Overview

**Agentic Commerce** means letting AI agents discover products, build carts, and complete purchases on a shopper's behalf. Reponse implements the Agentic Commerce Protocol (ACP) — a set of machine-readable feeds, APIs, and payment flows that allow agents to transact safely.

Prerequisites

Requirement	Description
Reponse workspace	Active workspace with products
API key	Workspace API key (Bearer token)
Stripe	Stripe account connected to your workspace with SPT (Shared Payment Tokens) enabled
Agent client	An AI agent capable of calling HTTP APIs (ChatGPT, Copilot, Gemini, etc.)

Architecture

Agentic commerce in Reponse is built on three pillars:

┌─────────────────────────────────────────┐
│           External AI Agent             │
└──────┬──────────────┬──────────────┬────┘
       │              │              │
  ┌────▼────┐   ┌─────▼─────┐  ┌────▼────┐
  │ACP Feed │   │MCP Server │  │A2A Proto│
  └────┬────┘   └─────┬─────┘  └────┬────┘
       │              │              │
  ┌────▼──────────────▼──────────────▼────┐
  │         Reponse Commerce Engine       │
  │  Catalog · Cart · Checkout · Orders   │
  └───────────────────────────────────────┘

Component	Purpose
ACP Feed	Machine-readable product feed optimized for agent consumption
MCP Server	Tool interface for MCP-compatible agents (Claude, Cursor)
A2A Protocol	JSON-RPC protocol for agent-to-agent task delegation

Discovery

AI agents discover your storefront via a standard manifest:

GET https://your-store.com/.well-known/acp.json

The manifest lists your endpoints, capabilities, and payment configuration. It is public (no auth required) and cached for 24 hours.

Product feed

The ACP feed exposes your full catalog in an agent-optimized, gzip-compressed JSON format:

GET /api/v1/feed
Authorization: Bearer YOUR_API_KEY

json

{
  "version": "1.0",
  "merchant": "Your Brand",
  "product_count": 42,
  "generated_at": "2026-05-26T06:00:00.000Z",
  "products": [
    {
      "id": "prod_xxx",
      "title": "Organic Cotton T-Shirt",
      "description": "Soft organic cotton, available in 5 colors",
      "price": 29.99,
      "currency": "EUR",
      "availability": "in_stock",
      "url": "https://your-store.com/products/organic-tee",
      "variants": [
        {
          "id": "var_1",
          "title": "Small / Black",
          "sku": "TS-SM-BLK",
          "price": 29.99,
          "inventory_quantity": 15,
          "option_values": { "Size": "Small", "Color": "Black" },
          "availability": "in_stock"
        }
      ]
    }
  ]
}

The response is Gzip-compressed (`Content-Encoding: gzip`). Most HTTP clients decompress automatically. Cache TTL is 1 hour.

Agent capabilities

An agent interacting with Reponse can perform these actions:

Capability	Endpoint	Description
Browse catalog	`GET /api/v1/feed`	Full product feed (gzip JSON)
Search products	`GET /api/v1/products`	Paginated search with filters
Create cart	`POST /api/v1/carts`	Start a new shopping cart
Add/remove items	`POST /api/v1/carts/{cart_id}/lines`	Modify cart contents
Apply discount	`POST /api/v1/carts/{cart_id}/promotions`	Apply promo codes
Checkout with SPT	`POST /api/v1/checkout/acp`	Complete purchase with Shared Payment Token

Checkout flow

The ACP checkout flow uses Stripe Shared Payment Tokens (SPT) for secure, agent-mediated payments:

Agent browses feed — discovers products via /api/v1/feed
Agent creates cart — calls POST /api/v1/carts and adds items
User authorizes payment — the agent's platform (e.g. ChatGPT) collects payment consent and issues a Shared Payment Token (SPT) via Stripe
Agent completes checkout — sends SPT to POST /api/v1/checkout/acp
Order created — Reponse creates a PaymentIntent, captures payment, creates the order, and sends confirmation emails
Agent confirms — the response includes order_id and order_number for the agent to relay to the shopper

bash

curl -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "cart_id": "cart_xyz789",
    "payment_token": "spt_1234567890abcdef",
    "shipping_address": {
      "name": "John Doe",
      "line1": "123 Rue de Rivoli",
      "city": "Paris",
      "postal_code": "75001",
      "country": "FR"
    },
    "customer_email": "john@example.com",
    "idempotency_key": "unique-request-id-abc"
  }' \
  https://your-domain.com/api/v1/checkout/acp

Successful response

json

{
  "checkout_session_id": "pi_3abc123def456",
  "status": "completed",
  "payment_intent_id": "pi_3abc123def456",
  "order_id": "uuid-of-created-order",
  "order_number": "ACP-f456",
  "order_summary": {
    "currency": "EUR",
    "subtotal": 59.98,
    "discount": 0,
    "shipping": 4.90,
    "total": 64.88,
    "line_items": [
      {
        "product_title": "Premium T-Shirt",
        "variant_id": "var_001",
        "quantity": 2,
        "unit_price": 29.99
      }
    ],
    "applied_discount_codes": []
  }
}

Checkout status values

Status	Meaning
`completed`	Payment succeeded. Order created and confirmation email sent.
`requires_action`	3D Secure or additional auth needed. Use `client_secret` to complete.
`processing`	Payment is being processed asynchronously.
`failed`	Payment failed. Check error details.

Troubleshooting

Symptom	Cause	Fix
ACP feed returns empty	No published products	Publish products in the dashboard
`401 Unauthorized`	Invalid API key	Check your API key is valid and hasn't been rotated
`400 Stripe not configured`	Missing Stripe keys	Ensure Stripe is connected in workspace settings
`400 No market configuration`	No market defined	Create at least one market with `is_domestic: true`
`402 Payment declined`	SPT rejected	Card issue on user's side — agent must request a new SPT
`400 Invalid payment token`	SPT expired or malformed	Agent must request a new SPT
Agent gets `404` on cart	Cart not found or wrong workspace	Verify cart_id belongs to the authenticated workspace

Overview

Prerequisites

Requirement	Description
Reponse workspace	Active workspace with products
API key	Workspace API key (Bearer token)
Stripe	Stripe account connected to your workspace with SPT (Shared Payment Tokens) enabled
Agent client	An AI agent capable of calling HTTP APIs (ChatGPT, Copilot, Gemini, etc.)

Architecture

Agentic commerce in Reponse is built on three pillars:

┌─────────────────────────────────────────┐
│           External AI Agent             │
└──────┬──────────────┬──────────────┬────┘
       │              │              │
  ┌────▼────┐   ┌─────▼─────┐  ┌────▼────┐
  │ACP Feed │   │MCP Server │  │A2A Proto│
  └────┬────┘   └─────┬─────┘  └────┬────┘
       │              │              │
  ┌────▼──────────────▼──────────────▼────┐
  │         Reponse Commerce Engine       │
  │  Catalog · Cart · Checkout · Orders   │
  └───────────────────────────────────────┘

Component	Purpose
ACP Feed	Machine-readable product feed optimized for agent consumption
MCP Server	Tool interface for MCP-compatible agents (Claude, Cursor)
A2A Protocol	JSON-RPC protocol for agent-to-agent task delegation

Discovery

AI agents discover your storefront via a standard manifest:

GET https://your-store.com/.well-known/acp.json

The manifest lists your endpoints, capabilities, and payment configuration. It is public (no auth required) and cached for 24 hours.

Product feed

The ACP feed exposes your full catalog in an agent-optimized, gzip-compressed JSON format:

GET /api/v1/feed
Authorization: Bearer YOUR_API_KEY

json

{
  "version": "1.0",
  "merchant": "Your Brand",
  "product_count": 42,
  "generated_at": "2026-05-26T06:00:00.000Z",
  "products": [
    {
      "id": "prod_xxx",
      "title": "Organic Cotton T-Shirt",
      "description": "Soft organic cotton, available in 5 colors",
      "price": 29.99,
      "currency": "EUR",
      "availability": "in_stock",
      "url": "https://your-store.com/products/organic-tee",
      "variants": [
        {
          "id": "var_1",
          "title": "Small / Black",
          "sku": "TS-SM-BLK",
          "price": 29.99,
          "inventory_quantity": 15,
          "option_values": { "Size": "Small", "Color": "Black" },
          "availability": "in_stock"
        }
      ]
    }
  ]
}

The response is Gzip-compressed (`Content-Encoding: gzip`). Most HTTP clients decompress automatically. Cache TTL is 1 hour.

Agent capabilities

An agent interacting with Reponse can perform these actions:

Capability	Endpoint	Description
Browse catalog	`GET /api/v1/feed`	Full product feed (gzip JSON)
Search products	`GET /api/v1/products`	Paginated search with filters
Create cart	`POST /api/v1/carts`	Start a new shopping cart
Add/remove items	`POST /api/v1/carts/{cart_id}/lines`	Modify cart contents
Apply discount	`POST /api/v1/carts/{cart_id}/promotions`	Apply promo codes
Checkout with SPT	`POST /api/v1/checkout/acp`	Complete purchase with Shared Payment Token

Checkout flow

The ACP checkout flow uses Stripe Shared Payment Tokens (SPT) for secure, agent-mediated payments:

Agent browses feed — discovers products via /api/v1/feed
Agent creates cart — calls POST /api/v1/carts and adds items
User authorizes payment — the agent's platform (e.g. ChatGPT) collects payment consent and issues a Shared Payment Token (SPT) via Stripe
Agent completes checkout — sends SPT to POST /api/v1/checkout/acp
Order created — Reponse creates a PaymentIntent, captures payment, creates the order, and sends confirmation emails
Agent confirms — the response includes order_id and order_number for the agent to relay to the shopper

bash

curl -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "cart_id": "cart_xyz789",
    "payment_token": "spt_1234567890abcdef",
    "shipping_address": {
      "name": "John Doe",
      "line1": "123 Rue de Rivoli",
      "city": "Paris",
      "postal_code": "75001",
      "country": "FR"
    },
    "customer_email": "john@example.com",
    "idempotency_key": "unique-request-id-abc"
  }' \
  https://your-domain.com/api/v1/checkout/acp

Successful response

json

{
  "checkout_session_id": "pi_3abc123def456",
  "status": "completed",
  "payment_intent_id": "pi_3abc123def456",
  "order_id": "uuid-of-created-order",
  "order_number": "ACP-f456",
  "order_summary": {
    "currency": "EUR",
    "subtotal": 59.98,
    "discount": 0,
    "shipping": 4.90,
    "total": 64.88,
    "line_items": [
      {
        "product_title": "Premium T-Shirt",
        "variant_id": "var_001",
        "quantity": 2,
        "unit_price": 29.99
      }
    ],
    "applied_discount_codes": []
  }
}

Checkout status values

Status	Meaning
`completed`	Payment succeeded. Order created and confirmation email sent.
`requires_action`	3D Secure or additional auth needed. Use `client_secret` to complete.
`processing`	Payment is being processed asynchronously.
`failed`	Payment failed. Check error details.

Troubleshooting

Symptom	Cause	Fix
ACP feed returns empty	No published products	Publish products in the dashboard
`401 Unauthorized`	Invalid API key	Check your API key is valid and hasn't been rotated
`400 Stripe not configured`	Missing Stripe keys	Ensure Stripe is connected in workspace settings
`400 No market configuration`	No market defined	Create at least one market with `is_domestic: true`
`402 Payment declined`	SPT rejected	Card issue on user's side — agent must request a new SPT
`400 Invalid payment token`	SPT expired or malformed	Agent must request a new SPT
Agent gets `404` on cart	Cart not found or wrong workspace	Verify cart_id belongs to the authenticated workspace

Agentic Commerce (ACP)

Overview

Prerequisites

Architecture

Discovery

Product feed

Agent capabilities

Checkout flow

Successful response

Checkout status values

Troubleshooting

Agentic Commerce (ACP)

Overview

Prerequisites

Architecture

Discovery

Product feed

Agent capabilities

Checkout flow

Successful response

Checkout status values

Troubleshooting