Finance & ERP · Integration
Bill
Add Bill to your product for your customers, and give your AI agents governed access to it.
Bill, styled BILL by the company and still widely searched as Bill.com, is where a finance team works its payables and receivables, so an embedded Bill integration puts your product inside that flow rather than beside it. You can create and read bills, look up vendors and customers, follow approval status, and see which payments have been sent, cleared or returned. Approvals shape the whole design: a bill does not become a payment because your product asked, it moves when the customer's own approval policy is satisfied, and payment operations are deliberately gated. Bill also authenticates per organisation with a developer key rather than a plain OAuth handshake, which fastn manages per tenant along with the API upkeep.
In your product
Embedded for your customers. Per-tenant auth, no per-customer code, maintained by fastn.
Each customer links their own Bill organisation, so a purchase captured in your product becomes a bill in theirs.
Show approval status in your product, so a requester can see who still has to sign off without opening Bill.
Read vendor records so your product pays the payee the finance team already vetted, not a name typed by a user.
Follow payment state through to cleared or returned, and update what your product shows accordingly.
For your AI agents
Governed, audited access for the agents you build, through the MCP server.
An agent answers which bills are waiting on an approver and how long they have been sitting there.
An agent drafts a bill from an invoice document and leaves approval to the people who own it.
An agent ties a payment back to the bill it settled, reading only that organisation's records.
Example prompt
Which bills are still waiting for approval, who is the approver, and which are due this week?
Set up Bill in 4 steps
- 01Enable the Bill connector from your fastn dashboard.
- 02Have each customer authorise their own Bill account, so calls run under their credentials rather than a shared key.
- 03Decide which invoices, payments and vendors 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 Bill integration
What you get by embedding it with fastn instead of building it yourself.
- Ship a Bill integration without building it. Your customers connect their own Bill 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 a Bill update is not your on-call problem.
- One integration serves your product and your agents. The same governed Bill 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
Tipalti
QuickBooks
RampOften used alongside
Tools the same teams tend to run next to Bill, across other categories.
Shopify
Stripe
BigCommerce
AfterShipBill integration FAQ
How do I add a Bill integration to my product?
Enable the Bill connector in your fastn dashboard, then let each customer authenticate their own Bill account. fastn handles the OAuth flow, token storage and refresh per tenant, so there is no Bill client code in your app and no per-customer branch in your codebase. Setup is 4 steps.
Do my customers each connect their own Bill account?
Yes. Every connection is scoped to the individual customer, so each authorises their own Bill 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 Bill 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 answers which bills are waiting on an approver and how long they have been sitting there.
Who maintains the Bill integration?
fastn does. When Bill 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 Bill 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 Bill 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 Bill integration?
A common starting point: each customer links their own Bill organisation, so a purchase captured in your product becomes a bill in theirs. 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 Bill integration cost?
It is included. Pricing is based on connected accounts, not on how many connectors you enable, so adding Bill does not change your per-connector cost. You can start free with 3 connected accounts.
Add Bill to your product
Start free with 3 connected accounts. No sales call required, and no per-customer integration code.