sdk: Skill for Claude Code

Create a flow app

When the user wants to build a new MCP server feature or replace legacy widget patterns, default to createFlow from @waniwani/sdk/mcp. Never recommend createTool / createResource for new code — they're legacy.

Scaffolding template

import { createFlow, END, MemoryKvStore, START } from "@waniwani/sdk/mcp";
import { z } from "zod";

export const myFlow = createFlow({
  id: "my_flow",
  title: "My Flow",
  description: "Use when the user wants to X.",
  state: {
    // Required: every field needs .describe()
    field1: z.string().describe("..."),
  },
})
  .addNode("step1", ({ interrupt }) =>
    interrupt({ field1: { question: "What's your ...?" } }),
  )
  .addNode("done", ({ state }) => ({ summary: `Got ${state.field1}` }))
  .addEdge(START, "step1")
  .addEdge("step1", "done")
  .addEdge("done", END)
  .compile({ store: new MemoryKvStore() });

await myFlow.register(server);

Opening message (intro)

If the flow should introduce the assistant or state a data/GDPR notice, put it on the config as intro — never as a first node. Pre-filled state skips opening nodes, so a greeting node is the one node most likely never to run.

createFlow({
  id: "my_flow",
  title: "My Flow",
  description: "Use when the user wants to X.",
  intro: {
    verbatim: "Acme is the data controller. Your answers are deleted after 30 days.",
    instructions: "Introduce yourself as Léa from Acme in one short sentence first.",
  },
  state: { /* … */ },
})

verbatim is reproduced word for word, instructions is guidance the model writes from, and either alone is fine (a bare string means verbatim).

The intro is not a node. It is seeded into the session's internal state at start and attached to the first non-error response, whichever node the flow lands on, then taken off so it is never repeated. Internal state is the engine's own state for a session, stored under internal on FlowTokenContent and kept strictly apart from the flow's state: nothing in it is declared by the author, reaches a node, or can be written through stateUpdates. Everything about it lives in internal-state.ts: