Bill.com APIConnect Bill.com without building on its API
Bill.com has a REST API. Self-serve sandbox sign-up for any developer, and production developer keys are generated by admins in a BILL production account. If you're reading the docs because you need Bill.com to talk to the rest of your stack, Caddi does that without you writing or maintaining integration code: you show it the job once, and it runs it across Bill.com and your other tools.
- APIREST (JSON)
- AuthDeveloper key
- AccessSelf-serve
What the Bill.com API gives you
- Type
- REST (JSON)
- Authentication
- Developer key plus session ID from POST /v3/login (username, password, org ID); separate API token for Spend & Expense
- Who can get access
- Self-serve sandbox sign-up for any developer, and production developer keys are generated by admins in a BILL production account.
- What it covers
- Accounts payable and receivable (vendors, bills, payments, customers, invoices), the BILL network, webhooks, and Spend & Expense.
- Limits
- 20,000 requests per developer key per hour, 3 concurrent requests per key per org, 200 logins per hour, and 60 calls per minute per token for Spend & Expense.
Official docs: developer.bill.com. Checked September 2026. Vendors change access terms, so confirm with Bill.com before you build.
Building on the Bill.com API vs. having Caddi run it
| The job | Build it on the API | With Caddi |
|---|---|---|
| Getting access | Register an app, get Bill.com credentials, and manage tokens and refreshes. | Connect your Bill.com account once. Caddi holds the connection. |
| Writing the integration | A developer maps fields, handles pagination, retries and rate limits, and writes the sync. | You show Caddi the Bill.com task the way you'd train a new hire. It writes verified code for it. |
| Steps the API doesn't cover | Screens with no endpoint stay manual, or need a separate RPA tool. | Caddi uses a secure, audited browser session where there's no API, in the same automation. |
| The other systems in the loop | Each extra tool is another API, another set of credentials, another integration to own. | One automation runs across all the tools the job touches. |
| Keeping it running | Someone owns the code when the API version, fields or your process change. | Every automation is reviewed before it runs in production, and every run is logged. |
Building on the API is the right call when you have engineers and the integration is your product. When the goal is getting Bill.com work off someone's desk, the build is the slow part.
What teams usually want the Bill.com API for
Bill to accounting sync
Caddi pushes new Bill.com bills into QuickBooks and confirms each entry.
Payment reconciliation
Caddi matches Bill.com payments to records and flags mismatches to the owner.
Approval routing
Caddi routes Bill.com approvals and notifies the approver when action is due.
Bill.com API questions
Does Bill.com have an API?
Yes. Bill.com has a REST API, authenticated with Developer key plus session ID from POST /v3/login (username, password, org ID); separate API token for Spend & Expense. The official documentation is at https://developer.bill.com/docs.
How do I get access to the Bill.com API?
Self-serve sandbox sign-up for any developer, and production developer keys are generated by admins in a BILL production account.
Does the Bill.com API have rate limits?
20,000 requests per developer key per hour, 3 concurrent requests per key per org, 200 logins per hour, and 60 calls per minute per token for Spend & Expense.
Can I connect Bill.com to my other tools without writing code against its API?
Yes. With Caddi you show the Bill.com task once, the way you'd train a new hire, and Caddi builds it as verified code that runs across Bill.com and the other tools the job touches. Where a step has no API, Caddi uses a secure, audited browser session in the same automation.
Do I need a developer to automate Bill.com with Caddi?
No. There is no integration code for you to write or maintain. Every automation Caddi builds for Bill.com is reviewed before it runs in production, and every run is logged.
Connect Bill.com without the build.
Drop your work email and pick a time. We'll show you Caddi running your Bill.com workflow end to end.