wayfinder-create-scenarios

Add scenarios to a Wayfinder plan

A scenario is a named override on the baseline's assumptions — {name, overrides: {param: value}}. Wayfinder then runs every scenario against every life-path (and Monte Carlo), so the user can see how each what-if changes the odds. Use the Wayfinder MCP tools.

1. Find the plan

list_plans to get names; confirm which plan. If unsure of its current numbers, get_plan(name).

2. Translate the what-if into overrides

Each scenario overrides one or more engine params. Common ones (percentages are fractions):

• spend_base — total annual spending (e.g. "spend $15k more" → baseline + 15000)
• essential_spend — the must-cover floor
• nominal_return — market return (e.g. a bear market → 0.04)
• inflation — e.g. high-inflation regime → 0.05
• sigma — market volatility
• semi_end_age — work longer / stop earlier
• end_age — plan to a different age (longevity)
• new_home — downsize target price

Name scenarios for humans: "Higher spend", "Bear market", "Retire at 62", "Live to 100".

3. Save them (replace the whole list)

Scenarios live as params.scenarios. update_plan merges keys but replaces the scenarios array wholesale, so include every scenario you want kept:

update_plan(name="Jane & John Doe", changes={"scenarios": [
  {"name": "Higher spend", "overrides": {"spend_base": 100000}},
  {"name": "Bear market",  "overrides": {"nominal_return": 0.04}},
  {"name": "Work to 70",   "overrides": {"semi_end_age": 70}}
]})

To add one, fetch the plan's existing scenarios first (or ask the user) and re-send the full list. To clear them, send {"scenarios": []}.

4. Show the effect

After saving, run the wayfinder-retirement-advising skill (or at least plan_monte_carlo and compare_lifepaths) so each scenario's money-left and success rate are visible. Call out which what-ifs break the plan (run dry) and which it survives.