PPAP Review Workbench (MCP App)

Deterministic Supplier Quality Engineer review workbench delivered as a genuine MCP server + MCP App UI for Langdock.

This is not a standalone dashboard. Langdock hosts the conversation and agent reasoning; this project stores structured PPAP case state and renders an interactive review UI via MCP Apps (ui://ppap-review/workbench.html).

What this project is

Role	Responsibility
Langdock Agent	Document intelligence/reasoning: classify, extract, compare, draft preliminary findings
PPAP MCP Server	Authoritative state + tools (create_ppap_case, decisions, summary, …)
PPAP MCP App	Interactive SQE review UI rendered inside Langdock
Human SQE	Final decision authority — no autonomous approve/reject

There are no LLM API calls inside this MCP project.

Architecture

Supplier PPAP Files
        |
        v
Langdock PPAP Agent
        |
        | create_ppap_case
        v
PPAP MCP Server
        |
        | open_ppap_workbench
        v
ui://ppap-review/workbench.html
        |
        v
Langdock embedded MCP App
        |
        | SQE decision
        v
set_finding_decision
        |
        v
MCP Server
        |
        v
Langdock follow-up

Local development

cd ppap-review-mcp
npm install
npm run build
npm run serve

• Health: http://localhost:3001/health
• MCP: http://localhost:3001/mcp

Useful scripts:

npm run dev          # watch UI + server
npm run dev:ui       # mock browser preview (VITE_MOCK_MODE=true)
npm run typecheck
npm run test
npm run test:smoke

Demo case PP-10482 is seeded automatically on server start.

Mock UI preview

npm run dev:ui

Shows a Mock Development Mode badge and loads the seeded case without an MCP host. Production builds do not enable this by default.

Free hosting (recommended: Render)

Use Render Free Web Service for a public HTTPS MCP URL Langdock can reach.

1. Go to https://dashboard.render.com and sign up (GitHub login).
2. New → Web Service
3. Connect repo: AdarshRajDS/ppap-review-mcp
4. Settings:
   • Runtime: Node
   • Build Command: npm ci --include=dev && npx vite build
   • Start Command: npx tsx server/index.ts
   • Instance type: Free
   • Health Check Path: /health
5. Deploy. Your URL will look like: https://ppap-review-mcp.onrender.com
6. In Langdock → Integrations → MCP, enter: https://ppap-review-mcp.onrender.com/mcp Auth: No Authentication (unless you set MCP_API_KEY)

Notes:

• Free tier sleeps after ~15 minutes idle; the first request can take 30–60s to wake.
• Netlify is only for static UI preview — do not use the Netlify URL in Langdock.

Public testing / tunnels

For quick local testing without Render, expose the local server with any temporary HTTPS tunnel (ngrok, Cloudflare Tunnel, localtunnel, etc.):

npm run serve
# then tunnel port 3001 → HTTPS

Example result:

https://example-public-host/mcp

Langdock setup

1. Deploy/expose the MCP server through HTTPS.
2. Open Langdock workspace settings.
3. Go to Integrations.
4. Add an MCP integration.
5. Enter: https://YOUR_HOST/mcp
6. Choose No Authentication for local/demo use, or API Key / Bearer auth when MCP_API_KEY is set.
7. Test the connection.
8. Enable these tools:
   • create_ppap_case
   • update_ppap_case
   • get_ppap_case
   • open_ppap_workbench
   • set_finding_decision
   • add_finding_comment
   • set_review_status
   • get_review_summary
9. Add the MCP integration/actions to the PPAP Review Agent.
10. In the Agent instructions, tell the Agent to:
    • create/update the PPAP case after analysis
    • then call open_ppap_workbench
    • use the returned human review state for later supplier communication

Exact connection URL format

https://YOUR_HOST/mcp

Local:

http://localhost:3001/mcp

Suggested test phrase

Review this PPAP submission. After analysis, create the PPAP case and open the PPAP Review Workbench for human SQE review.

Demo flow

1. User: "Review this PPAP submission."
2. Langdock analyzes documents.
3. Langdock calls create_ppap_case with case PP-10482 (or equivalent structured payload).
4. Langdock calls:

{ "caseId": "PP-10482" }

via open_ppap_workbench.

5. The MCP App opens inside Langdock.
6. SQE opens F-001, compares Drawing Revision C vs PSW Revision B.
7. SQE selects Supplier Clarification and comments:
   "Please submit a PSW matching the current drawing revision."
8. UI calls set_finding_decision through the MCP Apps bridge (not fetch to localhost).
9. User returns to chat:
   "Prepare the supplier clarification email for everything I marked."
10. Langdock reasons over the human-reviewed case and drafts the email.

Security

• Set MCP_API_KEY to require Authorization: Bearer <key> on /mcp.
• Do not expose the API key to the React UI.
• Treat all PPAP payloads as confidential business data.
• No secrets are returned to the UI.

Docker

docker build -t ppap-review-mcp .
docker run --rm -p 3001:3001 -v ppap-data:/app/data -e PORT=3001 ppap-review-mcp

Optional auth:

docker run --rm -p 3001:3001 -e MCP_API_KEY=your-secret ppap-review-mcp

Environment

See .env.example:

PORT=3001
MCP_API_KEY=
DATA_DIR=./data
NODE_ENV=development
VITE_MOCK_MODE=false

Project layout

ppap-review-mcp/
  server/          MCP + Express + persistence + tools
  ui/              React MCP App (single-file Vite build)
  data/            Local JSON store (server-authoritative)
  tests/           Unit + MCP smoke tests