├── holochain-aids ├── images │ ├── temp │ ├── Holochain 1Node 1App.png │ ├── Holochain 2Node 1App.png │ ├── Holochain 2Node 2App.png │ └── Holochain App Anatomy.png └── app-anatomy.md ├── images ├── hm-dna.png ├── hsd-dna.png ├── phv-dna.png ├── anatomy-of-a-node.png ├── healthcard-info-types.png ├── hm-deployment-example.png ├── holo-health-value-flow.png ├── hsd-deployment-example.png ├── phv-deployment-example.png ├── fhir-observation-resource.png └── holo-health app architecture.png ├── wip └── guiding-principles ├── README.md ├── holo-health-app-architecture.md ├── hsd └── healthcare-service-delivery-hApp.md ├── hm └── healthcare-market-hApp.md ├── phv └── personal-health-vault-hApp.md └── LICENSE.txt /holochain-aids/images/temp: -------------------------------------------------------------------------------- 1 | 2 | -------------------------------------------------------------------------------- /images/hm-dna.png: 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But, in the absence of a meme pool for now, I'm stashing these here. 4 | 5 | _**P1 Primacy-of-the-Individual**_ -- The preponderance of applications on the internet (Facebook, Amazon, Netflix, Google, Uber, Twitter, etc.) are designed around the primacy of the application over the individual. They serve the companies that have created them. Each application offers individual user accounts and maintains its own information about that individual. Increasingly, they are gathering information about the people who use those applications with an eye towards then pushing recommendations, products, or services at them. If an individual interacts with multiple such applications information about them is fragmented into each of these databases. Individuals have limited control over what information is gathered, how it is used and/or who it is shared with. The burden of keeping such information consistent, accurate and up-to-date falls to the individual (i.e., by updating each profile individually). _Holo-health_ reverses this picture by first and foremost serving the individual. 6 | 7 | _**P2 Personal-Information-Stewardship**_ -- individuals are the stewards of their own information and it is they who make the decisions about whether, how and with whom their information is shared. 8 | 9 | _**P3 Transparency**_ -- The more accurate, comprehensive and up-to-date the information that a _healthcare provider_ has about the totality of an individual's medical history, conditions and life events, the better they are able to diagnose accurately and coordinate care plans across a team of _healthcare providers_ collaborating with the individual. There is a natural tension between these last two principles (_P2_ and _P3). Per _P1 Primacy of the Individual_, each individual is free and empowered by _holo-health_ to find their own balance point between privacy and transparency and they can adjust this balance point over time. 10 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # holo-health 2 | _**Person-Centric Healthcare Ecosystems**_ on top of a _holochain_ based infrastructure. 3 | 4 | Code Status: **Pre-alpha Design**. Not for production use. This application has not been audited for any security validation. 5 | 6 | ## Goals 7 | 1. Create _**empowered health marketplaces**_ that enable _HealthCare Providers_ to offer health services (both online and in-person) that can be easily discovered and privately subscribed to by individuals. 8 | 1. Put _**individuals in charge**_ of their own **_healthcare data_** and their _**healthcare decisions**_. 9 | 1. Enable _**better health outcomes**_ by unifying all of an individual's health observations into a single _**Personal Health Record**_ (PHR). Observations added by _**any healthcare provider**_ in my ecosystem are added to my _PHR_. 10 | 1. _Design in_ direct support for compliance with relevant healthcare (e.g., HIPAA/HITECH) and personal information regulations (e.g., GDPR). 11 | 1. Support traditional _**currency-for-service**_ flows while also allowing an open-ended set of _agreement types_ to be used to support _**alternative reciprocal value flows**_ (e.g., _alternative currencies_, _barter_, or _gift economy_). 12 | 13 | ## Additional PoC Goals 14 | 1. _**Showcase Holochain Capabilities and Design Patterns**_ This _Proof of Concept_ (_PoC_) is intended to serve as a learning vehicle for both its primary author and (hopefully!) other holochain application developers. This includes viewing hApp's as micro-services that may be composed and choreographed in different ways (as opposed to just monolithic point solutions). Also, design choices tend to favor holochain capabilities even in cases when, in a true production project, alternate solutions may be preferable. 15 | 1. _**Encourage Collaboration.**_ Feedback and contributions from other members of the holochain community are welcomed! 16 | 17 | ## Architecture 18 | Refer to [Holo-Health Application Architecture](holo-health-app-architecture.md) to explore the overall architecture and to drill into the various hAapps that, collectively, comprise _holo-health_. 19 | 20 | # License 21 | 22 | Holo-health is software intended to foster the emergence and growth of _**Person-Centric Healthcare Ecosystems**_ on top of a _holochain_ based infrastructure. 23 | 24 | Copyright (C) 2018 Steve Melville, Evolutionary Enterprises LLC 25 | 26 | This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. 27 | 28 | The GNU General Public License does not permit incorporating your program into proprietary programs. 29 | 30 | Refer to the [LICENSE.txt file](LICENSE.txt) for license details. 31 | -------------------------------------------------------------------------------- /holochain-aids/app-anatomy.md: -------------------------------------------------------------------------------- 1 | # Anatomy of a Holochain App 2 | 3 | This document provides a quick look at the components making up a Holochain Application from both development and deployment viewpoints. Refer to the [Holochain Developers Portal](https://developer.holochain.org) for a much more complete set of documentation about developing holochain applications. 4 | 5 | ## Development View 6 | 7 | The following figure depicts the components comprising the development view of a holochain app. 8 | 9 | ![Figure 1. Development View](images/Holochain%20App%20Anatomy.png) 10 | 11 | _Figure 1. Development View of a Holochain App_ 12 | 13 | The components are all stored within an _application folder_. This folder contains: (1) a _DNA folder_, and (2) a UI folder. 14 | 15 | The DNA folder contains: (a) a _dna file_, (b) a _properties_schema.json file_. (c) One Zome folder for each Zome offered by this app. As noted in the diagram, a hash digest of the entire contents of the _DNA folder_ is included in the genesis entry within the DHT for the application, as well as local source chain on every node that joins this app. This makes it possible to validate that every node is running the same dna, properties and Zome code. Since the _UI folder_ is outside the _DNA folder_, the UI code is not included in the validation check. 16 | 17 | The structural elements of the app are stored in a _dna[.json, .yaml, .toml]_ file. As the different suffixes suggect, it can be written in JSON, YAML, or TOML. This file consists of... 18 | 1. **_application meta-data_**: name, UUID, version, description, a reference to the version of holochain on which this app depends and some configuration attributes for the DHT associated with this app. 19 | 2. **_zero or more Properties_**: application-specific strings available as _properties_ of the application. 20 | 3. **_zero or more Zomes_**: You can think of a Zome as a module within the app. 21 | 22 | Each Zome consists of: 23 | 1. **_zome metadata_**: name, description, type, configuration properties, the error handling style and the list of functions the zome exposes to other apps via bridges (discussed below). The `type` attribute specifies the type of language used to express the zome's behavior. Currently, this can be either js (for javascript), or zygo (Go's scripting language zygomys). With the Rust re-write of holochain, additional languages will be supported, basically anything that can be compiled or transpiled to _web assembly_). 24 | 2. **_zero or more functions_**: these implement the behavior of the zome. Each _function_ definition includes a code file and some _function metadata_ (name, callingType, and exposure). The `calling type` indicates whether the parameters passed to the function are simple strings or more complex JSON structures. The `exposure` specifies the visibility of the function in different scopes. There are three possibilities: 25 | 1. _only callable from within the zome itself_, signified by omitting this function entirely from the Zome Function list 26 | 2. _callable from other zomes within the same app_, signified by setting exposure to `zome` or 27 | 3. _callable from any zome in any app_, signified by setting exposure to `public`. Exposure defaults to `zome` if a function is included in the list of zome functions, but does not explicitly specify a value for its `exposure` attribute. 28 | 3. **_zero or more Zome Entry Types_**: these specify the data structures offered by the zome. _Entry types_ can either be simple strings, json structures, or _links_ (which is a special data structure used for creating semantic links between entries in the DHT). JSON data types require an accompanying Schema file specifying the json schema for the structure. 29 | 30 | ## Deployment View 31 | The following figure shows a the components of a single HApp (hApp1) deployed to a single node (MyPhone node). 32 | 33 | ![Figure 2. Deployment View](images/Holochain%201Node%201App.png) 34 | 35 | _Figure 2. Deployment View of a Single App Deployed to a Single Node_ 36 | 37 | All _holochain nodes_ maintain two persistent data stores for each _hApp_ the _node_ has joined: (1) a [**_local source chain_**](https://developer.holochain.org/Technical_Architecture) and (2) a **_shard_** of the _DHT_ for that _hApp_. The _local source chain_ is a hashChain that links a series of _entries_ (NOT _blocks_!). The initial entry (_H0_, referred to as the _genesis entry_ contains a reference to (hash of) the _DNA file_ for the _hApp_. This ensures that all nodes that join this _hApp_ are running the same application code (or can be detected if they attempt to run different code). The next entry (_H1_)contains a reference to the _user_key_ for this specific node. Subsequent entries (_H2_ .. _Hn_) each reference a _data record_ that encodes a change to the application state. All of the headers are _hashchained_ to their predecessor, thus enforcing a local ordering of state changes (on the _local source chain_) while also ensuring the integrity of the entire chain. 38 | 39 | Additionally, the _node_ runs a webserver that allows data to be retrieved from either the _local source chain_ or the _DHT_ and presented in a web browser (using the UI code defined in the _hApp's DNA folder_). 40 | 41 | Finally, the _node_ also runs a _DHT server_ that is responsible for helping to maintain a _World Model_. (https://developer.holochain.org/World_Model) by communicating with other nodes that have joined that _hApp_. 42 | 43 | In the following figure, we have extended the view to include a second node (_My Holoport Node_) for _hApp1_. 44 | 45 | ![Figure 3. Deployment View](images/Holochain%202Node%201App.png) 46 | 47 | _Figure 3. Deployment View of a Single App Deployed to a Two Nodes_ 48 | 49 | This shows the _gossip_ communication between the nodes. This channel is part of the holochain's _immune system_. As updates are propagated from _local source chains_ to the DHT sharded across multiple nodes. Each node validates the updates and, if invalid nodes are detected, the node originating the update can be flagged. Flagged nodes can then be excluded from further DHT updates, effectively banishing them from the application. The _gossip_ channel can also be used to detect which nodes are offline. 50 | 51 | The folloiwng figure shows the configuration of MyPhone node having _joined_ a second app (_hApp2_). 52 | 53 | ![Figure 4. Deployment View](images/Holochain%202Node%202App.png) 54 | 55 | _Figure 4. Deployment View of a Two Apps Deployed to Two Nodes_ 56 | 57 | Notice that _hApp2_ has its own set of components: _local source chain_, _dht shard_ for hApp2, _DHT server_ and _web server_. The figure also illustrates _bridging_ between apps. In this case, _hApp2_ has created a _bridge_ to _hApp1_ (which _hApp1_ has accepted). The presence of the bridge allows _hApp2_ to invoke any of the functions designated by _hApp1's_ DNA as being _bridge functions_. Note that bridges are directional. This means that _hApp1_ cannot invoked _hApp2's_ bridge functions unless it opens (and _hApp2_ accepts) a second bridge from _hApp1_ to _hApp2_. Also note that _**all bridges are local**_ to a node. 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | -------------------------------------------------------------------------------- /holo-health-app-architecture.md: -------------------------------------------------------------------------------- 1 | # Overview 2 | 3 | This document presents a high-level view of an _Application Architecture_ that supports the emergence of _**person-centric healthcare ecosystems**_ on top of a _holochain_ based infrastructure. Refer to the [holo-health project README](README.md) for an overview of the project, including its goals and guiding principles. 4 | 5 | # High-Level Application Architecture 6 | The following figure depicts a high-level view of the _Empowered Health Market Application Architecture_. 7 | ![Empowered Health Application Architecture](images/holo-health%20app%20architecture.png) 8 | **_Figure 1. Empowered Health Ecosystem Application Architecture_** 9 | 10 | Figure 1 shows four types of _holochain applications_: 11 | * [**_Personal Health Vault hApp (phv)_**](phv/personal-health-vault-hApp.md) -- This hApp is used to store and provide access to my own personal health information. Each person has their own instance of this hApp (and therefore, in holochain terms, their own DHT). All of my devices can join this hApp, making my health information accessible from any of my devices. I can also choose to allow close friends or family members to join so that, in the event I am incapacitated, they can authorize healthcare providers to access my health-data. The _phv_ consists of _HealthCards_ that record _health observations_, _care plans_, _medication records_, _diagnostic reports_, etc. _HealthCards_ will leverage industry standards for terminology (e.g., [LOINC](https://loinc.org) and [SNOMED CT](https://www.snomed.org)) and interoperability (e.g., [FHIR](https://www.hl7.org/fhir/resourcelist.html)). A HealthCard can be _self-reported_, captured from a _personal health device_ (e.g., health bracelet, smart watch), or the result of a service provided by a _Healthcare Provider_ (e.g., an examination, lab-test, prescription order, surgery result, etc.). Over time, the collection of _HealthCards_ provide a comprehensive _Personal Health Record_ that is completely under my control. _(NOTE: The initial Proof of Concept (PoC) will only support a very simplistic implementation of HealthCards.)_ 12 | * [_**Health Market hApp (hm)**_](hm/healthcare-market-hApp.md) -- This hApp provides a _public marketplace_ where _Health Care Providers_ can _**offer**_ healthcare services. Each _offer_ specifies the _terms_ under which people can avail themselves of that service. These _terms_ can include a list of the exact types of _personal health observations_ the _Healthcare Provider_ may need in order to deliver the service. As a trivial example, the _offer_ for an _Activity Recommendations Service_ could specify that it will recommend the number of _daily steps_ a person should take, provided they are willing to share their _age_, _weight_, and _gender_. Each Marketplace instance (DHT) can specify a set of principles that all providers in that marketplace are committed to following (enforced by the _membrane function_ that allows agents to join the marketplace). Example principles could include, for example, a commitment to pro-active, person-centric healthcare, a commitment to not share information with any outside agent without explicit permission from the consumer, etc. It is up to each _healthcare provider_ to decide what principles they are willing to publicly commit to following. Potential healthcare consumers can search for marketplaces whose principles align with their personal values and then search within that marketplace for services they feel may benefit them. If they find an _offer_ for a _service_ they want under _acceptable terms_, they can choose to _accept_ the _offer_. 13 | * [_**Health Service Delivery hApp (hsd)**_](hsd/healthcare-service-delivery-hApp.md) -- _Accepting_ an offer results in a new instance of the _Health Service Delivery hApp_ being created for which only the person who accepted the offer and the Healthcare Provider that posted the offer are added as members. The _hsd_ serves as a private channel between the two parties. Both the _agreement_ (which includes a reference to the _offer_ on which the _agreement_ was based) and the _requests_ and _responses_ made by either party, are recorded in the DHT for this hApp instance. The hApp will automatically check all _requests_ by a _Healthcare Provider_ for _Personal Health Information_. If any type of information is requested that does not conform to the types of information listed in the _offer_ bound to the _agreement_ for this _hsd_ hApp instance, the request is automatically rejected (and both the _response_ and the _rejection_ recorded in the _hsd's_ DHT). Otherwise, the requested information is retrieved from the _Personal Health Record_ and returned to the provider. The provider can then analyze the retrieved information and make a _recommendation_ back to the person. This _recommendation_ is itself an _observation_ that may be recorded in the person's _Personal Health Record_. Signing the result into the _Personal Health Record_ can then trigger the reciprocal value return (e.g., payment for the service). Recording all _requests_ and _responses_ in the DHT provides a non-forgeable, immutable, non-repudiable audit trail. This audit trail is required for both invoicing and regulatory compliance. Ideally, this can also be leveraged to address a key barrier to PHR adoption by allowing clear provenance and data integrity to be established for the health card. Health care practitioners (e.g., physicians) are reluctant to trust health records that have been in patient custody out of concern the record may be incomplete or have been altered. Because the _hsd_ stores each _HealthCard_ in an immutable, non-forgeable and non-repudiable way, healthcare practitioners can be confident that the observation or diagnostic report is complete and unchanged. However, see [Issue #2](https://github.com/evomimic/holo-health/issues/2). 14 | * _**Provider hApp (hp)**_ -- This type of hApp is intended to provide a _holochain-native application_ for use by _Healthcare Providers_. It is included for completeness and to indicate a potential future direction. However, use of such an hApp is NOT a pre-requisite for a _Healthcare Provider_ to participate in the _Empowered Health Ecosystem_. It is expected that most _providers_ already have their own _Electronic Medical Record_ (EMR) or _Electronic Health Record_ (EHR) systems. To require them to adopt a pure _holochain-native_ application architecture for their internal systems would pose a significant barrier to entry into the _Empowered Health Ecosystem_. Instead, an API-based approach will be followed initially. To participate in the _Empowered Health Ecosystem_, _Healthcare Providers_ will need to provision some _nodes_ that are configured to _join_ _Health Market_ and/or _Health Service Delivery_ hApp instances. Mapping to/from the _Healthcare Providers_ internal systems and the _holo-health_ applications will be the _Healthcare Providers_ responsibility. 15 | 16 | It is worth noting that this _application architecture_ enables better health outcomes, because the PHR provides a much more holistic and complete view of the patient's medical history, (since it includes information from multiple providers). Furthermore, it creates possibilities for profoundly different information sharing ecosystems. Consider, for example, that, **under the right _agreements_, _healthcare providers_ need never persistently store _Electronic Medical Records_ about individuals in their own internal systems**. Instead they can retrieve information about a patient from the patient's own _PHR_ whenever needed to, say, make a diagnosis, issue a medication order, etc. Not storing such information (which is considered _Protected Health Information_ -- _PHI_ -- in HIPAA/HITECH regulations) in their own systems represents a huge reduction in the risk of data exposure which can translate to significant cost-savings. 17 | -------------------------------------------------------------------------------- /hsd/healthcare-service-delivery-hApp.md: -------------------------------------------------------------------------------- 1 | # Health Service Delivery hApp 2 | The _Health Service Delivery hApp_ is one of a set of hApp's designed to work together to support the emergence of _**person-centric healthcare ecosystems**_ on top of a _holochain_ based infrastructure. Refer to the [holo-health project README](../README.md) for an overview of the project including its goals and guiding principles. Refer to [Holo-Health App Architecture](../holo-health-app-architecture.md) for an architectural overview. 3 | 4 | # Overview 5 | An instance of this _hsd_ hApp is created when a person _accepts_ a _Healthcare Service offer_ placed in the _Healthcare Market_ by a _Healthcare Provider_. The _hsd_ serves as a private channel between the two parties. Both the _agreement_ (which includes a reference to the _offer_ on which the _agreement_ was based) and the _requests_ and _responses_ made by either party, are recorded in the DHT for this hApp instance. This provides a secure, non-forgeable, immutable, non-repudiable audit trail that is necessary for both invoicing and regulatory compliance. 6 | 7 | The _Healthcare Service Delivery hApp_ is intended to (eventually) support a very broad range of services (including both electronic and in-person) offered under a broad range of _agreement types_, but the PoC will assume a very simplistic concept of _healthcare service delivery_. 8 | 9 | # Proof of Concept (PoC) Simplistic Implementation 10 | The goal for the initial Proof-of-Concept (PoC) is to demonstrate the basic application architecture and hApp collaboration model. The healthcare services targeted for initial implemented in the PoC. 11 | 12 | * The PoC will only a support a single, implicitly defined agreement_type with the following _service flow_: 13 | 1. _Healthcare provider_ issues _HealthInfoRequest_ for specified _observation codes_ from _consumer_ 14 | 1. The _hsd hApp_ will automatically check all such requests to ensure they comply with the terms specified in the _agreement_. If not, the request is rejected. 15 | 1. If the _request_ conforms to the _agreement_, the _hsd_ will build a _HealthInfoResponse_ to return to the _healthcare provider_. For each requested _observation code_ for which the consumer's _PersonalHealthRecord_ includes an _observation_, the _observation_ will be included in the response. 16 | 1. Upon receiving the _HealthInfoResponse_, the _hsd_ will invoke _handleResponse_ to trigger the _healthcare provider's_ analysis logic to analyze the personal health observations returned by the _consumer_ to arrive at a _health recommendation_. The response is NOT included in the list of _observation codes_ defined in the _offer_, the HealthInfoRequest is rejected. 17 | 1. All HealthInfoRequests, HealthInfoResponses, and Observations recorded are persisted to the DHT. 18 | 19 | ## Application Genesis 20 | Upon acceptance of an _offer_, _O_, from _service provider_, _P_, by a _service requester_, _R_: 21 | * A new _hsd_ instance _h_, should be created by one of _R_'s nodes., with _R_ as (initially) the only member (but see [Issue #5](https://github.com/evomimic/holo-health/issues/5)). 22 | * _R_ and _P_ should be added to the _invitedAgents_ list [see Issue #6](https://github.com/evomimic/holo-health/issues/6) for _h_, essentially authorizing any _nodes_ acting on behalf of either _R_ or _P_ to join _h_. 23 | * _R_ should be invited (via node-to-node messaging) to join the _h_. 24 | * The _hsd_ `genesis` function should ensure that only _node-agents_ of for _legal-agents_ who appear in the _invitedAgents_ list will be allowed to _join_ that _hsd_. 25 | * _(Future)_ If an additional confirmation is required, once _R_ has successfully joined _h_, there could be additional _accept_ function added to the _Agreement Zome_. 26 | 27 | ## DNA 28 | ![Figure 1. Health Service Delivery DNA](../images/hsd-dna.png) 29 | 30 | The _hsd_ hApp defines three zomes: 31 | 32 | ### Agreement Zome 33 | Designates an _agreement_ between a _healthcare provider_ who digitally signed an _offer_ into the _Health Marketplace_ and a _consumer_ who digitally signed their acceptance of the _offer_. The terms of the _agreement_ are as specified in the _offer_. 34 | 35 | _Agreement Schema_ 36 | 37 | `offeredByRef`: hash reference to the _healthcare provider_ agent that signed the _offer_ underlying this _agreement_ into the _Health Marketplace_. 38 | 39 | `acceptedByRef`: hash reference to the _consumer_ that accepted the _offer_. 40 | 41 | `offerRef`: hash reference to the signed _offer_. 42 | 43 | `validFrom`: the DateTime at which the Agreement became valid. 44 | 45 | `validThrough`: the DateTime at which the Agreement expires(d). 46 | 47 | `isActive`: simple indicator of whether the _agreement_ is currently active. 48 | 49 | `policies`: [string] -- in the PoC, a simple array of textual policies. These could evolve (after the PoC) to include a diverse array of _**pluggable governance**_ policies (e.g., governing cancellation, dispute resolution, decision authorities, non-disclosure and confidentiality, upgrades, backward compatibility, etc.), some of which may be computationally enforceable policies (i.e.,, _smart contracts_). 50 | 51 | Holochain's _validating DHT_ ensures that Agreements_ are: 52 | * _**Non-repudiable**_ -- neither party can claim they didn't enter into the _agreement_. The terms were baked into the _offer_ digitally signed by the _healthcare provider_. The _consumer's_ acceptance of those terms was digitally signed by the _consumer_ (and the body of the signed _agreement_ includes the hash of the _offer_). 53 | * _**immutable**_ -- the _agreement_ and _offer_ cannot be altered without changing their hash, making the change obvious. 54 | * _**non-forgeable**_ -- due to the combination of digital signing by both parties and the hash of the contents. 55 | 56 | The _Agreement_ zome provides the following _functions_: 57 | 58 | `getAgreement` -- allows an existing agreement to be retrieved from its id 59 | 60 | `withdrawAgreement` -- sets the `isActive` flag to `false` provided the request to 61 | 62 | `getOffer` -- allows retreival of the _offer_ associated with the _agreement_ 63 | 64 | 65 | BRIDGE FUNCTIONS: 66 | `createAgreement` -- allows a new _agreement_ to be made by a _consumer_ based on a (previously-) signed _offer_. 67 | 68 | ### HealthInfoRequest Zome 69 | 70 | SCHEMA: 71 | 72 | `byAgentRef` -- hash reference to the _healthcare provider_ agent who is making the _HealthInfoRequest_ 73 | 74 | `ofAgentRef` -- hash reference to the _consumer_ being asked to respond to this request. 75 | 76 | `underAgreementRef` -- hash reference to the _agreement_ under which the request is being made. 77 | 78 | `requestDate` -- the DateTime of the request. 79 | 80 | `infoRequested`: [string] -- the list of _observation codes_ indicating the types of of personal health information being requested. To be _valid_, this list must ONLY include _codes_ that are designated by the _offer_. 81 | 82 | 83 | The _HealthInfoRequest_ zome provides the following _functions_: 84 | 85 | `createRequest` -- used by the _healthcare provider_ to create a new HealthInfoRequest. 86 | 87 | `sendRequest` -- commits the request to the _hsd_ DHT 88 | 89 | ### HealthInfoResponse Zome 90 | 91 | 92 | 93 | SCHEMA: 94 | `status`: string 95 | 96 | `requestRef`: string 97 | 98 | `responseTime`: string (DateTime) 99 | 100 | `responseInfo: [ 101 | { 102 | code: string, 103 | value: number, 104 | units: string 105 | } 106 | ]` 107 | 108 | The _HealthInfoRequest_ zome provides the following _functions_: 109 | 110 | `createResponse` -- 111 | 112 | `sendResponse` -- 113 | 114 | `handleResponse` -- 115 | 116 | 117 | ## Proof of Concept (PoC) Deployment Architecture Example 118 | 119 | ![Figure 2. Example hsd hApp Deployment](../images/hsd-deployment-example.png) 120 | 121 | # Future Enhancements 122 | 123 | 1. Allow a _personal health vault_ hApp to retrieve all of the _agreements_ for which that person is a _consumer_ (across all _hsd_ instances for that _consumer_). 124 | 1. Handle an extended range of _agreement types_ that enable more complex _service flows_. 125 | * Pay-per-service transactions using a _**pluggable currency**_ 126 | * More complex _**service choreography**_. 127 | 1. Enhance privacy and security by supporting: 128 | * pairwise pseudonymous identities 129 | * encrypted payloads (using receiving agent's public key, so that only _that_ agent can decrypt the payload). 130 | 131 | 132 | -------------------------------------------------------------------------------- /hm/healthcare-market-hApp.md: -------------------------------------------------------------------------------- 1 | # Healthcare Market hApp (hm) 2 | The _Healthcare Market hApp (hm)_ is one of a set of _holo-health_ hApp's designed to work together to support the emergence of _**person-centric healthcare ecosystems**_ on top of a _holochain_ based infrastructure. For an overview of the project, including its goals and guiding principles, refer to the [holo-health project README](../README.md). For an architectural overview of holo-health, refer to [Holo-Health App Architecture](../holo-health-app-architecture.md) . 3 | 4 | # Overview 5 | This hApp provides a _public marketplace_ where _Health Care Providers_ can _**offer**_ healthcare services. Each _offer_ specifies the _terms_ under which people can avail themselves of that service. Each Marketplace instance (DHT) can specify a set of principles that all providers in that marketplace are committed to following. Potential healthcare consumers can search for marketplaces whose principles align with their personal values and then search within that marketplace for services they feel may benefit them. If they find an _offer_ for a _service_ they want and whose terms they find acceptable, they can choose to _accept_ the _offer_. _Accepting_ an offer results in a new instance of a [_Health Service Delivery hApp_](../hsd/healthcare-service-delivery-hApp.md) being created for which only the person who accepted the offer and the Healthcare Provider that posted the offer are added as members. Thus, although services are _offered_ publicly, the _service relationship_ between the _healthcare provider_ and the _consumer_ remains private. 6 | 7 | # Proof of Concept (PoC) Simplistic Implementation 8 | The goal for the initial Proof-of-Concept (PoC) is to demonstrate the basic application architecture and hApp collaboration model. As such, a very simplistic concept of healthcare market will be implemented in the PoC. 9 | 10 | 11 | ## Value Flow 12 | Figure 1 illustrates the high-level value flows for the Health Market and shows how the Zome entries are partitioned across the _Health Market hApp (hm)_ and the _Health Service Delivery hApp (hsd)_. 13 | 14 | ![Health Market Value Flows](https://github.com/evomimic/holo-health/blob/master/images/holo-health-value-flow.png) 15 | 16 | _Figure 1. Health Market Value Flows_ 17 | 18 | _HealthCare Providers_ create and publish _Offers_ to the _Health Market_ where they can be discovered by _Persons_. A Person can _accept_ an _offer_, creating a _Signed Agreement_ between them and the _Healthcare Provider_. 19 | 20 | ## DNA 21 | The DNA for the _Health Market hApp_ will include a single _Offer_ zome as shown in Figure 2. 22 | 23 | ![Figure 2. PoC Health Market hApp (hm) DNA](https://github.com/evomimic/holo-health/blob/master/images/hm-dna.png) 24 | 25 | _Figure 2. PoC Health Market hApp (hm) DNA_ 26 | 27 | 28 | The following fields are provided for the _Offer_ Zome Entry in the PoC: 29 | * `type: string` identifies the type of the offer. In the POC this is a simple string. Going forward a registry of _offer types_ can be included in the Health Market. 30 | * `by: agentHash` refers to the _healthcare provider_ that is extending the _offer_ 31 | * `description: String` provides a brief description of the _offer_ 32 | * `isActive: boolean` indicates whether this _offer_ is currently _active_. Only _active offers_ can be _accepted_. 33 | * `startDate: String` indicates the date when the _offer_ became or will become _active_. 34 | * `endDate: String` indicates the date when the _offer_ will expire. 35 | * `offerName: String` provides a short human-readable name for the _offer_. 36 | * `dataRequested: Array`provides a list of the Healthcare Observation types (e.g., _height_, _weight_, _age_, _bloodType_, _LDL_, _HDL_, etc.) that the _healthcare provider_ needs to receive from the consumer in order to delivery\ this service. 37 | * `valueReturned: String` indicates the type of Healthcare Observation that the _healthcare provider_ will return to the consumer based on analysis of the data gathered from the consumer. 38 | 39 | Note that the PoC will (initially) support only free services, i.e., it does not allow _offers_ to define a _currency flow_. 40 | 41 | The _Offer_ zome provides the following functions: 42 | * `createOffer` -- allows _healthcare providers_ to create and elaborate new _offers_. _Offers_ do not become available in the marketplace until they are published. 43 | * `publishOffer`-- makes an _offer_ visible in the market and available to be accepted. This function can optionally specify a `startDate` and/or an `endDate`. If no `startDate` is provided, the current date will be used. If no `endDate` is provided, the _offer_ is assumed to remain active until explcitly withdrawn. 44 | * `withdrawOffer` -- removes an _offer_ from the market. Note that _offers_ are not deleted and withdrawing an _offer_ has no affect on any _agreements_ that have previously been linked to that _offer_. This function can optionally specify a an `endDate`. If no `endDate` is provided, the _offer_ is withdrawn immediately (i.e., it's `isActive` attribute is set to `false`).. 45 | * `myOffers: [Offer]` -- allows _healthcare providers_ to retrieve the list of all of their offers. This function relies on offers having been anchored with _provider_ tags and _offerType_ tags. 46 | * `availableOffers: [Offer]`-- allows _consumers_ to retrieve the list of all of the offers in the marketplace, filtered by _offerType_ 47 | * `acceptOffer`-- allows a _consumer_ to accept an offer. Doing so: 48 | * will trigger the creation of a new instance of the _Health Service Delivery (hsd)_ hApp((../hsd/healthcare-service-delivery-hApp.md) for which only the person who accepted the offer and the Healthcare Provider that posted the offer are added as members. 49 | * the creation of an _agreement_ within the _hsd_, signed by the _consumer_, that includes a hash reference to the _offer_ signed by the _healthcare provider_ 50 | 51 | A `getOffer` _bridge function_ is provided so the _Health Service Delivery hApp_ can retrieve information about the _offer_ associated with an _agreement_. 52 | 53 | To provide more robust searching options (when the list of _Offers_ gets unwieldy), the [anchors mixin](https://github.com/holochain/mixins/tree/master/anchors) can be added to the _Offer_ zome. Anchors can be used to segregate _offers_ by _offerType_. This can be used to search and filter `myOffers` for _healthcare providers_ and `availableOffers` for consumers. 54 | 55 | ## Proof of Concept (PoC) Deployment Architecture Example 56 | 57 | ![Figure 3. PoC Health Market hApp (hm) Deployment Example](https://github.com/evomimic/holo-health/blob/master/images/hm-deployment-example.png) 58 | 59 | _Figure 3. PoC Health Market hApp (hm) Deployment Example_ 60 | 61 | The example shown in _Figure 3_ shows a total of seven _nodes_ belonging to three different _healthcare providers_ (Good Health, Thrive, Inc. and Get Healthy, Inc.) and two different _consumers_ (Steve and Vidya) participating in the Health Market. (NOTE: In this figure, an hApp deployed on a node is depicted as a rounded rectangle (e.g., _hm_hApp_). The internal anatomy of the hApp on a node (i.e., its _DHT server_, _DHT shard_, _local source chain_, and _web server_) is not shown, but keep in mind that all of these components are included for each deployment of a hApp to a node.) 62 | 63 | The _healthcare provider_ nodes are named "API Gateway" to suggest that they represent points of interface between the _healthcare provider's_ internal IT systems and the _holo-health_ environment. Presumaby, these nodes will include connections to/from internal IT systems for that provider (not shown). 64 | 65 | Notice that the _hm_hApp_ is sharded across all seven nodes. Also note that the _consumer nodes_ are hosting BOTH their own _PersonalHealthVault_ hApps AND the _hm_hApp_). 66 | 67 | # Future Enhancements 68 | The initial PoC design is limited in a number of significant ways. To truly foster the emergence of _person-centric healthcare ecosystems_ will require enhancements in several key areas: 69 | 1. _Healthcare Provider Agent Registry_ 70 | 2. Ability to automatically create pairwise pseudonymous identifiers, enabling _hsd consumers_ to establish a different identity with each _healthcare provider_ to reduce the risk of data breaches through correlation attacks. This may involve leveraging the holochain's [DPKI](https://github.com/holochain/dpki) hApp for managing sets of public/private key pairs. 71 | 2. Rich _offer types_ ontology, capable of expressing a comprehensive range of services, levaraging international standards 72 | 5. Robust set of standard _offer types_ 73 | * Support for _pluggable currency flows_. 74 | * In-person and online services 75 | 3. Support for associating offers with _market-defining guiding principles_ (e.g., _only responsibly-sourced ingredients_ , _no animal testing_, etc.) 76 | 3. Ability to characterize a _comprehensive range of services_, leveraging industry-standard terminology and service definitions 77 | 4. FHIR integration 78 | 79 | 80 | <_forward to [hsd Application Architecture](../hsd/healthcare-service-delivery-hApp.md)>_ 81 | 82 | 83 | 84 | 85 | -------------------------------------------------------------------------------- /phv/personal-health-vault-hApp.md: -------------------------------------------------------------------------------- 1 | # Personal Health Vault Application (phv) 2 | 3 | The _Personal Health Vault_ is one of a set of hApp's designed to work together to support the emergence of _**person-centric healthcare ecosystems**_ on top of a _holochain_ based infrastructure. Refer to the [holo-health project README](../README.md) for an overview of the project, including its goals and guiding principles. Refer to [Holo-Health App Architecture](../holo-health-app-architecture.md) for an architectural overview. 4 | 5 | A _**Personal Health Vault**_ is a private container for all of my health information. This hApp is inspired by and loosely patterned after the [holo-vault](https://github.com/holochain/holo-vault) application. _Holo-vault_ is intended as a general identity manager application that provides storage of _personal profile attributes_ and allows different subsets of those profile attributes to be mapped to _personas_ that can be shared with other applications (although the exact method for sharing is not clear to me). 6 | 7 | _Personal Health Vault_ is built around the concept of a _**HealthCard**_. 8 | 9 | Briefly, a _HealthCard_... 10 | is a private, but shareable, container of Health Information (any health request, event, condition). 11 | * is owned by the subject of the card, but carries no _Personally Identifying Information_ (_PII_). When shared it is only associated with a pseudonym. 12 | * are stored in a _Personal Health Journal_ that provides a complete, holistic view of my health events, conditions, and info. 13 | * can be categorized into 1 or more _categories_ 14 | * is _self-describing_, i.e., is associated with a descriptor that specifies what types of data elements are stored in that card. 15 | * is based on _terminologies_ (code systems & value sets) and resources specified by the [FHIR standard](http://hl7.org/fhir/) 16 | * constitutes a _common form factor_ for requesting, sharing & presenting health information. 17 | * may be shared under an _Agreement_ that specifies the authorities and responsibilities of each Party to the agreement. The Agreement may also specify some reciprocal value flow (i.e., people may get paid for sharing HealthCards with others). 18 | * Are protected such that _only authorized users under a valid agreement_ have access to the HealthCard. 19 | * Have an _audit trail_ of all accesses to that health card. 20 | 21 | ![Figure 1. Examples of HealthCard Information](https://github.com/evomimic/holo-health/blob/master/images/healthcard-info-types.png) 22 | _Figure 1. Examples of HealthCard Information_ 23 | 24 | ## Proof of Concept (PoC) Simplistic HealthCard Implementation 25 | For the initial Proof-of-Concept (PoC), a very simplistic concept of HealthCard will be used. The DNA for this Personal Health Vault app will offer a single _HealthObservation_ zome as shown in Figure 2. 26 | 27 | ![Figure 2. PoC Personal Health Vault DNA](https://github.com/evomimic/holo-health/blob/master/images/phv-dna.png) 28 | 29 | _Figure 2. Personal Health Vault DNA_ 30 | 31 | Each observation records one fact. 32 | * `subjectHash` refers to the person that is the subject of the observation 33 | * `observerHash` refers to the agent (person or organization) that made the observation 34 | * `code` indicates the type of fact (e.g., _height_, _weight_) 35 | * `number` is the value for this observation (in initial PoC, only numeric values are allowed for observations) 36 | * `units` is the unit of measure associated with the value 37 | * `date` is the observation date. 38 | 39 | The _Health Observation_ zome provides the following functions: 40 | * `recordSelfObservation` for creating new _Health Observations_ for which I am both the _subject_ and _observer_. 41 | * `myObservations` to return a list of all of my _HealthObservations_ 42 | 43 | A `recordObservation` _bridge function_ is included that allows other hApps (e.g., the _Health Service Delivery hApp_) to record observations where I am the _subject_, but another agent (e.g., a physician, medical lab, etc.) is the _observer_. 44 | 45 | To provide more robust searching options (when the list of _HealthObservation_ gets unwieldy), the [anchors mixin](https://github.com/holochain/mixins/tree/master/anchors) can be added to the _HealthObservation_ zome. 46 | 47 | ## Proof of Concept (PoC) Deployment Architecture Example 48 | 49 | The better I understand holochain's notion of _agent-centricity_, it seems _node-centric_ may be a more accurate label. A key principle of holochain is **_all state is local state_** and _nodes_ are the holders of local state. Each of my devices is a different _node_. According to my definition of agent, "any entity with the capacity to sense and respond to its environment", holochain _nodes_ do, indeed, qualify as _agents_. But they are distinct from _human agents_. In essence the "vault" pattern is a way of creating a _human-agent_ abstraction on top of a set of _node-agents_. 50 | 51 | To understand a possible deployment model for the _PoC Personal Health Vault hApp_, let's start with the anatomy of a single node in a holochain app. 52 | 53 | ![Anatomy of a Holochain Node](https://github.com/evomimic/holo-health/blob/master/images/anatomy-of-a-node.png) 54 | 55 | _Figure 4. Anatomy of a Single PHV Node_ 56 | 57 | All _holochain nodes_ maintain two persistent data stores for each _hApp_ the _node_ has joined: (1) a **_local source chain_** and (2) a **_shard_** of the _DHT_ for that _hApp_. The _local source chain_ is a hashChain that links a series of _entries_ (NOT _blocks_!). The initial entry (_H0_, referred to as the _genesis entry_ contains a reference to (hash of) the _DNA file_ for the _hApp_. This ensures that all nodes that join this _hApp_ are running the same application code (or can be detected if they attempt to run different code). The next entry (_H1_)contains a reference to the _user_key_ for this specific node. Subsequent entries (_H2_ .. _Hn_) each reference a _data record_ that encodes a change to the application state. All of the headers are _hashchained_ to their predecessor, thus enforcing a local ordering of state changes (on the _local source chain_) while also ensuring the integrity of the entire chain. 58 | 59 | Additionally, the _node_ runs a webserver that allows data to be retrieved from either the _local source chain_ or the _DHT_ and presented in a web browser (using the UI code defined in the _hApp's DNA folder_. 60 | 61 | Finally, the _node_ also runs a _DHT server_ that is responsible for helping to maintain a [World Model](https://developer.holochain.org/World_Model) by communicating with other nodes that have joined that _hApp_. 62 | 63 | The following figure shows an example deployment architecture for an instance of the _Personal Health Vault_ (phv) hApp. 64 | ![Personal Health Vault Deployment Example](https://github.com/evomimic/holo-health/blob/master/images/phv-deployment-example.png) 65 | 66 | _Figure 3. Personal Health Vault Deployment Example_ 67 | 68 | In this example, a new instance of the _phv_ app has been created, via 69 | 70 | `hcdev init --clone steves-phv-app` 71 | 72 | The clone operation copies the DNA file from the original _phv_ app (so it shares the same code as the _phv_ app), but gives it a different UUID (so it will have its own DHT). 73 | 74 | NOTE: Currently, once cloned, any linkage to the original app is lost. So if new versions of the _phv_ app's DNA are published, the cloned app will have to be manually updated. I have filed [Issue #154 DNA as 1st Class Object?](https://github.com/holochain/holochain-rust/issues/154) on the _holochain-rust_ project to enable cloned projects to be notified when new versions of the original app have been accepted, with the option to `pull` the new version into the cloned app. 75 | 76 | In the example, four _nodes_ have joined _steves-phv-hApp_: _Steve's Phone_, _Steve's LapTop_, _Steve's HoloPort_, and _Terri's Phone_. Each has its own _local source chain_, _DHT shard_, _WebServer_ and _DHT Server_. 77 | 78 | **_TODO: insert discussion of membrane functions and restrictions on what nodes can join an app_**. Where should such restrictions be specified? Decisions on whether to allow another hApp to _**bridge**_ this app can be encoded in the _bridgeGenesis callback functions_ of zomes. If any zome's _bridgeGenesis_ function returns `false` the bridge is not allowed to be established. I'm assuming decisions on whether to allow a _node_ to _**join**_ an hApp could similarly be encoded in the _genesis callback function_ of zomes. Is this a sound assumption??? see **[Issue #1](https://github.com/evomimic/holo-health/issues/1)** 79 | 80 | # Future Enhancements 81 | As noted above, the initial PoC implementation will include a very simplistic concept of _HealthObservation_. Going forward, the following enhancements are being considered: 82 | * Support for the full [FHIR Observation Resource](https://www.hl7.org/fhir/observation.html): 83 | ![FHIR Observation Resouce UML](https://github.com/evomimic/holo-health/blob/master/images/fhir-observation-resource.png) 84 | _Figure 4. UML Representation of the FHIR Observation Resource_ 85 | * Also, the concept of a HealthCard will be implemented so that different types of FHIR resources beyond _Observations_ (e.g., [DiagnosticReports](https://www.hl7.org/fhir/diagnosticreport.html), [Medications](https://www.hl7.org/fhir/medication.html), [Immunizations](https://www.hl7.org/fhir/immunization.html), etc.) 86 | * _**Obversation Provenence**_ Provide a full, persistent, chain of custody that confirms the source for each _observation_ is immutably and non-repudiably identified, and the the _observtion_ has not been altered in any way. 87 | * _**Add security protections**_ through encryption of data at rest using my _public key_ so that only I can decrypt the information. 88 | 89 | 90 | <_forward to [Healthcare Market hAPP Application Architecture](../hm/healthcare-market-hApp.md)>_ 91 | -------------------------------------------------------------------------------- /LICENSE.txt: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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No Surrender of Others' Freedom. 541 | 542 | If conditions are imposed on you (whether by court order, agreement or 543 | otherwise) that contradict the conditions of this License, they do not 544 | excuse you from the conditions of this License. If you cannot convey a 545 | covered work so as to satisfy simultaneously your obligations under this 546 | License and any other pertinent obligations, then as a consequence you may 547 | not convey it at all. For example, if you agree to terms that obligate you 548 | to collect a royalty for further conveying from those to whom you convey 549 | the Program, the only way you could satisfy both those terms and this 550 | License would be to refrain entirely from conveying the Program. 551 | 552 | 13. Use with the GNU Affero General Public License. 553 | 554 | Notwithstanding any other provision of this License, you have 555 | permission to link or combine any covered work with a work licensed 556 | under version 3 of the GNU Affero General Public License into a single 557 | combined work, and to convey the resulting work. The terms of this 558 | License will continue to apply to the part which is the covered work, 559 | but the special requirements of the GNU Affero General Public License, 560 | section 13, concerning interaction through a network will apply to the 561 | combination as such. 562 | 563 | 14. Revised Versions of this License. 564 | 565 | The Free Software Foundation may publish revised and/or new versions of 566 | the GNU General Public License from time to time. Such new versions will 567 | be similar in spirit to the present version, but may differ in detail to 568 | address new problems or concerns. 569 | 570 | Each version is given a distinguishing version number. If the 571 | Program specifies that a certain numbered version of the GNU General 572 | Public License "or any later version" applies to it, you have the 573 | option of following the terms and conditions either of that numbered 574 | version or of any later version published by the Free Software 575 | Foundation. If the Program does not specify a version number of the 576 | GNU General Public License, you may choose any version ever published 577 | by the Free Software Foundation. 578 | 579 | If the Program specifies that a proxy can decide which future 580 | versions of the GNU General Public License can be used, that proxy's 581 | public statement of acceptance of a version permanently authorizes you 582 | to choose that version for the Program. 583 | 584 | Later license versions may give you additional or different 585 | permissions. However, no additional obligations are imposed on any 586 | author or copyright holder as a result of your choosing to follow a 587 | later version. 588 | 589 | 15. Disclaimer of Warranty. 590 | 591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 599 | 600 | 16. Limitation of Liability. 601 | 602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 610 | SUCH DAMAGES. 611 | 612 | 17. Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | Copyright (C) 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . 675 | --------------------------------------------------------------------------------