Hyperledger Composer is a suite of tools for developing blockchain applications. It provides high-level abstractions like models, transactions, and participants to develop business networks. The document discusses upcoming releases of Composer that will add features like events, queries, and security enhancements. It also provides an overview of key concepts in Composer like modeling assets and participants, implementing transactions, and access control lists.

1. 1Page
Hyperledger Composer
Project Update
4th May 2017
Dan Selman, Maintainer
@danielselman

2. 2
Dan Selman - @danielselman
• Maintainer for Hyperledger Composer
• STSM & Chief Architect at IBM
• Previously ILOG and BEA Systems
• Expert in business rules and event
processing
• Passion for IT and business
collaboration

3. 3
Agenda
• Introduction
• Project outlook
• Playground demo
• Technical overview

4. 4Page
Introduction to
Hyperledger Composer

5. 5
Blockchain for business
• Blockchain builds on basic business concepts
– Business Networks connect businesses
– Assets flow over business networks
– Transactions describe asset exchange
– Participants submit transactions
– Contracts define the rules for transactions
– The ledger is a log of transactions
• Blockchain provides a shared, replicated ledger
– Consensus, immutability, finality, provenance

6. 6Page
What is Hyperledger Composer?
– Blockchains provide a low-level interface for business applications
– Smart contract code run on a distributed processing system
– Inputs go into an immutable ledger; outputs to a data store
– Applications are built on top of a low level of abstraction
– Hyperledger Composer
– A suite of high level application abstractions for business networks
– Emphasis on business-centric vocabulary for quick solution creation
– Features
– Model your business network, test and deploy
– Applications use APIs to interact with a business network
– Integrate existing systems of record using loopback/REST
– Open Tools, APIs and libraries to support these activities
– Exploits Hyperledger Fabric blockchain technology
– Fully open and part of Linux Foundation Hyperledger
Business Application
Hyperledger Composer
Hyperledger Fabric
https://hyperledger.github.io/composer/

7. 7Page
Benefits of Hyperledger Composer
Increases
understanding
Saves
time
Reduces
risk
Increases flexibility
Bridges simply from
business concepts to
blockchain
Develop blockchain
applications more
quickly and cheaply
Well tested, efficient
design conforms to best
practice
Higher level abstraction
makes it easier to
iterate

8. 8Page
Getting Started with Hyperledger Composer
– Start at
https://hyperledger.github.io/composer/
– Many useful links
– Getting started
– Documentation
– Chat
– Community
– GitHub

9. 9
Links
• We’re all over the internet!
– Website, tutorial, and docs: https://hyperledger.github.io/composer/
– Public playground: https://composer-playground.mybluemix.net/
– Source code: https://github.com/hyperledger/composer/
– NPM modules: https://www.npmjs.com/search?q=hyperledger+composer
– JSDoc: https://fabric-composer.github.io/jsdoc/index.html (to be moved)
– Docker images: https://hub.docker.com/u/fabriccomposer/ (to be moved)

10. 10
Community
• You can come and speak to us as well!
– Chat to us using Rocket.Chat at https://chat.hyperledger.org
• #composer and #composer-dev channels
– Ask (and answer!) questions on Stack Overflow using the hyperledger-composer tag
– Tweet us using the #Hyperledger #Composer hashtags!

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Project outlook

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Hyperledger Composer Outlook
– Now an official Hyperledger incubation project!
– Complete the programming model
– Events for notification and loose coupling of transaction processors
– Links for business network linkage
– Extensive query to support reporting and analytics
– Encryption of data and transactions
– Operational Enhancements
– Exploit Hyperledger Fabric V1: consensus, channels, CouchDB
– Build Activity Community
– Open calls every 2 weeks
– Rocket Chat
– Hyperledger incubation

13. 13Page© 2016 IBM Corporation
vehicle-lifecycle demo
(under development)

14. 14
Tentative Release Plan (subject to change!)
• Version 0.7.0 (released)
– HLF v1 Alpha 1 support
– Getting Started for v1
• Version 0.7.1 (May 5th)
– Support 0.6 and 1.0 connection
profiles in Playground
• Version 0.7.2 (May 19th)
• Vehicle Lifecycle Demo (iOS and Web)
• Ability to emit events from TP functions
• Version 0.7.3 (May 26th)
– Edit using web forms in Playground
• Version 0.8 (29th June)
– Run complex queries
– Support++ for HLF v1
– Security enhancements
• Version 0.9 (27th July)
– Native Node.js runtime in HLF
– ACL testing

15. 15Page
Technical Overview

16. Buyer
Owner Buyer
Insurer
Listings registryVehicle registry
"$class": "org.acme.vehicle.auction.VehicleListing",
"listingId": "LIST_1234",
"reservePrice": 500,
"description": "Car sale for playback 2",
"state": "FOR_SALE",
"vehicle": "VIN_123456"
"$class": "org.acme.vehicle.auction.Vehicle",
"vin": "VIN_123456",
"owner": "daniel.selman@uk.ibm.com"
net.biz.vehicle.auction
sell
car
offer bid
for car
offer bid
for car
Transactions
• (Sell)
• Offer
• Close Bidding
close
bidding
( Counterparties outside
the business network )
Car Auction Business Network
1 23
Business Network
Participants
Identity
Assets
Registries
Transactions
(Events)
(Links)
THIS DEMO
1. Modelling, testing and exposing the business network
2. Applications consuming the business network
3. Integrating existing systems with the business network
2
DMV
Existing
system
Auctioneer
OwnerApp
App
App

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Conceptual Components and Structure
Business Network Archive
Models ACLsScript File Metadata
Business Network is defined by Models, Script Files, ACLs and Metadata and
packaged in a Business Network Archive
Solution Developer models the business network, implements the script files that
define transaction behaviour and packages into a business network archive
Solution Administrator provision the target environment and may manage deploy
D
A

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The Model
• A domain specific language that defines:
• Assets
• Participants
• Transactions
• Matches how we talk about business networks
in the real world
Business Network Archive
Models
Transaction
Functions
ACLs Metadata

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The ACL
• Separates out access control from
business logic making it simpler
• Can build access control into
the business logic if needed
• ACL engine evaluates rules for all
access to assets
• Top down checking
• If no rule then denies access
Business Network Archive
Models
Transaction
Functions
ACLs metadata

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The Script File
• Provide transaction implementation logic
• Specified in Javascript
• Designed for any reasonable Javascript
developer to pick up easily
Business Network Archive
Models
Transaction
Functions
ACLs meta-data

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Metadata
• Name & version of the business network
• Markdown documentation for the solution
• Works with tools like Github to turn into a
HTML page
• Easily read in raw .md or HTML format
Business Network Archive
Models
Transaction
Functions
ACLs metadata

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The Archive
• The Business Network Archive
packages up the project to for
deployment to a runtime
• Can be deployed using CLI tools
• Can be packed/unpacked by a
developer to see its contents, check
it, work on it or send it.
• At deployment the archive is
executed within a chaincode
container
Business Network Archive
Models
Transaction
Functions
ACLs Metadata
Business Network Archive
Models
Transaction
Functions
ACLs meta-data
Models
Transaction
Functions
ACLs meta-data
create
Hyperledger
Fabric
Applicatio
n
Business
network
chaincode
container
deploy

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Extensive, Familiar, Open Development Toolset
CLI utilities
Data modelling JavaScript
business logic
Web playground
Editor support Existing systems and
data
$ composer
Client libraries
composer-client
composer-admin
Code generation
Swagger

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Modelling Business Networks: Composer Playground
– A interactive web tool for the development (and test) of business networks without installing
anything
– Developers & technical analysts
– Create business network definition
– DSL for specific assets,
participants & transactions in your
network
– Live content assist, syntax
checking
– Non-web options also possible
– Hosted & local playgrounds
– Atom & VSCode plug-ins
http://composer-playground.mybluemix.net

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Testing Business Networks: Composer Playground
– Test tab on playground
– Dynamically reflects defined model
– Creates default registries
– Create, read, update, and delete
resources interactively
– Submit transactions interactively
– Fabric and browser-only modes
– Multiple environments, e.g. test, prod

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Getting Started With Hyperledger Composer
Docker Images
JS Packages
Samples
Extensions
Local Composer Dev
Composer
Playground
Sample Angular 2 UI
Existing Systems
Integration tools
Final Application
Handed
to
UX/UI
Handed to
integratio
n
Once tested,
download to
use locally
Swagger REST API
- UI
- Playground
- Fabric
- Hello World
- Car Auction
- Farm to Fork
- Client
- Runtime
- Admin
- Loopback
Local or External
Hyperledger Fabric

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Model Development, Versioning and Distribution
– GitHub for development
– Use npm package format for metadata
– package.json version
– model files and business networks
– npm for distribution
– Distribute models and networks
– Networks depend on models
– Use npm dependencies
– Applications npm install BNDs
– Ensures consistency when application connects
to network
– See examples in sample-networks and sample-
models repositories
– These are loaded into playground
model
business
network
definition

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Applications and Javascript APIs
– JavaScript and REST APIs available
– composer-client & composer-admin npm
modules for app devs and admins
respectively
– Programming model JSDoc at
https://fabric-composer.github.io/jsdoc/
– Domain specific REST APIs also available
(see later)

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Generating APIs and sample applications
– Programmable business networks
– Direct consequence of a deployed model
– Query network to generate domain APIs
– Generate sample application for deployed
business network
– Yeoman questionnaire
yo fabric-composer[:angular]
– Also generate test cases using mocha and
chai node.js test packages
– composer generator tests
– Programmable business network provides
many more opportunities for interaction

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Generating APIs and sample applications
Hyperledger Fabric
(existing fabric)
– Business Network Archive
Business
network
chaincode
container
Application
Template
application
Yeoman
questionnaire
2. query
3. customize
5. API
Developer
4. run
User
1. yo fabric-composer-angular

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Command Line Interfaces
– Suite of commands to interact with an
operational business network
– Target use is scripting and interactive
operations
– Packaged as composer-cli in npm
– Generate full list with
composer –help. Individual (sub)
commands support -help
– CLI uses public APIs
– Users can create their own CLIs
$> composer –help
Commands:
archive <subcommand> Composer archive command
generator <subcommand> Composer generator command
identity <subcommand> Composer identity command
network <subcommand> Composer network command
participant <subcommand> Composer participant command
transaction <subcommand> Composer transaction command
Options:
--help Show help [boolean]
-v, --version Show version number [boolean]
Examples:
composer identity issue
For more information: http://fabric-composer.org/reference
$> composer transaction submit –help
composer transaction submit [options]
Options:
--help Show help [boolean]
-v, --version Show version number [boolean]
--connectionProfileName, -p The connection profile name [string]
--businessNetworkName, -n The business network name [string] [required]
--enrollId, -i The enrollment ID of the user [string] [required]
--enrollSecret, -s The enrollment secret of the user [string]
--data, -d Transactions JSON object [string] [required]

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Loopback and REST Support
– Exploit Loopback framework to create REST
APIs. https://loopback.io/
– Domain specific APIs very attractive to mobile
and web developers. Resources and
operations are business-meaningful
– Extensive test facilities for REST methods
using loopback
– Provides back-end integration with any
loopback compatible product
– e.g. IBM Integration Bus, API Connect,
StrongLoop
– Outbound notification (under
development)

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Exploiting the Loopback Connector: Example
– IBM Integration Bus Example
– Takes input from file, SAP or MQ
– Data mapping from CSV, BAPI/IDOC or binary form to JSON model definition of vehicle
– Currently inbound only
– Events support will eventually allow outbound integration

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Thank you!

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Key Concept: Assets
– Represents the resources being
exchanged in the business network
1. Define using asset keyword in model file
2. Assets have structure – domain relevant
class name, e.g. vehicle, house, bond
3. Set of properties, denoted by ‘o’ (letter).
4. Relationships to other resources,
denoted by ‘’. Optional elements are
allowed. Field validators can be provided
5. Stored in an asset registry. Registries
are first class abstraction.
1
2
3
4
5

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Key Concept: Participants
1 – Represent the counterparties in the business
network
1. Define using participant keyword in model file
2. Participants have a class name, relevant to
the domain, e.g. buyer, seller
3. Set of properties, denoted by ‘o’.
Relationships to other resources, denoted by
‘’. Optional elements are allowed. Field
validators can be provided
4. Like assets, can be sub-classed for refinement
5. Stored in a participant registry
2
3
5
4

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Key Concept: Transactions 1 2
– Represents the steps that govern resource
lifecycle, typically assets
1. Define using transaction keyword in model file
2. Assets have a class name, relevant to the
domain, e.g. sellVehicle, buyHouse
3. Set of properties, denoted by ‘o’.
Relationships to other resources, denoted by
‘’. Field validators can be provided
4. Stored in a transaction registry
• Implementation provided separately
3
4

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Key Concept: Transaction Processors
– Provide transaction implementation logic
– Provided in separate <tp>.js files
– @param & @transaction annotators
– Perform state changes on domain specific
resources using model defined syntax

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Key Concept: Access Control Lists
– Separate ACL from application logic
– Defined in a permissions.acl file in
business network definition
– Flexible model allowing both type and
instance access e.g. ‘create cars’ and
‘scrap my car’
– Standard ACL model
– Includes optional condition for more
sophisticated ACL checking
– Executed in order until first rule hit
– DENY has precedence over ALLOW