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io.github.ozten/cantrip

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MCP server for Cantrip — AI-powered GTM engine for solo founders

Source code Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package mcp-server-cantrip
Claude Code 
claude mcp add cantrip -e 'CANTRIP_API_KEY=<your cantrip_api_key>' -- npx -y mcp-server-cantrip@1.0.5
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "cantrip": {
            "command": "npx",
            "args": [
                "-y",
                "mcp-server-cantrip@1.0.5"
            ],
            "env": {
                "CANTRIP_API_KEY": "<your cantrip_api_key>"
            }
        }
    }
}

Environment variables

  • CANTRIP_API_KEY required secret Your Cantrip API key

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. mcp-server-cantrip
  2. Configuration
  3. Examples of How to use Cantrip
  4. Troubleshooting
  5. Architecture
  6. Tools (17)
  7. License

mcp-server-cantrip

Cantrip helps technical founders find their first customers with structured GTM workflows.

  • Nail your ICP — define ideal customer profiles, buyer pains, and value props
  • Research competitors — map the landscape and find where you can win
  • Get next actions — gap analysis tells you exactly what to work on, then does it for you

Works with Claude Code / Claude Desktop / Cursor — any MCP-compatible agent.

Quick start
  1. Get your API key at cantrip.ai (settings)
  2. Add the server:
claude mcp add cantrip -e CANTRIP_API_KEY=your-api-key -- npx -y mcp-server-cantrip
  1. Try this prompt:

"Initialize a Cantrip project for my product: [describe yours in one sentence]"

Configuration

The Quick start command above covers Claude Code. Verify it worked with claude mcp list or the /mcp command inside a session.

Claude Desktop / Cursor / manual JSON

All MCP clients use the same JSON block. Add it to the appropriate config file:

ClientConfig file
Claude Code (manual)~/.claude.json
Claude Code (project-scoped).mcp.json in project root
Claude Desktop (macOS)~/Library/Application Support/Claude/claude_desktop_config.json
Claude Desktop (Windows)%APPDATA%\Claude\claude_desktop_config.json
Cursor.cursor/mcp.json (project) or ~/.cursor/mcp.json (global)
{
  "mcpServers": {
    "cantrip": {
      "command": "npx",
      "args": ["-y", "mcp-server-cantrip"],
      "env": {
        "CANTRIP_API_KEY": "your-api-key"
      }
    }
  }
}

Note: The -y flag is required — without it, npx prompts for confirmation which hangs over stdio.

Windows (not WSL): Use "command": "cmd" with "args": ["/c", "npx", "-y", "mcp-server-cantrip"].

Project-scoped with teams: Use "${CANTRIP_API_KEY}" in the env value so each developer sets the key in their shell profile.

Project Context (.cantrip.json)

Each project directory contains a .cantrip.json file that tells Cantrip which project to target:

{
  "project": "my-saas"
}

This file is created automatically by cantrip_init (new project) or cantrip_connect (existing project). The agent manages it — you don't need to create it manually.

Multiple projects on the same machine? Each project directory gets its own .cantrip.json. The agent switches context by working in the right directory.

Examples of How to use Cantrip

After connecting Cantrip, try these prompts in order:

  1. "Initialize a Cantrip project for my product: [one sentence about what you're building]"
  2. "Find my likely ICP and top 3 buyer pains."
  3. "Research 5 competitors and tell me where I can win."
  4. "Give me a one-week GTM plan."

Troubleshooting

Server not found / no tools appear:

  • Run claude mcp list (Claude Code) or /mcp inside a session to check connection status.
  • Make sure the config is in the right file — Claude Code uses ~/.claude.json or .mcp.json, not ~/.claude/mcp.json.

Server hangs on startup:

  • Ensure you have -y in the npx args. Without it, npx waits for interactive confirmation that can never arrive over stdio.

"Cannot reach Cantrip API" errors:

  • Verify CANTRIP_API_KEY is set in the env block of your MCP config.
  • Check that https://api.cantrip.ai is reachable from your network.

Windows "Connection closed" errors:

  • Use "command": "cmd" with "args": ["/c", "npx", "-y", "mcp-server-cantrip"].

Architecture

Agent (Claude, etc.) ── MCP protocol (stdio) ──> mcp-server-cantrip ── HTTPS POST ──> https://api.cantrip.ai

The MCP server is a thin translation layer. It converts MCP tool calls into {command, args, flags} JSON envelopes and POSTs them to the Cantrip API. Zero business logic — identical contract to the CLI and React UI.

Tools (17)

Setup
ToolDescription
cantrip_connectConnect workspace to a project (reads/writes .cantrip.json)
cantrip_statusCheck if the daemon is running
cantrip_initCreate a new project and auto-connect
Core Commands
ToolDescription
cantrip_snapshotProject overview, drill into entity types
cantrip_nextList gap-analysis opportunities
cantrip_next_promptGenerate a context-rich LLM prompt for an opportunity
cantrip_next_runSpawn a background agent for an opportunity
cantrip_historyQuery the audit trail
Review
ToolDescription
cantrip_reviewList items pending review
cantrip_review_acceptAccept an inferred entity
cantrip_review_rejectReject an inferred entity
cantrip_review_resolveResolve an escalation
cantrip_review_dismissDismiss an escalation
Entity CRUD (generic)
ToolDescription
cantrip_entity_listList entities of a type
cantrip_entity_showShow entity detail
cantrip_entity_addCreate a new entity
cantrip_entity_editEdit an existing entity

Supported entity types: icp, pain_point, value_prop, experiment, channel, competitor, contact

License

MIT

Frequently asked questions

What is io.github.ozten/cantrip?

MCP server for Cantrip — AI-powered GTM engine for solo founders

How do I install io.github.ozten/cantrip?

It runs on your machine. In Claude Code: claude mcp add cantrip -e 'CANTRIP_API_KEY=<your cantrip_api_key>' -- npx -y mcp-server-cantrip@1.0.5. For other clients, paste the JSON configuration from this page into their MCP settings.

Does io.github.ozten/cantrip need an API key?

Yes. It expects CANTRIP_API_KEY, which you set in its configuration.

Is io.github.ozten/cantrip open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains io.github.ozten/cantrip?

It is published by ozten. AI.tn lists it but does not maintain or endorse it.

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