Spike

Use this skill when the user wants to feel out an idea before committing to a real build, validating feasibility, comparing approaches, or surfacing unknowns that no amount of research will answer. Spikes are disposable by design. Throw them away once they've paid their debt.

Load this when the user says things like "let me try this", "I want to see if X works", "spike this out", "before I commit to Y", "quick prototype of Z", "is this even possible?", or "compare A vs B".

When NOT to use this

• The answer is knowable from docs or reading code, just do research, don't build
• The work is production path, use writing-plans / plan instead
• The idea is already validated, jump straight to implementation

If the user has the full GSD system installed

If gsd-spike shows up as a sibling skill (installed via npx get-shit-done-cc --the agent), prefer gsd-spike when the user wants the full GSD workflow: persistent .planning/spikes/ state, MANIFEST tracking across sessions, Given/When/Then verdict format, and commit patterns that integrate with the rest of GSD. This skill is the lightweight standalone version for users who don't have (or don't want) the full system.

Core method

Regardless of scale, every spike follows this loop:

decompose  →  research  →  build  →  verdict
   ↑__________________________________________↓
                  iterate on findings

1. Decompose

Break the user's idea into 2-5 independent feasibility questions. Each question is one spike. Present them as a table with Given/When/Then framing: