MCP server reference: tools, auth and errors

Connect any MCP client to AXOFFICE: the address, authentication, tools, permissions and errors.

Overview

AXOFFICE runs an MCP server that uses the same API keys as the public API. Every call is limited to the company the key belongs to. Six tools read; one prepares a draft invoice that a person has to post.

Setting	Value
Transport	Streamable HTTP
Address	Shown on the Connect Claude or any MCP client card in Settings › Integrations
Authentication	An `Authorization: Bearer` header with an AXOFFICE API key
Read tools	Professional plan and above
Draft tool	Business plan

Connect from Claude Code

Terminal

claude mcp add --transport http --scope user axo https://tryaxo.com/api/v1/mcp --header "Authorization: Bearer YOUR_API_KEY"

Connect from a JSON configuration

JSON

{
  "mcpServers": {
    "axo": {
      "type": "http",
      "url": "https://tryaxo.com/api/v1/mcp",
      "headers": { "Authorization": "Bearer YOUR_API_KEY" }
    }
  }
}

Note

Copy the exact address from the card in AXOFFICE — it's set for your account. Replace YOUR_API_KEY with the key you created there.

Tools

Tool	What it returns	Needs
get_company_snapshot	Cash across accounts, receivables and payables	Read
list_invoices	Invoices matching filters such as status or customer	Read
get_invoice	One invoice with its lines and totals	Read
get_trial_balance	Every account's balance	Read
get_cash_forecast	The cash forecast	Read
search_customers	Customers matching a search	Read
create_draft_invoice	A new invoice saved as a draft, with no journal entry	Draft

Tools only return what your plan includes. The cash forecast, for example, needs the Business plan.

Permissions

Create the key from the MCP card and it gets exactly the permissions these tools need. A key made somewhere else may be missing some. When that happens the tool refuses, and the message names the missing permission, where to add it, and which other tools that key can't use.

Errors

You see	Why
Unauthorised (401)	The key is wrong, revoked or missing
Missing permission	The key lacks a permission the tool needs — the message names it
Requires the Business plan	The draft tool was used on a plan below Business

Important

Nothing an MCP client does posts to your ledger. A draft invoice it creates has no journal entry until a person checks it and posts it in AXOFFICE.