I built an MCP server that actually stops AI from breaking your rules — not just reminds it

Been vibe coding for a year. The pattern that kept destroying my projects:

• Session 1: "Never touch my auth system, PostgreSQL only, Stripe for payments"
• Session 4: AI suggests MongoDB "for better performance"
• Session 7: Auth rewritten while I asked about button colors

CLAUDE.md, .cursorrules, AGENTS.md — all suggestions. The AI reads them and does whatever it wants anyway.

So I built SpecLock. It's an MCP server that does two things differently:

1. Locks, not suggestions — when you say "never do X", it's stored with conflict detection, not just written to a file

2. Blocks before changes happen — checks every action against your locks before execution, fires a CONFLICT warning if something would violate them

MCP URL for Lovable/Cursor/Claude Code: https://speclock-mcp-production.up.railway.app/mcp

For Bolt.new (no MCP needed): just tell it "Install speclock and set up project memory"

It's been running on my own project for weeks. Tested it against adversarial phrasing ("I was wondering if we could use MongoDB?"), question framing, euphemisms — catches them at 95%+.

1,900+ downloads this week. Free, MIT license.

GitHub: github.com/sgroy10/speclock

Genuinely curious — what's the constraint you keep having to repeat to your AI that it keeps ignoring?