeGroup>

### Example Response

```json theme={null}
{
  "data": {
    "primary": {
      "id": "123e4567-e89b-12d3-a456-426614174000",
      "full_name": "Jane Doe",
      "email": "jane@acme.com",
      "phone": "+1-555-0100"
    },
    "merged_ids": ["456e7890-a1b2-34c5-d678-901234567890"],
    "fields_populated": ["phone", "linkedin_url"],
    "counts": {
      "notes": 3,
      "activities": 11,
      "tasks": 2,
      "emails": 18,
      "documents": 1,
      "list_memberships": 4
    }
  }
}
```

## Errors

| Status | Code                       | Description                                                         |
| ------ | -------------------------- | ------------------------------------------------------------------- |
| 400    | `validation_error`         | More than 20 duplicates, or `primary_id` appears in `duplicate_ids` |
| 401    | `invalid_key`              | Invalid or expired API key                                          |
| 403    | `insufficient_permissions` | Missing `write:contacts` permission                                 |
| 404    | `not_found`                | Primary or any duplicate ID was not found                           |
| 409    | `merge_conflict`           | Duplicates reference each other in a circular chain                 |
| 429    | `rate_limited`             | Rate limit exceeded                                                 |