# Find domains whose backlinks overlap a target's

Returns the domains whose backlinks overlap a target's, with how many linking domains they share. Use it to find link-building competitors.

Tool `web.backlinks.competitors` on Open web and SEO. Contract version 1, released 2026-10-27.

## Example call

Over REST, send the input in the body. Over MCP, pass the same input to `call_tool`.

cURL:

```bash
curl https://api.voxoria.ai/v1/tools/web.backlinks.competitors/calls \
  -H "Authorization: Bearer $VOXORIA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"input":{"target":"moz.com"}}'
```

Python:

```python
import os

import httpx

response = httpx.post(
    "https://api.voxoria.ai/v1/tools/web.backlinks.competitors/calls",
    headers={"Authorization": f"Bearer {os.environ['VOXORIA_API_KEY']}"},
    json={"input": {"target": "moz.com"}},
    timeout=60,
)
print(response.json())
```

TypeScript:

```ts
const response = await fetch("https://api.voxoria.ai/v1/tools/web.backlinks.competitors/calls", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.VOXORIA_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({"input": {"target": "moz.com"}}),
});
console.log(await response.json());
```

MCP (`tools/call` params):

```json
{
  "name": "call_tool",
  "arguments": {
    "tool": "web.backlinks.competitors",
    "input": {
      "target": "moz.com"
    }
  }
}
```

Both return [the full response](/docs/call-response.md): the call's ID, status and cost, with this tool's result in `output`.

## Input

| Input | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `target` | string | Yes |  | The domain or subdomain, without scheme or www, such as "moz.com", or the full URL of one page. 1 or more characters. |
| `page` | integer | No | `1` | Page of results, page_size per page. Domains come by shared_linking_domain_count, highest first. At least 1. |
| `page_size` | integer | No | `10` | Results per page. Each result adds to the price of the call. From 1 to 100. |

## Output

A successful call returns these blocks in its `output`. A field not marked required can be `null`.

### results

A list of rows. Always present, possibly empty.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `domain` | string | Yes | A domain whose backlinks overlap the target's. |
| `domain_rank` | integer | No | Authority of the domain from its own backlinks, from 0 to 100. Each provider computes its own; scores of different providers do not compare. |
| `shared_linking_domain_count` | integer | No | Domains that link to both this domain and the target. |
| `linking_domain_count` | integer | No | Domains that link to this domain. |

## Example output

The `output` of a real call, each list cut to 3 items.

```json
{
  "results": [
    {
      "domain": "ahrefs.com",
      "domain_rank": 60,
      "shared_linking_domain_count": 4921,
      "linking_domain_count": null
    },
    {
      "domain": "semrush.com",
      "domain_rank": 56,
      "shared_linking_domain_count": 4207,
      "linking_domain_count": null
    },
    {
      "domain": "hubspot.com",
      "domain_rank": 50,
      "shared_linking_domain_count": 2320,
      "linking_domain_count": null
    }
  ]
}
```