---
title: Usage Guidelines
description: "# API Reference ## Bulk Operations & Files ### POST /verifApiFile **Description:** Verify a file of email addresses. #### Parameters | Name | Type | Description | | --- | --- | --- | | secret | string | API…"
url: "https://verify550.com/documentation/usage-guidelines/"
updated: "2025-10-11"
category: API Controller Documentation
---

# Usage Guidelines

# API Reference

## Bulk Operations & Files

### POST /verifApiFile

**Description:** Verify a file of email addresses.

#### Parameters

| Name | Type | Description |
| --- | --- | --- |
| secret | string | API key |
| file | multipart/form-data | Email list file |

#### Responses

| Status | Body |
| --- | --- |
| 200 OK | ```json 10998 ``` |
| 401 Unauthorized | ``` Invalid key ``` |
| 402 Payment Required | ``` Insufficient credit ``` |

### POST /bulk

**Description:** Upload a bulk file for processing.

#### Parameters

| Name | Type | Description |
| --- | --- | --- |
| secret | string | API key |
| file | multipart/form-data | File to upload |

#### Responses

| Status | Body |
| --- | --- |
| 200 OK | ```json {"success":true,"id":10952,"job_id":1751481492,"message":"","filename":"5kphones.csv"} ``` |
| 401 Unauthorized | ``` Invalid key ``` |
| 402 Payment Required | ``` Insufficient credit ``` |

### GET /file

**Description:** Download a processed file.

#### Parameters

| Name | Type | Description |
| --- | --- | --- |
| secret | string | API key |
| id | string | File ID |
| type | string | File type |

#### Responses

| Status | Body |
| --- | --- |
| 200 OK | ``` File content (binary) ``` |
| 401 Unauthorized | ``` Invalid key ``` |
| 404 Not Found | ``` File not found ``` |

### GET /fileOld

**Description:** Legacy endpoint for downloading processed files.

#### Parameters

| Name | Type | Description |
| --- | --- | --- |
| secret | string | API key |
| id | string | File ID |
| type | string | File type |

#### Responses

| Status | Body |
| --- | --- |
| 200 OK | ```json {"status":"success","message":"File downloaded successfully","file_url":"https://example.com/file.zip"} ``` |
| 400 Bad Request | ``` Missing parameters ``` |
| 401 Unauthorized | ``` Invalid key ``` |
| 404 Not Found | ``` File not found ``` |

*Bulk Operations section formatting complete and styled consistently.*

## Additional Notes

- **Authentication:** Standard endpoints use `secret` parameter. Zapier endpoints use `api_key` parameter.
- **Credit System:** Email verification consumes credit; `402` indicates insufficient balance.
- **File Downloads:** Use `/file` for current files, `/fileOld` for legacy files.
- **Zapier Integration:** Endpoints with `Zap` suffix (`/zapierAuth`, `/verifySingleEmailZap`) are Zapier-optimized.

## Status Codes

The following status codes may be returned by the API:

| Code | Description | Common Endpoints |
| --- | --- | --- |
| 200 | Success | All endpoints |
| 400 | Missing/invalid parameters | All endpoints |
| 401 | Invalid API key | Authenticated endpoints |
| 402 | Insufficient credit | Email verification endpoints |
| 404 | Resource not found | `/file`, `/fileOld` |