# io.usefulapi/quaderno (remote · quaderno.usefulapi.io)

MCP server for Quaderno — tax-rate calculation, invoices, contacts, products, receipts & expenses.

- Trust score: 18/100 (low)
- Change this week: −49
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-03

## Components

- remote · `quaderno.usefulapi.io`: 18/100 (this document), [markdown](https://verifymcp.io/servers/io-usefulapi-quaderno/quaderno.md), [page](https://verifymcp.io/servers/io-usefulapi-quaderno/quaderno)

## Channel facts

- Endpoint: `https://quaderno.usefulapi.io/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.0.1`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-08-03.

- **Endpoint Security**: 46/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to connect, but we couldn't read the tool list to see what that exposes.
  - HTTPS not yet verified: we couldn't determine whether a plaintext access path exists.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 0/100
  - Transport check failed: declared streamable-http, but the endpoint returned HTTP 429.
- **Schema Quality & AI Usability**: 0/100
  - Schema not yet verified: we couldn't read the endpoint's schema.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 0/100
  - Tool coverage not yet verified: we couldn't read the endpoint's tools.
- **Capabilities**: 0/100
  - Capabilities not yet verified: we couldn't read the endpoint's capabilities.

**Unverified: 4 categories.** Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm.

## Install

### Claude

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

### Codex

```toml
[mcp_servers.io-usefulapi-quaderno]
url = "https://quaderno.usefulapi.io/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "io-usefulapi-quaderno": {
      "type": "remote",
      "url": "https://quaderno.usefulapi.io/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add io-usefulapi-quaderno --url https://quaderno.usefulapi.io/mcp --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  io-usefulapi-quaderno:
    url: "https://quaderno.usefulapi.io/mcp"
```

### Other

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

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-08-03 (score 18, −53)

- [security regression] Endpoint reachability: reachable → not serving MCP
- [security regression] Authorization: pass → unverified
- [security regression] Stability: 0.20 → unverified
- [security regression] Transport: pass → fail
- [functional regression] Tool coverage: 100 → unverified
- [functional regression] Capabilities: fail → unverified

### 2026-08-02 (score 71, +53)

- [security improvement] Authorization: unverified → pass
- [security improvement] Transport: fail → pass
- [functional regression] MCP protocol: unverified → fail
- [functional improvement] Endpoint reachability: not serving MCP → reachable
- [functional improvement] Tool coverage: unverified → 100
- [functional improvement] Stability: unverified → 0.20

### 2026-08-01 (score 18, −52)

- [security regression] Endpoint reachability: reachable → not serving MCP
- [security regression] Stability: 0.13 → unverified
- [security regression] Authorization: pass → unverified
- [security regression] Transport: pass → fail
- [functional regression] Capabilities: fail → unverified
- [functional regression] Tool coverage: 100 → unverified

### 2026-07-31 (score 70, +4)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-30 (score 66, −2)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-29 (score 68, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-28 (score 67, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-07-27 (score 67, +55)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

## MCP tools (23)

### `ping` (~33 tokens)

Ping (verify auth)

Verify the API key and connection by pinging Quaderno. Returns account/authentication status. Quaderno API: GET /ping.

### `calculate_tax` (~374 tokens)

Calculate tax rate

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 / GST / US sales-tax rules per jurisdiction. READ-ONLY (no record is created). Quaderno API: GET /tax_rates/calculate. Returns { name, rate, country, region, county, city, tax_code, status (taxable|non_taxable|not_registered|reverse_charge), tax_amount, subtotal, total_amount }.

Input parameters:

- `amount` (number): Transaction amount to compute the tax on.
- `currency` (string): ISO 4217 currency code (e.g. "USD").
- `date` (string): Transaction date (YYYY-MM-DD); defaults to today.
- `from_country` (string): The seller's country (2-letter ISO); defaults to the account country.
- `from_postal_code` (string): The seller's postal code.
- `product_type` (string): Whether the product is a good or a service.
- `tax_behavior` (string): Whether the amount includes tax or not.
- `tax_code` (string): Product tax code, e.g. "standard", "reduced", "exempt", "eservice", "ebook", "saas", "consulting".
- `tax_id` (string): The customer's tax ID / VAT number (may trigger reverse-charge).
- `to_city` (string): The customer's city (recommended for US sales tax).
- `to_country` (string, required): The customer's country — 2-letter ISO code (e.g. "US", "DE"). Required.
- `to_postal_code` (string): The customer's ZIP / postal code (recommended for US sales tax).
- `to_street` (string): The customer's street address (recommended for US sales tax).

### `list_invoices` (~211 tokens)

List invoices

List invoices, newest first, with optional filters. Quaderno API: GET /invoices. Returns invoice objects (id, number, issue_date, due_date, currency, contact, items, taxes, payments, state, total_cents, subtotal_cents), wrapped as { data, pagination } when more pages exist.

Input parameters:

- `contact` (string): Filter by customer (contact) id.
- `created_before` (string): Cursor for pagination: return records created before this id (from X-Pages-NextPage / a prior record id).
- `date` (string): Date range filter, e.g. "2026-01-01,2026-12-31".
- `page` (integer): Page number (legacy pagination; prefer created_before).
- `per_page` (integer): Entries per page (1-100, default 25).
- `q` (string): Search by invoice number, customer name, or PO number.
- `state` (string): Filter by invoice state.

### `get_invoice` (~50 tokens)

Get an invoice

Fetch a single invoice by id (full object incl. items, taxes, payments, permalink, pdf). Quaderno API: GET /invoices/{id}.

Input parameters:

- `id` (string, required): The resource id.

### `list_contacts` (~149 tokens)

List contacts

List contacts (customers/vendors), newest first. Quaderno API: GET /contacts. Returns contact objects (id, kind, first_name, last_name, contact_name, email, country, tax_id, tax_status, …), wrapped as { data, pagination } when more pages exist.

Input parameters:

- `created_before` (string): Cursor for pagination: return records created before this id (from X-Pages-NextPage / a prior record id).
- `page` (integer): Page number (legacy pagination; prefer created_before).
- `per_page` (integer): Entries per page (1-100, default 25).
- `q` (string): Search by contact name, email, or tax ID.

### `get_contact` (~35 tokens)

Get a contact

Fetch a single contact by id. Quaderno API: GET /contacts/{id}.

Input parameters:

- `id` (string, required): The resource id.

### `list_items` (~134 tokens)

List products (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_type, currency, stock, …), wrapped as { data, pagination } when more pages exist.

Input parameters:

- `created_before` (string): Cursor for pagination: return records created before this id (from X-Pages-NextPage / a prior record id).
- `page` (integer): Page number (legacy pagination; prefer created_before).
- `per_page` (integer): Entries per page (1-100, default 25).

### `get_item` (~36 tokens)

Get a product (item)

Fetch a single product/item by id. Quaderno API: GET /items/{id}.

Input parameters:

- `id` (string, required): The resource id.

### `list_credit_notes` (~165 tokens)

List credit notes

List credit notes (refund documents), newest first. Quaderno API: GET /credit_notes. Wrapped as { data, pagination } when more pages exist.

Input parameters:

- `contact` (string): Filter by customer (contact) id.
- `created_before` (string): Cursor for pagination: return records created before this id (from X-Pages-NextPage / a prior record id).
- `date` (string): Date range filter, e.g. "2026-01-01,2026-12-31".
- `page` (integer): Page number (legacy pagination; prefer created_before).
- `per_page` (integer): Entries per page (1-100, default 25).
- `q` (string): Search by number, customer name, or PO number.

### `get_credit_note` (~38 tokens)

Get a credit note

Fetch a single credit note by id. Quaderno API: GET /credit_notes/{id}.

Input parameters:

- `id` (string, required): The resource id.

### `list_receipts` (~157 tokens)

List receipts

List receipts, newest first. Quaderno API: GET /receipts. Wrapped as { data, pagination } when more pages exist.

Input parameters:

- `contact` (string): Filter by customer (contact) id.
- `created_before` (string): Cursor for pagination: return records created before this id (from X-Pages-NextPage / a prior record id).
- `date` (string): Date range filter, e.g. "2026-01-01,2026-12-31".
- `page` (integer): Page number (legacy pagination; prefer created_before).
- `per_page` (integer): Entries per page (1-100, default 25).
- `q` (string): Search by number or customer name.

### `get_receipt` (~37 tokens)

Get a receipt

Fetch a single receipt by id. Quaderno API: GET /receipts/{id}.

Input parameters:

- `id` (string, required): The resource id.

### `list_expenses` (~161 tokens)

List expenses

List expenses (bills you received), newest first. Quaderno API: GET /expenses. Wrapped as { data, pagination } when more pages exist.

Input parameters:

- `contact` (string): Filter by vendor (contact) id.
- `created_before` (string): Cursor for pagination: return records created before this id (from X-Pages-NextPage / a prior record id).
- `date` (string): Date range filter, e.g. "2026-01-01,2026-12-31".
- `page` (integer): Page number (legacy pagination; prefer created_before).
- `per_page` (integer): Entries per page (1-100, default 25).
- `q` (string): Search by number or vendor name.

### `get_expense` (~36 tokens)

Get an expense

Fetch a single expense by id. Quaderno API: GET /expenses/{id}.

Input parameters:

- `id` (string, required): The resource id.

### `list_tax_codes` (~45 tokens)

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_jurisdictions` (~43 tokens)

List tax jurisdictions

List the tax jurisdictions (id, name, country, region) where the account is registered to collect tax. Quaderno API: GET /jurisdictions.

### `list_webhooks` (~32 tokens)

List webhooks

List the account's configured webhooks (id, url, events). Quaderno API: GET /webhooks.

### `quaderno_request` (~97 tokens)

Raw read 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", "/evidence"). Quaderno API: GET {path}.

Input parameters:

- `path` (string, required): API path after /api, starting with a slash, e.g. "/tax_ids".
- `query` (object): Optional query params object.

### `create_contact` (~221 tokens)

Create a 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, postal_code, city, street_line_1/2, tax_status, language, discount, notes, processor/processor_id). Quaderno API: POST /contacts. Returns the created contact.

Input parameters:

- `contact_name` (string): The contact person's name at a company (companies only).
- `country` (string): 2-letter ISO country code.
- `email` (string): Contact email address.
- `fields` (object): Additional raw Quaderno fields merged into the request body (escape hatch for any field not typed above).
- `first_name` (string): For a person: their first name. For a company: the company name (Quaderno stores it here).
- `kind` (string, required): Contact kind.
- `last_name` (string): The person's last name (persons only).
- `tax_id` (string): The contact's tax ID / VAT number.

### `update_contact` (~163 tokens)

Update a 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 /contacts/{id}. Returns the updated contact.

Input parameters:

- `contact_name` (string): Contact person at a company.
- `country` (string): 2-letter ISO country code.
- `email` (string): Contact email address.
- `fields` (object): Additional raw Quaderno fields merged into the request body (escape hatch for any field not typed above).
- `first_name` (string): Person first name / company name.
- `id` (string, required): The resource id.
- `last_name` (string): Person last name.
- `tax_id` (string): Tax ID / VAT number.

### `create_item` (~172 tokens)

Create a product (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_type, currency, country, stock). Quaderno API: POST /items. Returns the created item.

Input parameters:

- `code` (string): SKU / product code.
- `currency` (string): ISO 4217 currency code.
- `fields` (object): Additional raw Quaderno fields merged into the request body (escape hatch for any field not typed above).
- `kind` (string): Whether it is a one-off or a subscription product.
- `name` (string, required): Product name.
- `product_type` (string): Whether the product is a good or a service.
- `unit_cost` (number, required): Unit price of the product.

### `create_invoice` (~266 tokens)

Create an 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 (currency, issue_date, due_date, po_number, notes, tag_list, custom_metadata, payment_details). Each item = { description, quantity, unit_price, tax_1_name?, tax_1_rate?, discount_rate?, … }. Quaderno API: POST /invoices. Returns the created invoice (incl. permalink, pdf).

Input parameters:

- `contact_id` (string): The id of an existing contact to invoice. Omit only if you pass a full `contact` object via `fields`.
- `currency` (string): ISO 4217 currency code.
- `due_date` (string): Due date (YYYY-MM-DD).
- `fields` (object): Additional raw Quaderno fields merged into the request body (escape hatch for any field not typed above).
- `issue_date` (string): Issue date (YYYY-MM-DD).
- `items` (array): Line items, e.g. [{ description, quantity, unit_price, tax_1_name, tax_1_rate }].
- `notes` (string): Free-text notes on the invoice.
- `po_number` (string): Purchase-order number.

### `create_transaction` (~232 tokens)

Create a transaction

MUTATES Quaderno data — record a sale or refund transaction (Quaderno computes tax and produces the compliant document). Provide the customer, items, and payment. Use `fields` for any other attribute (date, currency, shipping_address, evidence, processor, processor_id, processor_fee_cents, exchange_rate, po_number, notes, tags, custom_metadata). Quaderno API: POST /transactions. Returns the created invoice/credit-note object.

Input parameters:

- `currency` (string): ISO 4217 currency code.
- `customer` (object): The customer contact object (or reference), e.g. { first_name, last_name, email, country, tax_id }.
- `fields` (object): Additional raw Quaderno fields merged into the request body (escape hatch for any field not typed above).
- `items` (array, required): Required. Transaction line items, e.g. [{ description, amount, quantity, tax_code, product_type }].
- `payment` (object): Payment object, e.g. { payment_method, amount, date }.
- `type` (string): Transaction type (default "sale").

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/io-usefulapi-quaderno/quaderno#diagnostics

## Score history

- 2026-08-03: 18
- 2026-08-02: 71
- 2026-08-01: 18
- 2026-07-31: 70
- 2026-07-30: 66
- 2026-07-29: 68
- 2026-07-28: 67
- 2026-07-27: 67
- 2026-07-26: 12

## Links

- Remote endpoint: https://quaderno.usefulapi.io/mcp
- Repository: https://github.com/m190/usefulapi-mcp
- Changelog RSS feed: https://verifymcp.io/servers/io-usefulapi-quaderno/quaderno/changelog.xml
- Changelog JSON feed: https://verifymcp.io/servers/io-usefulapi-quaderno/quaderno/changelog.json
- HTML version of this page: https://verifymcp.io/servers/io-usefulapi-quaderno/quaderno