Agent Checkouts Skill

A Claude Code skill that buys products through the Crossmint Agent Checkouts API using a stored server-side API key — no user JWT required.

Give the agent a product URL and what you want; it creates a reusable buyer profile, creates the checkout with your shipping and payment preferences baked in, then polls the checkout and answers each user-action prompt until the order completes.

Install

npx skills add Crossmint/agent-checkouts-skill

Install globally (available in every project) or target a specific agent:

npx skills add Crossmint/agent-checkouts-skill --global
npx skills add Crossmint/agent-checkouts-skill --agent claude-code

Prerequisites

• Node.js 18+ (built-ins only — no npm install). You already have it if you installed this skill with npx.
• A Crossmint server-side API key (sk_production_...) with all Agent Checkouts scopes enabled (see below). Create one in the Crossmint console under Integrate → API Keys → Server-side keys.

Required API key scopes

When you create the server-side key, enable the entire Agent Checkouts scope family (agent-checkouts.*). The skill exercises checkouts, buyer profiles, and user actions, so a key missing any of these will fail mid-flow with a 403. Turn all of them on:

Scope	Used for
agent-checkouts.create	Create a checkout
agent-checkouts.read	Poll a checkout's status
agent-checkouts.update	Answer user actions / cancel a checkout
agent-checkouts.buyer-profiles.create	Create a buyer profile
agent-checkouts.buyer-profiles.read	Retrieve a buyer profile
agent-checkouts.buyer-profiles.update	Update a buyer profile
agent-checkouts.buyer-profiles.delete	Delete a buyer profile

If the console offers a group toggle for Agent Checkouts, just select all of it. The names above are the scope family as documented; if a specific scope isn't listed in the console yet (Agent Checkouts is still unstable), enable every Agent Checkouts scope shown.

⚠️ Real money. Agent Checkouts run in production against real merchants. A successful checkout places a real, paid order. The skill always sets a spend cap (maxCost) and gets your approval of the total before the call that executes payment — because submitting that action charges immediately, with no confirmation step afterward.

Usage

Once installed, just ask in natural language:

Buy the medium black tee from https://merchant.example/products/classic-tee, cheapest shipping, cap it at $60.

The first time, the agent asks for your Crossmint API key (stored locally at ~/.crossmint/agent-checkouts.json, mode 0600) and offers to create a buyer profile with your name, email, phone number, and shipping address.

What the agent does

1. Key — checks for a stored key; asks for one if missing.
2. Buyer profile — reuses an existing profile or creates one.
3. Checkout — sends the product URL plus a natural-language request that encodes variant, quantity, shipping method, payment method, and billing preference. Sensible defaults (cheapest shipping, pay by card, bill to shipping address) are applied and stated if you don't specify.
4. Poll & respond — polls status; when the checkout needs input (shipping choice, payment, confirmation), it fills what it knows and asks you for the rest, then submits — until the order succeeds, fails, or is cancelled.

Under the hood

All API calls go through a dependency-free CLI:

node scripts/checkout.mjs <command> [...]

Command	Purpose
set-key <key> / key-status / clear-key	Manage the stored API key.
profile-create / profile-get / profile-update / profile-delete	Manage buyer profiles.
checkout-create	Create a checkout for a product URL.
checkout-get	Poll a checkout's status.
checkout-respond	Answer a pending user action.
checkout-cancel	Cancel a checkout.

Authentication is a single Crossmint server-side key sent as X-API-KEY; the host (production vs staging) is chosen automatically from the key prefix. For a one-off run you can pass the key via the CROSSMINT_API_KEY environment variable instead of storing it.

Files

The skill lives in the agent-checkouts/ directory (a subdirectory, not the repo root, so npx skills add copies the whole skill — scripts and reference included — rather than treating a root SKILL.md as a single-file skill).

Path	What it is
agent-checkouts/SKILL.md	Orchestration instructions the agent follows.
agent-checkouts/reference/agent-checkouts-api.md	Full endpoint and field reference.
agent-checkouts/scripts/checkout.mjs	The CLI wrapper over the API.