buy_add_to_cart

Connect to https://mcp.agentcard.sh/mcp with the user’s connection token (or a buy_token for org-owned accounts).

Not in the default tools/list. It is still callable by exact name, and appears when the client sends the x-expert-tools: 1 header.

What it does

Add a product (by id from buy_search_products or the menu digest) to the cart. Returns the updated cart with subtotal. For a RESTAURANT item flagged (has options), FIRST call buy_get_item_options, have the user choose, and pass the chosen ids here as options — a required option group must be satisfied or the add is rejected with options_required (then fetch options and re-add with selections; a persistent options_required usually means a required NESTED sub-choice is still missing). Grocery items and no-option restaurant items need no options.

Inputs

Field	Type	Description
`merchant` (required)	string
`product_id` (required)	string
`quantity`	number	default 1
`options`	array	restaurant items only: the chosen options from buy_get_item_options

Returns

None.

Example call

{
  "tool": "buy_add_to_cart",
  "arguments": {
    "merchant": "\u2026",
    "product_id": "\u2026"
  }
}

MCP

Organization tools

User tools

What it does

Inputs

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Example call

​What it does

​Inputs

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​Example call

What it does

Inputs

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Example call