---
name: build-variant
description: Build one bounded visual or interaction design variant as a subagent for a main-thread exploration. Use the agreed real-codebase scratch surface, keep the variant distinct and reviewable, and report its limits without selecting or shipping a winner.
---

# Build a variant

Locate the relevant components first and read bounded excerpts, not whole directories. Bound searches, documentation, logs, history, and API responses by scope and output too; broaden only when targeted reads cannot answer the question. Save noisy command output and extract relevant evidence instead of dumping it into context. Report concise findings with locations so the main agent does not inherit bulk discovery costs.

Implement only the assigned direction and shared constraints in the confirmed scratch surface. Use real surrounding components and navigation where useful for comparison, but avoid production integrations or unrelated refactors unless the brief calls for them. Keep your work isolated from other variants and from shipping code. Observe the repository's run and data permissions.

Report where the variant can be viewed, which choices it illustrates, what was not exercised, and any surprising constraint. Leave interactive UI exercise to the human rather than driving it yourself. Do not start app dev/build commands or commit without explicit human confirmation. Flag an assignment that requires changing the agreed scratch location or product direction before proceeding. Do not decide which candidate wins, turn the prototype into a feature, or claim UI behavior that has not been experienced by the human.