> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gu1.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Check CUIT in Corpus

> Verify whether a CUIT exists in the holder corpus — returns found true or false with HTTP 200. No billing.

## Overview

Checks whether a **CUIT** (11 digits) appears in the processed holder corpus. Returns `found: false` with HTTP **200** when the CUIT is absent (not an error). **No billing.**

## Endpoint

```
GET https://api.gu1.ai/api/integration-services/ar_gueno_holder_intelligence_service/cuits/{cuit}/exists
```

## Path parameters

<ParamField path="cuit" type="string" required>
  Argentina CUIT/CUIL — **11 digits**, no dashes.
</ParamField>

## Response

<ResponseField name="success" type="boolean">
  `true` on HTTP 200.
</ResponseField>

<ResponseField name="data.integrationCode" type="string">
  `ar_gueno_holder_intelligence_service`
</ResponseField>

<ResponseField name="data.cuit" type="string">
  Echo of the requested CUIT.
</ResponseField>

<ResponseField name="data.found" type="boolean">
  `true` if the holder exists in corpus; `false` otherwise.
</ResponseField>

<ResponseField name="data.snapshotDate" type="string | null">
  Optional snapshot date (`YYYY-MM-DD`) when the holder exists.
</ResponseField>

## Errors

| HTTP | `error.code`          | When                       |
| ---- | --------------------- | -------------------------- |
| 503  | `SERVICE_UNAVAILABLE` | Holder backend unavailable |
| 500  | `INTERNAL_ERROR`      | Unexpected error           |

## Examples

### Found

```bash theme={null}
curl -s \
  -H "Authorization: Bearer YOUR_API_KEY" \
  "https://api.gu1.ai/api/integration-services/ar_gueno_holder_intelligence_service/cuits/20384648798/exists"
```

```json theme={null}
{
  "success": true,
  "data": {
    "integrationCode": "ar_gueno_holder_intelligence_service",
    "cuit": "20384648798",
    "found": true,
    "snapshotDate": "2026-06-24"
  }
}
```

### Not found (still HTTP 200)

```json theme={null}
{
  "success": true,
  "data": {
    "integrationCode": "ar_gueno_holder_intelligence_service",
    "cuit": "20999999999",
    "found": false
  }
}
```