Model Context Protocol
The accounting MCP server
LedgerMCP exposes a complete double-entry accounting system as 50 MCP tools. Any AI assistant that speaks MCP can create books, import transactions, post balanced entries, reconcile, and report; on a ledger that enforces its own correctness.
https://ledgermcp.com/mcp · streamable HTTP · OAuth or bearer key
The tool surface
50 tools: 21 read, 29 write. Books and bank accounts; transaction import with batch dedupe; categorize, split, and transfer with validation; tags for vendors, projects, and clients; reconciliation; trial balance, P&L, balance sheet, and 1099 reports; receipts; and a books-integrity audit the agent can run on itself. Every write is audit-logged with the acting credential recorded.
The full reference with parameters lives at /docs; the agent-readable version is /llms.txt. Both generate from the registry the server actually runs.
Invariants, not prompts
Agent safety here does not depend on the agent being careful. Four rules are enforced in Postgres: entries must balance at commit; postings are immutable, with corrections as linked reversals; idempotency keys make every retry safe; balances are computed from postings, never stored. An agent physically cannot leave the books in a broken state.
Connect a client
- Claude: Settings, Connectors, add custom connector with the URL above. Sign in with an email code.
- ChatGPT: developer mode, add connector by URL, OAuth sign-in.
- Claude Code, agents, scripts: create an API key in Settings and send it as a bearer token. Read-only keys can report but never write.
Common questions
What is an accounting MCP server?
An MCP server exposes tools that AI assistants can call through the Model Context Protocol. An accounting MCP server exposes bookkeeping: posting entries, importing transactions, reconciling, and reporting. LedgerMCP ships one built into real double-entry accounting software.
How is this different from the QuickBooks MCP server?
Intuit’s MCP server is a companion to a paid QuickBooks subscription. LedgerMCP is the opposite shape: the ledger itself was designed for agents, the full write surface is exposed as tools, and the software is free.
Which clients can connect?
Claude (connectors, Desktop, Claude Code), ChatGPT (developer-mode connectors), and any MCP-compatible client over streamable HTTP. OAuth sign-in or bearer API keys, including read-only keys.
What stops an agent from corrupting the ledger?
The database. Entries must balance or the write is rejected; postings are immutable with corrections as linked reversals; every tool call that writes carries an idempotency key so retries never double-post; and every write lands in an append-only audit log the owner can reverse.
Is there documentation an agent can read?
Yes. Human docs live at ledgermcp.com/docs; machine-readable instructions live at ledgermcp.com/llms.txt. Both are generated from the same tool registry the server runs, so they never drift.
Point your agent at a real ledger
Free to start. The whole accounting surface, one MCP URL.