MCP RC Long-Running Task Prototype

Repository: https://github.com/StevenBucher98/mcp-rc-long-running-task-poc

Focused prototype for MCP 2026-07-28 behavior around:

• Long-running tool calls that return quickly with a task handle
• Task lifecycle methods: tasks/get, tasks/update, tasks/cancel
• Elicitation clarification while long-running work is still in progress

What Is In Scope

The server intentionally exposes only two tools:

1. start_report_task

• Starts an async task and immediately returns structuredContent.task.id

2. personalized_greeting

• If name is not provided, returns inputRequired asking for a name
• Continue with requestState + inputResponses.name to get a random greeting

Quick Start

Clone and run:

git clone https://github.com/StevenBucher98/mcp-rc-long-running-task-poc.git
cd mcp-rc-long-running-task-poc
npm install
npm run test:scenarios

Or, if you already have the repo locally:

npm install
npm run test:scenarios

The scenario runner builds and starts the server, runs the tests, prints UX-style and raw request/response output, then stops the server.

Scenario Runner

npm run test:scenarios

This single command:

• builds the server
• starts the server
• runs both scenario suites
• prints UX-style and raw JSON-RPC request/response output
• stops the server when finished

What it verifies:

• Task lifecycle basics
  • create task via tools/call (start_report_task)
  • update progress via tasks/update
  • read status via tasks/get
  • cancel via tasks/cancel
• Long-running behavior
  • starts a long-running task (default 90000 ms)
  • confirms tool call returns quickly (non-blocking)
  • continues with other calls during execution (personalized_greeting, tools/list)
  • polls until completion and prints final result

Optional Flags

node scripts/test-state-and-long-running.mjs \
  --long-duration-ms 90000 \
  --quick-threshold-ms 4000 \
  --wait-for-completion \
  --greeting-name Taylor

• --long-duration-ms: duration for long-running task
• --quick-threshold-ms: max acceptable create-call latency
• --wait-for-completion: wait until long-running task is complete (default behavior)
• --no-wait-for-completion: skip waiting at the end
• --greeting-name <name>: name used for greeting elicitation replay (if omitted and terminal is interactive, you will be prompted)

Endpoints

• POST /mcp
• GET /health

Share With Others

• Repo URL: https://github.com/StevenBucher98/mcp-rc-long-running-task-poc
• To run quickly: npm install && npm run test:scenarios