Claude Code skills and memories

What a Claude Code skill is

A skill is a folder with a SKILL.md file in it. The frontmatter says what the skill is for, and the Markdown under it holds the instructions. Claude Code reads only the description at the start of a session and loads the rest when the skill is used, either because you typed its name after a slash or because your request matched the description.

---
description: How to run the billing tests in this repo. Use when the user asks to run or fix billing tests.
---

1. Start the local database with docker compose up db.
2. Run pnpm test billing.
3. If a date test fails at random, freeze the clock first.

Saved as .claude/skills/billing-tests/SKILL.md, that runs as /billing-tests. Where skills go, the frontmatter fields and what to do when one will not trigger are all in our Claude Code skills guide.

Where skills stop

Look at step 3 in that skill. Nobody knew to write it until a session lost an hour to a test that failed one run in four. Claude found the fix, the session ended, and the fix stayed in that conversation. A skill only holds it if you stop and write it in yourself.

That is the part FixMyPrompt keeps. When Claude gets something right, it saves the steps that worked as a memory: when they apply, what to do, how to check, and what looked right but failed. The next session in that folder sees what is saved and pulls the full steps when one fits.

A saved memory, for illustration

#12 Flaky date tests in billing-api       short name: fix-flaky-date-test
Use when: a date or invoice test passes and fails on reruns
Steps:
  1. Freeze the clock in {{test_file}} before the first assertion.
  2. Seed the random generator with a fixed value.
  3. Run the file 5 times in a row.
Check: 5 passes in a row
Avoid: raising the timeout. It hid the failure for a day and it came back.

Run a memory as a slash command

Give a memory a short name and Claude Code lists it in the slash menu. Ask Claude to save it with one ("save that as a memory with the short name fix-flaky-date-test"), or set it later on the Memories page. Claude Code puts MCP commands under the server name, so it runs as:

> /mcp__fmp__fix-flaky-date-test tests/invoice.test.ts

Each {{blank}} in the steps becomes an argument. Type the value after the command, or leave it out and the memory arrives marked with what was not filled in, so Claude knows to ask you. The command runs whichever version of the memory is marked in use.

Skill, memory or CLAUDE.md?

A long CLAUDE.md is often procedures that belong in a skill. To see what yours costs every session, paste it into the CLAUDE.md checker.

The FixMyPrompt plugin for Claude Code

The plugin adds the fmp MCP server and a session-start hook. When a session starts, the hook tells Claude which folder it is in and to check the memories saved for it, so you do not have to ask. The hook is plain Node and you can read every line of it in the plugin repo before you install.

It also ships its own skills, each a single SKILL.md you can read as an example. /fmp:sign-in connects the session-start hook to your account. /fmp:doctor checks your CLAUDE.md, AGENTS.md and Cursor files and writes fixed ones with every change listed. /fmp:import reads your past sessions on your machine and saves the lessons in them as drafts for you to look over. Those need Pro.

Set it up

In Claude Code, add the marketplace and install the plugin:

/plugin marketplace add GDM-Digital-Media-Group/fmp-plugins
/plugin install fmp@fmp-plugins

Restart Claude Code, run /mcp, pick fmp and sign in. Your browser opens FixMyPrompt to approve the connection, once per machine. To skip the hook and add only the server:

claude mcp add --transport http fmp https://fixmyprompt.net/api/mcp

The Free plan covers one connected tool, 25 memories and 300 memory reads a month. Plans with more are on the pricing page.

Questions