> ## Documentation Index
> Fetch the complete documentation index at: https://dev.nickel.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Tool Reference
> Every tool the Nickel MCP server offers, and which ones ask before they run
Your assistant chooses tools on its own, so you don't need to name them. This page is for knowing what the assistant can and can't do in your account, and what each change will do before you confirm it.
**Asks first** marks a tool that changes your account. Your client shows you the exact action and waits for you to confirm before it runs — see [Permissions and confirmations](/mcp/permissions). Every other tool only reads.
Tools take amounts in **cents**: `amountInCents: 125000` is \$1,250.00. Your assistant converts for you, and Nickel's confirmation shows amounts in dollars. If your client also displays the raw tool call, that display shows cents. The one exception is a spreadsheet you import, whose amount column is in dollars.
## Invoices and customers
In Nickel, an invoice and a **payment link** are the same thing: a page your customer opens to pay you.
| Tool | What it does | Asks first |
| - | - | - |
| `search_customers` | Finds customers by name or email, or looks up a list of up to 200 email addresses at once. | No |
| `get_customer` | Gets one customer, with their saved payment methods. | No |
| `create_customer` | Creates a customer. At least one email is required, because that's where invoices and receipts go. | Yes |
| `update_customer` | Changes a customer's name, emails, or phone numbers. A new list of emails or phone numbers replaces the old one. | Yes |
| `create_invoice` | Creates an invoice for an existing customer, with optional attachments and QuickBooks line items. It doesn't send the invoice. | Yes |
| `search_invoices` | Searches invoices with the same filters as the dashboard: status, past due, amount, dates, sent or unsent. | No |
| `get_invoice` | Gets one invoice with its payment progress, every payment against it, and any payments recorded outside Nickel. | No |
| `update_invoice` | Changes an invoice's number, amount, due date, issue date, or memo. Lowering the amount to what the customer has already paid marks it paid. | Yes |
| `delete_invoice` | Deletes an invoice. One that already has a payment against it is archived instead. | Yes |
| `send_invoice` | Emails the invoice to the recipients you name. Every call sends again, so a second send works as a reminder. | Yes |
| `record_invoice_payment` | Marks an invoice paid, fully or partly, for money you received outside Nickel, such as a check or cash. No money moves. Reminders continue for any amount still owed. | Yes |
| `void_invoice_external_payment` | Undoes a payment recorded outside Nickel, or unapplies a check deposit. It can't undo money collected through Nickel — refund that instead. | Yes |
When QuickBooks Online is connected, the customers and invoices you create can sync to it, and recording or voiding a payment on a synced invoice updates the matching payment in QuickBooks.
## Recurring invoices
| Tool | What it does | Asks first |
| - | - | - |
| `search_recurring_invoices` | Lists recurring invoice schedules, soonest next invoice first. | No |
| `get_recurring_invoice` | Gets one schedule and its 12 most recent invoices. | No |
| `create_recurring_invoice` | Creates a schedule and its first invoice, due on the start date. The first invoice isn't emailed. The schedule starts charging automatically once the customer pays that invoice and saves a payment method, or once you activate it in the dashboard. | Yes |
| `update_recurring_invoice` | Changes the amount, cadence, dates, number, or memo for future invoices, and reprices the current open invoice unless a payment on it is already in progress. | Yes |
| `cancel_recurring_invoice` | Stops the schedule for good and archives the open invoice. Paid invoices aren't touched or refunded. A synced open invoice has to be voided in QuickBooks separately. | Yes |
## Payments and refunds
| Tool | What it does | Asks first |
| - | - | - |
| `search_payment_activities` | Searches the same activity as the dashboard's Transactions page: payments in and out, refunds, returns, chargebacks, deposits, withdrawals, interest, and fees. | No |
| `get_payment` | Gets one customer payment: its status, its payout to your bank, refunds, any failure reason, and a receipt PDF. | No |
| `refund_payment` | Refunds a payment in full or in part. A full refund of a payment that hasn't settled cancels it instead, when the payment method allows. | Yes |
| `charge_payment_methods_on_file` | Charges one or more invoices to the customer's saved payment methods, for the full balance or an amount you choose, now or on a future date. | Yes |
| `request_payment_method_on_file` | Emails customers a link to save a card or bank account with you. | Yes |
| `create_ach_payment_method_on_file` | Saves a customer's bank account for future debits, together with the authorization they signed. The signed authorization is required. | Yes |
| `create_ach_payment_methods_on_file` | Saves up to 25 customers' bank accounts at once, each with the authorization that customer signed, and asks you to confirm once for the whole batch. Each account saves or fails on its own, and a customer who already has that account isn't saved twice, so sending a batch again is safe. It can also add an email to a customer that has none, since a saved bank account needs one. | Yes |
## Vendors
A **delivery method** is how a vendor receives your payments: ACH to their bank account, a mailed check, or an international wire.
| Tool | What it does | Asks first |
| - | - | - |
| `search_vendors` | Finds vendors by name or email. | No |
| `get_vendor` | Gets one vendor, with their delivery methods. | No |
| `create_vendor` | Creates a vendor. Payment confirmations go to the emails you give. | Yes |
| `update_vendor` | Changes a vendor's name, emails, or billing address. | Yes |
| `update_vendor_ach` | Sets the vendor's bank account for ACH, replacing any earlier one. | Yes |
| `update_vendor_check` | Sets the address Nickel mails checks to, replacing any earlier one. | Yes |
| `update_vendor_wire` | Sets the vendor's international (SWIFT) wire details. Each wire payment carries a \$20 fee. | Yes |
| `request_vendor_delivery_details` | Emails vendors a secure link to enter their own payment details, so you never handle their account numbers. | Yes |
| `delete_vendor_delivery_method` | Removes one of a vendor's delivery methods. | Yes |
| `delete_vendor` | Deletes a vendor. A vendor linked to QuickBooks can't be deleted. | Yes |
Changing or removing a delivery method doesn't affect payments already scheduled — they still go to the old details. Cancel and reschedule them if the old details are wrong.
## Bills
| Tool | What it does | Asks first |
| - | - | - |
| `create_bill` | Records a bill you owe an existing vendor, with optional attachments. It doesn't pay the bill. | Yes |
| `search_bills` | Searches bills by vendor, paid status, amount, and dates, or looks up a list of up to 200 invoice numbers at once. | No |
| `get_bill` | Gets one bill with its payment progress, including scheduled payments and their estimated arrival. | No |
| `update_bill` | Changes a bill's amount, due date, description, or invoice number. | Yes |
| `delete_bill` | Deletes a bill that hasn't been paid and isn't waiting on approval. | Yes |
| `record_bill_payment` | Marks a bill paid for money you sent outside Nickel. No money moves. | Yes |
| `void_bill_external_payment` | Undoes a bill payment recorded outside Nickel. | Yes |
## Paying bills and approvals
| Tool | What it does | Asks first |
| - | - | - |
| `get_merchant_payment_methods` | Lists the bank accounts, cards, and Nickel Banking accounts you can pay bills from. | No |
| `check_bill_approval` | Tells you whether a payment would need approval, and who can approve it. | No |
| `pay_bill` | Pays one or more bills, now or timed to arrive by a date you choose. Each vendor gets a payment confirmation email. A payment your approval policy covers goes to your approvers instead. | Yes |
| `get_bill_payment` | Gets one payment you sent a vendor: its delivery status, estimated arrival, any failure, and a receipt PDF. | No |
| `cancel_bill_payment` | Cancels a scheduled payment, or one that's still pending. A payment that has already settled can't be cancelled. | Yes |
| `get_approval_policy` | Shows your bill approval policy: the amount above which payments need approval, and who approves. | No |
| `create_approval_policy` | Sets your bill approval policy, replacing any existing one. | Yes |
## Recurring bills
| Tool | What it does | Asks first |
| - | - | - |
| `search_recurring_bills` | Lists recurring vendor payment schedules. | No |
| `get_recurring_bill` | Gets one schedule and its 12 most recent bills. | No |
| `create_recurring_bill` | Creates a schedule that creates **and pays** a bill every cycle. The first payment goes out on the start date. If your approval policy covers it, the schedule waits for approval before anything is paid. | Yes |
| `cancel_recurring_bill` | Stops the schedule for good and voids the current unpaid bill. A payment already scheduled or on its way isn't reversed; cancel it separately with `cancel_bill_payment` if it hasn't settled. | Yes |
## Nickel Banking and check deposits
These tools appear only when your organization has an active Nickel Banking account.
| Tool | What it does | Asks first |
| - | - | - |
| `list_nickel_banking_accounts` | Lists your accounts with their settled balances and pending card holds. | No |
| `list_nickel_banking_cards` | Lists your debit cards: status, last four digits, limits, and spend. Never the full card number. | No |
| `list_check_deposits` | Lists deposited checks, and how much of each hasn't been applied to an invoice yet. | No |
| `deposit_check` | Deposits a paper check from photos of its front and back, and can apply it to invoices in the same step. | Yes |
| `apply_check_deposit_to_invoice` | Marks an invoice paid with money from a check you deposited. If the bank returns the check, Nickel unapplies it. | Yes |
## Importing from a spreadsheet
Each import reads a CSV or Excel file of up to 500 rows. The assistant maps your columns to Nickel's fields. Rows that match a record you already have are skipped, and each import reports which rows it created, skipped, and couldn't import.
| Tool | What it does | Asks first |
| - | - | - |
| `bulk_import_vendors` | Creates vendors from names and emails. Payment details in the file aren't imported. | Yes |
| `bulk_import_customers` | Creates customers from names, emails, and phone numbers. Every row needs an email. | Yes |
| `bulk_import_bills` | Creates bills for vendors that already exist. It doesn't pay them. | Yes |
| `bulk_import_invoices` | Creates invoices for customers that already exist. It doesn't send them, and they don't sync to QuickBooks. | Yes |
## QuickBooks
| Tool | What it does | Asks first |
| - | - | - |
| `get_accounting_integration_status` | Tells you whether QuickBooks Online or QuickBooks Desktop is connected. Only QuickBooks Online syncs records created through these tools. | No |
| `get_quickbooks_accounts_and_items` | Lists the QuickBooks accounts and items to categorize bills or invoices with. | No |
## Team and notifications
| Tool | What it does | Asks first |
| - | - | - |
| `get_team` | Lists your team members, their roles, and pending invites. | No |
| `get_workspace_role` | Shows what one role can and can't do, and who has it. | No |
| `get_notification_settings` | Shows who gets which notifications, and how your invoices appear to customers. | No |
| `update_my_notifications` | Turns your own notification emails on or off. It can't change anyone else's. | Yes |
## Files
Tools that take a file — an invoice or bill attachment, check photos, a spreadsheet to import — take the ID of a file you've uploaded. `upload_file` returns that ID and a URL to send the file's contents to. Your client uploads straight to that URL, so the file never passes through the conversation.
| Tool | What it does | Asks first |
| - | - | - |
| `upload_file` | Prepares an upload and returns a file ID and a one-hour upload URL. | No |
* Accepted types are PDF, JPEG, PNG, WebP, CSV, and Excel (`.xlsx`), up to 25 MB each.
* Check photos must be JPEG, PNG, or WebP. Convert a HEIC photo, or a scanned PDF of a check, to one of those first.
* A tool call can take up to 10 files. `create_ach_payment_methods_on_file` takes one per customer, so up to 25.
* A file can only be used in the organization that uploaded it.
## What stays in the dashboard
Some things have no tool, so your assistant will point you to the dashboard for them:
* Approving or rejecting a bill payment waiting on approval.
* Pausing a recurring invoice or recurring bill, or changing a recurring bill's amount, cadence, or dates.
* Removing a bill approval policy.
* Inviting, removing, or changing the role of a team member.
* Setting a limit or expiry on a customer's saved payment method.
## Where to go next
How confirmations and approval policies work.
Add the server to your assistant.