# Xero MCP Server

An [MCP](https://modelcontextprotocol.io) server for the [Xero](https://www.xero.com)
Accounting API (2.0). It lets an AI agent read one Xero organisation's contacts, invoices and
bills, payments, chart of accounts and financial reports (profit and loss, balance sheet, aged
receivables and payables) and, on explicit request, create contacts, invoices and payments or
change an invoice's status.

- Transport: MCP Streamable HTTP at `POST /mcp`, health probe at `GET /health`
- Stateless and multi-tenant: the access token and organisation id arrive on every request as
  HTTP headers and are never stored; every tool is listed from the first `tools/list`
- Python 3.12, [uv](https://docs.astral.sh/uv/), FastMCP, httpx
- License: Apache-2.0, Copyright 2026 MSPbots.ai

## Authentication headers

| Header | Required | Type | Default | Allowed values | Description | Example |
|---|---|---|---|---|---|---|
| `X-Xero-Access-Token` | Yes | string | none | - | Xero OAuth 2.0 access token (a leading `Bearer ` is accepted and ignored) | `your-access-token` |
| `X-Xero-Tenant-Id` | Yes | string | none | - | Id of the Xero organisation (tenant) to work on | `your-tenant-id` |

Where to get them:

- Create an app in the Xero developer portal (developer.xero.com, **My Apps -> New app**) and
  authorise it for the organisation with the OAuth 2.0 authorisation-code flow. Request the
  scopes the tools need: `accounting.contacts`, `accounting.transactions`,
  `accounting.settings` and `accounting.reports.read` (the `.read` variants for read-only use).
- The token response holds a short-lived access token; whoever stores the connection must
  refresh it with the refresh token. This server never refreshes or stores
  tokens.
- The tenant id comes from `GET https://api.xero.com/connections` with that token; each
  organisation the user authorised has its own `tenantId`.

How credentials are sent to Xero: every call goes to `https://api.xero.com/api.xro/2.0/...`
with `Authorization: Bearer <token>` and `xero-tenant-id: <tenant id>`. Writes also carry a
fresh `Idempotency-Key` header, so a retried write cannot create a second record. Values that
look like unresolved templates (`${...}`) are treated as missing.

A request to `/mcp` without both headers gets HTTP 401 naming the missing one.

## Tools

All tools return a JSON string. Ids are UUIDs. List tools return 100 records per page with
`{count, page, has_more, next_page}`. Dates are `YYYY-MM-DD`; Xero's legacy `/Date(...)/`
values in responses are converted to ISO 8601.

| Tool | Purpose | Parameters (required in **bold**) |
|---|---|---|
| `xero_navigate` | Describe the tools of one Xero area (changes nothing) | **domain** (`contacts`, `invoices`, `payments`, `accounts`, `reports`) |
| `xero_back` | List every Xero area and its tools (changes nothing) | - |
| `xero_status` | Check the connection: organisation name, country, base currency, financial year end | - |
| `xero_contacts_list` | List contacts (customers and suppliers), 100 per page | page, where |
| `xero_contacts_get` | Get one contact's full profile | **contactId** |
| `xero_contacts_create` | Create a contact (**write**) | **Name**, EmailAddress, FirstName, LastName, Phone, AccountNumber, TaxNumber, IsCustomer, IsSupplier |
| `xero_contacts_search` | Search contacts by name, contact person, account number or email | **term** |
| `xero_invoices_list` | List invoices and bills, newest first, without line items | page, Status (`DRAFT`, `SUBMITTED`, `AUTHORISED`, `PAID`, `VOIDED`, `DELETED`), Type (`ACCREC`, `ACCPAY`) |
| `xero_invoices_get` | Get one invoice or bill in full (line items, tax, payments, amount due) | **invoiceId** |
| `xero_invoices_create` | Create a sales invoice or bill, DRAFT by default (**write**) | **Type** (`ACCREC`, `ACCPAY`), **ContactID**, **LineItems** (Description, Quantity, UnitAmount, AccountCode, TaxType), Date, DueDate, Reference, Status (`DRAFT`, `SUBMITTED`, `AUTHORISED`) |
| `xero_invoices_update_status` | Submit, authorise or void an invoice (**write**, voiding is permanent) | **invoiceId**, **Status** (`SUBMITTED`, `AUTHORISED`, `VOIDED`) |
| `xero_payments_list` | List payments, newest first | page, Status (`AUTHORISED`, `DELETED`) |
| `xero_payments_get` | Get one payment | **paymentId** |
| `xero_payments_create` | Record a payment against an authorised invoice or bill (**write**) | **InvoiceID**, **AccountID**, **Amount**, **Date**, Reference |
| `xero_accounts_list` | List the chart of accounts, optionally by type or class | Type, Class (`ASSET`, `EQUITY`, `EXPENSE`, `LIABILITY`, `REVENUE`) |
| `xero_accounts_get` | Get one account | **accountId** |
| `xero_reports_profit_and_loss` | Profit and Loss for a date range | **fromDate**, **toDate** |
| `xero_reports_balance_sheet` | Balance Sheet as at a date | **date** |
| `xero_reports_aged_receivables` | Money owed by customers, aged by days overdue | **date**, contactId |
| `xero_reports_aged_payables` | Money owed to suppliers, aged by days overdue | **date**, contactId |

Reports come back flattened as `{name, titles, date, columns, sections: [{title, rows:
[{label, values}], total}]}` instead of Xero's nested rows and cells.

Errors come back as a JSON envelope instead of an exception:

```json
{"error": {"code": "invalid_argument", "message": "Xero returned HTTP 400 for Invoices: A validation exception occurred - Account code '999' is not a valid code", "retryable": false}}
```

`code` is one of `not_configured`, `unauthorized`, `not_found`, `invalid_argument`,
`rate_limited`, `upstream_error`; Xero's validation messages are included. Xero allows 60
calls per minute and 5,000 per day per organisation; 429, 5xx and network errors are retried
with backoff (honouring `Retry-After`), and writes are safe to retry because of the idempotency
key.

## Run locally

```bash
uv sync
uv run python -m xero_mcp          # listens on 0.0.0.0:8080
```

or with Docker:

```bash
docker build --platform linux/amd64 -t xero-mcp:dev .
docker run --rm -p 8080:8080 xero-mcp:dev
```

Configuration (environment variables, all optional): `MCP_HTTP_HOST` (default `0.0.0.0`),
`MCP_HTTP_PORT` (default `8080`), `LOG_LEVEL` (default `INFO`). Credentials are never read
from the environment.

## Testing example

```bash
# list tools
curl -s http://localhost:8080/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "X-Xero-Access-Token: your-access-token" \
  -H "X-Xero-Tenant-Id: your-tenant-id" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

# unpaid sales invoices
curl -s http://localhost:8080/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "X-Xero-Access-Token: your-access-token" \
  -H "X-Xero-Tenant-Id: your-tenant-id" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"xero_invoices_list","arguments":{"Type":"ACCREC","Status":"AUTHORISED"}}}'
```

Unit tests (no network access needed):

```bash
uv run pytest
```

## Delivery notes

- **Tool count (20).** Kept as is because the tool names are an existing contract.
- **Aged reports.** Xero's aged receivables / payables reports require a contact
  (`contactId`), and the API has no all-contacts version. With `contactId` the tools return
  Xero's report; without it they return a per-contact ageing summary (current, 1-30, 31-60,
  61-90, over 90 days past due) built from open authorised invoices dated on or before `date`,
  using today's amount due.
- **Searching.** `xero_contacts_search` uses Xero's `searchTerm` parameter, so names with quotes
  are found and cannot break the filter; other filters escape their values.
- **Write tools.** `xero_contacts_create`, `xero_invoices_create`, `xero_payments_create` and
  `xero_invoices_update_status` change the books; their descriptions tell the agent to use them
  only on explicit request. Status changes are annotated destructive because voiding cannot be
  undone. Per-record validation errors that Xero returns with HTTP 200 are reported as errors.
- **No interactive prompts.** Older versions asked the user for filters before unfiltered
  lists, which a stateless gateway cannot relay; lists now page instead.

## License

Apache License 2.0 - see [LICENSE](LICENSE) and [NOTICE](NOTICE).