MCP · API · SDKs

Accounting for the agentic era.

Your AI agents can read and run your books through Oscar, and our accountants check the result.

Oscar opens to new clients soon. Join the waitlist and we will write to you first.

Your agent · Oscar

What do we owe Hetzner, and how does the September VAT return look?

oscar.get_open_items(company_id, as_of="2026-09-30")oscar.preview_vat_return(company_id, period_from="2026-09-01", period_to="2026-09-30")

€89.25 is open, due 14 October. The preview of the September return shows €2,140.60 of VAT to pay.

Checked by your accountant

01 · MCP

A remote MCP server

Add Oscar as a connector in Claude, ChatGPT, Cursor or any other MCP client. The server speaks Streamable HTTP and signs you in with OAuth 2.1: the consent page shows what the agent asks for, and you choose the organization it reaches.

A second address gives the read tools only, for an agent that must not change anything.

https://oscaraccountant.com/mcp/readonly

Connect your agent

Run this in a terminal, then run /mcp in Claude Code to sign in.

claude mcp add --transport http oscar https://oscaraccountant.com/mcp

  • Record supplier invoices

    Your agent records a supplier invoice and posts it, and follows the invoices sent to the inbox address of your company.

  • Create and issue sales invoices

    Your agent drafts a sales invoice, corrects it, and issues it with its number when you are ready.

  • Match bank payments to invoices

    Your agent reads your bank transactions and the matches Oscar proposes, and confirms or rejects them.

  • Find what is unpaid and overdue

    Your agent sees what customers owe you and what you owe suppliers, aged at any date.

  • Check the VAT return before it is filed

    Your agent previews the VAT return of a period and its invoice listing, before your accountant files it.

  • Read the books

    The trial balance, the general ledger and every journal entry, for any period.

  • Find what is missing

    Your agent lists the bank payments that still need a receipt or a decision.

  • Ask a person to decide

    When a booking needs a judgement, your agent proposes it, and a person confirms it in Oscar.

90 tools in all, each limited by your permissions.

02 · API and SDKs

A public REST API, and SDKs for it

An OpenAPI 3 contract, API keys scoped to read or write, idempotency keys for safe retries, and errors with stable codes. The TypeScript, Python, Rust and PHP SDKs and the oscar CLI are generated from the same contract.

The official packages

  • TypeScript@oscaraccountant/sdk
  • Pythonoscaraccountant
  • Rustoscaraccountant
  • PHPoscaraccountant/sdk
  • CLI@oscaraccountant/cli

The same call in each SDK: the profit and loss statement of September

$ npm install @oscaraccountant/sdk
import { Oscar } from '@oscaraccountant/sdk';

const oscar = new Oscar(); // reads OSCAR_API_KEY
const pnl = await oscar.reports.profitAndLoss(companyId, {
  date_from: '2026-09-01',
  date_to: '2026-09-30',
});

04 · Safety

Human in the loop, by design

  • Permissions per key and per tool

    A key or a connection acts with the role of its person, narrowed by its scopes. The MCP server lists only the tools that the role, the scopes and the company allow, and the API checks every call again.

  • An append-only ledger

    Every change to the books is a command of the accounting core. A posted entry is never edited or deleted: a correction is a new entry, and the audit log records who did what.

  • People make the judgements

    An agent never runs an exemption, a classification of money received or the reopening of a period. It proposes one, and a person confirms it in the app.

  • Your accountant checks and files

    Your agent records and drafts. Our accountants check the books, prepare the VAT returns and file them with EMTA.

05 · Workflows

What your agent can do with Oscar

  • Forward invoices and let your agent reconcile them

    Supplier invoices sent to the private inbox address of your company become drafts. Oscar proposes matches with your bank payments, and your agent confirms or rejects them, as far as your permissions allow.

  • Ask your agent for the VAT position before you pay a supplier

    Your agent reads what you still owe the supplier and previews the VAT return of the period. Nothing is written.

  • Your agent pulls this month's P&L into your board update

    One call returns the profit and loss statement of a period in the Estonian scheme, with a comparison period when you want one.

Bring your agent. Our accountants check its work.

One flat price, with MCP and the API included.