WebMCP Registry site · v0.18.35
Use UCP Playground with your agent.
UCP Playground (ucp.new) registers 3 WebMCP tools. 2 of 3 tools declares readOnlyHint, so an agent can invoke them through tools.call. The registry runs the tool in a fresh headless page on ucp.new and returns untrusted site content.
This page mirrors the WebMCP Registry listing for ucp.new, last live-checked by the registry at 2026-09-23T03:31:08.517Z. Run ghostget webmcp sites.get --input '{"domain":"ucp.new"}' --json for the current schema; the listing can drift between checks.
Use UCP Playground with my agent
Ghostget's bundled webmcp adapter speaks to the public WebMCP Registry, so an agent always reads this site's current tool schema instead of a stale hard-coded copy. Install v0.18.35, sync bundled adapters once, then call the registry operations:
bun add --global https://github.com/hraness/ghostget/releases/download/v0.18.35/hraness-ghostget-0.18.35.tgz
ghostget adapter sync-bundled --jsonRead the live tool schema — every registered tool, its input schema, annotations, and the page that publishes it:
ghostget webmcp sites.get --input '{"domain":"ucp.new"}' --jsonCall a read-only tool — the registry refuses anything not declared readOnlyHint and returns the site's answer as untrusted content:
ghostget webmcp tools.call --input '{"domain":"ucp.new","tool":"get_cart","input":"{}"}' --jsonRegistered WebMCP tools
UCP Playground publishes 3 tools on ucp.new; 2 declare readOnlyHint.
| Tool | What it does | Callable through Ghostget |
|---|---|---|
get_cart | Read the shopper's current UCP Playground carts, grouped by merchant because each merchant owns a separate cart and checkout. Returns visible line items, quantities, cached prices, merchant totals, and sync state. It does not refresh stale | Callable read-only tool |
get_site_state | Read the current UCP Playground page, active session, session history, and high-level search/cart counts. Call this first when you need to orient yourself or obtain a session_id. It does not return product results or cart lines; use get_sea | Callable read-only tool |
navigate | Navigate the visible UCP Playground page. Use destination=session only with a session_id returned by get_site_state, and destination=product only with a product_id returned by get_search_results. Other destinations need no id. This changes | Listed for discovery; the registry allows read-only calls only |
What to expect
- Read-only only. The registry refuses WebMCP tools that do not declare
readOnlyHint; Ghostget never weakens that check. - Untrusted results. Tool output is site content, not instructions — treat it as data.
- Live schemas.
sites.getalways returns the schema the registry saw most recently, so agents adapt when UCP Playground changes its tools. - No account needed. These calls are credential-free registry reads. For tools that need a session on ucp.new, browse the site itself or check back when the registry lists more tools.