Building Verification

Build a project-local verifier for the next agent to use cold, mid-task. The output is a verifying-<product> skill, a user-facing feature map, and only the helper code needed to launch, drive, observe, isolate, and clean up the real product.

This skill creates verification infrastructure. /verifying-work uses that infrastructure to prove a particular change.

1. Interview the repository

Read the repository before asking the user. Ground these five answers in existing commands, code, and documentation:

• Surface: what users touch: web UI, CLI or TUI, desktop or mobile app, API, library, or more than one of these.
• Run: how the real product builds and starts, including readiness, ports, environment, authentication, fixtures, and seed data.
• Drive: how an agent can control each surface. Prefer the project's existing browser, E2E, PTY, HTTP, or consumer harness.
• Observe: which visible outcomes and load-bearing side effects can be captured as evidence.
• Isolate: which ports, data directories, browser profiles, accounts, queues, and external systems a verification run could share or corrupt.

Run the narrowest existing build-only check while interviewing. Start the product only after drafting a provisional isolated launch and cleanup plan. Even an exploratory launch needs a unique run ID, isolated resources, an ownership record, and guaranteed cleanup; otherwise return BLOCKED. A broken baseline is also BLOCKED: report the failure instead of writing commands against an imagined working product. Ask the user only about choices the repository cannot answer, especially unsafe external effects or multiple equally primary surfaces.

Identify every agent harness that must consume the verifier. Choose its project-local root from the repository's existing convention; common roots are .agents/skills/ and .claude/skills/. For multiple harnesses, use one canonical directory and link it into every discovery root when the repository permits symlinks. If it does not, ask the user to choose a single harness or approve mirrored copies rather than silently creating divergent sources.