# Usefulapi Quaderno MCP server

Source: https://glimind.com/server/mcp-registry%2Fio.usefulapi%2Fquaderno
Registry id: `mcp-registry/io.usefulapi/quaderno`
Status: auth-required (checked 2026-10-27T03:35:47.403Z)

## Verdict

Usefulapi Quaderno MCP server answered 100% of Glimind's liveness checks over 30 days, better than 42% of MCP servers, with 60 ms median handshake and 0 outages in 90 days. Its agent-readiness grade is A (96/100) across 23 tools, costing an agent about 4,884 tokens to load. Checked every few minutes; no tool is ever called.

## Measurements (30 days)

| Metric | Value | Better than |
|---|---|---|
| Uptime, 30 days | 100% | 42% of MCP servers |
| Median handshake latency | 60 ms | 88% of MCP servers |
| p95 handshake latency | 370 ms | — |
| Checks in 30 days | 217 | — |
| Outages, 90 days | 0 | — |
| Median recovery | — | — |
| Agent-readiness score | 96/100 (A) | 82% of MCP servers |
| Tools | 23 | — |
| Tool-list size for an agent | ~4,884 tokens | 38% of MCP servers |
| Days observed | 28 | — |

## Install

```json
{
  "mcpServers": {
    "usefulapi-quaderno-mcp-server": {
      "type": "http",
      "url": "https://quaderno.usefulapi.io/mcp"
    }
  }
}
```

Claude Code:

```sh
claude mcp add --transport http usefulapi-quaderno-mcp-server https://quaderno.usefulapi.io/mcp
```

## Tools (23)

- `calculate_tax`: Calculate the correct tax rate/amount for a sale given the customer's location and product. This is Quaderno's flagship endpoint — it applies the right VAT / GS
- `create_contact`: MUTATES Quaderno data — create a contact (customer or vendor). Provide kind plus a name; use `fields` for any other Quaderno contact attribute (phone_1, region,
- `create_invoice`: MUTATES Quaderno data — create an invoice for a contact. Provide contact_id (or a contact via `fields`) and items; use `fields` for any other attribute (currenc
- `create_item`: MUTATES Quaderno data — create a product/item in the catalog. Provide name + unit_cost; use `fields` for any other attribute (code, description, tax_class, tax_
- `create_transaction`: MUTATES Quaderno data — record a sale or refund transaction (Quaderno computes tax and produces the compliant document). Provide the customer, items, and paymen
- `get_contact`: Fetch a single contact by id. Quaderno API: GET /contacts/{id}.
- `get_credit_note`: Fetch a single credit note by id. Quaderno API: GET /credit_notes/{id}.
- `get_expense`: Fetch a single expense by id. Quaderno API: GET /expenses/{id}.
- `get_invoice`: Fetch a single invoice by id (full object incl. items, taxes, payments, permalink, pdf). Quaderno API: GET /invoices/{id}.
- `get_item`: Fetch a single product/item by id. Quaderno API: GET /items/{id}.
- `get_receipt`: Fetch a single receipt by id. Quaderno API: GET /receipts/{id}.
- `list_contacts`: List contacts (customers/vendors), newest first. Quaderno API: GET /contacts. Returns contact objects (id, kind, first_name, last_name, contact_name, email, cou
- `list_credit_notes`: List credit notes (refund documents), newest first. Quaderno API: GET /credit_notes. Wrapped as { data, pagination } when more pages exist.
- `list_expenses`: List expenses (bills you received), newest first. Quaderno API: GET /expenses. Wrapped as { data, pagination } when more pages exist.
- `list_invoices`: List invoices, newest first, with optional filters. Quaderno API: GET /invoices. Returns invoice objects (id, number, issue_date, due_date, currency, contact, i
- `list_items`: List products/items in the catalog, newest first. Quaderno API: GET /items. Returns item objects (id, code, name, kind, product_type, unit_cost, tax_class, tax_
- `list_jurisdictions`: List the tax jurisdictions (id, name, country, region) where the account is registered to collect tax. Quaderno API: GET /jurisdictions.
- `list_receipts`: List receipts, newest first. Quaderno API: GET /receipts. Wrapped as { data, pagination } when more pages exist.
- `list_tax_codes`: List the product tax codes Quaderno supports (id, name, description) — used as the tax_code on products / tax calculations. Quaderno API: GET /tax_codes.
- `list_webhooks`: List the account's configured webhooks (id, url, events). Quaderno API: GET /webhooks.
- `ping`: Verify the API key and connection by pinging Quaderno. Returns account/authentication status. Quaderno API: GET /ping.
- `quaderno_request`: Power-user escape hatch: GET any Quaderno API path not wrapped by a dedicated tool. READ-ONLY — only GET is allowed. Path is taken after /api (e.g. "/tax_ids", 
- `update_contact`: MUTATES Quaderno data — update an existing contact. Only the fields you pass are changed; use `fields` for any attribute not typed here. Quaderno API: PUT /cont

Measured by Glimind (https://glimind.com): MCP handshake + tool list only, no tool is ever called. CC BY 4.0.