waniwani.config.ts names the MCP server, hands the host an overview at connect time, and tunes the template’s search tool and tracking.
Every kit app has one waniwani.config.ts at its root, default-exporting defineApp({ ... }). The CLI reads it to name the server, and the runtime forwards the rest to the host and to the SDK.
waniwani.config.ts
import { defineApp } from "@waniwani/kit";export default defineApp({ name: "oney", title: "Oney: split your payment", overview: `You help shoppers split a purchase into instalments with Oney.RULES:- Never quote a monthly amount yourself. Call check-eligibility and let it do the arithmetic.- Never list the plans in text. Show the select-plan widget and let it render them.`,});
What this app is and how its tools fit together, handed to the host LLM once in the initialize handshake: which tool to reach for, what order things happen in, how to read what comes back, tone, guardrails. Reaches the wire as the MCP server’s instructions.How a single tool behaves belongs in that tool’s own description. A description travels with every tools/list and reaches the model at the moment it is choosing that tool. The overview is read once at connect, so a client that connected before an edit keeps the old copy until it reconnects, and a host is free to drop it altogether. Put nothing load-bearing in it.
Whether the template registers the tool at all. false is the only way an app can decline it. A deployment with no corpus behind it is better off without the tool than with one answering confidently out of the wrong file.
Framing prepended to the answer text. Retrieved passages are third-party text on their way into a prompt; this is where an app says they are reference material rather than instructions.
The whole answer when no passage comes back: nothing matched, the search outran timeoutMs, or the knowledge base failed. An app whose corpus carries regulated information should write both halves in its own words, the refusal the user reads and the human to go to instead. preamble is not applied on top of it.
Flush the tracking transport after each tool call. This is the one that matters on serverless: an invocation frozen between tool calls takes any unsent batch with it.
Replace flow state fields marked with redacted() before they are tracked. Wire it to an env var to keep real values in development and redact in production.
