Spike an idea through experiential exploration — build focused experiments to feel the pieces of a future app, validate feasibility, and produce verified knowledge for the real build. Spikes live in `.planning/spikes/` and integrate with GSD commit patterns, state tracking, and handoff workflows.

Two modes:

• Idea mode (default) — describe an idea to spike
• Frontier mode (no argument or "frontier") — analyzes existing spike landscape and proposes integration and frontier spikes

Does not require prior new-project setup — auto-creates .planning/spikes/ if needed.

<execution_context> @/.claude/gsd-core/workflows/spike.md @/.claude/gsd-core/workflows/spike-wrap-up.md @~/.claude/gsd-core/references/ui-brand.md </execution_context>

<runtime_note> Copilot (VS Code): Use vscode_askquestions wherever this workflow calls AskUserQuestion. </runtime_note>

Idea: $ARGUMENTS

Available flags:

• --quick — Skip decomposition/alignment, jump straight to building. Use when you already know what to spike.
• --text — Use plain-text numbered lists instead of AskUserQuestion (for non-Claude runtimes).
• --wrap-up — Package spike findings into a persistent project skill for future build conversations. Runs the spike-wrap-up workflow.

Parse the first token of $ARGUMENTS: - If it is `--wrap-up`: strip the flag, execute the spike-wrap-up workflow - Otherwise: pass all of $ARGUMENTS as the idea to the spike workflow end-to-end.

Preserve all workflow gates (prior spike check, decomposition, research, risk ordering, observability assessment, verification, MANIFEST updates, commit patterns).