vinkius-labs/mcp-fusion

✨ What's New

MCP Elicitation — Human-in-the-Loop for Agentic Workflows

A new first-class DSL that enables MCP tool handlers to pause execution, request user input via the MCP client, and resume with typed responses — zero boilerplate, full type inference.

Highlights

• \sk()\ callable namespace — Single import, dual-mode API. Form fields (\sk.string(), \sk.number(), \sk.boolean(), \sk.enum()) or URL redirect (\sk.redirect())
• *Fail-fast \AskResponse* — Boolean guards (.accepted, .declined, .cancelled) with a .data\ getter that throws on non-accepted access
• *.interactive()* — Opt-in on \FluentToolBuilder\ or \FluentRouter\ — zero overhead when not used
• AsyncLocalStorage transport — Per-request isolation, no handler signature changes, works across stdio/SSE/Streamable HTTP
• Multi-step wizards — Sequential \wait ask()\ calls for conversational flows

Quick Example

\\ ypescript
import { initVurb, ask } from '@vurb/core';
const f = initVurb();

const deploy = f.mutation('infra.deploy')
.withString('app_id', 'Application ID')
.interactive()
.handle(async (input) => {
const prefs = await ask('Confirm settings:', {
region: ask.enum(['us-east-1', 'eu-west-1'] as const),
confirm: ask.boolean('I confirm'),
});
if (prefs.declined) return f.error('CANCELLED', 'Aborted.');
return { deployed: true, region: prefs.data.region };
});
\\

Test Suite

• 72 new tests across 4 test files (DSL, response guards, transport isolation, server wiring)
• 5213+ tests passing across the monorepo

Documentation

• Full documentation at vurb.vinkius.com/elicitation

Full Changelog: https://github.com/vinkius-labs/vurb.ts/blob/main/CHANGELOG.md