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From YouTube: Agoric + Protocol Labs // Zoe and ERTP: Offer Safety for Smart Contracts - Dean Tribble
Description
As part of Agoric + Protocol Labs Speaker Series, Agoric co-founder Dean Tribble gave a talk about the Zoe smart-contracts platform and ERTP (electronic rights transfer protocol). Zoe is a framework for building smart contracts like auctions, swaps, decentralized exchanges, and more. Zoe itself is a smart contract written in JavaScript and running on the Agoric platform.
https://agoric.com/documentation/zoe/guide/
A
I'm
gonna
introduce
a
thing
called
Zoe
and
I'll
tell
you
where
it
exists
as
we
go
go
through
this
in
the
Agora
stack.
First
I
have
a
question:
how
many
people
here
have
actually
interacted
with
a
smart
contract
about
half
the
audience?
I
think
the
other
half
of
you
are
lying,
but
we'll
talk
about
that
in
a
moment.
So,
oh
so
the
problem
here
is
this
is
not
actually
moved
there.
We
go.
Oh
now,
I
wonder
if
it'll
work,
so
I'm
gonna
talk
about
the
background.
A
I'll
tell
you
a
little
about
a
little
bit
about
Zoe
I
will
talk
about
the
electronic
rights
transfer
protocol.
That
is
behind
that
in
our
platform
and
then
wrap
it
up
just
so,
you
see
where
we're
going.
Yes,
it
worked.
Okay,
so
we've
been
working
on
smart
contracts.
I
worked
on
the
first
production,
smart
contract
back
in
1989,
so
in
case
you
aren't
doing
the
math.
A
Yet
with
this
lovely
liquor
here
that
was
before
blockchain,
and
so
that
is
a
electron,
a
a
contract
like
expression
in
code
where
the
execution
of
the
code
enforces
the
terms
of
the
contract,
so
it
controls
the
rights
transfer.
It
controls
the
conclusion.
It
controls
the
parts
of
a
company
that
could
be
made
operational.
That
can
be
made
precise
and
objective,
and
so
a
lot
of
people
can
think.
Okay,
so
bitcoin
is
actually
a
smart
contract
right
it's
code.
A
This
is
arranging
the
coordination
between
multiple
third
parties
to
move
money
back
and
forth,
but
we
were
working
on
this
thirty
years
ago.
So
what
happened
since
well
I
can
go
to
a
web
site
put
in
a
bid
for
an
article
it
automatically
processes.
If
I
win
the
auction
it
automatically
pays,
though
the
person
who
put
up
the
goods
and
the
money
transfers
there's
automated
dispute
resolution.
That
sounds
like
a
smart
contract.
It
is,
however,
called
eBay,
eBay
venmo,
PayPal
much
of
lyft
and
uber
much
of
Amazon.
A
All
of
those
are
software
systems
where
most
of
the
actual
execution
of
rights,
an
actual
execution
of
contract
like
behavior,
between
independent
third
parties
that
are
not
at
the
company,
is
orchestrated
by
software,
and
so
smart
contracts
have
already
happened.
There's
already,
you
know
hundreds
of
billions
of
dollars
of
market
cap
in
smart
contracts,
and
so
now,
of
course,
all
I.
You
know
I'll
ask
again
of
the
people
who
have
said
no
before
how
many
of
you
have
talked
to
a
smart
contract
and
no
one
bought
anything
for
Amazon,
okay,
good
okay.
A
So
if
smart
contracts
are
already
successful,
where
do
blockchains
come
in?
What
do
they
do
for
us?
So,
from
my
perspective,
right,
a
blockchain
is
multiple
independent
computers,
agreeing
on
things
while
the
independent
computers,
where
that
means
different
administrative
zones
different
jurisdictions,
so
that
there's
no
administrative,
single
point
of
failure
shall
we
say-
and
they
have
to
agree
on
things,
so
they
vote
to
agree
on
data.
Well,
that's
easy!
That's
just
sort
of
timestamp
this
stuff,
but
harder
is
vote
to
agree
on
choices.
A
I
took
this
money
and
I
gave
it
to
Dave,
not
Alice,
and
that's
what
requires
consensus
that
work.
That's
where
blockchains
really
brought
new
technology
to
the
system
and
finally,
they
they
agree
on
the
results
of
computation
and
that's
where
smart
contracts
come
in
and
so
what
the
net
result
is
is
instead
of
having
to
do
our
smart
contracts
with
a
trusted
third
party
like
eBay
or
PayPal
or
venmo,
or
whoever
I
can
instead
have
a
high
integrity,
neutral.
A
Third
party,
trustless
third
party
pick
your
term,
but
it's
a
it's
a
it's
a
platform
that
I
can
rely
upon
to
execute
correctly.
So
now,
I
can
directly
engage
in
contract
like
behavior,
with
total
strangers
executing
code.
That
I
rely
on
the
correct
execution
of,
and
that's
nice,
that's
a
new,
a
new
ability
to
express
software
and
have
it
enable
cooperation.
So
we've
been
building
a
platform
up
from
this
and
remember:
we
did
smart
contracts
before
there
were
block
chains.
A
So,
from
my
perspective,
block
chains
essentially
introduced
a
new
kind
of
computer
made
from
agreement
rather
than
silicon,
so
we
did
cryptographic
protocols
between
machines.
Now
some
of
those
machines
happen
to
be
replicated
across
the
and
there's
protocols
to
do
that,
but
it's
still
coordination
among
independent
machines,
above
that
we
build
a
computational
layer
of
simple,
sequential
transactional
units
of
computation
that
normal
programmers
can
understand.
It's
familiar
from
nodejs
or
browser
programming
would
have
you
embedded
in
a
world
of
asynchronous
communication
right
the
world
out.
A
A
Communication
protocol
between
block
chains
between
machines
between
machines
and
block
chains,
and
so
we
layer
on
top
of
that
that
connects
our
independent
units
of
computation,
which
we
call
vats,
and
on
top
of
that,
we
build
an
execution
model
for
us.
It's
in
JavaScript,
but
the
general
architecture
applies
to
multiple
languages,
I'm,
pretty
sure,
there's
someone
here
who
would
like
it
in
rust
and
that
stitched
together
using
a
protocol.
We
call
cap
TP.
A
So
that's
a
remote
invocation
remote
object
protocol
that
just
it
gets
marshaled
on
to
the
underlying
IBC
data
channels
and
because
IBC
handles
all
of
the
relay
between
block
chains
and
agreement
on
consensus
and
all
the
details
of
transport
authentication
and
ordering
we
can
just
layer.
On
top
of
that.
The
same
way
we
would
layer
on
top
of
TCP,
and
so
we
do
marshaling
of
messages
between
between
machines,
and
so
what
that
means
is
I
can
have
what
I've
got
a
lightsaber
here.
I
can
have
a
there.
We
go.
A
You
can
see
a
little
green
dot,
UT
a
green
dot
there.
Great
so
I
can
have
a
object
on
in
one
VAT
on
one
machine.
Send
a
message
to
an
object
on
another
VAT
on
another
machine.
It's
just
an
asynchronous
message:
it
doesn't
know
whether
the
VAT
is
local,
whether
the
VAT
is
on
the
same
chain,
whether
the
VAT
is
on
a
different
chain,
and
it
took
IBC
and
Inter
blotching
communication
to
cross
the
bridge
across
that
boundary,
whether
it's
on
a
private
chain,
a
private
machine,
etc.
A
It's
just
an
async
message
and
eventually
the
answer
will
come
back
and
those
different
technologies
just
affect
what
the
latency
is
of
that
response.
Okay
and
then
above
that,
now
we're
at
the
object
level
now
we're
programming
in
JavaScript.
You
saw
JavaScript
on
the
screen
before
and
so
above
that
we
then
build
objects
that
let
us
easily
express
contract
like
behavior,
so
escrow
agents,
auctions,
futures
forwards,
etc.
Those
kinds
of
things
you
can
build
as
JavaScript
objects
only
because
they
can
reach
out
over
the
network
to
other
machines
or
contracts
on
other
machines.
A
That
auction
can
on
one
machine,
can
be
auctioning
off
a
concert
ticket
that
hosted
on
another
machine
and
when
I
may
say,
another
machine
I
mean
another
chain
or
a
private
chain
or
what-have-you.
Okay,
so
that
gets
us
to
contracts
and
to
do
that
we
have
a
protocol
called
electronic
rights.
Transfer.
A
Protocol
and
I'll
talk
some
of
that
about
that
in
a
minute,
but
that
gives
us
the
ability
to
abstract
across
how
we
do
exclusive
transfer
of
rights,
transfer
of
ownership,
confirmation
of
the
quality
of
an
item,
all
those
kinds
of
things
and
I'll
talk
a
little
bit
about
each
of
those.
But
what
we're
doing
tonight?
What
I'll
introduce
tonight
first
is
what
we
call
Zoe
when
we
went
out
and
started
plotting
building
the
stack.
We
came
up
with
this
idea
and
we
realized
it
would
be
very
exciting,
but
we
were
we
wanted
to.
A
You
know
nucleate
it
for
a
while,
and
so
we
haven't
talked
about
it
outside
and
so
I'm
talking
about
it
essentially
for
the
first
time
here
tonight,
as
something
we've
articulated,
occasionally
as
secret
sauce
that
we
intend
to
be
in
our
in
our
smart
contract
framework,
and
so
that
gives
us
what
we
consider
to
be
a
better
model
for
doing
smart
contracts,
so
before
I
quite
dive
in
a
little
bit
more
background.
So
several
people
here
have
worked
with
smart
contracts.
A
What's
wrong
with
this
picture
and
don't
say
it's
meta
mask
because
they're
doing
some
really
awesome
stuff
with
our
security
technology.
What's
wrong
with
it
is
that
the
user
here,
which
thankfully
is
another
face
of
Dan,
is
sending
a
bunch
of
money
to
essentially
a
random
number,
and
hopefully
that
random
number
is
a
friend
of
yours,
but
while
I've
been
random,
I'm,
usually
not
a
number.
So
that
interface
scares
me
it's
very
low
level
and
it's
not
just
meta
masks.
It's
pretty
much
all
the
platforms
right,
that's
the
loony
wallet
for
cosmos.
A
You
see
the
same
thing
in
all
the
other
platforms
and
it's
not
just
payments,
it's
also
the
applications.
This
is
Eunice
WAP
on
the
left,
I'm,
putting
together
a
trade
which
might
be
for
a
lot
of
money
and
I'm,
saying
pay
it
and
what
am
I
paying
well
at
the
end
of
the
day
in
these
applications,
I'm
paying
a
random
number
I'm
gonna
send
my
money
to
the
other
end
of
some
chain,
and
hopefully
software
runs.
A
That
does
what
I
expect
and
some
point
in
some
address
that
I,
hopefully
have
control
of
assuming
I
didn't
get
my
random
number
wrong.
A
bunch
of
different
money
appears,
and
maybe
I
discover
that
right,
it's
a
very
low
level,
very
fragile
experience
that
we're
cobbling
together
to
get
a
blockchain
experience.
A
A
It's
that
I
want
to
spend
some
money
for
a
quid
pro
quo
right,
I'm,
not
sending
you
money,
I
want
to
buy
a
concert
ticket
and
if
I'm
not
gonna,
get
my
concert
ticket,
then
I
don't
want
to
give
you
the
money
all
right,
and
so
this
is
a
Eunice
WAP
variant
that
we
built
where
you
know
same
expression.
Only
of
course
the
money
is
coming
from
purses
that
are
named
so
I.
Don't
just
have
a
pile
of
ether.
A
I've
got
my
business
account
or
my
operating
account,
or
what
have
you
and
when
I
say
when
I
say
pay,
I
don't
get
here,
send
some
money
to
a
random
number
I
get
an
offer.
An
offer
is
multiple
parts.
It's
what
do
I?
What
am
I
offering?
What
are
the
goods
I'm
willing
to
pay
and
what
do
I
expect
to
get
from
that?
A
What
do
I
want
to
get
out
of
this
exchange,
and
so
that
offer
is,
you
know,
pay
3,000
Lulla
from
my
savings
account
and
I
expect
to
receive
2,000
somalian
into
my
marketing
account,
okay
or
purse,
as
we
call
them.
That's
a
much
safer
interaction
as
long
as
it's
enforced
as
long
as
I'm
actually
protected
so
saying
my
offer.
This
way
actually
buys
me
something
from
it
from
a
safety
point
of
view.
So
thus
we
have
Zoe
we're
in
testing
it.
Now
we
have
a
proof
of
concept.
A
So
what
does
it
do?
So?
This
is
what
so
Zoey
you
know
it's
about
using
offers
everywhere,
and
they
show
up
in
a
bunch
of
places.
You
already
saw
it
in
the
user
interface
I
just
saw
that
screen
back
there
with
two
people
talking
to
each
other.
It's
like
wait.
Why
are
they
talking
to
so?
Let's
say
I
want
to
do
the
audit
I
want
to
sell
the
that
concert
ticket
the
seller.
You
know
in
an
auction:
it's
not
that
the
guy
with
a
concert
ticket
is
the
auctioneer
or
necessarily
is
running
the
auction.
A
They
just
want
to
sell
it
in
an
option
so
in
some
sense
they're
a
customer
of
the
auction
as
well,
so
they
create
an
offer
that
says
yeah
I'm
willing
to
sell
my
concert
ticket,
but
I
need
to
make
at
least
this
much
money.
I
need
to
make
at
least
know.
I
need
to
make
at
least
X
moolah,
for
this
concert
ticket
I.
Think
of
that
as
the
reserve
on
their
auction
right
and
now
a
bidder
comes
in.
What
does
a
bitter
do?
Will
a
bitter
wants
to
pay
at
most?
A
Why
moolah
in
exchange
for
a
concert
ticket
my
gosh,
they
better
get
that
concert
ticket
or
they
better
get
their
money
back.
That's
what
they're
expecting
and
so
Zoe
an
important
thing
here,
and
this
is
what
Zoe
provides
us
pervade.
What
we
call
pervasive
escrow
right:
it's
not
that
the
that
the!
Why
moola
that
the
user
is
bidding
goes
to
the
auctioneer
and
then
you
hope
the
auctioneer
is
honest,
and
you
hope
that
if
you
lose
the
auction,
they
give
it
back,
which
is
what
you
see
in
typical
smart
contracts
on
other
platforms.
A
It's
instead
those
assets
go
into
Zoey
and
Zoey,
escrows
them
and
then
securely
notifies
the
auction
that
hey
there
is
a
legitimate
offer
with
real
assets
for
y
moolah
to
get
that
concert
ticket.
So
now
the
auctioneers
code
is
much
simpler.
It
doesn't
have
any
of
the
money
handling
and
it
just
figures
out.
A
Here's
how
I'm
going
to
of
all
the
offers
present
where
the
two
offers
of
import
right
now
are
the
highest
bidder
for
a
concert
ticket
that
wants
to
give
the
most
moolah
and
the
person
with
a
concert
ticket
that
is
trying
to
get
moolah
right
and
those
two
offers
are
compatible.
And
so
now
Zoey
does
a
rearrangement.
That
says
you
know
it
is,
can
assistant
with
the
constraints
that
all
of
you
have
provided
that
I
take
the
concert
ticket
from
him
and
give
it
to
him.
A
I
take
the
moolah
from
him
and
give
it
to
him
so
so
that
now
the
seller
will
get
moola
and
the
highest
bidder
will
get
a
concert
ticket
and
Zoey
will.
Let
will
allow
the
auction
to
specify
that
reallocation.
It
will
check
a
couple
of
key
properties.
The
first
is
that
all
of
those
offer
constraints
are
met,
which
is
to
say,
I'm,
not
charging
the
bidder
more
moolah
than
they
were
willing
to
pay
and
I'm,
paying
the
the
auctioneer
at
least
as
much
as
he
required
to
fork
over
the
concert
ticket.
A
And
if
that
happens,
then,
then
then
Zoey
will
cause
the
reallocation
happen
and
oh
and
and
it'll
also
before
I
go
there.
It'll
also
make
sure
that
of
the
reallocation.
Of
course,
currency
is
conserved
right,
so
assets
are
conserved,
I
can't
manufacture,
moolah
out
of
whole
cloth.
That
would
be
shocking
and
so
Zoey
enforces
that
on
a
continuing
basis,
and
so
it
does
a
transfer.
A
And
finally,
it
exits
and
Zoey
provides
the
rewards
to
all
of
the
parties,
so
the
winnings
to
the
winning
bidder,
the
refunds
to
all
of
the
bidders
that
put
money
in
that
was
escrowed
in
Zoey,
but
they
didn't
win
it
and
the
important
characteristic
there
is
their
offer
said
that
they
need
a
concert
ticket
before
any
of
their
money
gets
forked
over
to
the
seller,
and
so
there
is
absolutely
nothing
that
the
auctioneer
can
do.
There's
nothing
that
the
seller
can
do
in
order
to
get
the
money
from
a
wedding,
but
from
a
losing
bidder.
A
The
only
way
they
can
get
the
money
is
to
provide
another
concert
ticket
that
that
Zoey
recognizes
as
the
thing
that
was
required
by
those
bidders,
and
so
you
have
this
safety
property
that
we
call
offer
safety.
Now.
Software
engineering
is
a
history
of
improving
safety
properties,
right
type,
safety,
memory,
safety,
concurrency
safety
and
they
didn't
magically
make
all
the
bugs
go
away,
but
for
each
of
those
categories
they
really
did
take
80%
of
them
off
the
table
right
once
you
had
memory
safety.
A
Suddenly,
you
know
all
of
those
random
pointer
rights
or
or
walking
off
into
memory
or
buffer
overflows.
They
just
went
away
right,
they're
just
gone.
It
wasn't
that
they
suddenly
turned
into
some
different
hard.
No,
they
were
just
gone.
There
was
still
20%
of
the
bugs
left
and
those
are
hard
bugs,
but
they
were
already
there,
but
taking
80%
off
the
table
awesome,
and
so
this
is
a
safety
property.
Now
I
have
this
separation
of
concerns.
Well,
the
guarantee
I
provide
to
the
clients
right
is
that
either
they
will
get
their
desired
payout.
A
They
will
get
the
thing
they
wanted,
or
they
will
get
a
refund
and
they're.
You
know
one
of
the
two
and
I'll
talk
a
little
later
about
how
they
might
get
both,
but
but
they
are
that,
but
they
get
that
regardless
of
the
behavior
of
the
contract.
They
get
that
even
if
the
contract
gets
upgraded
in
the
middle
of
this
execution
unit.
A
That
seems
to
me
like
a
significant
step
forward
in
the
safety
that
we
provide
all
of
the
clients
if
we
want
millions
and
millions
or
billions
of
users
on
these
platforms,
but
it
also
gives
guarantees
to
the
client
to
the
servers
to
the
coast
right
to
the
contracts,
which
is
to
say
the
contracts,
don't
get
the
money
directly,
they
don't
have
to
worry
about,
dropping
it
or
returning
in
or
or
accidentally
having,
someone
steal
it.
So
suddenly
they
opie
pulmonic.
A
Have
platform
assurance
that
the
asset
the
offer
is
describing
is
synchronously
available
right
that
the
contract
execution
can
do
a
reallocation,
synchronously
and
it
just
works,
and
that
turns
out
to
be
really
nice.
It
simplifies
their
that
it
simplifies
the
architecture
of
those
code
and
they
get
the
assurance
that
the
assets
will
be
delivered
on
completion,
that
they
won't
wander
away,
that
there
will
be
a
failure
or
a
library
gets
removed.
A
A
A
You
would
like,
as
a
user
of
a
smart
contract,
to
not
be
concerned
about
them
so
offer
safety
addresses
several
of
these,
but
it's
not
a
complete
solution
right
so
offer
safety
clearly
addresses
Prodigal,
because
you
know
the
bad
code
can't
get
my
money
unless
it
provides
me
what
I
want
and
now
I
don't
care
what
it
does
with
the
money.
I
got
what
I
want
right,
yeah
as
a
client,
the
other
is
greedy.
You
know
you
can
get
something
stuck
so
there's
another
safety
property
right
once
we
identified
offer
safety
as
a
thing.
A
We
generalize
that
to
what
we
call
market
safety
properties
properties
that
make
it
safer
that
do
the
same
kind
of
thing
that
memory
safety
did,
that
make
it
safer
to
participate
and
build
a
market
right,
so
exit
safety
right
and
and
the
first
element
of
exit
safety
is,
of
course,
the
contract
at
any
time.
Getting
the
getting
an
offer
can
simply
say
yeah,
not
enough
money
or
you
want
it
too
soon.
Nope
nope,
I'm,
gonna,
eject
that
offer
I'm
done
right.
So
from
the
contracts
perspective
you
know
they
can
respond.
A
Teas
double
do
the
clients.
Have
you
know
great
I
put
my
offer
in
if
it's
satisfied,
I
will
get
what
I
want.
If
it
exits,
I
will
get
back.
My
I
will
get
a
refund
of
everything
I
put
in
what
if
they
just
sit
there
right
and
it
turns
out
there's
well
depending
on
the
price
of
ether.
There
are
some
there's
hundreds
of
millions
of
dollars
just
sitting
there
in
a
few
contracts
that
are
stuck
right.
A
So
we
have
exit
rules
which
are
all
about
who
can
terminate
a
particular
offer.
Multiple
offers
go
into
a
contract
who
can
terminate
so
so
I'll
give
you
several
of
the
rules
that
are
currently
supported
in
the
proof-of-concept
on
demand
means
the
offers
there
until
the
client
says.
Yeah
give
me
that
back
and
that's
a
race
right.
The
the
contract
might
be
busy
trying
to
take
your
offer
and
provide
you
the
goods
on
the
other
side.
So
it
is
a
race,
but
back
to
what
you
want.
A
Architectural
assurance
of
it
is
not
possible
in
the
architecture
of
zowie
for
the
contract
code
that
you
don't
necessarily
trust,
because
it
might
be
that
you
are
doing
business
with.
You
know
an
interesting
business
that
someone
you
met
on
the
street
recommended
to
you,
and
it
needs
to
be
the
case
that
that
cannot
obstruct
you
requesting
zoe
to
return
your
offer
and
the
offer
goods
being
returned
refunded
to
you,
and
so
that's
architectural,
your
property,
even
if
the
contract
doesn't
want
to.
Even
if
the
contract
goes
into
an
infinite
loop,
yeah.
A
It
might
be
the
time
on
the
long
now
clock
as
long
as
it
is
an
agreed
reference
that
the
contract
and
the
participants
of
the
contract
understand
and
can
agree
on
right.
That's
what
that's
what
you
require
and
then
obviously
there's
some
that
are
very
easy,
very
fast,
very
simple,
but
fundamentally,
particularly
in
a
world
of
cross,
train
cooperation
distributed
across
multiple
machines.
I
might
on
a
chain
over
here
be
using
as
a
reference
the
block
height
of
that
chain
over
there
right.
So
it's
not
my
local
block.
A
I
did
some
interesting
thing
over
there,
because
I
migrated
my
contract
or
because
that's
where
the
market
is
for
the
for
the
the
the
covered
call
that
I'm
trying
to
trying
to
sell
and
then
finally
there's
it's
up
to
the
contract
right.
You
know,
I
I
can
request
as
a
client
to
get
my
offer
back,
but
it's
entirely
up
to
the
contract,
whether
it
does
so
and
I've
read
the
code
and
it's
got
a
policy
and
I
like
it.
A
Great
that's
fine,
so
there's
various,
but
the
most
important
one
is
one
you
get
automatically
and
of
course
it's
the
one
that
we
haven't
yet
implemented,
because,
but
we
know
how
to
which
is
on
failure
right.
If
there's
any
critical
failure
of
the
contract
it
turfs
it
divides
by
zeroes,
it
has
a
no,
you
know,
uses
too
much
resources
infinite
loops
whatever.
Well,
you
know
that
failure
means
that
the
infrastructure
can
detect
it
and
all
of
the
offers
there
just
instantly
rejected
they're
instantly
ejected.
A
A
Okay.
So
now
we
can
say
a
little
bit
more
about
the
detail
of
these
things
and
I
must
apologize.
I
have
the
you
know
if
anyone
seen
earlier
talks
in
this
series
where
Markham
has
done
is
absolutely
fabulous.
Animations
all
over
the
place.
Most
of
my
animation
is
in
my
wildly
waving
hands
and
at
best
you
get
the
the
fade
in
Zen
right.
So,
okay.
So
how
does
this
work?
So
as
a
client?
A
My
wallet,
not
me,
you
know,
so
this
is
just
code
but
as
a
client
I'll
construct
an
offer
by
providing
what
I'm
willing
to
offer
on
this
description
of
it.
What
I
want
for
that,
the
Contra
ticket,
an
exit
rule
by
Thursday-
or
you
know,
whenever
I
ask
right.
You
know
the
on-demand
rule
and
a
payment
that
actually
provides
the
assets.
I
said
I
was
willing
to
pay.
A
I
said:
I'd
pay
for
moolah
I'd,
better,
have
the
formula
in
a
payment
that
goes
to
Zoe
and
gets
escrow
right,
and
then
that
goes
and
then
what
I
get
for
that
is
I
hand
that
off
to
Zoe
with
the
description
of
here's,
the
here's,
the
for
quatloos,
you
know
here's
what
I'm
willing
to
let
those
go
for.
Otherwise
you
have
to
return
them
to
me
and
what
I
get
back
from?
A
That's
what
I
pass
to
the
contract,
so
I'm
passing
to
the
contract,
an
object
that
proves
that
that
it
can
verify
represents
control
over
the
ability
to
the
assets
that
I
end
the
offer
that
I
have
that
I
have
registered
with
Zoe
and
on
completion
that
payout
promised
that
I
got
from
Zoe.
So
I
got
it
from
a
trusted
path
in
exchange
for
the
goods
that
I
provided
it
will
resolve
to
being
my
winnings,
or
my
refund
I
mentioned
earlier-
that
maybe
I
get
both
in
the
auction
case.
A
I
had
I
might
have
said,
pay
at
most
40
quatloos
and
if
it
only
cost
20,
because
it's
an
auction
and
there
was
no
other
bidders
or
that
was
the
bid
well
I'm
gonna
get
the
concert
ticket
and
20
of
my
quatloos
back.
So
that's
not
the
full
refund
case,
where
I
got
ejected
without
satisfaction.
I
got
a
successful
offer,
I
got
some
winnings
and
I
also
got
a
refund,
and
the
refund
comes
on
essentially
the
same
path.
So
it's
a
nice
simple
compositional
system,
the
abstractions
are
fairly
simple
but
they're
incredibly
powerful.
A
So
you
know
one
one,
one
last
round
of
things,
so
the
operations
that
Zoe
the
framework
provides
to
the
clients
to
the
people
outside
or
the
programs
outside
of
the
smart
contract
are
a
trusted
path
to
contracts.
Right
you
know,
I
want
to
get
I
want
to
get
not
to
a
random
object
on
the
other
end.
That
really
promises
is,
you
know,
swap
no
really
I
want
to
talk
to
a
trusted
agent,
the
Zoe
and
say
here's
the
contract
that
I
need
to
connect
to.
A
A
Well,
you
asked
Zoe
here's
the
contract
I'm
trying
to
do
business
with
what
software
are
you
running
for
it
right,
you're,
the
platform
it's
executing
on,
tell
me
what
it'll
actually
do
and
then
finally,
Zoe
is
the
one
I
got
when
I
got
that
escrow
receipt
I
also
got
the
ability
to
exit
and
so
I'm,
not
gonna.
Ask
the
contract,
as
you
exit,
I'm
gonna,
ask
Zoey,
saying
yeah
that
contract.
You
know
that
offer
I
gave
you
yeah
give
it
back.
I
went
out
and
you
will
interact
with
the
contracts
of
the
contract.
A
Knows
it,
but
the
contract
isn't
allowed
to
obstruct
my
exit
and
then
finally,
of
course,
Zoe
provides
the
payouts
once
I
adds
it
huge
so
that
that's
what
it
provides
to
the
clients
for
contracts.
This
is
on
the
inside
now
I'm
on
the
inside
I'm
running
on
top
of
Zoe.
So
the
key
thing
is,
of
course,
I
got
running
on
top
of
Zoe
by
instantiating
myself
there,
so
that
so
there's
a
mechanism
to
be
able
to
deploy
and
instantiate
contracts,
and
so
it's
our
it's
a
contract,
runtime
API.
A
If
you
will-
and
it
lets
it
notifies
me,
it
lets
me
react
to
new
offers
that
are
available
and
remember.
These
are
offers
where
the
assets
are
synchronously
available,
so
I'm
in
ASEA
an
asynchronous
world,
but
I
can
send
it.
Synchronously
interact
with
all
the
offers
and
assets
that
I'm
supposed
to
compute
in
terms
of,
and
finally,
it
supports
the
reallocate
operation
that
preserves
currency
can
conserves
currency
and
and
ensures
the
constraints
of
the
offers
are.
A
Honored
are
honored,
so
there's
a
few
nice
side
effects
of
this
model
at
Osaka
a
couple
people
reported
to
me
at
the
the
DEF
CON
that
people
were
starting
to
get
concerned
about
how
asynchronous
the
world
look
right.
The
simple,
smart
contract
models
were
simple:
deterministic
synchronous
machines
that
that
you
know
had
three
endrin
sea
bugs,
but
hey
it's
simple,
and
that
was
nice.
The
problem
is
the
world
is
not
that
nice.
The
world
is
in
a
synchronous,
place
right,
so
sharding
brings
up
a
synchrony
cross
chain.
A
Communication
brings
up
a
synchrony
games
and
handling
events
and
high
frequency
machines.
Bring
up
a
synchrony
Oracle's
bring
up
a
synchrony
all
these
things
at
asynchronous
system,
and
this
was
maybe
making
people
concerned
because
the
simple
model
of
the
world
was
was
starting
to
Creek
one
of
the
nice
things
about
this
is
that
when
an
offer
is
presented
to
Zoe
it
handles
the
escrowing
asynchronously
right.
A
Our
infrastructure
is
entirely
async,
so
it
so
it
can
span
multiple
machines
and
so
forth,
and
so
the
that
whole
process
of
saying
you
know
here's
for
quatloos,
where
for
quatloos
is
actually
a
tier
2
token
implemented
on
that
chain
over
there.
So
it
might
take
some
negotiation
to
get
it
all
escrowed
carefully,
but
once
that's
done
my
offer
goes
in
and
so
from
the
contracts
perspective.
You
just
get
synchronous
access
to
the
offers
as
I
mentioned,
but
but
so
all
the
data
is
is-is-is
escrowed,
bye-bye
Zoe,
and
then
the
notification
happens
to
the
contract.
A
So,
as
far
as
the
contracts
concern
it's
just
living
in
a
simple
synchronous
world,
it
has
it's
insulated
for
some
from
some
of
the
async
mcgarrett
ease
of
the
rest
of
the
world
and
then
finally,
as
a
result,
one
of
the
nice
consequences
out
of
this
is
that
we
get
uniform
handling
of
Tier
one.
You
know
base
tokens
on
the
platform
you're
running
on
tier
1,
tier
2,
sorry,
layer,
1,
layer,
2,
synthesized
tokens,
equivalent
of
ERC
to
20
or
C
721
and
off
chain
assets.
A
So,
if
you're,
using
IBC
to
bring
over
assets
pegged
from
another
chain
cross
chain
assets,
all
those
kinds
of
things,
those
all
can
be
transferred
uniformly
I
can
have
a
payment,
and
you
know
whether
it's
pegged
over
from
another
chain
or
a
local
token.
The
payment
architecture
is
the
same.
The
process
of
escrowing
is
the
same.
A
The
code
that
manipulates
it
is
the
same
and
that's
hugely
simplifying
across
across
these
platforms
as
anyone's
built
contracts
in
something
like
aetherium,
where
how
you
handle
a
payment
in
ether
and
how
you
handle
a
payment
in
an
e
rc
20
token
are
radically
different,
they're.
Nothing
like
each
other
right,
ok,
so
that's
an
intro
to
Zoe
I'm
gonna
talk
a
little
bit
about
that
right.
A
The
electronic
rights
protocol
that
helps
transfer
protocol
that
helps
us
build
this,
and
this
is
the
the
protocol
that
lets
us
AB
tract
in
the
asynchronous
world
across
all
these
different
transactions.
So
it
provides
so
your
TP
for
IDEs
at
that
foundation
turns
out
it's
actually
pretty
simple
and
there's
a
bunch
of
these
protocols
where
the
hard
problem
is
getting
the
right
little
boundary.
So
all
the
pieces
fit
together
in
a
bunch
of
scenarios.
So
there's
a
purse,
that's
like
an
account.
It's
a
holder
of
digital
assets
right,
so
it's
got
a
balance.
A
It's
got,
you
know
various
other
other
other
properties
and
I
can
withdraw
from
it
a
payment.
So
the
payment
is
how
I
transfer
digital
assets
currencies.
Concert.
Tickets,
you
know
covered
calls
whatever
it
is.
I
can
have
a
payment
that
contains
one
of
those
assets.
A
mint
for
one
of
these
assets
easily
is
the
thing
that
creates
them
that
can
instantiate
a
brand
new.
One
of
these
assets
is
a
mint.
A
So
I
mentioned
quatloos
I
mentioned
eath
I
mentioned
concert
tickets,
not
all
accounts
are
not
all
purses
can
contain
all
awesomes.
Each
kind
of
purse
contains
a
particular
asset
so
for
any
particular
asset
type
asset
kind,
I,
don't
mean
asset
class,
because
that
means
a
specific
thing
to
finance
folks
right,
but
you
know
for
concert:
tickets
versus
quatloos
I
have
a
collection
of
these
things.
A
Call
you
know,
I
have
a
units,
you
know,
I,
don't
have
400
I've
got
400
quatloos
right,
so
I've
got
items
that
have
units
and
these
purses
and
payments
and
mints
and
assays
are
all
parameterised
by
those
units.
So
I
have
a
purse
of
quatloos
I.
Have
a
payment
of
quatloos
I
have
a
mint
that
will
make
quatloos
and
I
have
an
assay
that
will
verify
that.
The
thing
that
you
just
presented
me
is
in
fact
a
thing
of
quatloos
is
a
payment
of
quatloos
or
a
description
of
loser.
A
What
happens
so
it's
it's
the
tool
that
I
get
to
use
in
my
programmatic
system
to
be
able
to
plug
all
this
together.
Okay,
so
I
need
to
hurry
up
here.
So
I
will
I
always
try
to
give
a
little
bit
of
code,
but
there's
only
two
pages
worth
so
on.
The
left
is
mints
and
payments,
so
I
can
mint
so
up
there,
I
I
make
a
mint
for
the
concert
tickets
ion.
That
is
on
the
right,
I
pull
out
the
assay.
A
Remember
it's
the
thing
that
will
validate
that
it
that
a
concert
ticket
is
the
real
concert.
Ticket
and
I
give
it
to
the
venue.
If
someone
was
to
say,
hey
I
want
to
give
you
a
concert
ticket
to
go
to
this
concert.
The
place
you're
gonna
want
to
want
to
go
to
the
authoritative
source,
to
authenticate
that
concert
to
get
make
sure
it's
real
is
to
go
to
the
venue,
that's
giving
the
concert
and
see
if
they're
gonna
honor
this
concert
ticket
right.
A
So
that's
what
we
do
we
this
buy
buy,
but
by
construction
you
get
you
get
the
assay
from
the
place
that
you
believe
and
now
I'm
into
seat.
A
a
for
a
seat
efore
that
that
is
a
the
units
of
that
concert.
Tickets
are
denominated
in
is
seats
and
I'll,
send
it
to
Carol
with
received
ticket
and
pass
her
a
ticket
right.
So
now,
Carol
receives
a
payment
for
a
digital
asset,
which
is
the
concert
ticket
of
the
CD
floor.
Okay,
so
now
what
happens
on
the
SA
side
is
Carol
gets
this?
A
Well,
what
does
she
do
with
it?
She
just
got
as
far
as
she
knows,
a
pointer
to
a
ball
of
mud.
It's
just
an
object
in
a
programming
language.
She
needs
to
validate
that.
She
got
the
real
thing,
so
the
assay
is
the
tool
to
do
that.
Right
I
can
do
assay,
claim
all,
and
that
does
two
things
it.
It
only
succeeds
if
it
actually
is
a
concert
ticket
that
the
assay
will
is
standing
behind,
where
the
assay
is
the
the
assay
from
the
venue.
A
If
it's,
if
it's
supposed
to
be
quite
loose,
you
use
the
assay
for
quatloos.
If
it's
supposed
to
be
gold,
you
use
a
careful
scale
and
you
assay
the
gold
right
and
and
when
she
has
claimed
that
she
also
knows
that
not
only
is
it
valid,
but
that
she
has
exclusive
access.
So
now,
no
one
else
in
the
world
has
access
to
this
concert
ticket,
and
we
have
succeeded
at
a
commercial
transfer
to
her
of
the
concert
ticket
now
purses
are
the
holder
of
assets.
A
They
also
provide
a
mechanism
that
gives
exclusive
access,
because
underneath
the
covers,
it's
actually
built
with
an
essay
which
is
I
can
take
this
purse.
I
I
can
take
this
payment
and
just
deposit
it
in
my
account,
where
I've
got
a
purse
for
concert,
tickets
and
I
deposit,
a
payment
of
concert
tickets,
and
it
goes
yep
I've
now
got
a
concert
ticket
in
my
purse.
You
can
pull
it
up
in
your
UI
to
be
able
to
show
it
to
people
or
whatever
and
then
purses
you
can
also
withdraw.
A
In
other
talks,
I
would
go
forward
and
talk
about
escrows
and
that
sort
of
thing
now
I
do
want
a
reminder
here,
because
the
heart
of
the
RTP
is
the
assay
function
that
that
exclusive
transfer
is
so
important.
Is
that
that
that
I'm,
that
I'm
going
to
reiterate
that
it?
It
takes
something
that
you're
suspicious
of
right,
something
that
you
just
got
from
a
stranger
or
maybe
someone
that
you
got
from
something
you
got
from
someone.
You
do
business
with
regularly,
but
you
no
good
fences
make
good
neighbors
and
on
success.
A
It
gives
you
back
something
you
can
rely
on.
It
gives
you
back
something
that
your
trusted
Authority
vouchers
for
and
assures
that
you
have
unique
access
to
it.
Those
are
huge,
be
a
huge,
huge
value
to
be
able
to
express
in
a
couple
of
lines
of
code
systemically
for
any
asset
representable
in
the
program
you
know,
so
that
means
fungible
assets
non
fungible
assets,
though
the
whole
point
of
having
units
is
I,
can
have
units
which
are,
as
I
said,
denominated
natural
numbers.
A
A
A
This
Friday
Menashe
starts
in
the
evening
and
then
it
goes
to
the
weekend
where
people
can
start
building
on
our
platform
and
a
variety
of
others
and
in
particularly
they
can
start
to
use
Zoe,
and
you
know
you
saw
the
the
wallet
UI
and
they
can
build
with
that
and
so
forth.
We
will
be
updating
the
api's
based
on
what
we've
already
learned
from
having
B
and
being
able
to
build
on
it
now
and
from
what
we
learned
from
people
building
on
it.
The
hackathon
and
our
development
going
forward,
adding
things
like
modular
offers.
A
So
I
don't
want.
You
know
at
the
right
price.
I'll
get
two
tickets
right.
You
know
so
I'm
willing
to
make
an
offer
for
more
than
one
item
in
a
single
offer:
dis,
Junction's
I'll
get
a
ticket
for
this
seat
or
for
that
seat.
You
know
all
of
these
kinds
of
more
complex
offers
are
easy
to
add
support
for
we're.
Just
you
know,
starting
slow,
adding
that
that
thing
I
mentioned
of
exit
safety
on
a
crash,
hugely
important
for
actual
production
use.
A
You
know
it's
interesting
and
exciting
in
the
media
technology
before
that
and
then
finally,
there's
some
additional
er
TP
features
that
we'll
be
adding
like
what
we
call
a
preemption
hierarchy
right,
I
own,
the
house,
I
rent
it
to
you.
I
can
preempt
it
and
take
the
house
back
or
something
okay.
So
that's
our
roadmap.
So
you
know
final.
Two
slides
here
offers
affect
the
entire
stack
of
doing
smart
contracts
for
any
purpose.
A
As
far
as
we
can
tell
right
so
even
the
user
interface
to
start
with
the
wallet
interaction,
the
trusted
path
to
ask
the
user.
What
do
they
want
to
do?
The
audit
trail
instead
of
saying?
Well,
you
threw
money
at
this
random
number
and
you
threw
money
at
that.
Random
number:
good
luck
with
that.
Instead,
it's
no
no
I
signed
I
authorized
a
transaction
for
a
particular
purpose.
A
You
know
all
these
kind
of
building
up
an
ecosystem,
whether
it's
defy
or
connecting
to
the
real
finance
system
or
doing
a
freight
management
or
any
of
those
kinds
of
things
that
people
are
working
on.
It's
hugely
important
that
each
component
is
safe
from
the
next,
because
otherwise,
without
that,
it's
easy
to
end
up.
A
Unknowingly
engineering,
cascading
system
failures
across
multiple
of
these
different
fragile
programs
and
that's
not
a
way
to
get
to
a
successful
world,
and
so
this
is
at
all
levels
of
programming,
a
tool
to
help
us
really
bring
the
diverse
economy
that
we
all
live
in
that
we
all
want
to
get
that.
We
all
want
to
get
online
helps
us
bring
it
into
the
decentralized
world
of
web
3.
So
thank
you
very
much
and
custom.
B
B
A
Or
this
is
the
way
you
wanted.
This
is
where
you
want
to
migrate
to
there's
a
lot
of
it.
That's
required
I
mean
there's
a
lot
of
really
smart
people
there
solving
hard
problems
that
I,
don't
that
I
don't
solve,
but
there's
a
big
chunk
of
that
that
you
know
like
it
like.
With
the
the
corporation
talked
earlier,
a
big
chunk
of
that
can
be
brought
online
and
automated
can
be
objectified
and
encode
and
then
leave
the
hard
parts
for
humans
to
sort
out.
B
B
A
So
yeah
so
I
actually
think
it'll
it'll
be
exciting,
partly
because
of
the
alignment
of
how
they
think
about
things.
The
the
you
know,
one
of
the
things
when
we've
talked
to
two
to
two
folks
out
in
the
mainstream
world
financial
freight
what-have-you
is
again
that's
where
some
of
that
signal
of
wow
there's
a
really
low
level.
It
doesn't
quite
match
how
we
think
about
this
stuff,
and
so
so
you
know
to
the
folks
that
I've
talked
to
its
resonated.
You
know
they
go.
Oh
offers
duh.
B
A
Right,
so
there
is
a
so
there
is
an
answer
to
that
which
might
be
longer
than
I
can
talk
about
here.
Mostly
it's
by
construction.
You
know,
as
a
as
a
user.
I've
got
a
starting
point
for
the
contracts
I
want
to
talk
to
my
mechanism,
for
getting
to
them
should
be
reporting
to
me
on
the
platform
that
they
are
on.
You
know,
or
I'm,
deploying
on
a
particular
public
chain
and
that's
the
the
services
I
want
to
go
to
right.
A
If
I
look
for
you
know
where
do
I
want
to
run
my
my
my
currency
exchange,
you
know
one
of
the
bits
of
information
that
I'm
gonna
get
when
I
do
a
web
search
on
that
is.
You
know
this
is
running
on
someone's
basement.
That's
a
Dex
being
run
by
a
large
financial
institution.
That
knows
what
they're
doing
okay,
I
kind.
B
A
There
will
be
multiple
high
integrity,
central
hubs
on
multiple
chains
that
can
all
you
know,
provide
some
level
of
cross
across
collaboration,
cross
corroboration
of
the
quality
of
these
different
chains,
and
they
will
have
different
kinds
of
security.
Different
levels
of
security
be
appropriate
for
different
businesses,
have
different
performance
characteristics
and
so
forth.
The
important
thing
is
it's
not
the
the
ability
to
do
asynchronous
messaging.
A
A
You
know,
and
so
I
decided
it's
on-
that
high
reliability
thing,
but
I'm
gonna
use
the
same
polished
UI,
whether
I'm
talking
to
the
bookie
down
the
street,
or
you
know
the
betting
in
the
casino
in
Vegas,
or
you
know,
we're
off
to
Monaco
right
and
so,
and
so
the
construction
is
where
you
make
those
trust
decisions.
It's
not
something
you
dynamically
have
to
worry
about
when
software
is
executing.
B
A
B
B
A
One
of
the
nice
things
from
from
an
ecosystem
point
of
view
is,
you
know,
our
stack
is
all
open
source
and
it's
not
that
Zoe
takes
over
the
world.
Zoe
is
a
host
of
contracts
that
can
coexist
with
other
hosts
of
contracts.
Indeed,
we've
talked
about
Zoe
v2,
where
you
aren't
necessarily
escrowing
the
assets
themselves.
You
might
be
escrowing
a
covered
call
for
the
assets
and
the
money
to
pay
for
it.
A
So
you
know
you
need
to
pay
in
quatloos,
but
you
have
samolians,
you
don't
want
to
do
the
conversion
unless
you
win,
you
know
so.
There's
there's,
there's
lots
of
ability
for
those
mechanism
to
coexist
and
we're
very
supportive
of
people
coming
up
with
new
safety
properties.
You
know,
there's
a
interesting,
exciting,
very
cool
crypto
niche
that
I
would
like
to
see
cross
to
the
mainstream,
which
is
a
thousand
decks
or
more
larger
right,
and
so
anything
that
can
help
us
get
over.
A
A
So
that's
a
great
question
and
we
use
those
terms
specifically
because
so
people
think
with
care
about
how
the
pieces
all
fit
together.
In
our
experience,
it's
not
limited
to
those
use
cases.
It's
it's
it's
one
where,
where
I
can
make
an
offer
for
the
infrastructure
that
is
going
to
want
to
charge
micro
cents
for
a
magic
weapon
in
a
game,
there's
no
reason
why
it
doesn't
use
the
same
framework
if
I
want
to
be
able
to
buy
a
stack
of
interesting
papers.
A
You
know,
I,
have
a
multiplicity
of
offer,
saying
I'll
pay,
five
cents
of
paper
right
and
you
know
I
can
do
subscriptions.
I
can
do
that.
I
can
do
all
sorts
of
cooperative
arrangements
because
mostly
this
is
you
know
a
lot
more
about,
in
some
sense
the
right
of
contract.
It's
it's!
The
quid
pro
quo
quid
pro
quo
piece
of
here's,
what
I'll
offer
here's
what
I
want
in
exchange
and
whether
that's
barter
or
whether
that's
services
that
an
Oracle
will
validate
you
performed
for
me.
A
Those
are
all
those
are
all
those
can
all
be
expressed
and
confirmed
with
an
assay
that
can
that
can
measure
in
an
Oracle
sense?
Well,
did
you
actually
perform
the
good?
You
know
the
the
service
outside
of
the
chain
that
I
was
actually
expecting
so
so
well.
There
are
almost
certainly
things
that
it's
not
well-suited
for
we
haven't.
We
don't
have
any
particular
list
of
those
we're
not
many
identification
of
those.
Yes,
Kate
Kate
SAR
Kate
implemented
a
bunch
of
this
stuff.
There.
A
A
That
represents
some
kind
of
future
right
on
this
pool,
but
but
we
haven't
constructed
that
so
that
it
comes
out
as
an
offer
as
opposed
to
no
no,
it's
just
an
asset
that
represents
that
right
and
if
I
want
to
trade,
it
back
in
I
go
through
a
short-term
offer.
So
there's
some
things
that
we
haven't.
You
know
with
that
there
there
are
complex
arrangements
that
don't
naturally
fall
into
offer
safety
so
far,
but
that's
the
kind
of
thing
that
we'll
be
working
on
more
abstractions
for.
B
A
The
question
was:
is
there
a
lower
bound
on
economic
value
where
the
computational
cost
makes
this
unreasonable?
The
answer
is
almost
certainly,
but
the
operations
are
actually.
You
know
just
a
couple
of
message
sends
in
JavaScript
right.
You
know
browsers,
do
millions
of
these
all
the
time,
and
so
so
the
computation
is
actually
pretty
cheap
for
doing
this
stuff.
One
of
the
nice
things
about
strong
abstractions
is
all
of
that
interaction
doesn't
require
any
crypto
at
all
right.
A
It's
it's
straw,
it's
using
the
secure
properties
of
language
and
strong
confinement
to
achieve
strong
relationships
and
strong
trade
exchanges
in
a
very
lightweight
fashion.
So
the
answer
is
yes,
absolutely
they're,
they're
high
frequency
trading
applications
or
those
kinds
of
things
that
could
use
this,
maybe
not
in
a
book.
A
You
know,
maybe
not
with
with
you
know
the
current
consensus,
algorithm
and
transaction
rates,
but
architectural
e,
as
I
said
we,
you
know,
we
there's
no
fundamental
reason
why
a
few
messages
in
another
system
won't
cover
most
scenarios
till
you
do
real-time
systems
this
way
they
can
pay
for
we
in
in
an
earlier
incarnation
of
this
technology
in
in
the
90s.
We
had
a
similar
architecture
that
was
paying
for
a
high-frequency
network
bandwidth
on
a
network
at
the
packet
granularity
and
so
from
a
performance
and
scaling
point
of
view.