Plugin

Invoice by Ouroboros Apps

Early access

Approved freelance invoices, rates, due dates, and late terms. For freelancers and independent consultants.

The assistant quotes the sealed invoice. A new line or a different rate after that needs an accepted change.

Server URL

Connect

• Claude: Customize, then Connectors, then Add custom connector. Paste the URL and sign in.
• Cursor: add this to ~/.cursor/mcp.json or .cursor/mcp.json, then restart and sign in.
• Grok: grok.com/connectors, New Connector, Custom, then the URL.

ChatGPT's directory doesn't list this yet. Use developer mode until it does. That's the early-access route.

{
  "mcpServers": {
    "invoice": {
      "url": "https://invoice-continuity2.vercel.app/mcp"
    }
  }
}

Tools

These names and descriptions are what the server returns from tools/list before you sign in.

• list_invoices List the signed-in freelancer's invoices. Use a returned id with read_invoice. Do not guess an invoice.
• begin_invoice Start a draft invoice. Draft figures are not an approved commitment until seal_invoice. Currency is a three-letter code. Amounts later are minor units of that currency and are the freelancer's figures.
• read_invoice Read the invoice before answering. Quote only this record. Draft status is not an approved commitment. Proposed changes do not authorize a new line, a different rate, a discount, or a new due date.
• place_line Add one line: description, quantity, rate in whole minor units, and unit hour, each, or day. After the invoice is sealed, a new line is refused until accept_invoice_change applies an add_line suggestion.
• describe_line Correct a line description while the invoice is still a draft. After approval, a different description is refused. Use suggest_invoice_change with add_line for a different line.
• quote_line_rate Set the rate already chosen for one line, as a whole number of minor units in the invoice currency. After the invoice is sealed, a different rate is refused until accept_invoice_change applies a change_rate suggestion.
• set_line_quantity Set the quantity on one line. After the invoice is sealed, a different quantity is refused until accept_invoice_change applies an adjust_quantity suggestion.
• set_invoice_due Set the due date as a calendar day in YYYY-MM-DD form. After the invoice is sealed, a different date is refused until accept_invoice_change applies a move_due_date suggestion.
• write_late_terms Record late terms: grace days, and a basis of none, flat_fee, or percent_per_period. flat_fee uses feeMinor and a percent of 0. percent_per_period uses percent and a fee of 0. After approval, a different basis, grace, fee, or percent is ref
• offer_discount Record a discount the freelancer is putting on the invoice. kind none uses value 0. kind percent takes a whole number from 1 to 100. kind fixed takes a whole number of minor units. After the invoice is sealed, a different discount is refuse
• seal_invoice Mark the current draft as the approved invoice. Pass confirmed true only after the freelancer explicitly approves the lines, quantities, rates, due date, late terms, and any discount already on the draft.
• suggest_invoice_change Record a suggested change. This does not change the invoice. kind add_line requires description, quantity, rateMinor, and unit. kind change_rate requires lineId and rateMinor. kind apply_discount requires discountKind, discountValue, and di
• accept_invoice_change Apply one suggested invoice change after the freelancer explicitly approves that change. Pass confirmed true only then. This is the path that may add a line, change a rate, apply a discount, or move the due date. Calling it is not a substit