Setup @vitest-agent/plugin

Wire @vitest-agent/plugin into this project's Vitest configuration and emit the canonical 2.0 config. Work through the seven steps below in order. The flow is deterministic — verify each prerequisite, then make a small number of edits to one config file.

1. Verify Vitest 5.0 or newer

Read the project's package.json and any workspace-root package.json. Find the installed vitest version. If vitest is missing, or the version is below 5.0, stop and tell the user to install it first, e.g. pnpm add -D vitest@latest. Do not continue until Vitest 5.0+ is present — the plugin requires it.

2. Verify @vitest-agent/plugin

Look for @vitest-agent/plugin in dependencies or devDependencies of the project package.json. If it is missing, install it as a dev dependency with the project's package manager (npm / pnpm / yarn / bun — detect from the lockfile or the packageManager field). The plugin's MCP loader (bin/start-mcp.sh) requires the package to be present in the user's node_modules.

3. Verify a coverage provider

Check for @vitest/coverage-v8 or @vitest/coverage-istanbul. If neither is installed, install @vitest/coverage-v8 as a dev dependency by default. The canonical config below sets coverage.provider: "v8"; if the user already has the istanbul provider, keep their choice and adjust the emitted provider value to match.

4. Detect the existing config shape

Look for vitest.config.ts, vitest.config.js, or vitest.config.mjs at the project root. If the file exists in plain defineConfig({ ... }) form, convert it to the async-arrow pattern shown in step 5 — this preserves type inference for AgentPlugin.discover(). Convert silently and note the conversion in the final summary; the file is git-tracked and reversible.

5. Emit (or rewrite) the canonical 2.0 config

Write the project's Vitest config to this canonical shape:

import { AgentPlugin } from "@vitest-agent/plugin";
import { defineConfig } from "vitest/config";

export default async () => {
  const { projects, tags } = await AgentPlugin.discover();
  return defineConfig({
    plugins: [
      AgentPlugin({
        coverageTargets: AgentPlugin.COVERAGE_LEVELS.standard.coverageTargets,
      }),
    ],
    test: {
      projects,
      tags,
      coverage: {
        enabled: true,
        provider: "v8",
        thresholds: AgentPlugin.COVERAGE_LEVELS.standard.thresholds,
      },
    },
  });
};

The 2.0 options surface has five fields — console, coverageTargets, transport, reporter, and onRunEvent — and coverageTargets is the only one this skill ever emits. Leave console, reporter, onRunEvent, and transport at their defaults; the plugin wires its built-in default reporter and the Ink mount internally. The coverageTargets value comes from the standard preset so the user gets a sensible tier without picking one; they edit the file to switch presets (none / basic / standard / strict / full).

Coverage is split: the coverage.thresholds block lives on Vitest's native test.coverage config, while coverageTargets lives on the AgentPlugin() call. Both are sourced from the same preset so they stay consistent.

6. Migrate pre-2.0 patterns when upgrading

If the existing AgentPlugin({ ... }) call carries any pre-2.0 option, strip it and surface the change in the final summary. The rewrite is one-way; the source file is git-tracked, so write directly rather than prompting for a diff preview. Removed options and their migration targets:

• reporter: eventSourcedReporter (and the import) — removed. The plugin owns the default reporter; drop it.
• onRunEvent: live.event — removed for the same reason.
• coverageThresholds at the AgentPlugin level — moves to Vitest's native test.coverage.thresholds.
• autoUpdate — replaced by Vitest's native test.coverage.thresholds.autoUpdate, or the AgentPlugin.COVERAGE_AUTOUPDATE preset helpers.
• consoleMode, consoleOutput, detail — superseded by the single console field.
• format, mcp, coverageConsoleLimit, omitPassingTests, githubActions, githubSummary, githubSummaryFile, projectFilter, the nested reporterOptions wrapper, cacheDir, logLevel, and logFile — all removed in 2.0. Drop them; none has a replacement on the AgentPlugin options surface.

7. Confirm to the user

Print a short summary of what changed (config written or rewritten, dependencies installed, pre-2.0 options stripped). Suggest running an initial test to populate the database — run_tests({}) via the MCP server, or the project's test script. Point the user at {{skill configure}} for the read-only view of the resolved settings.