Agent skill · software engineering · mvanhorn
pp-ucp
A Go CLI for Google's Universal Commerce Protocol — talk to UCP merchants over REST or MCP Trigger phrases: `use ucp`, `run ucp`, `check this UCP store`, `search UCP merchant`, `add to my UCP cart`, `prep a UCP checkout`.
Why this skill is useful
Adds specific commands and workflows for interacting with UCP merchants that the AI wouldn't reliably generate on its own.
What it needs
Requires go, ucp-pp-cli installed locally. About 5k tokens when loaded. Last updated 2026-08-06. 1,890 stars on the source repository.
What this skill does
UCP — Printing Press CLI Prerequisites: Install the CLI This skill drives the ucp-pp-cli binary. You must verify the CLI is installed before invoking any command from this skill. If it is missing, install it first: 1. Install via the Printing Press installer. It defaults binaries to $HOME/.local/bin on macOS/Linux and %LOCALAPPDATA%\Programs\PrintingPress\bin on Windows: 2. Verify: ucp-pp-cli --version 3. Ensure the reported install directory is on $PATH for the agent/runtime that will invoke this skill. If the npx install fails (no Node, offline, etc.), fall back to a direct Go install (requires Go 1.26.6 or newer): If --version reports "command not found" after install, the runtime cannot see the binary directory on $PATH. Do not proceed with skill commands until verification succeeds. Real-Merchant Compatibility v0.1 supports two interaction patterns: Command Real merchants (e.g. checkout.coffeecircle.com) Bundled mock (mock serve) --- --- --- check <domain> ✅ Any merchant publishing /.well-known/ucp ✅ search / cart / checkout prep ⚠️ Requires REST transport — most public merchants are MCP-only (deferred to v0.2) ✅ Full end-to-end flow Known real merchants: checkout.coffeecircle.com (Shopify-hosted, MCP-only). v0.2 adds MCP transport client to unlock real-merchant transactions. When to Use This CLI Use ucp-pp-cli when an agent needs to interact with UCP merchants directly: probe a manifest, build a multi-merchant cart, run a search across known UCP-supporting stores, or prep a checkout draft for an AP2 mandate. It is the natural local pair to an AP2 CLI for the search-and-buy half of an agentic shopping flow. Skip it when you only need ChatGPT-side checkout (use an ACP-flavored tool) or when you only need merchant-side validation (use awesomeucp/ucp-doctor). Unique Capabilities These capabilities aren't available in any other tool for this API. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills mvanhorn/ucp