Connected to the way you work

Your workflow.
Clearer email data.

Bring selected contacts into FairValid, add verification to your site, or build checks into your own application.

Explore integrations Read the API docs

Your workspace permissions and credit rules still apply.

Google SheetsHubSpotMailchimp

FairValidYour workspace. Your results.

Customer APISite widget

Supported ways to work. Connections require your authorization.

Bring your existing contacts

Less copying.
More context.

Import a selected source, review what you are checking, and keep the connection between each contact and its result.

From your spreadsheet

Google Sheets

Choose a worksheet or import from a publicly readable sheet link. Bring the rows you need into a verification list.

Public-link imports are read-only. FairValid does not write results back to Sheets.

Read the Google Sheets guide

From your CRM

HubSpot

Choose a contact list and keep the source contact identity attached to the verification result.

CRM fields stay unchanged by default. Review any available write-back action before choosing it.

Read the HubSpot guide

From your audience

Mailchimp

Choose an audience and review your selected contacts while keeping subscription and consent state intact.

Verification does not subscribe or unsubscribe anyone. Review optional mapped write-back separately.

Read the Mailchimp guide

Start with the contacts you select. Review the import and its credit requirements before running verification.

Built for your application

A clear API.
A controlled workflow.

Submit one address or a bulk job from your server. Read the results as work progresses, and use signed events when a job completes.

Scoped keys and spending caps
Grant the access you need. Set a lifetime credit cap and revoke a key when its work is done.
A sandbox before live checks
Test keys accept reserved example addresses without provider calls or credit use.
Signed completion webhooks
Verify event signatures and deduplicate event IDs. Retry the same request with the same idempotency key.

Open the API reference

Email verification for AI agents

Connect an agent through MCP using Streamable HTTP at https://mcp.fairvalid.com/mcp. Use OAuth sign-in or connect a native or server-backed client with a FairValid API key in its Authorization header.

Check an address, submit a batch, read job state and results, request cancellation, or read your live balance. Live checks run asynchronously; an accepted job is not a completed mailbox check.

Set up ChatGPT, Claude, Hermes, Grok or Codex

Submit a jobPOST /api/v1/jobs

REQUESTReserved example addresses

curl -X POST "$FAIRVALID_BASE_URL/api/v1/jobs" \
  -H "Authorization: Bearer $FAIRVALID_API_KEY" \
  -H "Idempotency-Key: my-import-2026-10-05" \
  -H "Content-Type: application/json" \
  -d '{"emails":["deliverable@example.com",
                 "unknown@example.com"]}'

Use a Test key for this sandbox example.
Keep all privileged keys on your server.

Documented request format. This illustration sends no requests.

At the point of entry

Give your forms
a clearer signal.

Add a site-scoped verification widget to your form. Configure how your site handles each outcome and set a daily credit budget.

Allow the exact site origins
Keep the widget tied to the websites you configure.
Choose your outcome rules
Decide which results stop submission and which warn or allow. An uncertain result stays uncertain.
Keep privileged access private
The public site ID is not a privileged API key. Pause or revoke a site to stop new admissions.

Read the widget guide

Make it part of your workflow.

Start with your workspace, explore the guides, and choose the connection that fits.

Start free Explore the guides

API jobs and signed webhooks are documented in the API reference.

Less copying.More context.