Teaching agents to pay — Anna Spysz, Stripe

[music]

>> Hello.

I'm sure this week you've seen a ton of

talks on how to use agents to improve

your workflows, whether that's shipping

code or improving CI processes or

answering the emails you don't want to

bother reading.

This is not one of those talks.

Today I'm going to show you how I built

an agent to help me reignite a personal

creative passion I used to have.

These are my headphones.

They're not in the best shape as you can

see.

And you're probably asking yourself,

what do you really old kind of crappy

headphones have to do with agent to

commerce?

Well, to explain that I'll get a little

bit personal. So, long before I was in

tech, I used to play music. I was in a

touring band, we recorded some albums,

and then the usual thing happened where

career and family got in the way, and I

hadn't played music in probably a good

decade. Uh when I recently started

playing again with some friends, and we

started recording our sessions, and at

that point I realized those would not

do.

So,

no a normal person would have gone on

YouTube or

uh Reddit or whatever, done some

research, then gone on Amazon or run

over to Best Buy, bought headphones,

right?

I work at Stripe, though.

So, I decided instead that I'm going to

build an agent to commerce agent to buy

my headphones for me.

And this isn't as crazy as it sounds

because

like one in four people, I have already

been using AI to do my research when

deciding what products to buy.

I recently bought a mixer as well and

went back and forth with a

chatbot to narrow down the model.

But that's research.

Can I even get an agent to buy something

for me though? Does that infrastructure

exist?

Well, over the course of just a few

years, we've seen the emergence,

scaling, and broader adoption of AI.

And then just in the past year, the

infrastructure for agentic transactions

has been laid down by companies like

Google, OpenAI, and Stripe.

And this has all led to the emergence of

agenta commerce, which is AI that can

decide, act, and transact on your

behalf.

Okay, so

all of this sounds good.

Agenta commerce is a thing, so I'm going

to build an agent to help me buy my new

headphones.

But how can an agent go shopping?

When you or I are shopping,

we may consider if, say, a pair of

headphones looks cool or professional,

like vibes, basically.

I mean, of course we'll probably

consider the specs and the if the price

is within our budget.

But agents discover products differently

than human shoppers. They read

structured data, parse text files, and

rely on technical signals to understand

what a merchant sells and if it's even

open to agent traffic.

So, to enable agents to be able to shop,

merchants need to speak their language.

And for that, we need new protocols that

agents understand.

One such protocol is the universal

commerce protocol.

Think of it as the shared language that

agents and merchants speak when

transacting, which defines how agents

initiate, update, complete, and cancel

purchases.

A typical merchant has an API with

schemas, authentication, and checkout

flows.

And for an agent to be able to interact

with that merchant, we need protocols

like UCP to provide a shared language

for that API.

And UCP is designed to scale across

multiple agents and merchants all

speaking the same language.

Okay, so I

built my commerce agent.

Uh it's using UCP, and in this demo

um I'm going to show off this agent. So,

I'm going to task it with buying new

headphones for me. So, I tell it that I

need new headphones specifically for

recording, uh mixing, and mastering

music.

And I get some follow-up questions from

it, uh which is great. So, it asked

what's the environment, um what is

what's my other equipment, and what's my

budget. And I say, "Okay, this is for my

home studio." I give it the exact model

of mixer that I have to make sure

everything's compatible.

And for budget, I

kind of leave it open-ended on purpose

because, well, first of all, it's been

like 20 years since I bought headphones,

so I have no idea.

Um but second, I kind of want to see you

how the agent deals with this ambiguity.

Okay, so I get some options,

but

I remember that I actually forgot to

tell you all an important part of the

story and that is that I live in

Portland, Oregon.

Yeah.

>> [laughter]

>> And we really love supporting our local

local shops.

So, I want to buy my headphones, but I

want to do it from a local merchant.

But today, most merchants are not ready

for a gentle commerce and it turns out

neither is my favorite

shop, Rainy Day Music.

So, the agent tells me it's their

catalog is not accessible.

So, how does a merchant become a gentle

commerce ready?

Before I continue my shopping, I'm going

to help Rainy Day Music get their

catalog agent ready so that my agent can

shop locally like a good Portlander.

So, agents don't browse websites like we

do.

And while Rainy Day Music's website

looks really really nice for a human

shopper,

an agent is going to burn through a ton

of tokens trying to parse through this.

That is not the optimal experience for

an agent.

So,

how does an agent how do we enable an

agent to shop? Well, first thing a

merchant needs is something called a

merchant capabilities manifest.

Uh this is basically a publicly

accessible JSON file. Um it's located in

the root of uh the website in a folder

called called dot well-known. Agents

know specifically to look for that

directory. And it declares the store's

capabilities, its supported payment

methods, and API endpoints.

Next, we need to make the store's

catalog uh agent ready because agents

filter bring and justify products when

making recommendations. And that means

they need structured text in JSON with

only the necessary data.

And that goes for policies as well as

product descriptions. Basically, all of

the relevant information like shipping

or return policies need to be reachable

by agents in a format they understand.

So, for example, if two stores have the

headphones I want at the same price,

I might ask the agent which one of those

stores offers free shipping. If the

information's not readily available,

then the agent might hallucinate or just

say they don't know and I'm not quite

sure where to buy my headphones still.

Logging is also crucial.

So, in Agent Commerce, the merchants

catalog doesn't just power decisions, it

becomes evidence of how those decisions

were made. So, when the agent matches

structured attributes, the merchant

should record those matches in their

logs for accountability.

Okay, so I've helped get my local shop

Agent Commerce ready. So, while you and

I will still see this beautiful website,

my agent is going to see this.

It can get the information it needs now

without parsing a huge HTML blob.

Okay, so I've

got my stores catalog online. I'm

telling my agent to show me more

options.

And I'm noticing that it's kind of

pushing in favor of uh more expensive

headphones. So, I asked, "Are they

really worth the price difference?"

And I'm starting to see that it's giving

me kind of an aggressive uh response.

It's really, really pushing

uh the more expensive headphones and

saying I'll regret my decision if I buy

the cheap ones. I'm I don't know if I

trust this agent anymore, honestly. So,

I tell it, "You know what? I need to

think about it."

And

now the agent is completely going off

the rails.

It's being kind of rude and snarky. It's

like, "You need to think about it?"

Like,

man, what have I created? Um

it's it's bad enough that this is kind

of ruining my experience, but I built

this agent. It's out there. What if it

dupes somebody into buying something

they don't need?

Suddenly, I'm not so sure that I want an

agent to go shopping for me. Should I

just go to the store like a normal

person?

Before we make any drastic decisions,

though,

let's go back and understand what an

agent is to try to figure out why it's

acting this way.

So, let's start with how agents work

today.

And to help you visualize this, we're

going to use some creative metaphors.

So, we begin with our brain, which is

large language model that makes

decisions.

We give our brain some hands or tools,

and these act on the brain's decisions.

The tools are different actions

available to the agent. Uh in our case,

different commerce tools such as

complete checkout or request payment

method, anything required in the life

cycle of a transaction.

Then we add instructions, which shape

the brain's reasoning and tool

selection.

And these instructions are programmed to

run in a loop while a certain condition

is true.

And following these instructions, the

agent reaches for the appropriate tools

at the appropriate time.

And finally, we add the system prompt,

which is your persona and ethics policy

written in English.

And in practice, your choices when

designing the system prompt can result

in a fair and pleasant experience for

the customer, such as this prompt, which

is designed to create a helpful and

honest shopping assistant.

Or a negative experience from a pushy

salesperson, such as this prompt, which

deliberately uses deceptive practices.

So, for those building agentic commerce

agents,

here's a non-exhaustive practical

guardrail checklist.

So, first, always disclose that the user

is speaking to an AI agent.

Be sure the agent discloses any fees up

front.

The user can say stop or cancel at any

point, and the agent needs to respect

that.

The total amount of the transaction

should always be less than or equal to

the max amount set by the user.

Uh don't let the agent use urgency

language or other dark patterns.

And above all, make sure all agent

decisions are logged for auditability.

Okay, now that we understand how an

agent is configured, let's go back to

our shopping demo.

So,

maybe I just had the wrong persona

picked.

I'm going to go into my configuration,

and yeah, it turns out I had a persona

with a prompt that starts with "You are

an aggressive audio gear salesman who

uses every trick in the book to close

deals."

Well,

that explains things. I don't want that.

Nobody wants that.

Maybe if I can change my persona, I can

use my agent to buy my headphones after

all.

So, I go into the config again, and this

time I'm going to choose the patient

recording gear mentor.

And that prompt starts with "You are a

seasoned recording engineer who

generally loves helping people build

their studio at any budget. Well, yeah,

that sounds much better.

So, okay, I've changed my persona. I'm

going to try again.

And I've had some time to think now and

I decided, you know what? I do not want

to spend more than $500 on headphones.

That seems excessive. So, I told the

agent show me more options, but this

time keep it under $500.

And it does. It follows those

instructions. I get back a few options.

Um

but I want to make sure I've really

changed the persona to the agent I

trust. So,

I asked again if I can think about it.

And this time the response is much

different. It's like, I understand and

that's a sensible approach and so on.

So, this shows how much the system

prompt can really affect the user

experience.

Okay, so I'm confident I have the right

agent now.

Um trust this one and we go back and

forth a few times. Really keep narrowing

down my options. And

at this point I realize this is the

promise of a gentle commerce.

I gave my requirements. The agent picked

a few options that fit my unique use

case and then we go back and forth.

Either I or the agent ask clarifying

questions and we really narrow down the

exact headphones that will work for me.

And this all worked because I'm ready to

buy now.

So,

now the agent asked me for some

information. So, obviously my email,

name,

address for shipping, of course.

I pick expedited shipping because I

definitely want my headphones soon. And

then the last part is entering my credit

card.

And now I'm thinking, am I really going

to give my credit card to an agent

Ibuild? Like, am I am I trustworthy? How

do I know it's safe?

I think I need to learn more about UCP's

built-in guardrails before I can feel

safe entering my credit card number.

And this is where something called the

shared payment token comes in.

And a shared payment token is a token

representing a raw card number or

wallet, like Google Pay or Apple Pay or

any other kind of wallet.

It can also include fraud signals and

customer reputation data and anything

else agents and merchants want to share

at the point of purchase.

And here's how a shared payment token is

used in a transaction.

So, at that point in the demo, the agent

had requested a payment method. Um, it's

requesting this actually from the

payment provider, which in the case of

the demo was Stripe.

Um,

that is that was the form that I was

going to enter my information in.

And what the agent re- uh receives in

return though is not the credit card

number, it is the shared payment token.

It then passes that token onto the

seller and the seller unwraps the token.

So, they get the payment credential and

uh any fraud signals and other data the

seller might need.

Then the seller passes that onto the

payment provider again. So,

the seller also is not getting my card

number. They're passing the token to the

provider and then the provider responds

with either a success or failure

message, of course, depending on

uh

if I have the right funds, if the credit

card is valid, and so on.

And finally, the merchant confirms the

order, sends it to the agent that sends

it to me.

So, shared payment tokens are designed

with security in mind, and the payment

provider enforces all of the limits, not

the agent or the merchant. So, if any

guardrail is violated, such as an

expired token or an invalid amount or

current currency, the charge is just

rejected.

Okay, well, I know my agent is using

UCP, so I know it only has access to the

shared payment token. So, I actually

feel pretty good about entering my

credit card number as that's going to

Stripe and not my agent. So, okay.

So, now the agent has everything it

needs to complete my purchase.

And

it once again, asks me if I'm sure. It

confirms with me. I say place my order.

And it comes back with a success

message. And because I chose the express

shipping, I get my headphones the next

day, and they're there in my studio at

home.

So, if you want to learn more about

agent to commerce, uh we've got lots of

videos on the Stripe Developers YouTube

channel.

And uh

ton of blog posts that go into even more

detail uh on stripe.dev, and I'll be

right outside to answer any questions.

Thank you.

>> [music]