The claiming-age and clawback questions are where general advice fails hardest, and these run the actual provincial and state rules rather than a national average. simulate_purchase is the one people do not expect: it prices a large expense in years of retirement rather than dollars, which is the form the decision is actually made in.
A retirement planning MCP server with real tax engines behind it: every Canadian province and US state, CPP, OAS, GIS and Social Security. It runs year-by-year projections, answers claiming-age questions with breakeven maths, and simulates what a purchase or a windfall does to the rest of the plan.
- run_projection and run_full_analysis — a year-by-year retirement projection for one person, or the projection, score and insights in one call
- calculate_score and generate_insights — a 0–100 readiness score, and personalized optimization recommendations
- calculate_tax and estimate_benefit — income tax for any province or state, and CPP, OAS or Social Security at a chosen claiming age
- calculate_cpp_timing and calculate_ss_timing — breakeven analysis across CPP ages 60 to 70, and Social Security 62 to 70 against full retirement age
- calculate_gis and calculate_meltdown — GIS eligibility, clawback and provincial supplement, and an RRSP meltdown or Roth conversion strategy
- simulate_purchase and simulate_windfall — what a one-time or recurring expense costs the plan, and where an inheritance or bonus is best allocated
- compare_spending_strategies and map_financial_data — fixed, Guyton-Klinger and VPW withdrawal rules compared, and YNAB or bank exports converted into inputs
- run_monte_carlo, run_backtest and compare_scenarios — probabilistic success with percentile bands, every historical window since 1871 on Shiller data, and one to four scenarios side by side
- optimize_withdrawal_order and optimize_pension_split — the best claiming and withdrawal sequence, and pension income splitting to minimise combined tax
A free API key from cinder.fi/mcp, then connect to https://mcp.cinder.fi/mcp over Streamable HTTP or SSE with Authorization: Bearer. Clients without remote support can bridge with npx -y mcp-remote. In Claude Code the plugin installs the server plus a skill that sequences the tools, and reads the key from CINDERFI_MCP_KEY. The free tier allows 5 calls a day and the 14 single-person tools; Monte Carlo, the optimizers, backtesting, scenario comparison and couples projections are on the paid tier.
One command plus a key — claude mcp add cinderfi --transport http https://mcp.cinder.fi/mcp -H "Authorization: Bearer YOUR_API_KEY", then supply credentials