T:0 MCP Server

What is T:0 MCP Server?

T:0 MCP Server is T:0's hosted MCP endpoint (https://docs.t0.ai/mcp) that gives AI assistants access to your company's books in T:0: invoices, vendor bills, payments, customers, vendors and live financial statements. It authenticates with a T:0 API key.

T:0 describes itself as an AI-native finance team for start-ups and scale-ups. It connects to the banks, cards, payment processors and payroll providers a company already uses, categorizes transactions as they arrive, and keeps the ledger current with deterministic accounting rules. The MCP server lets founders, finance leads and their AI tools query that ledger from Claude, Cursor, Windsurf or a custom agent, instead of exporting reports by hand.

How to use T:0 MCP Server?

You need a T:0 account and a T:0 API key, found under Connections → API Keys in the T:0 dashboard. Send the key as a bearer token:

Authorization: Bearer <YOUR_API_KEY>

Keep the key out of shared files and chats; it grants access to your financial data.

Claude Code

claude mcp add --transport http t0 https://docs.t0.ai/mcp \
  --header "Authorization: Bearer $T0_API_KEY"

Set T0_API_KEY in your shell first so the key is not typed into the command history.

Claude Desktop and claude.ai

Custom connectors in the Claude apps are added by URL (Settings → Connectors → Add custom connector). Because this server needs an API key header rather than a browser sign-in, use a client that supports custom headers, or follow T:0's own Claude Desktop instructions, which add an http server with an Authorization header in the Developer config.

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "t0": {
      "url": "https://docs.t0.ai/mcp",
      "headers": {
        "Authorization": "Bearer <YOUR_API_KEY>"
      }
    }
  }
}

VS Code

{
  "servers": {
    "t0": {
      "type": "http",
      "url": "https://docs.t0.ai/mcp",
      "headers": {
        "Authorization": "Bearer <YOUR_API_KEY>"
      }
    }
  }
}

To check the connection, T:0 suggests asking: "Can you list the five most recent invoices from my t0 account?"

Key features of T:0 MCP Server

• Read access to receivables and payables: invoices, vendor bills, payments and their line items.
• Customer and vendor records, by list or by ID.
• Live financial statements: balance sheet, profit and loss, and cash flow.
• Chart of accounts lookup for the entity.
• Write actions to create records and post manual journal entries.
• A generic record lookup and a record-type discovery tool for anything not covered by a typed tool.
• Built-in search over the T:0 help center.

T:0 MCP Server tools

The server exposes 23 tools, grouped as follows:

• Lists: list_invoices, list_vendor_bills, list_customers, list_vendors, list_payments, list_line_items and list_bill_line_items return typed lists.
• Single records: matching get_one_* tools such as get_one_invoice, get_one_vendor_bill and get_one_payment fetch one record by ID.
• Reports: balance_sheet, profit_and_loss and cash_flow_statement return financial statements; list_the_entity_s_chart_of_accounts returns the chart of accounts.
• Writes: create_records and post_a_manual_journal_entry change data in your books, so review these calls before approving them.
• Generic and docs: discover_the_exposed_record_types, get_one_record_of_any_type and search-documentation.

Use cases of T:0 MCP Server

• Month-end review: "Show me this month's profit and loss and compare it to last month."
• Cash questions: "What does our cash flow statement look like for the last quarter?"
• Receivables follow-up: "List unpaid invoices and the customers they belong to."
• Vendor analysis: "Which vendors did we pay the most this year?"
• Board prep: pull a balance sheet and P&L into an assistant to draft board-meeting notes.
• Bookkeeping corrections: "Post a manual journal entry to reclassify this expense," with you approving the write.

Troubleshooting T:0 MCP Server

• "Credential missing" or auth errors: the client is not sending the key. The server accepts it as Authorization: Bearer (or an x-api-key header); check the header in your config.
• Tool-not-found or empty results: confirm the API key is valid in Connections → API Keys and that the config file was saved before restarting the client.
• Client config not picked up: reload Cursor or restart Claude Desktop after editing the config file.
• Need a tool that isn't listed: T:0 asks you to email support@t0.ai.