MCP Client

An MCP client is the AI assistant that initiates tool calls against an MCP server — the half of the connection sitting on the user's side, translating a plain-language request like "categorize my June transactions" into the specific tool calls that actually do the work.

Any assistant that implements the protocol can act as a client to BalanceMCP's server; it isn't limited to one specific product. What makes a client trustworthy isn't its own judgment or carefulness — it's that every tool it calls runs under the exact same database-level rules regardless of which client is calling: balanced entries only, an append-only journal, no posting into a locked period, and tenant isolation that keeps one user's books invisible to another's session entirely.

A client only has access to what the tools it's given actually allow — there's no way for a client to reach past a tool's own scope into some broader capability. Reconciling an account through a client still requires calling reconcile_account with the right arguments; there's no shortcut around the interface the server exposes.

The API key a client uses is what ties every one of its tool calls back to a specific user's books — a client with a valid key can do everything that key's tools allow, which is exactly why the key itself, not the client's own behavior, is the thing worth protecting carefully.