canonical: https://jentic.com/apis/millionverifier.com/millionverifier

# MillionVerifier API

Jentic publishes the only available OpenAPI specification for MillionVerifier API, keeping it validated and agent-ready. MillionVerifier is a real-time email verification service that classifies email addresses as deliverable, risky, disposable, or part of a catch-all domain to protect sender reputation. The v3 API exposes two endpoints - a single-email verification call and a credit balance check - both authenticated by an API key passed as the API query parameter.

## For AI agents

Verify whether an email address is deliverable, risky, disposable, or catch-all in real time and check remaining MillionVerifier credits.

## Scope

Does not send email, harvest addresses, or run bulk file verification - use for real-time single-address verification and credit balance checks only.

## Capabilities

- Verify a single email address in real time and receive a deliverability classification
- Distinguish deliverable inboxes from risky, disposable, or catch-all addresses before sending
- Pre-screen newly captured leads at sign-up to keep an email list clean
- Check remaining MillionVerifier credits before queuing a verification batch
- Reduce bounce rate on outbound campaigns by filtering invalid addresses upstream

## Use cases

### Sign-Up Form Email Verification

Before accepting a new sign-up, an agent calls MillionVerifier on the submitted email address and rejects disposable or undeliverable entries at the door. The user gets immediate feedback and the database stays clean of bounce-prone records.

Example prompt: On form submit, call GET / with email=<submitted_email> and reject the form when the result is 'disposable' or 'invalid'.

### Outbound Campaign List Cleaning

Before sending a marketing or transactional campaign, an agent verifies each address through MillionVerifier and drops invalid or risky entries. Sender reputation stays high and bounce rates stay below ESP thresholds.

Example prompt: For each email in the campaign list, call GET / with the email and drop the row if result is anything other than 'ok'.

### Credit Monitoring

An agent watches the credit balance on the account and pings the team when it falls below a threshold so verification jobs do not stall mid-campaign. The credits endpoint returns the remaining balance for the API key in a single call.

Example prompt: Call GET /credits daily and post a Slack alert when the remaining count is below 10000.

### Agent Email Verification via Jentic

Through Jentic, an agent verifies addresses by intent rather than by hand-coding the API call. The MillionVerifier API key sits in your Jentic One instance and is injected as the API query parameter so an agent never holds the credential.

Example prompt: Use Jentic search 'verify an email address', load the schema for GET /, and execute with the email address in the query string.

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/` | Verify a single email address |
| GET | `/credits` | Check remaining credits |

## Key resources

- **Verification** — Verify a single email address in real time
- **Account** — Check remaining credits on the MillionVerifier account

## Why Jentic

- **Setup:** Wiring MillionVerifier by hand means appending your key to the 'API' query parameter on every call to api.millionverifier.com and handling the single-address verification response yourself. Through Jentic you install once, import MillionVerifier from the API Directory, store the key once, and your agent calls it.
- **Permission scoping:** MillionVerifier exposes just two read operations, verifying an address and checking the credit balance, and both carry their input as query parameters rather than a path resource. Scope the agent to the operations it needs, so it can verify addresses without also being able to read your credit balance unless you add that.
- **Credential handling:** Your MillionVerifier API key is stored once, encrypted, by your own Jentic One instance and added to the request's 'API' query parameter at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'verify an email address' or 'check my verification credits', and Jentic returns the matching MillionVerifier operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

## Related APIs

- **ZeroBounce API** — Email verification competitor with similar real-time and bulk surfaces.
- **NeverBounce API** — Real-time email verification with strong ESP integrations.
- **Hunter.io API** — Finds emails by domain and verifies them - pairs well as a discovery layer above MillionVerifier.

## FAQ

### Why is there no official OpenAPI spec for MillionVerifier API?

MillionVerifier does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call MillionVerifier API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

### What authentication does the MillionVerifier API use?

The API uses an API key passed as the 'API' query parameter on each request (the apiKeyQuery security scheme). Through Jentic, the key is held in the encrypted vault and appended to the query at execution time so it never enters the agent's context.

### Can I distinguish disposable emails from catch-all domains?

Yes. The single GET / verification call returns a result classification that separates deliverable, undeliverable, risky/catch-all, and disposable addresses, which lets you treat each class differently in your sign-up or campaign flow.

### What are the rate limits for the MillionVerifier API?

MillionVerifier scales by purchased credits rather than a hard request rate; each verification consumes one credit. Use GET /credits to monitor remaining balance and contact MillionVerifier support if you need negotiated throughput limits.

### How do I verify an email address through Jentic?

Run pip install jentic, search for 'verify an email address', load the schema for GET /, and execute with email=<address>. Jentic injects your stored API key into the API query parameter automatically.

### Can I verify multiple emails in one call?

Not on this real-time v3 endpoint. GET / verifies one address at a time. For batch verification, MillionVerifier offers a separate bulk file upload product that is not part of this real-time API.

### Can I limit what my agent is allowed to do with the MillionVerifier API?

Yes. The MillionVerifier API exposes just two read operations, verifying a single email address and checking your credit balance, and your self-hosted Jentic One instance lets you decide which of them an agent may call. Your own rules can allow the agent to verify addresses while blocking it from reading your credit balance, and the API key is only ever added to the request at execution time rather than handed to the agent. That way the agent runs exactly the operations you permit and nothing else.