WebMCP Today

⚡ WebMCP Today

WebMCP Today is a registry for declarative packages that add WebMCP tools to sites that do not expose them. A package describes a site's tools and the API requests they use. The browser extension installs packages locally and registers their tools on matching pages.

The registry is live at webmcp.today.

OpenAI WebMCP Challenge: Judge Testing

The live site now registers four read-only WebMCP tools directly from webmcp.today. These tools require no WebMCP Today extension or local bridge.

Test in ChatGPT desktop

1. Use an up-to-date ChatGPT desktop app and a model with WebMCP enabled.
2. Open https://webmcp.today in ChatGPT's in-app browser.
3. Ask ChatGPT to use the site's tools with one of the sample prompts below.

Test in Chrome 149+

1. Open chrome://flags/#enable-webmcp-testing, enable WebMCP testing, and relaunch Chrome.
2. Open https://webmcp.today.
3. Use Chrome's WebMCP-capable agent or tool inspector to discover and invoke the site tools.

Site tool inventory

Tool	Purpose
search_packages	Search all currently servable registry packages by package metadata or tool text, with optional domain filtering.
get_package	Return the latest served package document for a package ID.
compare_packages	Compare two to four packages, including common and package-unique tool names.
verify_site_tools	Show which registry packages match a URL and the tool descriptors those packages would expose there.

Sample prompts:

• "Search WebMCP Today for Reddit packages, then show me the full details of the best match."
• "Find packages for Reddit and Google, then compare the best match for each."
• "Verify which registry-provided tools are available for https://news.ycombinator.com/news."

Eligibility and self-sufficiency

The annotated pre-webmcp-challenge tag marks commit 60e3660, the baseline before challenge-specific work. NEW-WORK.md is the dated changelog for work after that tag.

The judge path is self-sufficient within this repository: the Next.js web app uses its own public API, database, schema package, and curated seed package. It does not load code or package data from webmcp-packages or another repository at runtime.

Licensing remains split as documented in License: the server and database are AGPL-3.0-only under the root LICENSE; the reusable schema, engine, MCP bridge, curated packages, skill, and extension carry their own MIT licenses.

Agent Skill

Install the public skill for researching, creating, validating, and safely testing a WebMCP Today package:

npx skills@1.5.22 add robertn702/webmcp-today --skill create-webmcp-package

The skill creates webmcp-package.json and stops before registry publication.

Packages

Path	What
packages/schema	@webmcp-today/schema — published zod package format
packages/engine	@webmcp-today/engine — API execution engine
packages/db	Drizzle + Neon schema and client
packages/mcp	@webmcp-today/mcp-bridge — published public-beta registry MCP server + local bridge for live WebMCP tools
apps/web	Next.js registry UI + public REST API
apps/extension	WXT extension: package lookup + WebMCP tool injection

Quickstart

bun install
bunx turbo run build --filter="@webmcp-today/mcp-bridge..."
bun run typecheck && bun run lint && bun run test

# web (needs apps/web/.env — see .env.example)
cd packages/db && bun run db:migrate   # fresh local Neon only
cd apps/web && bun run dev             # http://localhost:3000
bun run scripts/seed.ts                # optional: seed the curated packages

# extension (Chrome 149+; enable chrome://flags/#enable-webmcp-testing only for Chrome native-agent discovery)
cd apps/extension && bun run dev

The extension's local bridge fallback works without the WebMCP testing flag. Enable the flag when you want Chrome's native agent to discover the extension's tools.

Development

Prerequisites: bun@1.3.14 (pinned in root package.json packageManager), Node for Next.js/WXT and some CLIs. The local MCP bridge requires Node 20 or newer or Bun.

Setup:

bun install
bunx turbo run build --filter="@webmcp-today/mcp-bridge..." # creates the opencode.json MCP entrypoint
cp apps/web/.env.example apps/web/.env   # then fill real values

apps/web/.env needs DATABASE_URL (Neon), a per-environment BETTER_AUTH_SECRET (openssl rand -base64 32), a shared OAUTH_PROXY_SECRET for local/Preview/Production (openssl rand -base64 32), the development GitHub OAuth App credentials (callback http://localhost:3000/api/auth/callback/github), and BETTER_AUTH_URL=http://localhost:3000. Leave OAUTH_PROXY_PRODUCTION_URL unset locally; in Vercel Preview and Production it is https://webmcp.today and routes OAuth through the production GitHub OAuth App callback.

bun run --filter @webmcp-today/db db:migrate   # or cd packages/db && bun run db:migrate — applies Drizzle migrations to Neon
# schema changes: bun run --filter @webmcp-today/db db:generate && db:migrate (db:push for quick prototyping)

bun run --filter @webmcp-today/web db:seed     # or cd apps/web && bun run db:seed — runs scripts/seed.ts, seeds curated packages

These are ordinary fresh-database setup commands. They do not reset an existing database.

Historical migration baseline: packages/db/migrations/0000_init.sql is the initial schema baseline and will not replay against an existing deployed Neon database. Never reset or recreate production data to apply it. For schema changes, generate and review a new Drizzle migration and apply it with db:migrate. Run db:seed only for fresh or local databases until it is idempotent and version-aware; use a reviewed production procedure for curated seed changes.

Running locally:

• Web: cd apps/web && bun run dev → http://localhost:3000 (Next.js). Extension's default registry URL points here.
• Extension: cd apps/extension && bun run dev → WXT dev server on http://localhost:5173, launches a dedicated Chrome profile at .wxt/chrome-profile/ with --enable-features=WebMCP,WebMCPTesting force-enabled (chrome://flags still shows "Default" — check chrome://version). One instance only — second crashes on profile lock and corrupts .output/. Model Context Tool Inspector is installed once into that profile and persists.
• Local bridge: configure the native host in packages/mcp/README.md, then start node packages/mcp/dist/index.js. Its MCP tools invoke live WebMCP tools in the selected normal Chrome tab without Chrome DevTools MCP, a remote-debugging port, or chrome.debugger. The built-in fallback works without the WebMCP testing flag; enable it only for Chrome's native agent to discover the tools.
• Ports: web 3000 / WXT 5173. Find strays with lsof -nP -i :3000 -i :5173; killing a bun wrapper does NOT kill its node child.

Quality gates: bun run typecheck && bun run lint && bun run test before every commit — same as CI (.github/workflows/ci.yml via oven-sh/setup-bun@v2 1.3.14 + --frozen-lockfile). Pre-commit runs husky + lint-staged (eslint + prettier on staged source, prettier on json/md/css/yaml) and enforces CLAUDE.md -> AGENTS.md symlink drift.

Deeper context: root AGENTS.md (stack, conventions, decisions log, cross-cutting gotchas) and nested apps/web/AGENTS.md (package-install registry model, served truth, env/t3-env notes) + apps/extension/AGENTS.md (dev browser, silent-fallback trap, selector-rot recipe).

License

Split, so the pieces worth adopting stay permissive:

• AGPL-3.0-only — the server: apps/web and packages/db (root LICENSE). Run a modified copy as a network service and you owe your users the source.
• MIT — everything built to be adopted freely: packages/schema (package format), packages/engine (execution engine), packages/mcp (MCP server), packages/curated-packages (curated packages), and apps/extension (browser extension). Each carries its own LICENSE.

Community-submitted packages are not code and are not covered by either license. Publishing one grants the registry a permanent license to host and redistribute it, and offers it onward under CC0 1.0 — see the terms (apps/web/app/(registry)/terms). packages/curated-packages is the first-party exception: it ships as MIT source.

Contributions are covered by the agreement in CONTRIBUTING.md.