Finance & ERP · Integration
Expensify
Add Expensify to your product for your customers, and give your AI agents governed access to it.
Embed an Expensify integration so your customers can work their own expenses, expense reports, receipts, policies, and approvals from inside your product. Spend writes are idempotent, so a retry after a timeout does not submit the same expense twice, and every call is logged per tenant so a line can be traced back to the event that created it. fastn handles per-customer authorisation and API upkeep, and each customer's own policies and account mappings are configuration rather than code.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Let customers connect their own Expensify account so expenses created in your product land in their policy.
Create expenses and attach receipts from your product so users do not re-enter the same spend.
Read report and approval status so your product shows where a claim sits without switching tools.
Trigger your product when a report is submitted, approved, or reimbursed.
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
An agent reads a submitted report and its line items before answering an approver's question.
An agent creates an expense or submits a report within governed permissions, with every write idempotent and logged.
An agent reacts to an approval event and runs the next accounting step.
Example prompt
List expense reports awaiting approval for more than five days and show the total on each.
Set up Expensify in 4 steps
- 01Open the Expensify connector from your fastn dashboard.
- 02Have each customer authenticate their own Expensify account.
- 03Map the policies, categories, and account mappings your product uses, then enable actions and triggers.
- 04Call them from your product, or expose them to an agent through the MCP server.
Why teams use the Expensify integration
What you get by embedding it with fastn instead of building it yourself.
- Ship an Expensify integration without building it. Your customers connect their own Expensify account inside your product and work their invoices, payments and vendors there, with no per-customer code on your side.
- Handle the part that actually costs time: financial writes must be idempotent and reconcilable, because a duplicate is an accounting problem rather than a bug. fastn owns the auth, token refresh, rate limits, pagination and breaking-change fixes, so an Expensify update is not your on-call problem.
- One integration serves your product and your agents. The same governed Expensify connection powers in-product features and gives AI agents scoped, audited access, so you move financial records without hand-keying them between systems without wiring it twice.
Used by these teams
Compare with
Bill
Brex
NetSuiteOften used alongside
Tools the same teams tend to run next to Expensify, across other categories.
Shopify
Stripe
BigCommerce
AfterShipExpensify integration FAQ
How do I add an Expensify integration to my product?
Enable the Expensify connector in your fastn dashboard, then let each customer authenticate their own Expensify account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no Expensify client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own Expensify account?
Yes. Every connection is scoped to the individual customer, so each authorises their own Expensify account and only ever sees their own invoices, payments and vendors. 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 Expensify 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 reads a submitted report and its line items before answering an approver's question.
Who maintains the Expensify integration?
fastn does. When Expensify 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.
Is the Expensify integration safe for financial writes?
Writes are idempotent, so a retry after a timeout does not post a document twice, and every call is logged per tenant so an entry can be traced back to the event that created it. That matters more in finance than anywhere else, because a duplicate is a number somebody has to explain.
Can it handle each customer's own chart of accounts?
Yes. ERP deployments are configured to the business, so account structures, required fields and fiscal calendars differ per customer. Those are mapped per tenant as configuration, not hard-coded.
What about Expensify rate limits during a first import?
Backfills are throttled deliberately. ERP limits are often account-wide rather than per-integration, so an unthrottled import can exhaust a customer's allowance and disrupt their other integrations.
What can I build with the Expensify integration?
A common starting point: connect their own Expensify account so expenses created in your product land in their policy. 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 Expensify integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding Expensify does not change your per-connector cost. You can start free with 3 connected accounts.
Add Expensify to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.