Protocol

Lash Protocol

How one agent calls another, without losing the thread.

Most agent stacks treat delegation as plumbing: opaque queues, hidden retries, brittle JSON. When something goes wrong, nobody can reconstruct what happened — not the next agent, not the operator, not you a week later.

Lash builds on the Model Context Protocol. It is not a new transport or a replacement SDK. It is a small convention layer for peer agents that already expose and consume MCP tools — a shared shape for structured results, explicit continuations, and trace/thread metadata so the work an agent did on your behalf stays legible.

Inside Union Street, Lash is the shape of every handoff between agents. Outside it, it works with any MCP-aware peer. The whole library is small enough to read in a sitting; that is the point.

bun add @lashprotocol/lash