Claude Error Collector
An MCP server for Claude Code that learns from your corrections. When you tell Claude "that was wrong" or "no, do it like this", it records the lesson as a rule in your CLAUDE.md - so the same mistake doesn't happen twice.
How It Works
- You correct Claude during a coding session
- Claude recognizes the correction and calls the
record_errortool - The server derives a rule and writes it to the appropriate
CLAUDE.md - Claude reads that rule in future sessions and avoids repeating the mistake
The server automatically detects whether you're in a project directory (writes to project CLAUDE.md) or your home directory (writes to ~/.claude/CLAUDE.md).
Tools
record_error
Records a correction and saves it as a learned rule.
| Parameter | Type | Required | Description |
|---|---|---|---|
error_description | string | yes | What was wrong |
correction | string | yes | What is correct |
rule | string | yes | Derived guideline, e.g. "ALWAYS use X instead of Y" |
project_dir | string | no | Current working directory (for finding project CLAUDE.md) |
list_errors
Lists all learned rules from the relevant CLAUDE.md.
| Parameter | Type | Required | Description |
|---|---|---|---|
project_dir | string | no | Current working directory |
Output Format
Rules are stored in a ## Learned Rules section in your CLAUDE.md:
## Learned Rules
- ALWAYS use async/await for API calls, NOT .then() chains
- Google Apps Script uses Logger.log(), NOT console.log()
- Confluence API expects ADF format, NOT Wiki markup
Installation
git clone https://github.com/henningziech/claude-error-collector.git
cd claude-error-collector
./install.sh
The install script handles everything:
- Installs dependencies and builds the project
- Registers the MCP server with Claude Code (
claude mcp add)
No manual CLAUDE.md editing needed — the server provides its own instructions to Claude via MCP server metadata.
Restart Claude Code after installation to activate.
Manual Installation
If you prefer to set things up manually:
npm install && npm run build
claude mcp add error-collector -- node /path/to/claude-error-collector/dist/index.js
CLAUDE.md Resolution
The server finds the right CLAUDE.md using this logic:
- If
project_diris provided: walk up the directory tree looking forCLAUDE.md - If found and not in the home directory: use it (project-level rules)
- Fallback:
~/.claude/CLAUDE.md(global rules)
Duplicate Detection
Before writing a rule, the server checks existing rules using case-insensitive substring matching. If the new rule is already covered by an existing one (or vice versa), it skips the write.
License
MIT