Cinderfi

Tax-aware retirement planning for Canada and the US, available as a Claude Code plugin, an Agent Skills skill, and a Model Context Protocol server.

Compatible with Claude Code, Cursor, VS Code Copilot, OpenAI Codex, Gemini CLI, Goose, and any other MCP- or Agent Skills-compatible agent.

What it does

19 tools covering:

• Retirement projections (single + couples)
• CPP / OAS / Social Security timing
• Tax calculations (all Canadian provinces + US states)
• GIS eligibility and clawback analysis
• RRSP meltdown / Roth conversion strategy
• Monte Carlo simulation
• Withdrawal order optimization
• Historical backtesting (Shiller 1871–2024)
• Purchase and windfall impact simulators
• Scenario comparison
• Personalized retirement insights

Claude Code plugin

The fastest path in Claude Code — installs the MCP server plus a retirement-planning skill that sequences the tools:

/plugin marketplace add cinderfi/cinderfi-mcp
/plugin install cinderfi@cinderfi

Then set your key so the server authenticates:

export CINDERFI_MCP_KEY=your_api_key   # from https://cinder.fi/mcp

Agents that support the auth.md protocol can also register for their own credential through a user-approved claim ceremony — no pasted key required.

Get started (any client)

1. Get a free API key at cinder.fi/mcp
2. Connect your agent to https://mcp.cinder.fi/mcp

Claude Desktop

{
  "mcpServers": {
    "cinderfi": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://mcp.cinder.fi/mcp"],
      "env": {
        "AUTHORIZATION": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Any MCP-compatible client

• Endpoint: https://mcp.cinder.fi/mcp
• Auth: Authorization: Bearer YOUR_API_KEY (or the auth.md registration flow)
• Transports: Streamable HTTP, SSE

Pricing

	Free	Pro
Calls/day	5	Unlimited
Single-person tools	✅	✅
Couples tools	—	✅
Monte Carlo	—	✅
Optimizer	—	✅
Backtest	—	✅
Scenario comparison	—	✅

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