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

# Upload File for Verification

> Upload a file of email addresses for bulk verification. Max **10 MB** and **100,000 emails** per file. Processing is asynchronous — poll `GET /verifyFileStatus/{file_id}`. (These are the API upload limits; larger files — up to 100 MB / 1M addresses in CSV/TXT — can be verified through the in-app List Verification upload.)



## OpenAPI

````yaml /openapi-verifier.json post /verifyFile
openapi: 3.1.0
info:
  title: Mailercloud Email Verifier API
  version: 1.0.0
  description: >-
    Verify email addresses programmatically — single/batch real-time
    verification and bulk file verification. Credit-based: each billable
    verification consumes one credit. Create API keys at
    [app.mailercloud.com/email-verifier/api-keys](https://app.mailercloud.com/email-verifier/api-keys).
servers:
  - url: https://verify.mailercloud.com
security:
  - bearerAuth: []
tags:
  - name: Verification
  - name: Bulk Files
paths:
  /verifyFile:
    post:
      tags:
        - Bulk Files
      summary: Upload File for Verification
      description: >-
        Upload a file of email addresses for bulk verification. Max **10 MB**
        and **100,000 emails** per file. Processing is asynchronous — poll `GET
        /verifyFileStatus/{file_id}`. (These are the API upload limits; larger
        files — up to 100 MB / 1M addresses in CSV/TXT — can be verified through
        the in-app List Verification upload.)
      operationId: upload-verification-file
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              required:
                - file
              properties:
                file:
                  type: string
                  format: binary
                  description: CSV/TXT file of email addresses.
      responses:
        '200':
          description: File accepted for processing.
          content:
            application/json:
              schema:
                type: object
                properties:
                  file_id:
                    type: string
                  file_name:
                    type: string
                  records:
                    type: integer
                  duplicate_count:
                    type: integer
                  status:
                    type: string
                    example: pending
        '400':
          description: Missing `file` field, malformed multipart, or no valid emails found.
        '401':
          description: Missing or invalid API key.
        '413':
          description: File exceeds 10 MB or 100,000 emails.
        '422':
          description: File could not be parsed.
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        Your Email Verifier API key, sent as `Authorization: Bearer
        YOUR_API_KEY`. Create keys at
        [app.mailercloud.com/email-verifier/api-keys](https://app.mailercloud.com/email-verifier/api-keys).

````