MCP Generator

Generate minimal MCP servers for Rocket.Chat with only the tools your project needs. Reduces context bloat by 80-95%.

The Problem

Existing MCP servers expose all 547 Rocket.Chat API endpoints, burning ~115k tokens per agent loop. Most projects need 2-10 tools. Every unused tool definition wastes tokens and money on every agentic iteration.

The Solution

This generator produces production-ready MCP servers covering only the workflows you select. Generated tools contain real decision logic — not thin API wrappers.

Quick Start

npm install
npx tsx src/index.ts generate --capabilities "onboard new team members" --output ./my-server

Or with explicit workflow IDs:

npx tsx src/index.ts generate --workflows "minimal-chatbot,cicd-notifier" --output ./my-server

Or with a config file (.mcp-generator.yaml):

provider: rocketchat
capabilities:
  - onboard new members
  - CI/CD notifications
output: ./my-server
name: my-rc-mcp

npx tsx src/index.ts generate

CLI Commands

Command	Description
generate	Generate a minimal MCP server
list	Show all available workflows with token costs
measure --all	Token savings comparison table
measure --capabilities "..."	Measure savings for natural language input

Available Workflows

Workflow	Steps	Tokens	Savings	Features
onboard-team-member	5	~184	88.8%	decision logic
customer-support-bot	5	~163	90.1%	decision, events, retry
cicd-notifier	5	~162	90.2%	decision, retry
team-standup	5	~137	91.7%	retry
content-moderation	6	~138	91.6%	decision, events
channel-management	5	~145	91.2%	decision
message-search	3	~128	92.2%
file-sharing	3	~120	92.7%
analytics-reporter	4	~108	93.4%	decision, retry
webhook-integration	4	~139	91.6%
notification-bot	2	~126	92.4%	decision
minimal-chatbot	3	~98	94.1%	retry

What Makes This Different

Other generators produce thin API wrappers:

// Thin wrapper
server.tool("onboard_user", {}, async ({ username, channels }) => {
  await client.post("/api/v1/users.create", { username });
  for (const ch of channels) {
    await client.post("/api/v1/channels.invite", { roomId: ch });
  }
});

This generator produces platform-level tools with real logic:

// Generated: decision logic, error handling, rollback
server.tool("rc_onboard_team_member", {}, async ({ username, email, role }) => {
  const existing = await client.get("/api/v1/users.info", { username });

  if (existing?.user != null) {
    userId = existing.user._id;
  } else {
    const created = await client.post("/api/v1/users.create", {
      username, email, password: crypto.randomUUID().slice(0, 16),
    });
    userId = created.user._id;
  }

  // Role-based channel selection, per-channel error handling,
  // welcome DM with skip-on-failure strategy
});

Architecture

User input (NL / config / flags)
    │
    ├─ [NL Parser] ── fuse.js fuzzy matching → workflow templates
    │
    ├─ [ProviderSpec] ── generic platform interface (RC first impl)
    │
    ├─ [WorkflowTemplate] ── decision points, error handlers, rollback
    │
    ├─ [Code Emitter] ── Handlebars → TypeScript with real if/else/try/catch
    │
    ├─ [Token Counter] ── measures and reports savings
    │
    └─ Generated Output: MCP Server + RC App (if events needed)

Generated Output

Single workflow (no events):

my-server/
  server/src/
    index.ts          # MCP server entry
    client.ts         # RC HTTP client
    tools/
      minimal-chatbot.ts
  package.json
  gemini-extension.json
  .env.example

Workflows with real-time events (monorepo):

my-server/
  server/            # MCP server
  rc-app/            # Rocket.Chat App event bridge
    app.json
    src/index.ts     # Listens for events, forwards via HTTP callback
  package.json
  gemini-extension.json

gemini-cli Integration

Install generated server as a gemini-cli extension:

gemini extensions install ./my-server

Or configure manually in ~/.gemini/settings.json:

{
  "mcpServers": {
    "rocketchat": {
      "command": "node",
      "args": ["./my-server/server/dist/index.js"]
    }
  }
}

Development

npm install
npm test              # 88 tests
npm run test:workflows # 54 workflow tests
npm run benchmark     # token savings report

Token Savings Benchmark

Combo scenarios across a 10-iteration agent loop:

Scenario	Tools	Tokens	Full	Savings
Messaging only	1	~98	~1648	94.1%
Support team	2	~301	~1648	81.7%
DevOps	3	~427	~1648	74.1%
Team lead	3	~466	~1648	71.7%
Full admin	4	~575	~1648	65.1%

Average single-workflow savings: 91.7%

Tech Stack

• TypeScript (strict mode)
• Handlebars (deterministic codegen, zero LLM)
• fuse.js (natural language matching)
• commander + @inquirer/prompts (CLI)
• vitest (88 tests)
• @modelcontextprotocol/sdk (in generated output)
• @rocket.chat/apps-engine (in generated RC App)