Cursor AI Persistent Memory:
Give Cursor a Brain That Survives Every Session

The problem: Cursor starts from zero, every time

You spend the first 10–20 minutes of every Cursor session re-explaining your project: the tech stack, the constraints, the bugs you just fixed, the naming conventions your team agreed on last week. This is not Cursor's fault — it has no state between sessions. But it is your problem, and it compounds every day.

In a mature codebase this re-briefing is a daily cost, and it adds up over a year just to put the AI back where you left it.

The solution: cachly — persistent memory for Cursor via MCP

cachly is the persistent memory layer for AI coding assistants. It integrates with Cursor via the Model Context Protocol (MCP) — Cursor's standard extension interface — and provides tools that give Cursor long-term memory, root-cause tracing, and failure prediction.

The core loop is simple: cachly captures lessons from every session and every git commit, stores them in a knowledge graph with causal edges, and injects a concise briefing at the start of each new Cursor session. Cursor arrives knowing your stack, your recent bugs, and what the team learned yesterday.

Setup: one command, under 2 minutes

npx @cachly-dev/mcp-server@latest autopilot

The wizard detects Cursor automatically, writes the MCP config to~/.cursor/mcp.json, and authenticates you with a single browser click. No API keys in config files. No YAML to hand-edit. Done.

Then it runs brain_from_git — reading your last 100 commits and extracting lessons from the bug fixes, reverts, and decisions in them. Cursor starts with what your recent history teaches.

What the Cursor MCP config looks like

// ~/.cursor/mcp.json (auto-written by setup)
{
  "mcpServers": {
    "cachly": {
      "command": "npx",
      "args": ["@cachly-dev/mcp-server@latest", "start"],
      "env": {
        "CACHLY_INSTANCE_ID": "your-instance-id"
      }
    }
  }
}

You can also add this manually if you prefer, then paste your instance ID from the cachly dashboard. But the setup wizard is faster.

What Cursor can do with cachly memory

Session briefing — zero typing required

Every Cursor session starts with session_start — automatically called at the first tool use. cachly sends back a structured briefing: your recent work, open bugs, team lessons, and your latest memory crystal (a compressed wisdom snapshot). Cursor reads the full context before you type a word.

Instant root-cause analysis

Describe a bug in plain language: causal_trace("payment webhook 500 on retry"). cachly follows the causal graph in your brain and returns the root cause, the failure chain, and the fix that resolved it before.

Failure prediction before deploy

Before pushing to production, call brain_predict. cachly scans your brain for recurring failure patterns and returns weighted warnings about what is likely to break — ranked by confidence, backed by your own historical data. Not generic advice. Predictions specific to your codebase.

Automatic learning from commits

The setup installs a git post-commit hook. Every commit you make is automatically sent to cachly via learn_from_attempts. Bug fixes, reverts, refactors — all become lessons in the brain. Cursor's memory grows with every line of code your team writes, without any manual effort.

cachly vs Cursor's built-in context window

Does cachly work with Cursor Rules?

Yes — they're complementary. Cursor Rules (.cursorrules) are great for static, project-specific coding standards. cachly is for dynamic, session-aware memory: what broke last week, what the team decided yesterday, what patterns predict failures in your specific codebase.

Many developers use both: Cursor Rules for stable conventions, cachly for living institutional memory.

GDPR, privacy, and data residency

cachly runs on Hetzner servers in Nuremberg, Germany — inside the EU. All data stays in the EU. There is no PII extraction from your code or commit messages beyond what you explicitly teach the brain. GDPR-native by design.

Need your own infrastructure? Self-hosted and air-gapped deployments are part of the Enterprise plan, on request.

Get started in 2 minutes

# Install and configure cachly for Cursor
npx @cachly-dev/mcp-server@latest autopilot

# In any Cursor session, verify it works:
# cachly will call session_start automatically
# and Cursor will receive your full briefing

The free tier includes 25 MB of brain storage and 500 recalls a month. No credit card needed. Upgrade when you need more storage or a team Brain.