> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lastaccountingcompany.com/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP server

> Connect Claude, ChatGPT, Cursor, VS Code, or your own agents to your company's books over MCP.

Give any MCP-capable AI client direct, tenant-isolated access to your company's books. The LAC MCP server exposes the same capabilities as the [REST API](/api-reference) — books, VAT, statements, documents, invoicing, and Björn — as 31 typed tools.

|               |                                                                                                  |
| ------------- | ------------------------------------------------------------------------------------------------ |
| **Endpoint**  | `https://api.app.lastaccountingcompany.com/mcp`                                                  |
| **Transport** | Streamable HTTP, stateless (MCP spec `2025-11-25`)                                               |
| **Auth**      | OAuth (hosted clients) or a portal API key as a bearer token: `Authorization: Bearer lac_sk_...` |

## Authentication

Two ways in:

* **OAuth** — for hosted clients like claude.ai and ChatGPT. Add the endpoint URL in your assistant's connector settings; it walks you through signing in with your normal LAC portal account (Google) and authorizing. On the consent screen you pick **which business the connection is for** — accounts with access to multiple businesses choose one business per connection. OAuth connections act with **operator** access: they can read the books and statements, upload documents, draft and send invoices, and message Björn — never approve payroll, change company settings, or manage access or keys, no matter your own portal role.
* **Portal API key** — for clients that send custom headers (Claude Code, Cursor, VS Code, the OpenAI Responses API, anything speaking streamable HTTP). Create one in **Settings → API access** (see [getting started](/)) and send it as a bearer token. Like OAuth connections, keys are minted per business. The tools you see follow the key's scope: **read-scope keys see only the read tools**; write-scope keys see all 31.

## Connect a client

### claude.ai (web)

In claude.ai: **Settings → Connectors → Add custom connector**, and enter:

```
https://api.app.lastaccountingcompany.com/mcp
```

Claude opens the LAC sign-in (your normal Google portal login) and asks you to authorize and pick the business. Disconnecting the connector in Claude ends its access.

### ChatGPT (web)

In ChatGPT: **Settings → Connectors** (requires developer mode / a plan with custom connectors) → add the same URL. ChatGPT runs the same OAuth sign-in.

### Claude Code

```bash theme={null}
claude mcp add --transport http lac \
  https://api.app.lastaccountingcompany.com/mcp \
  --header "Authorization: Bearer lac_sk_..."
```

Then ask, for example: "What's our VAT position for June?"

### Cursor

Add to `~/.cursor/mcp.json` (or the project's `.cursor/mcp.json`):

```json theme={null}
{
  "mcpServers": {
    "lac": {
      "url": "https://api.app.lastaccountingcompany.com/mcp",
      "headers": {
        "Authorization": "Bearer lac_sk_..."
      }
    }
  }
}
```

### VS Code

Add to `.vscode/mcp.json` in your workspace:

```json theme={null}
{
  "servers": {
    "lac": {
      "type": "http",
      "url": "https://api.app.lastaccountingcompany.com/mcp",
      "headers": {
        "Authorization": "Bearer lac_sk_..."
      }
    }
  }
}
```

### OpenAI API (Responses)

```python theme={null}
response = client.responses.create(
    model="gpt-5",
    tools=[{
        "type": "mcp",
        "server_label": "lac",
        "server_url": "https://api.app.lastaccountingcompany.com/mcp",
        "authorization": "lac_sk_...",
        "require_approval": "always"
    }],
    input="Which invoices are overdue, and by how much?"
)
```

### Generic JSON

For any client that takes a standard MCP server config:

```json theme={null}
{
  "mcpServers": {
    "lac": {
      "type": "streamable-http",
      "url": "https://api.app.lastaccountingcompany.com/mcp",
      "headers": {
        "Authorization": "Bearer lac_sk_..."
      }
    }
  }
}
```

The server is stateless — no session setup, safe to retry.

## Tool reference

31 tools (18 read / 13 write). Read tools are available to every key; write tools appear only for write-scope keys and OAuth connections.

### Read tools (all keys)

| Category    | Tool                       | Description                                                                                   |
| ----------- | -------------------------- | --------------------------------------------------------------------------------------------- |
| Company     | `get_company_profile`      | Company profile: name, business ID (Y-tunnus), VAT period cadence.                            |
| Company     | `get_overview`             | Dashboard in one call: key metrics, attention items, books readiness.                         |
| Company     | `get_agent_status`         | Björn's live status and document-ingest progress.                                             |
| Books       | `get_books`                | General-ledger rows, paginated; range accepts `YYYY-MM`, `YYYY-Qn`, `YYYY`, or `this_month`.  |
| Books       | `get_vat`                  | The VAT view for a period.                                                                    |
| Statements  | `get_financial_statements` | Income statement, balance sheet, or cash-flow statement as a nested tree of lines.            |
| Statements  | `drill_statement_line`     | The transactions behind one or more account codes on a statement line.                        |
| Statements  | `get_analytics`            | Time series over the books for a range.                                                       |
| Documents   | `list_documents`           | Uploaded evidence and the ingest state of each document.                                      |
| Messaging   | `list_messages`            | The conversation history with Björn; `limit` returns the most recent N messages (default 50). |
| Filings     | `get_filings`              | VAT preview, drafts, filed returns, and the standing authorization state.                     |
| Filings     | `list_output_packages`     | Published VAT, financial-statement, and CIT output packages.                                  |
| Invoicing   | `list_invoices`            | Sales invoices with their statuses; `limit` caps each list (default 100).                     |
| Invoicing   | `get_invoice`              | One invoice in full detail.                                                                   |
| Invoicing   | `list_invoice_customers`   | The billing-customer party book.                                                              |
| Invoicing   | `list_recurring_invoices`  | Recurring invoice templates.                                                                  |
| Connections | `list_connections`         | Health of bank, Stripe, Procountor, Fennoa, inbox, and Sheets connections.                    |
| Imports     | `list_imports`             | Migration/import runs and their statuses.                                                     |

### Write tools (write-scope keys)

| Category    | Tool                         | Description                                                                                         |
| ----------- | ---------------------------- | --------------------------------------------------------------------------------------------------- |
| Documents   | `upload_documents`           | Upload base64-encoded files into the document-ingest pipeline.                                      |
| Documents   | `update_document`            | Rename a document or attach a context note for bookkeeping.                                         |
| Documents   | `delete_document`            | Delete an uploaded document. **Destructive.**                                                       |
| Messaging   | `send_message`               | Send a message to Björn, the AI accountant.                                                         |
| Filings     | `request_filing_review`      | Ask LAC to review a filing period.                                                                  |
| Filings     | `set_filing_authorization`   | Set or withdraw the standing authorization for LAC to file on the company's behalf.                 |
| Invoicing   | `create_invoice_draft`       | Draft a sales invoice (amounts in cents, VAT rates in basis points); drafting never sends anything. |
| Invoicing   | `send_invoice`               | Send a drafted invoice to the customer. **Destructive:** external delivery.                         |
| Invoicing   | `create_credit_note`         | Create a credit note against a sent invoice. **Destructive.**                                       |
| Invoicing   | `request_payment_reminder`   | Request a payment reminder for an open invoice.                                                     |
| Invoicing   | `upsert_invoice_customer`    | Create or update a billing customer in the party book.                                              |
| Connections | `trigger_connection_sync`    | Trigger a data sync on an existing connection.                                                      |
| Connections | `request_service_connection` | Ask LAC to set up a service connection, e.g. a Suomi.fi mandate.                                    |

## Security

* **Use read-only keys for analysis agents.** A key with `read` scope exposes only the 18 read tools — the agent physically cannot send an invoice or delete a document.
* **Keep a human in the loop for destructive tools.** `send_invoice`, `create_credit_note`, and `delete_document` are annotated destructive in the tool definitions; configure your client to require confirmation before calling them (most clients respect the annotation by default).
* **Mind prompt injection when combining servers.** If an agent has the LAC server alongside other MCP servers or web access, content fetched from elsewhere could try to steer it into calling LAC write tools. Prefer read-only keys in mixed-tool setups, and review write actions.
* **Revoke instantly.** Keys are revoked in the portal under Settings → API access; a revoked key loses MCP access immediately. OAuth connections end when you disconnect the connector in the client.
* **API keys are company credentials, not personal ones** — they keep working if the person who created them leaves. Revoke or rotate keys in Settings → API access when an admin departs.
* **Tenant isolation and audit.** Every tool call is scoped to the key's company and audited, like every REST request.

## What's deliberately not exposed

Some actions require an interactive admin or approver in the portal and are not available as MCP tools or to API keys at all:

* **Payroll entirely (read and write)** — payroll data and actions require an admin/approver in the portal UI.
* **Company settings changes.**
* **Member and access management** — inviting people, changing roles.
* **API key management** — a key can never mint or revoke keys.

This is the same boundary as the REST API: agents can prepare and inform; humans approve.