Cursor· Cursor

Custom stores, custom tools, and auto-review for the Cursor SDK

We've shipped a batch of new functionality across the TypeScript and Python SDKs. You can now choose how agent and run metadata is persisted, expose your own functions to the agent as tools, route local tool calls through auto-review, and nest subagents to any depth. This release also brings a set of reliability, performance, and platform fixes that make local and cloud SDK agents easier to run in production scripts, CI, and custom integrations. Custom tools You can now hand the local agent your own tools by passing function definitions through `local.customTools`, on `Agent.create()` or per `send()`. The SDK exposes them to the agent through a built-in MCP server called `custom-user-tools`, so the model calls your code through the same path and the same permission gate as any other MCP tool. Before this, exposing a custom capability meant standing up your own stdio or remote HTTP MCP server and wiring it into the agent. Now a function definition is enough. Custom tools are also visible to every subagent of a parent agent, so a tool you define once is available throughout the whole run. Auto-review …

Announced

04 Jun 2026 00:00 UTC