coldstart — Claude Code MCP server: code index and agent memory
File and symbol index plus a notebook where the agent writes notes anchored to your code. Agents stop rediscovering the repo every session.
claude mcp add coldstart -- npx -y @cstart/coldstartWhat coldstart does
Two layers in one tool. Navigation: a static index of paths, symbol names, exports, and the import graph; answers which files matter for a task in milliseconds, no embeddings. The notebook: notes the agent writes after real tasks — what a file does, how a flow spans modules, which invariants hold. Each note ties to specific files; when code drifts and a note goes stale, the server flags it instead of serving it as fact.
One-step setup: coldstart init at the project root. The command creates config, wires hooks for your chosen client (Claude Code, Codex, or Cursor), spins up the notebook, and warms the index in the background. You manually specify which client to configure during init.
Requires Node.js 18 or later. No models, no services, no embeddings — just an index and text notes stored locally.
What it helps with
- locate files by symbol name, import, or function call
- recall what the agent learned about a module in the last session
- see which files change together in git history
- detect when a note is stale because code changed
Example prompts for the agent
- Find all files that call
processPayment - What does the
src/authmodule do and how does it connect to the rest? - Remember:
EmailServicesends mail via SendGrid, config in.env
How to install coldstart
Platform CLI
claude mcp add coldstart -- npx -y @cstart/coldstartPlatform CLI
codex mcp add coldstart -- npx -y @cstart/coldstartConfig file
{
"mcpServers": {
"coldstart": {
"command": "npx",
"args": [
"-y",
"@cstart/coldstart"
]
}
}
}Config file
{
"servers": {
"coldstart": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@cstart/coldstart"
]
}
}
}Platform CLI
gemini mcp add coldstart npx -y @cstart/coldstartStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about coldstart
How do I install coldstart in Claude Code?
Global: npm install -g @cstart/coldstart, then coldstart init in your project. It prompts for client and experience (cli or mcp), creates coldstart.md, adds the import to CLAUDE.md, registers navigation and notebook hooks in .claude/settings.json.
What does coldstart do?
Gives agents fast code navigation (index of files, symbols, imports) and a notebook for project notes. The agent writes the notes; they anchor to files. When a file changes, the note is marked stale.
Do I need to run a separate process?
No. The index updates in the background when files change; the notebook lives locally in .coldstart/notebook/. No embeddings or models involved.
