Checkbook.io
PaymentsSend and collect money through Checkbook.io without a bank portal: digital payments the recipient claims and routes themselves, paper checks printed and mailed, multi-party payments each party endorses, invoices, and recurring subscriptions. Agents can stage a payment for approval before any funds move, manage saved payees and every payment-account type, and pull attachments and printable checks down as PDFs.
What This Integration Enables
Most payment APIs treat approval as your problem. They give you a send call, and if you want a review step you build it yourself in the layer above, which means the send call is always sitting there, one bad branch away from moving real money. Checkbook.io is unusual in that it ships the pause as a first-class object. Create Digital Payment Approval, Create Physical Check Approval, and Create Multi-Party Payment Approval take exactly the same fields as their send counterparts, but nothing is printed, no recipient is notified, and no funds are reserved while the approval is pending. Approve Payment is what turns a staged record into a live payment. That is a vendor drawing the same line FlowRunner draws, and it is why this connector is a better fit for agent-driven disbursement than most of the payments category.
The second thing worth understanding is that Checkbook inverts who picks the rail. A digital payment is claimed, not pushed: the recipient gets a notification and chooses between a direct bank transfer, an instant debit card push, a virtual card, a printable or mailed check, or a wallet. Funds leave the sending account only when they claim it, so an unclaimed payment costs nothing and Get Payment is the poll that tells you whether anything actually happened. That matters for the population most disbursement systems handle badly: claimants, contractors, gig workers, tenants, and one-time payees whose account details you do not have and should not want to collect.
Underneath those two ideas the surface is broad. Physical checks are printed, stuffed, mailed, and tracked for you, with a mail class you choose per payment. Multi-party payments carry an endorsement chain, so an insurance or construction settlement can require a lienholder or a public adjuster to sign off before the final payee can claim. Invoices run the same machinery in reverse for money coming in, and payment and invoice subscriptions cover standing obligations with individual runs skippable. A directory of saved payees holds bank and card details once so later payouts reference a stored account instead of re-collecting numbers. Bank accounts, debit cards, virtual cards, wallets, wire accounts, PayPal, Venmo, and Interac are each managed as their own account type. Mailboxes turn inbound paper checks into structured records a flow can match against open invoices. Marketplace sub-users get their own API key pair so a platform can onboard sellers who send and receive under their own identity. Attachments and printable checks stream as PDFs into FlowRunner file storage and come back as a URL a later step can email or archive.
There are no triggers here, and that is a design fact rather than a gap. Checkbook posts events to a webhook URL configured on the account through Update User, so a flow reacts by receiving those callbacks on a FlowRunner endpoint. Everything else is driven by a schedule or by an event somewhere else, meaning a bill approved in the ERP, a claim closed in the claims system, or a payment run opening at month end.
Without FlowRunner
With FlowRunner
Use Case Scenarios
A payment run that cannot send itself
Approved bills sit in Xero or a review base in Airtable. On a schedule, the agent pulls the approved set, calls Get Directory Entries to resolve each payee to a saved record, and calls Get Bank Accounts to confirm the funding account is verified rather than pending. Everything that resolves cleanly becomes a Create Digital Payment Approval, each with the source document attached. Everything that does not, meaning a payee with no directory entry, an amount that moved since approval, or a duplicate reference, is held back as an automation exception with the reason attached. The staged run and the exception list land in Slack together. Nobody has been notified of a payment, nothing has been reserved, and the run is entirely reversible with Delete Payment Approval. It becomes money only when a person calls it.
Paying people who will not take an electronic payment
Some payees will not claim a digital payment: an estate, a contractor without online banking, a recipient who simply wants paper. The agent handles them on the same run with Create Physical Check Approval, choosing a tracked mail class where the amount justifies it and supplying a return address so undeliverable mail comes back somewhere a person watches. Once released, Get Checkbook Tracking follows the envelope and Get Payment reports the clearing state, which can be weeks later because a mailed check clears when it is deposited. Where the sender prints on their own stock instead, Print Payment produces the PDF into FlowRunner file storage, and the flow stops short of a retry loop because Checkbook caps printing at five attempts per payment.
Inbound paper mail reconciled against open invoices
Checks still arrive in envelopes. A Checkbook mailbox turns them into records, and the agent works the queue: Get Mail Items lists what arrived, Get Mail Item reads the checks found inside with their amounts and numbers, and Get Mail Item Attachment pulls the scanned images. Each check is matched against open bills in Xero, and the confident matches are proposed as settled. The ones that are not confident, a payment short by a discount somebody took, a check with no invoice number on it, a remittance covering four invoices at once, go to a person with the scan attached rather than a reference to it. The agent does the reading and the matching. A human decides what an ambiguous check was actually for.
Human-in-Loop Highlight
The gate on this connector is structural, not advisory, and the distinction is the whole point. Send Digital Payment and Create Digital Payment Approval take the same fields. The only difference is which verb the flow holds. Call the first one and the recipient is notified immediately and can claim the money; Void Payment then works only while the payment is still unpaid, which makes your undo a race against somebody else's inbox. Call the second and nothing is printed, nobody is contacted, and no funds are reserved. So the design rule for an agent on a production Checkbook connection is that the send verbs are not its to hold. Its only way to propose a disbursement is Create Digital Payment Approval, Create Physical Check Approval, or Create Multi-Party Payment Approval, and the single action that commits money, Approve Payment, sits behind a person.
That turns the pause into something better than an approval message. The agent assembles the whole run, resolves every payee against the directory, checks the funding account is verified, attaches the source document to each staged record, and separates the exceptions out. Then it stops and asks in Slack: "Payment run staged for March 14: 34 payments to 31 payees, total 128,450. 3 held back, reasons attached. Release all 34?" Update Payment Approval means a reviewer who spots a wrong amount can correct the staged record instead of rejecting the run and asking for it again, and Delete Payment Approval discards anything that should never have been proposed. That is human-in-the-loop as Orchestration as a Service means it. The tedious, error-prone assembly moves to the agent. The irreversible act stays with a person, and the platform is arranged so it cannot accidentally be otherwise.
Two other actions deserve the same treatment for their own reasons rather than by analogy. Create Virtual Card returns the full spendable card number, expiry, and security code exactly once, and Create API Key returns the secret and the webhook signing key exactly once. Neither can be read back, so anything that logs the response is logging a live credential, and both belong in a controlled flow with a named owner rather than in a general automation path. Update Bank Account is the quiet one: changing which account is the default silently changes what funds every payment that does not name an account, and a template-bound value on that toggle is exactly the kind of change nobody notices until a payment run draws on the wrong account.
Agent Capabilities
105 actionsPayments
16- Send Digital Payment Sends money by email address or text-enabled phone number, letting the recipient choose how to receive it. Funds leave the sending account only when they claim it, so an unclaimed payment costs nothing. The description travels with wire and SWIFT settlement, so a vague one can get the payment returned.
- Send Physical Check Prints a paper check and mails it, with no action needed from the recipient. Mail class trades cost against speed, and the tracked classes return a tracking number. The check clears when it is deposited, which can be well after the send date.
- Send Multi-Party Payment Issues one payment made out to several parties, the digital equivalent of a check with two names on the pay-to line. Every party endorses in turn and the last one to claim receives the funds.
- Get Payments Lists payments sent and received with filters for direction, status, free text, and a date range. The read behind reconciliation and behind sweeping for payments stuck unpaid past their expiry.
- Get Payment Retrieves one payment with its current status, amount, recipient, check number, and check image link. The poll that tells a flow whether a send actually settled.
- Void Payment Cancels a payment that has not been claimed or cleared, releasing the funds. It cannot undo a payment that already reached a paid state, and the recipient's claim link stops working immediately.
- Resend Payment Notification Sends the claim notification again to the same address or number. It cannot redirect the payment, and it only helps while the payment is still unpaid.
- Deposit Payment Claims a received payment into one of your own accounts, the programmatic equivalent of clicking through the claim page. The destination has to be a rail the sender allowed.
- Endorse Payment Records one party's endorsement on a multi-party payment, moving it along the chain toward the final recipient. Takes the endorser's name as it appears on the payment and an optional signature image.
- Preview Payment Renders what a check will look like before any money moves, returning the image as Base64. Nothing is created, nothing is charged, and the recipient is never contacted, which makes this the right thing to put in front of an approver.
- Print Payment Generates the printable PDF into FlowRunner file storage and returns a URL. Capped at five prints per payment, so never put this in a retry loop.
- Get Payment Attachment Downloads the document supplied when the payment was created as a PDF into FlowRunner file storage. Fails when the payment has no attachment.
- Get Payment Deposit Details Reports which rail the recipient chose and which of their accounts the money landed in. Only meaningful once the payment has been claimed.
- Get Payment Failure Details Explains why a payment failed, returning the return code and reason from the network. The action to reach for when deciding whether to retry on another rail, ask for new details, or write the payment off.
- Get Payment Tracking Returns carrier tracking numbers for a mailed check. Tracking exists only for the tracked mail classes.
- Get Payment Verification Code Retrieves the code a recipient may be asked for when claiming a payment. Treat it as sensitive, because the code plus the claim link is the payment.
Payment Approvals
9- Create Digital Payment Approval Stages a digital payment that will not send until someone approves it. Same fields as Send Digital Payment, but the recipient is not notified and no funds are reserved while it is pending.
- Create Physical Check Approval Stages a paper check that will not print or mail until someone approves it. Nothing is printed and no postage is bought, so a rejected request costs nothing.
- Create Multi-Party Payment Approval Stages a multi-party payment for review before any named party is contacted. The usual shape for insurance and construction disbursements, where the payee list itself is what needs checking.
- Approve Payment Releases a staged approval as a live payment. This is the moment the recipient is notified and the funds are committed, and it is the one action on this connector that should always pass through a person.
- Get Payment Approvals Lists staged approvals with the same direction, status, search, and date filters as Get Payments. The read behind an approval queue.
- Get Payment Approval Retrieves a single staged approval with its amount, recipient, memo, and status.
- Update Payment Approval Edits a staged approval before release, so a reviewer can fix an amount, a memo, or a recipient instead of rejecting the whole request and asking for it again.
- Delete Payment Approval Discards a staged approval so it can never be released. The clean way to reject.
- Get Payment Approval Attachment Downloads the document attached to a staged approval as a PDF into FlowRunner file storage, so a reviewer reads the source bill rather than a reference to it.
Invoices
6- Create Invoice Bills someone with an invoice they can pay online. The reverse direction from a payment: money comes in rather than going out.
- Get Invoices Lists invoices sent and received with direction, status, search, and date filters.
- Get Invoice Retrieves one invoice with its amount, payer, status, direction, and attachment link.
- Pay Invoice Pays an invoice billed to you, moving money out to the issuer.
- Void Invoice Cancels an unpaid invoice, withdrawing the request for payment.
- Get Invoice Attachment Downloads the invoice's attached document as a PDF into FlowRunner file storage.
Subscriptions
6- Create Payment Subscription Sets up a recurring outgoing payment that Checkbook sends on its own, weekly or monthly, with no further calls from the flow.
- Create Invoice Subscription Sets up recurring billing, so the same invoice is issued weekly or monthly without the flow running again.
- Get Subscriptions Lists recurring payment and invoice subscriptions with the usual filters.
- Get Subscription Retrieves one subscription with its interval, start date, remaining cycles, autopay setting, latest cycle status, and the run indexes already skipped.
- Update Subscription Skips individual runs or toggles autopay. The skip list is written wholesale rather than appended to, so read the current list first or previously skipped runs come back.
- Delete Subscription Cancels a subscription so no further runs are scheduled.
Directory
7- Create Directory Entry Saves a payee so future payments reference them instead of restating their details. The foundation of a vendor master that lives where the payments happen.
- Get Directory Entries Lists saved payees with their attached payment accounts, paginated and searchable by name or email.
- Update Directory Entry Edits a saved payee's name, email address, or mailing address.
- Delete Directory Entry Removes a saved payee and every payment account attached to it.
- Add Bank Account To Directory Entry Attaches a payee's bank account so payments push straight to it with nothing for the payee to claim.
- Add Card To Directory Entry Attaches a payee's debit card for instant pushes. The fastest rail Checkbook offers and the usual choice for claims and gig payouts.
- Remove Directory Account Detaches one payment account from a payee, leaving the payee and their other accounts in place.
Checkbooks
5- Order Checkbook Orders physical check stock printed with a bank account's details, for a sender who writes checks by hand rather than having Checkbook mail them.
- Get Checkbooks Lists checkbook orders with their status, paginated and searchable.
- Get Checkbook Retrieves one checkbook order with its status, order date, shipping address, and template.
- Get Checkbook Tracking Returns carrier tracking numbers for a mailed checkbook order.
- Cancel Checkbook Cancels an order before it ships. Only possible while the order is pending, and final once done, so a replacement has to be ordered fresh.
Mailboxes
6- Create Mailbox Provisions a physical mailing address that receives paper mail on your behalf, so incoming checks arrive as scanned digital records instead of post.
- Get Mailboxes Lists the mailboxes on the account with their street addresses and status.
- Get Mailbox Retrieves one mailbox with its full street address and status.
- Get Mail Items Lists the mail received at a mailbox, newest first, with a date range and free text search. The queue an inbound reconciliation flow works through.
- Get Mail Item Retrieves one piece of received mail, including any checks found inside with their amounts and numbers.
- Get Mail Item Attachment Returns the scanned images of a received piece of mail, which is how the physical document behind a mailbox entry is actually read.
Bank Accounts
9- Get Bank Accounts Lists linked bank accounts with each one's status, type, last four digits, and whether it is the default or billing account. The check that a funding account is verified rather than pending.
- Add Bank Account Links a bank account by routing and account number. The right choice when mailed or printed checks are involved, because tokenized account numbers from an aggregator cause conflicts on deposit.
- Add Bank Account With Plaid Links accounts using a Plaid processor token, verifying instantly and skipping the micro-deposit wait.
- Add Bank Account With Instant Verification Links an account by signing in to the institution directly, verifying instantly without micro-deposits.
- Get Bank Institutions Lists the banks that support instant verification, with the institution id each is addressed by.
- Release Micro-Deposits Sends the two small verification deposits to a pending account, starting the verification cycle.
- Verify Micro-Deposits Confirms the two amounts and moves a pending account to verified, which is what lets it fund outgoing payments.
- Update Bank Account Renames an account or changes which one is the default or billing account. Changing the default silently changes what funds every payment that does not name an account.
- Remove Bank Account Unlinks a bank account from the Checkbook user.
Cards
4- Get Cards Lists the debit cards on the account with last four digits, creation date, and default flag.
- Add Card Adds a debit card that payments can be pushed to instantly. The billing address has to match what the issuer holds, and only the last four digits are readable back afterward.
- Update Card Renames a card, changes its billing address, or makes it the default for incoming pushes.
- Remove Card Removes a debit card from the account.
Virtual Cards
6- Get Virtual Cards Lists issued virtual cards with their last four digits and expiry.
- Create Virtual Card Issues a new virtual card number the recipient can spend against, returning the full number, expiry, and security code exactly once. Treat the response as money: anything that logs it is logging a spendable credential.
- Update Virtual Card Renames a virtual card, updates its billing address, or makes it the default.
- Remove Virtual Card Cancels a virtual card so nothing further can be charged to it. The fast lever when a card is in doubt.
- Get Virtual Card Transactions Lists the charges made against a virtual card over a date range. The read behind reconciling what a supplier actually spent against what was authorized.
- Get Virtual Card Transaction Retrieves one transaction with its merchant, amount, timestamp, and settlement status.
Wallets
4- Get Wallets Lists the wallets on the account.
- Create Wallet Creates a wallet to hold a prefunded balance inside Checkbook. The external routing and account numbers are revealed exactly once in this response.
- Update Wallet Renames a wallet.
- Delete Wallet Closes a wallet.
Wire Accounts
4- Get Wire Accounts Lists accounts registered for wire transfers with their last four digits and routing numbers.
- Add Wire Account Registers a bank account for wires. The wire routing number differs from the ACH one for the same account, so take it from the bank's wire instructions rather than from a check.
- Update Wire Account Renames a registered wire account.
- Remove Wire Account Removes a registered wire account.
Alternative Rails
12- Get PayPal Accounts Lists the PayPal accounts registered for receiving payments.
- Add PayPal Account Registers a PayPal account so payments can be pushed to it.
- Update PayPal Account Renames a registered PayPal account.
- Remove PayPal Account Removes a registered PayPal account.
- Get Venmo Accounts Lists the Venmo accounts registered for receiving payments.
- Add Venmo Account Registers a Venmo account, identified by the email address or phone number the account uses.
- Update Venmo Account Renames a registered Venmo account.
- Remove Venmo Account Removes a registered Venmo account.
- Get Interac Accounts Lists the Interac accounts registered for receiving payments.
- Add Interac Account Registers an Interac account so payments can be pushed to a Canadian recipient, identified by the email address or phone number on their Interac e-Transfer profile.
- Update Interac Account Renames a registered Interac account.
- Remove Interac Account Removes a registered Interac account.
Users
3- Get User Returns the profile behind the API keys: name, business name, verification status, contact details, the next check and invoice numbers, the KYB record, and the branding on outgoing payments. The poll that confirms verification has actually settled.
- Update User Updates that profile, covering personal details, the business KYB record, payment branding, the webhook URL, and the next check and invoice numbers. This is where the webhook endpoint is set, and a successful call means accepted for review rather than verified.
- Add Signature Stores the account holder's signature so it can be printed on checks. Worth doing during onboarding, because larger payments can require one on file.
Marketplace
3- Create Marketplace User Creates a sub-user under a marketplace account and returns that user's own API key pair. How a platform onboards sellers, contractors, or tenants who each send and receive in their own name.
- Get Marketplace Users Lists sub-users with each one's Checkbook id, your own identifier, and verification status. A sub-user has to be verified before they can create payments.
- Delete Marketplace User Removes a sub-user and revokes their keys. Takes the Checkbook generated id rather than the identifier you supplied, and refuses to delete a user with active transactions.
API Keys
3- Get API Keys Lists the keys issued for the user with each key's name, publishable half, and expiry. The read behind rotating a key before it lapses rather than after a flow starts failing.
- Create API Key Issues a new key pair and returns the secret along with the webhook signing key, both shown exactly once. Capture them in the same flow run, because neither can be read back.
- Delete API Key Revokes a key immediately. Anything still authenticating with it fails at once, so switch consumers over first and take care not to revoke the key the connection itself is using.
Sandbox
2- Simulate Payment Status Forces a payment into a chosen status in the sandbox and fires the matching webhook, so a flow's handling of paid, failed, and returned payments can be tested without real settlement. Refused in production.
- Simulate User Status Forces a marketplace user into a chosen verification status in the sandbox, so onboarding flows can be exercised without waiting on real KYB or KYC review. Refused in production.
Frequently Asked Questions
What can FlowRunner do with Checkbook.io?
FlowRunner agents can run Send Digital Payment, Send Physical Check, and Send Multi-Party Payment in Checkbook.io, plus 102 more actions.
Does connecting Checkbook.io to FlowRunner require OAuth?
No. Checkbook.io connects to FlowRunner with an API key, no OAuth flow required.
Can Checkbook.io trigger a FlowRunner workflow automatically?
Checkbook.io doesn't currently expose triggers in FlowRunner. It connects as an action step inside workflows started by another trigger.
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