Finance & ERP · Integration
Exact Online
Add Exact Online to your product for your customers, and give your AI agents governed access to it.
Embed an Exact Online integration so your customers can work their own sales and purchase invoices, general ledger accounts, journal entries, customers, and suppliers from inside your product. Financial writes are idempotent, so a retry after a timeout does not post a document twice, and each administration is mapped per tenant because account structures and fiscal calendars differ per customer. fastn handles per-customer authorisation, token refresh, and API upkeep, and backfills are throttled so a first import does not exhaust a customer's allowance.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Let customers connect their own Exact Online administration so invoices post from your product without hand-keying.
Create sales invoices and journal entries from your product, mapped to each customer's own ledger accounts.
Read customers, suppliers, and outstanding invoices so your product reports on real balances.
Trigger your product when an invoice is created or paid, or when a journal entry is posted.
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
An agent reads outstanding invoices before answering a question about what is owed.
An agent drafts or posts an invoice within governed permissions, with every write idempotent and logged.
An agent reacts to a payment event and runs the next reconciliation step.
Example prompt
List sales invoices more than 30 days overdue and group the totals by customer.
Set up Exact Online in 4 steps
- 01Open the Exact Online connector from your fastn dashboard.
- 02Have each customer authenticate their own Exact Online administration with OAuth.
- 03Map the ledger accounts, invoice fields, and fiscal periods 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 Exact Online integration
What you get by embedding it with fastn instead of building it yourself.
- Ship an Exact Online integration without building it. Your customers connect their own Exact Online 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 Exact Online update is not your on-call problem.
- One integration serves your product and your agents. The same governed Exact Online 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
Xero
NetSuite
MoneybirdOften used alongside
Tools the same teams tend to run next to Exact Online, across other categories.
Shopify
Stripe
BigCommerce
AfterShipExact Online integration FAQ
How do I add an Exact Online integration to my product?
Enable the Exact Online connector in your fastn dashboard, then let each customer authenticate their own Exact Online account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no Exact Online client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own Exact Online account?
Yes. Every connection is scoped to the individual customer, so each authorises their own Exact Online 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 Exact Online 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 outstanding invoices before answering a question about what is owed.
Who maintains the Exact Online integration?
fastn does. When Exact Online 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 Exact Online 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 Exact Online 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 Exact Online integration?
A common starting point: connect their own Exact Online administration so invoices post from your product without hand-keying. 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 Exact Online integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding Exact Online does not change your per-connector cost. You can start free with 3 connected accounts.
Add Exact Online to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.