Reference & Lookup Data · Integration
Validity
Add Validity to your product for your customers, and give your AI agents governed access to it.
Validity sells trust in contact data. The part that behaves like a lookup, and the part worth embedding, is email verification: you submit an address, BriteVerify reports whether it is deliverable, and your product decides whether to keep it. Alongside that sits Everest, where a sender watches inbox placement, complaint rates and the reputation of the domains they send from. Both are read surfaces. Neither is a system your product writes records into, and neither volunteers anything until you ask, so there is nothing to subscribe to and everything to cache. Verification is metered per address checked, which is the whole reason each customer connects their own account instead of sharing yours. Credential storage is fastn's problem, tenant by tenant, and so is every change the vendor ships.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Have each customer connect their own Validity account so verification is metered against the tenant whose list is being checked.
Verify an address at the point of signup, so a typo is caught while the person is still on the page to fix it.
Check a list before a send rather than after, since a hard bounce costs sender reputation that takes weeks to earn back.
Cache a verification result per address, because an address that verified this morning has not changed by this afternoon.
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
An agent verifies an address before it is added anywhere, and reports the result rather than assuming it is fine.
An agent reads deliverability reporting for a sending domain and explains what moved.
An agent states that it can check and report but cannot mail anything, because this connector exposes no sends.
Example prompt
Verify these addresses and tell me which of them would bounce if we sent to them today.
Set up Validity in 4 steps
- 01Enable the Validity connector in your fastn dashboard.
- 02Have each customer supply their own Validity credentials, so verification volume is billed to them.
- 03Decide which addresses get verified and when, and set a cache window per address so the same check is not paid for twice.
- 04Call it from your product and expose the same connection to your agents through the MCP gateway.
Why teams use the Validity integration
What you get by embedding it with fastn instead of building it yourself.
- Ship a Validity integration without building it. Your customers connect their own Validity account inside your product and work their lookups, results and reports there, with no per-customer code on your side.
- Handle the part that actually costs time: these are metered read sources, so an uncached lookup on every page view burns the customer's allowance. fastn owns the auth, token refresh, rate limits, pagination and breaking-change fixes, so a Validity update is not your on-call problem.
- One integration serves your product and your agents. The same governed Validity connection powers in-product features and gives AI agents scoped, audited access, so you answer questions from an authoritative outside source without holding that data yourself without wiring it twice.
Used by these teams
Compare with
ClearbitWorks well with
Mailchimp
SalesforceOften used alongside
Tools the same teams tend to run next to Validity, across other categories.
HubSpot
Notion
Snowflake
BoxValidity integration FAQ
How do I add a Validity integration to my product?
Enable the Validity connector in your fastn dashboard, then let each customer authenticate their own Validity account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no Validity client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own Validity account?
Yes. Every connection is scoped to the individual customer, so each authorises their own Validity account and only ever sees their own lookups, results and reports. That per-tenant isolation is the point of an embedded integration: you support the long tail of customer setups without maintaining an integration per customer.
Can AI agents use this Validity integration?
Yes. The same connection is exposed to your agents through the fastn MCP gateway, with permissions scoped per tenant and every call audited. An agent verifies an address before it is added anywhere, and reports the result rather than assuming it is fine.
Who maintains the Validity integration?
fastn does. When Validity changes an endpoint, deprecates a field or alters its auth, the fix lands in the connector rather than in your backlog, and your customers' connections keep working.
Whose credentials does a Validity lookup run under?
Each customer's own. Quota and cost land on the customer that caused them rather than on a shared key you have to meter and re-bill, and one heavy customer cannot exhaust another's allowance.
How should Validity results be cached?
Per tenant, with a window that matches how fast the underlying data actually moves. Validity is a read source rather than a system of record, so the same query returns the same answer until the source changes, and caching is the difference between a sustainable integration and one that exhausts a customer's allowance on a busy page.
What can I build with the Validity integration?
A common starting point: have each customer connect their own Validity account so verification is metered against the tenant whose list is being checked. Teams also use it for the other use cases listed above, and expose it to agents for governed reads and writes.
How much does the Validity integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding Validity does not change your per-connector cost. You can start free with 3 connected accounts.
Add Validity to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.