ERDL MCP Server

Deterministic rules for AI Agents. Say it once. Never repeat.

ERDL (Entity-Rule Definition Language) gives your Agent deterministic rules. 30 built-in presets. Unlimited personal rules. Free forever.

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Why ERDL?

Without ERDL	With ERDL
"Don't use any" — forgotten in 5 turns	Rules enforced deterministically, every tool call
"Write shorter sentences" — ignored	Writing rules fire before every output
"Confirm before adding deps" — skipped	Blocked until you confirm
"Why did you do that?" — no answer	erdl_explain shows the full decision trail

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Quick Start

npx -y @openoba-ai/erdl-mcp

30 rules active immediately. No account. No configuration. No API key.

中文用户：

npx -y @openoba-ai/erdl-mcp --lang zh

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Free vs Pro

	Free	Pro
5 MCP Tools	✅	✅
30 Preset Rules	✅	✅
Unlimited Personal Rules	✅	✅
Chinese / English	✅	✅
All 11 Operators	✅	✅
MIT Open Source	✅	✅
Execution Rings 1–2 (REQUEST_HUMAN, ESCALATE, ROLLBACK, QUARANTINE)	—	✅
Guardian Agent Role (监管者模式)	—	✅
Audit Export (OCSF / OTLP)	—	✅
Team Rules (组织级规则共享)	—	✅
Dashboard (规则命中统计)	—	✅
Enterprise Compliance Packs (GB/Z 185, NIST, EU AI Act)	—	Enterprise

Get a Pro License →

One-command Install

# macOS / Linux
curl -fsSL https://raw.githubusercontent.com/OpenOBA/erdl-mcp-server/master/scripts/install.sh | bash

# Windows (PowerShell)
iwr https://raw.githubusercontent.com/OpenOBA/erdl-mcp-server/master/scripts/install.ps1 | iex

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Why ERDL vs SKILL.md / Prompt Rules?

	Prompt-Based Rules	ERDL MCP Server
Execution	LLM "tries" to follow	Deterministic engine — guaranteed
Visibility	Invisible, can't tell if it worked	erdl_explain shows every decision
Reliability	LLM may ignore or forget	Zero hallucination — condition match is mathematical
Testing	Manual	erdl_simulate with 3 auto-scenarios
Portability	Single platform	All MCP-compatible Agents

ERDL rules don't suggest. They don't hope. They enforce.

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What's Included

30 Built-in Rules

Category	Rules	Scope
coding	10	TypeScript quality, Git discipline, dependency hygiene
engineering	10	Workflow discipline: honesty, no shortcuts, pipeline gates
writing	7	Tone, formatting, clarity
design	3	Tailwind-first, responsive, accessible

5 MCP Tools

Tool	Purpose
erdl_evaluate	Action Guard — check rules before every tool call
erdl_simulate	Test a rule against 3 scenarios before creating
erdl_create_rule	Create a rule from natural language
erdl_list_rules	List all active rules
erdl_explain	Full decision trail for any action

MCP Resources

Resource	Content
erdl://rules/list	All rules as JSON
erdl://status	Server runtime status

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Installation

Any MCP Client

{
  "mcpServers": {
    "erdl": {
      "command": "npx",
      "args": ["-y", "@openoba-ai/erdl-mcp@latest"]
    }
  }
}

Or let ERDL generate the config for your client:

npx @openoba-ai/erdl-mcp@latest --setup

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or the equivalent path on your OS.

Cursor

Add to .cursor/mcp.json in your project root.

OpenClaw

openclaw mcp set erdl '{"command":"npx","args":["-y","@openoba-ai/erdl-mcp@latest"]}'

VS Code / GitHub Copilot

Add to .vscode/mcp.json or the Copilot MCP configuration.

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Creating Your First Rule

You: "Never use `any` in TypeScript."

Agent: 1. erdl_simulate → tests the rule against 3 scenarios
       2. erdl_create_rule → saves to ~/.openoba/rules/
       3. Rule is now active. Next `any` will be blocked.

You: "Why did you reject my code?"
Agent: erdl_explain → shows every rule that fired

Or create rules manually in ~/.openoba/rules/:

rules:
  - id: MY-001
    name: no_console_log
    description: Don't commit console.log statements
    category: coding
    triggers: [write_file, edit, apply_patch]
    when: "tool.args.path match \"\\.tsx?$\""
    then: DENY "Remove console.log before committing"
    priority: 10
    enabled: true

📚 Full tutorial: Create Your First ERDL Rule → (English)

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CLI Reference

npx @openoba-ai/erdl-mcp@latest          # Start MCP server (always latest)
npx @openoba-ai/erdl-mcp@latest --lang zh # Chinese mode
npx @openoba-ai/erdl-mcp@latest --pro-key sk-xxx  # Activate Pro license
npx @openoba-ai/erdl-mcp@latest --upgrade  # Upgrade to latest
npx @openoba-ai/erdl-mcp@latest --uninstall  # Clean removal
npx @openoba-ai/erdl-mcp@latest --help     # Full usage

Stuck on an old version? npx caches your first install. If --version shows an older release, clean the cache:

npm cache clean --force

Then re-run: npx @openoba-ai/erdl-mcp@latest

Run from Source

git clone https://github.com/OpenOBA/erdl-mcp-server.git
cd erdl-mcp-server
npm install
npm run build
node bin/erdl-mcp.js --version

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License

MIT · OpenOBA · @OpenOBA

Built by AI + Human. Deterministic architecture, not prompt engineering.