Complete Guide

What is Agentic Commerce? How AI Shopping Agents Buy for You

The complete guide to understanding agentic checkout: how AI agents autonomously complete purchases, transforming ecommerce from manual checkout to machine customers buying on your behalf.

12 min read
For Merchants & Engineers

Quick Definition

Agentic commerce is ecommerce where AI agents autonomously complete purchases on behalf of users. Instead of humans browsing and clicking checkout, users delegate shopping tasks to AI assistants like ChatGPT or Claude, which discover products, evaluate options, and execute transactions programmatically through merchant APIs.

What's New Right Now

  • ChatGPT Shopping: Integrated with select merchants including Etsy. Walmart partnership announced October 2025.
  • Perplexity Payments: Checkout via PayPal and Venmo now available in Perplexity AI assistant.
  • ChatGPT Instant Checkout: OpenAI launched Instant Checkout, allowing users to buy directly from merchants like Etsy in chat, powered by the Agentic Commerce Protocol.
  • Google Agent-to-Agent Protocol (A2A): Google launched A2A to enable AI agents to communicate and coordinate actions across platforms, with 50+ partners including PayPal, Salesforce, and ServiceNow.
  • Agent Payment Protocol (AP2): Google announced AP2, an open protocol for secure agent-led payments using verifiable digital credentials, with 60+ partners including Mastercard, PayPal, and American Express.
  • Visa Trusted Agent Protocol: Initiative for identifying and authenticating legitimate shopping agents.
Sam Altman

Sam Altman

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CEO, Open AI

Released: September 29, 2025
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Understanding the Concept

What is Agentic Commerce?

Agentic commerce represents a fundamental shift in how online transactions occur. Rather than users manually navigating websites, comparing products, filling out forms, and completing checkout, they delegate the entire purchasing process to an AI agent. The user provides intent ("Reorder my coffee beans," "Buy a birthday gift for my mom under $50"), and the agent autonomously handles discovery, evaluation, and transaction completion.

This isn't an incremental improvement to existing checkout flows. It's a new transaction paradigm. The "shopper" is software, not a human. The merchant's job shifts from optimizing button placement and form fields to exposing structured APIs that agents can reliably query, interpret, and use to transact.

For merchants, this means enabling programmatic access to product catalogs, inventory status, pricing, and checkout. For users, shopping becomes a delegation task rather than a manual chore. For agents, completing purchases requires authentication, consent management, delegated payments, and robust error recovery, with minimal human intervention after initial approval.

Agentic commerce vs. adjacent concepts

Conversational commerce

You chat with a bot for recommendations, then you complete checkout. In agentic commerce, the agent, under your consent, can place the order autonomously.

Chatbot

Answer questions and guide shoppers. Agentic agents have delegated authority to complete the transaction end-to-end (with approvals as needed).

Recommendation engines

Predict and suggest products. Agents research, select, and purchase, not just suggest.

What agentic commerce is not

Not just recommendations:

Agents complete purchases, not merely suggest items.

Not autofill:

Agents make decisions, handle errors, and adapt to constraints, beyond form filling.

Not RPA:

Agents use structured, documented APIs (with idempotency and webhooks), not brittle screen scraping.

Not a single protocol:

It's a category/architecture. Multiple approaches (e.g., ACP, MCP, A2A, AP2) can work together.

Note: High-value, age-restricted, or first-time purchases can require explicit human approval based on policy.

Real-World Applications

Use Cases & Examples

Agentic commerce delivers measurable value across diverse shopping scenarios. Here are the most common patterns and their real-world impact.

Agentic Commerce Examples in Production

ChatGPT Shopping & OpenAI Instant Checkout

ChatGPT can complete purchases (Etsy live), with Shopify integration announced; Walmart has said it's exploring a partnership.

Perplexity Buy with Pro

Perplexity's 'Buy with Pro' lets users purchase via PayPal and Venmo from AI search results.

Vertical AI Shopping Agents

Industry-specific agents for electronics, fashion, and groceries handling repeat purchases and price monitoring.

B2B Procurement Agents

Enterprises are adopting procurement agents that automate sourcing, supplier comparisons, and draft POs via API-driven workflows (e.g., SAP's Sourcing Agent).

01

Subscription Replenishment

Your coffee consumption is predictable. The agent knows you brew 2 cups daily and your current bag has maybe 5 days left. Rather than letting you run out or forcing you to remember to reorder, it checks your preferred merchant, finds your usual beans are in stock, notices there's a 15% discount on the 2lb bag, and places the order automatically.

This isn't speculative, it's based on actual purchase history, confirmed SKU, and delivery timing that ensures arrival before you run out. Merchants often see improved retention and customer lifetime value because the friction of remembering to reorder simply disappears. The agent handles variant confirmation by cross-referencing previous purchases, eliminating the "wrong product" problem that plagued earlier automation attempts.

02

Price-Watch Automation

You've been eyeing a standing desk for months. It's $399 but you'd buy it at $320. Instead of manually checking prices or setting up unreliable alerts, you tell your agent: "Buy this if it drops below $320." The agent monitors continuously, and when a flash sale hits at $315, it validates stock availability, confirms shipping costs won't push the total over budget, and completes checkout in seconds.

The speed matters because good deals vanish quickly. Users report significantly faster purchase execution and the elimination of "saw the deal but it sold out while I was checking out" scenarios. The agent re-validates price and stock at checkout and aborts if the total exceeds the threshold, preventing the classic flash-sale trick where advertised prices revert during checkout. This is opportunistic commerce, buying only when conditions align perfectly with your constraints.

03

Enterprise Procurement Automation

A manufacturing facility's inventory system detects that aluminum stock will hit reorder thresholds in 72 hours. The procurement agent queries approved supplier APIs, compares bulk pricing across three vendors, verifies lead times, checks for recent quality issues in the ERP system, and places a 500-unit order with the optimal supplier, within pre-approved vendor lists and budget thresholds.

Companies using these systems report automating routine procurement with high order accuracy. The key difference from consumer use cases is approval workflows and constraint enforcement: the agent never exceeds budget caps, always uses approved vendors, and escalates anomalies (like sudden 40% price spikes) for human review. This is high-stakes automation where mistakes are expensive, which is why audit trails, rollback capabilities, and clear decision logs are non-negotiable.

Value Analysis

Benefits and Trade-offs

Agentic commerce delivers measurable improvements in conversion rates, support costs, and customer lifetime value, and can deliver improvements within a quarter depending on baseline, catalog complexity, and payment/SCA mix. Early adopters report meaningful conversion improvements, driven by the elimination of checkout friction and decision paralysis.

However, this shift introduces new challenges around trust, explainability, and compliance that merchants must address deliberately. Users need transparency into agent decisions, clear consent mechanisms, and confidence that automation won't result in unwanted purchases or compliance violations. The trade-offs are real but manageable with proper infrastructure.

What You Gain

Higher conversion rates by eliminating checkout friction. Agents don't exhibit human drop-off; failures are mainly technical (auth, stock, SCA). Retries and idempotency reduce abandonment-like failures. The path from intent to completed order typically takes seconds to a minute.

Reduced support costs as agents autonomously handle product questions, inventory checks, order tracking, and basic returns. Can reduce Tier-1 volume; expect a temporary spike during rollout and more complex exceptions routed to humans.

Improved customer lifetime value through subscription automation and proactive reordering. Customers who would have churned due to inconvenience stay because agents handle the tedious parts.

True 24/7 revenue generation without requiring night staff or international support teams. Agents operate across all time zones simultaneously, capturing purchase intent whenever it emerges.

What You Must Manage

Trust barriers prevent adoption if users fear unauthorized purchases or opaque decision-making. Transparent consent flows, spending limits, and clear approval thresholds address this, but building trust takes time and iteration.

Explainability requirements mean you need comprehensive audit trails. Users asking "why did you buy this?" expect clear answers showing what options were considered, how decisions were weighed, and why this choice won.

Product data quality becomes critical because sparse metadata breaks agent decision-making. Missing specifications, vague descriptions, or incorrect inventory status lead to poor choices and higher return rates until data improves.

Compliance complexity increases with automated purchasing. Log consent receipts and decision rationale per order; gate age-restricted SKUs; enforce region/country rules at API time. Age verification, regional restrictions, prescription requirements, and export controls all need programmatic enforcement with proper error handling and escalation paths.

How to Measure Success

Track these metrics to validate agent performance and identify optimization opportunities:

Agent conversion rate

Median time-to-order

Chargeback rate

Agent success rate (no manual fallback)

Auth approval rate

Refund/return rate vs human baseline

% orders requiring human approval

CSAT for agent-placed orders

Technical Approach

Implementation Patterns

Four core capabilities enable agentic commerce. These patterns are protocol-agnostic and work with ACP for merchant APIs, A2A for agent coordination, MCP for tool access, and AP2 for payments, alongside existing standards (OAuth 2.0, OpenID Connect) and network-level verification emerging (e.g., Trusted Agent Protocol). Choose the integration approach that fits your stack.

STANDARDS YOU WILL TOUCH

OAuth 2.0OpenID ConnectPCI DSS 4.xJWTEMV 3-D SecurePayment TokenizationWebhooksIdempotency KeysOpenTelemetry

Identity & Consent

OAuth 2.0 with granular scopes. Users grant explicit permissions for specific capabilities: view products, place orders under $100, access history. DPoP or mTLS token binding where supported. Every transaction includes consent receipts, mandate IDs, and audit trails.

Watch out: Vague scope descriptions lead to blind approvals

Product Catalog APIs

Expose structured APIs with search, filtering, variants, and live inventory. Agents convert natural language queries ("organic coffee under $20 with free shipping") into API parameters and get machine-readable responses.

Quality metadata is non-negotiable: complete descriptions, specifications, images, and accurate stock status enable intelligent agent decisions.

Watch out: Sparse metadata breaks decision-making

Checkout Automation

Stateless cart APIs with idempotency keys. Agents create carts, apply discounts, calculate shipping, and complete checkout. Minimize round-trips; make every write idempotent; support async confirmation via webhooks.

Stock reservation/hold windows and concurrency controls prevent oversells. SCA exemptions where allowed; fall back to challenge when required.

Watch out: Missing idempotency causes double-charging

Payment Delegation

Processors like Stripe support delegated charging via Payment Intents and Setup Intents (off_session) with stored payment methods. Connect merchant platform/marketplace setups. PCI-DSS maintained: agents never touch raw card data.

Watch out: Never pass raw card data through agents

Real-Time Updates

Webhooks notify agents of status changes: shipped, delivered, delayed. Verify signatures, retry with exponential backoff, ensure idempotency in webhook handlers to avoid double-processing. Agents monitor autonomously and alert users only when needed. Include tracking numbers and ETAs.

Watch out: Webhook failures break agent awareness

REFERENCE ARCHITECTURE

1.User Intent
Natural language request to agent
2.Agent Processing
Parse intent, extract constraints
3.Product API
Query catalog, inventory, pricing
4.Cart API
Idempotent cart creation
5.Payment Processor
Tokenized payment, SCA where required
6.Webhooks
Order status updates to agent
7.Post-Purchase
Returns, learning, trust signals

Critical patterns: Retries with exponential backoff, rate limiting (per-agent), circuit breakers on API failures, idempotency keys on all write operations. See idempotency and webhook docs.

EDGE CASES TO HANDLE

Age restrictions
Price fluctuations
Multi-merchant cart
Regional limits
Payment failures
Price at checkout drift
Rate limiting
Address validation
Address normalization
Stock changes
Return windows
Pre-order/backorder

Protocols Powering Agentic Commerce

Agentic commerce isn't a single API; it's a stack. In practice you'll combine merchant commerce surfaces (ACP), agent-tool interfaces (MCP), agent interoperability (A2A), and secure payments (AP2):

ACP (Agentic Commerce Protocol)

A merchant-facing API schema so agents can search products, price offers, build carts, and place orders with idempotency and webhook callbacks. ACP defines resources and events that map cleanly to autonomous checkout.

MCP (Model Context Protocol)

Connect agents to merchant tools/data (catalog, inventory, shipping) via a standardized, secure interface.

A2A (Agent-to-Agent)

Interoperability between agents: discovery, messaging, and coordination for multi-party purchase flows.

AP2 (Agent Payments Protocol)

Standardized agent payments with signed mandates, risk roles, and multi-rail support (cards, A2A/open-banking, stablecoins).

Note: "A2A payments" (account-to-account bank transfers) are a payment rail that AP2 can use; not the same as A2A agent interoperability.

Protocol Comparison: ACP vs MCP vs A2A vs AP2

ACP

Purpose

Merchant commerce APIs (catalog, cart, checkout)

Transport

REST/JSON

Auth

OAuth 2.0

Maturity

Emerging

Maintained By

OpenAI + Stripe

MCP

Purpose

Agent↔tool/data access

Transport

JSON-RPC 2.0 (stdio/WebSocket/HTTP)

Auth

Host-provided

Maturity

Early production

Maintained By

Anthropic

A2A

Purpose

Agent interoperability/coordination

Transport

HTTP/gRPC (varies)

Auth

mTLS and/or OAuth service creds

Maturity

Pilot

Maintained By

Google + partners

AP2

Purpose

Payment mandates & multi-rail

Transport

REST/JSON

Auth

Signed mandates (e.g., JWS)

Maturity

Draft/early pilots

Maintained By

Google Cloud + PSPs