Speclock

@sgroy10

About Speclock

AI Constraint Engine — enforces CLAUDE.md, .cursorrules, AGENTS.md rules as laws. 51 MCP tools, 991 tests. Official MCP Registry. npx speclock protect

#constraint-engine #code-quality #developer-tools #claude-code #cursor #mcp #security #pre-commit

Config

Add this server to your MCP-compatible client using the configuration below.

{
  "mcpServers": {
    "speclock": {
      "command": "npx",
      "args": [
        "-y",
        "speclock",
        "serve"
      ]
    }
  }
}

Tools

No tools detected

Fetch the live tool list by running this server in a temporary sandbox using the button above.

Overview

What is Speclock?

Speclock is an AI constraint engine that enforces project rules across every AI coding session. It stops AI assistants from breaking constraints you have defined, such as "never touch the auth system" or "database must stay PostgreSQL."

How to use Speclock?

Install in your project with npx speclock protect, wire up MCP for supported clients using speclock mcp install <client> (e.g., claude-code, cursor, windsurf, cline, codex), then verify with speclock doctor. Default mode is advisory (warnings only); hard enforcement is enabled with --strict or SPECLOCK_STRICT=1.

Key features of Speclock

Semantic conflict detection (100/100 score, 0% false positives)
Hard enforcement mode that blocks AI from proceeding
Pre‑commit hooks and MCP integration for all major AI tools
Tamper‑proof audit trail with HMAC‑SHA256 chain
SOC 2 / HIPAA compliance exports
Encrypted storage (AES‑256‑GCM) and RBAC with API key auth
Policy‑as‑Code DSL using YAML rules

Use cases of Speclock

Prevent AI from modifying auth, payment, or patient‑record files
Enforce database technology choices across sessions (e.g., PostgreSQL only)
Block deletion or disabling of critical systems (e.g., patient data, audit logging)
Protect regulatory‑sensitive workflows that require SOC 2 or HIPAA compliance
Extend guardrails to no‑install platforms like Lovable or Bolt.new

FAQ from Speclock

How is Speclock different from Claude Memory, Mem0, or .cursorrules?

Those tools only remember context but do not block the AI from violating constraints. Speclock enforces rules with semantic detection, hard enforcement, and a tamper‑proof audit trail.

What enforcement modes does Speclock offer?

Advisory mode (default) issues warnings letting the AI decide; hard mode (--strict) blocks the AI from proceeding when a violation is detected.

Does Speclock work with all AI coding tools?

Speclock supports Claude Code, Cursor, Windsurf, Cline, Codex, and also works on npm-based platforms like Bolt.new, Aider, and Lovable (via URL‑based MCP).

How does the semantic engine work?

It uses Gemini Flash hybrid for universal domain coverage, understanding synonyms, euphemisms, temporal evasion, and compound sentences — not just keyword matching.

What are the installation requirements?

Node.js and npm are required. Install with npx speclock protect or add the MCP configuration manually. No persistent backend is needed; data stays local unless you opt into the public Saves Wall.

Frequently asked questions