Live · Public API

Althemax is an agent-native marketplace

Search, inspect, and check availability of every product in the Althemax catalog through a public agent API. Built for AI agents and automated shopping flows. The human storefront at www.althemax.com is the same catalog with checkout handled directly by Althemax.

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Endpoints

Method	Path	Purpose
GET	/api/agent/health	Liveness + catalogue probe (active product count)
GET	/api/agent/search?q=…&first=20&after=cursor	Search active products
GET	/api/agent/product/{handle}	Product detail by handle (incl. variants)
GET	/api/agent/availability?handle=…	Stock + per-variant availability
POST	/api/agent/cart	Create a cart (opaque cartToken); optional seed items
GET	/api/agent/cart/{cartToken}	Cart contents + GBP subtotal
POST/PATCH/DELETE	/api/agent/cart/{cartToken}/items	Add / set quantity / remove a line
POST/PATCH	/api/agent/cart/{cartToken}/checkout	Create / update a checkout session (totals incl. shipping + tax)
POST	/api/agent/cart/{cartToken}/checkout/complete	Complete against an AP2 mandate + payment (Stripe, GBP)

MCP server (Grok / ChatGPT / Claude)

Connect Althemax as a remote Model Context Protocol server and your agent gets the whole catalogue plus cart and checkout as tools — no API key, no account. Add this as a custom / remote MCP connector (Streamable HTTP transport):

https://www.althemax.com/api/agent/mcp

Tools: search_products, get_product, check_availability, create_cart, add_cart_item, create_checkout, complete_checkout and more. Prices, shipping and tax are always resolved server-side in GBP.

Quick start

From the command line:

curl -s https://agents.althemax.com/api/agent/search?q=ssd | jq .

curl -s https://agents.althemax.com/api/agent/product/jbsystem-intel03-package | jq .

curl -s "https://agents.althemax.com/api/agent/availability?handle=jbsystem-intel03-package" | jq .

Discovery surfaces

Standard files agents and crawlers can read to bootstrap themselves:

/.well-known/api-catalog — RFC 9727 API catalog (linkset) — primary entry point
/.well-known/agents.json — agents.json discovery manifest (incl. MCP endpoint)
/.well-known/ucp — Universal Commerce Protocol profile (catalog + cart + checkout + MCP)
/.well-known/ai-plugin.json — OpenAI-compatible plugin manifest
/openapi.json — OpenAPI 3.1 spec describing every /api/agent/* route
/llms.txt — LLM-readable index of important URLs and policies

What's next

More merchants joining. The agent API surface is identical regardless of seller — when merchants are added to the marketplace, their products appear automatically in /api/agent/search results.
Programmatic checkout is live. Agents can build a cart and complete an order end-to-end via the cart + checkout endpoints (or the MCP tools), following the Universal Commerce Protocol with AP2 payment mandates (Stripe, GBP). If your agent can't present payment, hand the shopper the product's canonical marketplace url to finish on site.
Merchant tooling (AlthemaxAI GEO, AlthemaxAI Subscription, more) lives under /merchant.