mcpbeat

Benchmark E2e

vercel/benchmark-e2e

End-to-end benchmark suite for vercel-plugin. Runs realistic projects through skill injection, launches dev servers, verifies everything works, analyzes conversation logs, and produces an improvement report for overnight self-improvement loops.

1k tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
240
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/vercel/vercel-plugin --skill benchmark-e2e

The instruction itself

11 sections, as written by the author

Benchmark E2E

Single-command pipeline that creates projects, exercises skill injection via claude --print, launches dev servers, verifies they work, analyzes conversation logs, and generates actionable improvement reports.

Quick Start

# Full suite (9 projects, ~2-3 hours)
bun run scripts/benchmark-e2e.ts

# Quick mode (first 3 projects, ~30-45 min)
bun run scripts/benchmark-e2e.ts --quick

Options:

| Flag | Description | Default |

|------|-------------|---------|

| --quick | Run only first 3 projects | false |

| --base <path> | Override base directory | ~/dev/vercel-plugin-testing |

| --timeout <ms> | Per-project timeout (forwarded to runner) | 900000 (15 min) |

Pipeline Stages

The orchestrator chains four stages sequentially, aborting on failure:

  • runner — Creates test dirs, installs plugin, runs claude --print with VERCEL_PLUGIN_LOG_LEVEL=trace
  • verify — Detects package manager, launches dev server, polls for 200 with non-empty HTML
  • analyze — Matches JSONL sessions to projects via run-manifest.json, extracts metrics
  • report — Generates report.md and report.json with scorecards and recommendations

Contracts

run-manifest.json

Written by the runner at <base>/results/run-manifest.json. Links all downstream stages to the same run.

interface BenchmarkRunManifest {
  runId: string;           // UUID for this pipeline run
  timestamp: string;       // ISO 8601
  baseDir: string;         // Absolute path to base directory
  projects: Array<{
    slug: string;          // e.g. "01-recipe-platform"
    cwd: string;           // Absolute path to project dir
    promptHash: string;    // SHA hash of the prompt text
    expectedSkills: string[];
  }>;
}

The analyzer and verifier read this manifest to correlate sessions precisely instead of guessing from directory listings.

events.jsonl

The orchestrator writes NDJSON events to <base>/results/events.jsonl tracking pipeline lifecycle:

// Each line is one JSON object:
{ "stage": "pipeline", "event": "start", "timestamp": "...", "data": { "baseDir": "...", "quick": false } }
{ "stage": "runner",   "event": "start", "timestamp": "...", "data": { "script": "...", "args": [...] } }
{ "stage": "runner",   "event": "complete", "timestamp": "...", "data": { "exitCode": 0, "durationMs": 120000 } }
// On failure:
{ "stage": "verify",   "event": "error", "timestamp": "...", "data": { "exitCode": 1, "durationMs": 5000, "slug": "04-conference-tickets" } }
{ "stage": "pipeline", "event": "abort", "timestamp": "...", "data": { "failedStage": "verify", "exitCode": 1, "slug": "04-conference-tickets" } }

report.json

Machine-readable report at <base>/results/report.json for programmatic consumption:

interface ReportJson {
  runId: string | null;
  timestamp: string;
  verdict: "pass" | "partial" | "fail";
  gaps: Array<{
    slug: string;
    expected: string[];
    actual: string[];
    missing: string[];
  }>;
  recommendations: string[];
  suggestedPatterns: Array<{
    skill: string;   // Skill that was expected but not injected
    glob: string;    // Suggested pathPattern glob
    tool: string;    // Tool name that should trigger injection
  }>;
}

Overnight Automation Loop

Run the pipeline repeatedly with a cooldown between iterations:

while true; do
  bun run scripts/benchmark-e2e.ts
  sleep 3600
done

Each run produces timestamped report.json and report.md files. Compare across runs to track improvement.

Self-Improvement Cycle

The pipeline enables a closed feedback loop:

  • Runbun run scripts/benchmark-e2e.ts exercises the plugin against realistic projects
  • Read gapsreport.json lists which skills were expected but never injected, with exact slugs
  • Apply fixes — Use suggestedPatterns entries (copy-pasteable YAML) to add missing frontmatter patterns; use recommendations to fix hook logic
  • Re-run — Execute the pipeline again to verify the gaps are closed
  • Compare — Diff report.json across runs: verdict should trend from "fail""partial""pass"

For overnight automation, combine with the loop above. Wake up to reports showing exactly what improved and what still needs work.

Prompt Table

Prompts never name specific technologies — they describe the product and features, letting the plugin infer which skills to inject.

| # | Slug | Expected Skills |

|---|------|----------------|

| 01 | recipe-platform | auth, vercel-storage, nextjs |

| 02 | trivia-game | vercel-storage, nextjs |

| 03 | code-review-bot | ai-sdk, nextjs |

| 04 | conference-tickets | payments, email, auth |

| 05 | content-aggregator | cron-jobs, ai-sdk |

| 06 | finance-tracker | cron-jobs, email |

| 07 | multi-tenant-blog | routing-middleware, cms, auth |

| 08 | status-page | cron-jobs, vercel-storage, observability |

| 09 | dog-walking-saas | payments, auth, vercel-storage, env-vars |

Cleanup

rm -rf ~/dev/vercel-plugin-testing

How to use it

Copy the folder

Take vercel/benchmark-e2e from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.