Logistics & Supply Chain · Integration
Lob
Add Lob to your product for your customers, and give your AI agents governed access to it.
Lob sends physical mail through an API, so it sits closest to shipments, tracking events and orders even though the payload is a printed document rather than a parcel. The API at api.lob.com/v1 uses HTTP Basic auth with the API key as the username and an empty password, and it separates live keys from test keys, where test keys create objects that render a PDF proof but are never printed. Core resources are addresses, postcards, letters, self mailers, cheques and templates, and a mail piece can reference a saved template with merge variables instead of inline HTML. Every send is effectively irreversible after a short cancellation window, which is the detail that surprises implementers used to queued email. Delivery progress arrives as tracking events such as mailed, in transit, processed for delivery and re-routed, sourced from postal scans, so timing is approximate and a piece can go quiet for days. Address verification is a separate endpoint and returns a deliverability grade you should check before spending postage. fastn keeps each customer's live and test keys apart and handles the per-tenant credentials and upkeep.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Let a customer connect their own Lob account so mail is printed on their postage and their branding
Trigger a templated letter or postcard from a workflow in your product, such as a renewal or dunning notice
Verify and normalise a customer's postal address before saving it to your own records
Show delivery tracking events for each mail piece next to the record that generated it
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
Let an agent draft a mail piece and hold it for human approval, since a send cannot be recalled once printed
Have an agent check address deliverability and flag undeliverable records, audited per tenant
Give an agent read access to tracking events so it can answer where a letter has got to
Example prompt
Has the renewal letter we sent to this customer through Lob been delivered yet?
Set up Lob in 4 steps
- 01Enable the Lob connector from your fastn dashboard.
- 02Have each customer authorise their own Lob account, so calls run under their credentials rather than a shared key.
- 03Decide which shipments, tracking events and orders your product needs, map those fields, then enable the actions and triggers you want.
- 04Call it from your product and expose it to your agents through the same governed connection.
Why teams use the Lob integration
What you get by embedding it with fastn instead of building it yourself.
- Ship a Lob integration without building it. Your customers connect their own Lob account inside your product and work their shipments, tracking events and orders there, with no per-customer code on your side.
- Handle the part that actually costs time: tracking data arrives from many carriers in inconsistent formats and at unpredictable times. fastn owns the auth, token refresh, rate limits, pagination and breaking-change fixes, so a Lob update is not your on-call problem.
- One integration serves your product and your agents. The same governed Lob connection powers in-product features and gives AI agents scoped, audited access, so you keep physical movement and stock visible inside your product without wiring it twice.
Used by these teams
Compare with
AfterShip
EasyPost
Cin7Often used alongside
Tools the same teams tend to run next to Lob, across other categories.
NetSuite
Shopify
Stripe
QuickBooksLob integration FAQ
How do I add a Lob integration to my product?
Enable the Lob connector in your fastn dashboard, then let each customer authenticate their own Lob account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no Lob client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own Lob account?
Yes. Every connection is scoped to the individual customer, so each authorises their own Lob account and only ever sees their own shipments, tracking events and orders. 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 Lob integration?
Yes. The same connection is exposed to your agents through the fastn MCP gateway, with permissions scoped per tenant and every call audited. Let an agent draft a mail piece and hold it for human approval, since a send cannot be recalled once printed
Who maintains the Lob integration?
fastn does. When Lob 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.
Can I track shipments from Lob inside my product?
Yes. Shipment and tracking events are read per customer and can trigger your workflows, so status changes surface in your product instead of your users checking a carrier site.
What does my product get back from Lob as things move?
Whatever Lob actually holds. Where it moves goods, that is shipment and tracking events, read per customer and delivered as they land. Where it holds stock, levels can be read on demand or kept in step through events, so your product is not deciding on a stale count. Where it carries orders and documents between trading partners, it is the acknowledgement, ship notice or status change that says what moved.
What can I build with the Lob integration?
A common starting point: let a customer connect their own Lob account so mail is printed on their postage and their branding. 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 Lob integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding Lob does not change your per-connector cost. You can start free with 3 connected accounts.
Add Lob to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.