MCP Server — AI Graph Inspection

@cnstra/mcp is an MCP server that gives AI tools (Claude Code, Cursor, VS Code, Windsurf) live access to your neuron graph. It uses the same registry you create with createPersistRegistry from '@cnstra/core' — one file, one line.

Tools exposed:

• cns_get_context — START HERE: CNStra concept guide + neuron list
• cns_get_graph — full architecture with all connections
• cns_get_neuron — deep dive into one neuron
• cns_list_neurons — quick overview of all neurons
• cns_list_collaterals — all collaterals with owners and subscribers

Setup

1. Install

npm i -D @cnstra/mcp

2. Create cns-mcp.ts

First, create a registry. Two options:

Option A — per-file (recommended for larger projects):

// src/neurons/registry.ts
import { CNSPersistOptionsRegistry } from '@cnstra/core';
export const registry = new CNSPersistOptionsRegistry();

// src/neurons/deck.ts — each neuron registers itself
import { registry } from './registry';
registry
    .register('deckNeuron', deckNeuron)
    .register('cardNeuron', cardNeuron, { deckCreated: 'deck-created' }) // explicit collateral names
    .registerCollateral('userLogin', userLogin); // standalone collateral (no neuron owner)

Option B — all at once (simpler for small projects):

// src/neurons/registry.ts
import { createPersistRegistry } from '@cnstra/core';
import { deckNeuron, cardNeuron, uiNeuron } from './index';

export const registry = createPersistRegistry({ deckNeuron, cardNeuron, uiNeuron });

Then the MCP entry point:

// cns-mcp.ts  ← dev-only, not imported from prod entry point
import { startCNSMCPServer } from '@cnstra/mcp';
import { cns } from './src/cns';
import { registry } from './src/neurons/registry';

await startCNSMCPServer(cns, registry);

3. Run init to register with all AI tools

npx @cnstra/mcp init

Writes MCP config for every tool found in the project:

Tool	Config file
Claude Code	.claude/settings.json → mcpServers
Cursor	.cursor/mcp.json → mcpServers
VS Code	.vscode/mcp.json → servers
Windsurf	.windsurf/mcp.json → mcpServers

After init, open the project in any of these tools — the MCP server starts automatically.

What the AI gets

The server exposes three MCP mechanisms — tools that support any subset will benefit:

Resources (auto-loaded on connect in tools that support them):

• cnstra://context — concepts, rules, neuron list
• cnstra://graph — full neuron graph

Prompts (slash-commands / @ references):

• understand_project — context + full graph in one shot

Tools (called on demand):

• cns_get_context, cns_get_graph, cns_get_neuron, cns_list_neurons, cns_list_collaterals

Example: cns_get_graph output

# CNS Graph

## deckNeuron

**Emits:**
  - `createdAtButtonClick` → cardNeuron
  - `createdAtOnboarding` → cardNeuron
  - `renamed`
  - `archived`

**Reacts to:**
  - `createDeckButtonClicked` from **uiNeuron**
  - `userOnboarded` from **onboardingNeuron**

Zero prod overhead

@cnstra/mcp is a dev dependency. cns-mcp.ts is never imported in production. The MCP server process only runs when an AI tool starts it.