Invoice Simple MCP server Let your AI agent do your Invoice Simple paperwork.

ToolWhat it doesAccess

• list_invoices Invoices by status, client or date, with balances. read

  Returns invoices with client, total, balance due, due date and status (Draft, Sent, Overdue, Paid). Newest first.

  MCP callinvoice_simple_read → list_invoices

  REST endpointGET https://cotlet.dev/api/v1/invoice-simple/invoices

  Parameters

  Parameters: list_invoices

  Name	Type	Description
  status string	string	draft, sent, overdue, paid or all. Default: all.
  client string	string	Client name.
  page integer	integer	Page number. Default: 1.

  Example response

  {
    "invoices": [
      {
        "invoice_number": "INV0142",
        "client": "Lee Residence",
        "total": "850.00",
        "balance_due": "850.00",
        "due": "2026-11-01",
        "status": "Overdue"
      }
    ],
    "page": 1
  }

• get_invoice One invoice with lines, tax, payments and history. read

  Returns the invoice lines, tax, discount, payments recorded and when it was sent and viewed.

  MCP callinvoice_simple_read → get_invoice

  REST endpointGET https://cotlet.dev/api/v1/invoice-simple/invoices/{invoice_number}

  Parameters

  Parameters: get_invoice

  Name	Type	Description
  invoice_number string required	string	Invoice number from list_invoices.

  Example input

  {
    "invoice_number": "invoice number"
  }

  Example response

  {
    "invoice_number": "INV0142",
    "client": "Lee Residence",
    "items": [
      {
        "description": "Bathroom tile repair",
        "quantity": 1,
        "rate": "850.00"
      }
    ],
    "tax": "0.00",
    "payments": [],
    "sent": "2026-10-18",
    "viewed": "2026-10-19"
  }

• create_invoice Creates a draft invoice for a client. write

  Creates the invoice with your default terms, tax and notes. It stays a draft until send_invoice, so it runs at once.

  MCP callinvoice_simple_write → create_invoice

  REST endpointPOST https://cotlet.dev/api/v1/invoice-simple/invoices

  Parameters

  Parameters: create_invoice

  Name	Type	Description
  client string required	string	Client name; a new name creates the client.
  items object[] required	object[]	Lines: description, quantity, rate.
  due_date string	string	ISO date. Default: your terms.
  notes string	string	Notes shown on the invoice.

  Example input

  {
    "client": "client",
    "items": [
      "items"
    ]
  }

  Example response

  {
    "invoice_number": "INV0151",
    "client": "Maria Lopez",
    "total": "1,240.00",
    "status": "Draft"
  }

• send_invoice Emails an invoice to the client. writeasks first

  Sends the invoice with its payment link, if you set one up, to the client's email or the addresses you pass. By default you confirm each call; you can switch that off for this tool.

  MCP callinvoice_simple_write → send_invoice

  REST endpointPOST https://cotlet.dev/api/v1/invoice-simple/invoices/{invoice_number}

  Parameters

  Parameters: send_invoice

  Name	Type	Description
  invoice_number string required	string	Invoice number from list_invoices.
  to string[]	string[]	Recipient emails. Default: the client's email.
  message string	string	Email message.

  Example input

  {
    "invoice_number": "INV0151"
  }

  Example response

  {
    "invoice_number": "INV0151",
    "status": "Sent",
    "sent_to": [
      "maria@example.com"
    ]
  }

• mark_invoice_paid Records a payment on an invoice. writeasks first

  Adds a payment such as cash, check or bank transfer and updates the balance due. No card is charged. By default you confirm each call; you can switch that off for this tool.

  MCP callinvoice_simple_write → mark_invoice_paid

  REST endpointPOST https://cotlet.dev/api/v1/invoice-simple/invoices/{invoice_number}/paid/mark

  Parameters

  Parameters: mark_invoice_paid

  Name	Type	Description
  invoice_number string required	string	Invoice number from list_invoices.
  amount string required	string	Amount, e.g. 850.00.
  method string	string	cash, check, bank_transfer or other.
  date string	string	ISO date. Default: today.

  Example input

  {
    "invoice_number": "invoice number",
    "amount": "amount"
  }

  Example response

  {
    "invoice_number": "INV0142",
    "payment": {
      "method": "Check",
      "amount": "850.00"
    },
    "balance_due": "0.00",
    "status": "Paid"
  }

ToolWhat it doesAccess

• list_estimates Estimates by status or client. read

  Returns estimates with client, total and status, so the agent can follow up or convert the accepted ones.

  MCP callinvoice_simple_read → list_estimates

  REST endpointGET https://cotlet.dev/api/v1/invoice-simple/estimates

  Parameters

  Parameters: list_estimates

  Name	Type	Description
  status string	string	draft, sent, accepted or all. Default: all.
  page integer	integer	Page number. Default: 1.

  Example response

  {
    "estimates": [
      {
        "estimate_number": "EST0058",
        "client": "Maria Lopez",
        "total": "1,240.00",
        "status": "Sent",
        "date": "2026-10-28"
      }
    ],
    "page": 1
  }

• create_estimate Creates a draft estimate for a client. write

  Creates the estimate from your lines. It stays a draft until send_estimate, so it runs at once.

  MCP callinvoice_simple_write → create_estimate

  REST endpointPOST https://cotlet.dev/api/v1/invoice-simple/estimates

  Parameters

  Parameters: create_estimate

  Name	Type	Description
  client string required	string	Client name.
  items object[] required	object[]	Lines: description, quantity, rate.
  notes string	string	Notes shown on the estimate.

  Example input

  {
    "client": "client",
    "items": [
      "items"
    ]
  }

  Example response

  {
    "estimate_number": "EST0061",
    "client": "Tom Becker",
    "total": "2,300.00",
    "status": "Draft"
  }

• send_estimate Emails an estimate to the client. writeasks first

  Sends the estimate to the client's email or the addresses you pass. By default you confirm each call; you can switch that off for this tool.

  MCP callinvoice_simple_write → send_estimate

  REST endpointPOST https://cotlet.dev/api/v1/invoice-simple/estimates/{estimate_number}

  Parameters

  Parameters: send_estimate

  Name	Type	Description
  estimate_number string required	string	Estimate number from list_estimates.
  to string[]	string[]	Recipient emails. Default: the client's email.

  Example input

  {
    "estimate_number": "estimate number"
  }

  Example response

  {
    "estimate_number": "EST0061",
    "status": "Sent",
    "sent_to": [
      "tom@example.com"
    ]
  }

• convert_estimate Turns an estimate into a draft invoice. write

  Copies the estimate lines into a new draft invoice. Nothing is sent, so it runs at once.

  MCP callinvoice_simple_write → convert_estimate

  REST endpointPOST https://cotlet.dev/api/v1/invoice-simple/estimates/{estimate_number}/convert

  Parameters

  Parameters: convert_estimate

  Name	Type	Description
  estimate_number string required	string	Estimate number from list_estimates.

  Example input

  {
    "estimate_number": "estimate number"
  }

  Example response

  {
    "estimate_number": "EST0058",
    "invoice_number": "INV0152",
    "total": "1,240.00",
    "status": "Draft"
  }

ToolWhat it doesAccess

• list_clients Clients with contact details and what they owe. read

  Returns clients with email, phone and the total of their unpaid invoices.

  MCP callinvoice_simple_read → list_clients

  REST endpointGET https://cotlet.dev/api/v1/invoice-simple/clients

  Parameters

  Parameters: list_clients

  Name	Type	Description
  query string	string	Name, email or phone.
  page integer	integer	Page number. Default: 1.

  Example response

  {
    "clients": [
      {
        "name": "Lee Residence",
        "email": "lee@example.com",
        "phone": "555-0142",
        "owing": "850.00"
      }
    ],
    "page": 1
  }