├── LICENSE
├── README.md
├── dev_docs.md
├── diagram.md
├── diagram1.png
├── faq.md
├── ideas.md
├── lipmaa.png
├── logo.png
├── message_format.md
├── roadmap.md
└── sync.png


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545 | LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
546 | OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
547 | EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
548 | OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
549 | TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM
550 | PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
551 | CORRECTION.
552 | 
553 |    16. Limitation of Liability.
554 | 
555 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL
556 | ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM
557 | AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
558 | INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO
559 | USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED
560 | INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE
561 | PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER
562 | PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
563 | 
564 |    17. Interpretation of Sections 15 and 16.
565 | 
566 | If the disclaimer of warranty and limitation of liability provided above cannot
567 | be given local legal effect according to their terms, reviewing courts shall
568 | apply local law that most closely approximates an absolute waiver of all civil
569 | liability in connection with the Program, unless a warranty or assumption
570 | of liability accompanies a copy of the Program in return for a fee. END OF
571 | TERMS AND CONDITIONS
572 | 
573 | How to Apply These Terms to Your New Programs
574 | 
575 | If you develop a new program, and you want it to be of the greatest possible
576 | use to the public, the best way to achieve this is to make it free software
577 | which everyone can redistribute and change under these terms.
578 | 
579 | To do so, attach the following notices to the program. It is safest to attach
580 | them to the start of each source file to most effectively state the exclusion
581 | of warranty; and each file should have at least the "copyright" line and a
582 | pointer to where the full notice is found.
583 | 
584 | <one line to give the program's name and a brief idea of what it does.>
585 | 
586 | Copyright (C) <year> <name of author>
587 | 
588 | This program is free software: you can redistribute it and/or modify it under
589 | the terms of the GNU General Public License as published by the Free Software
590 | Foundation, either version 3 of the License, or (at your option) any later
591 | version.
592 | 
593 | This program is distributed in the hope that it will be useful, but WITHOUT
594 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
595 | FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
596 | 
597 | You should have received a copy of the GNU General Public License along with
598 | this program. If not, see <http s ://www.gnu.org/licenses/>.
599 | 
600 | Also add information on how to contact you by electronic and paper mail.
601 | 
602 | If the program does terminal interaction, make it output a short notice like
603 | this when it starts in an interactive mode:
604 | 
605 | <program> Copyright (C) <year> <name of author>
606 | 
607 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
608 | 
609 | This is free software, and you are welcome to redistribute it under certain
610 | conditions; type `show c' for details.
611 | 
612 | The hypothetical commands `show w' and `show c' should show the appropriate
613 | parts of the General Public License. Of course, your program's commands might
614 | be different; for a GUI interface, you would use an "about box".
615 | 
616 | You should also get your employer (if you work as a programmer) or school,
617 | if any, to sign a "copyright disclaimer" for the program, if necessary. For
618 | more information on this, and how to apply and follow the GNU GPL, see <http
619 | s ://www.gnu.org/licenses/>.
620 | 
621 | The GNU General Public License does not permit incorporating your program
622 | into proprietary programs. If your program is a subroutine library, you may
623 | consider it more useful to permit linking proprietary applications with the
624 | library. If this is what you want to do, use the GNU Lesser General Public
625 | License instead of this License. But first, please read <http s ://www.gnu.org/
626 | licenses /why-not-lgpl.html>.
627 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
  1 | ![](logo.png)
  2 | 
  3 | # The Pigeon protocol
  4 | 
  5 | The Pigeon protocol is an off-grid, serverless, peer-to-peer protocol
  6 | for building software that works on poor internet connections, or
  7 | entirely offline.
  8 | 
  9 | 
 10 | # Project Status
 11 | 
 12 | HIBERNATION. Pigeon was an exploration of ideas that I embarked on in 2020. Now (2021) I am changing my focus. If more people are interested in the project I might start work on it again. Please let me know by raising an issue. For now, I am shifting my focus to other areas unless interest in the project changes.
 13 | 
 14 | # Table of contents
 15 | 
 16 | - [Introduction](#introduction)
 17 | - [Why build software that follows the Pigeon protocol?](#why-build-software-that-follows-the-pigeon-protocol)
 18 | - [How does the Pigeon protocol benefit users?](#how-does-the-pigeon-protocol-benefit-users)
 19 |     - [Data is backed up by default](#data-is-backed-up-by-default)
 20 |     - [Data can be shared anywhere](#data-can-be-shared-anywhere)
 21 |     - [Data is tamper-resistant](#data-is-tamper-resistant)
 22 |     - [Data is always available](#data-is-always-available)
 23 | - [Use-case scenarios](#use-case-scenarios)
 24 | - [Software implementation ideas](#software-implementation-ideas)
 25 | - [Implementations](#implementations)
 26 | - [How does the Pigeon protocol work?](#how-does-the-pigeon-protocol-work)
 27 | - [What do Pigeon messages look like as data?](#what-do-pigeon-messages-look-like-as-data)
 28 | - [Constraints and Design Philosophy](#constraints-and-design-philosophy)
 29 | - [What the Pigeon protocol is not trying to address](#what-the-pigeon-protocol-is-not-trying-to-address)
 30 | - [How the Pigeon protocol differs from Sneakernet](#how-the-pigeon-protocol-differs-from-sneakernet)
 31 | - [How the Pigeon protocol differs From Secure Scuttlebutt](#how-the-pigeon-protocol-differs-from-secure-scuttlebutt)
 32 | - [Influences](#influences)
 33 | - [Getting involved with the Pigeon protocol development](#getting-involved-with-the-pigeon-protocol-development)
 34 | - [For more information](#for-more-information)
 35 | 
 36 | # Introduction
 37 | 
 38 | This document will describe why you may want to build software that
 39 | follows the Pigeon protocol, how the protocol works, and how you can
 40 | write software that follows this protocol.
 41 | 
 42 | This document provides a reference to the Pigeon protocol
 43 | specifications, and is written for developers.
 44 | 
 45 | # Why build software that follows the Pigeon protocol?
 46 | 
 47 | Software that follows the Pigeon protocol can operate online or
 48 | offline, regardless of connectivity quality. This allows you to focus
 49 | on software development, instead of worrying about network types and
 50 | quality, or third-party services.
 51 | 
 52 | # How does the Pigeon protocol benefit users?
 53 | 
 54 | The Pigeon protocol outlines several ways users can benefit from using
 55 | software that follows this protocol.
 56 | 
 57 | This section consists of the following subsections:
 58 | 
 59 | - [Data is backed up by default](#data-is-backed-up-by-default)
 60 | - [Data can be shared anywhere](#data-can-be-shared-anywhere)
 61 | - [Data is tamper-resistant](#data-is-tamper-resistant)
 62 | - [Data is always available](#data-is-always-available)
 63 | 
 64 | ## Data is backed up by default
 65 | 
 66 | Software that follows the Pigeon protocol allows users to store data
 67 | on their nodes, and copy their data to other nodes. By copying data to
 68 | other nodes, this not only backs up data, but also provides users with
 69 | data they can access offline.
 70 | 
 71 | ## Data can be shared anywhere
 72 | 
 73 | Every user in the mesh has a local database. You can share your
 74 | database entries anywhere, such as CD-R, email, public forums, and
 75 | [USB dead drops](https://en.wikipedia.org/wiki/USB_dead_drop).
 76 | 
 77 | ## Data is tamper-resistant
 78 | 
 79 | Entries in the database are cryptographically signed. Because the
 80 | entries are signed, you don't have to worry about malicious third
 81 | parties tampering with your data.
 82 | 
 83 | ## Data is always available
 84 | 
 85 | Any data the user is currently accessing is already available offline,
 86 | and in case of a sudden internet outage, or poor connectivity issues,
 87 | the access to the data is not affected, because the data doesn't rely
 88 | on an internet connection.
 89 | 
 90 | You can "follow" peers, by copying their database to your
 91 | machine. Updates are performed by retrieving newer bundles from your
 92 | peers. This allows you to share your peers' bundles on behalf of
 93 | them. This is useful when the peer is unavailable and another peer
 94 | wants their bundle.
 95 | 
 96 | The act of sharing peers' data on behalf of other peers is called
 97 | "gossiping".
 98 | 
 99 | # Use-case scenarios
100 | 
101 | The Pigeon protocol may be useful in scenarios such as:
102 | 
103 | * Systems with low connectivity or uptime such as remote sensor
104 |   logging, maritime systems, solar systems with intermittent power,
105 |   IoT systems with poor network connectivity.
106 | * Store-and-forward message gateways, such as a
107 |   [data mule](https://en.wikipedia.org/wiki/Data_mule).
108 | * Censorship resistant applications, such as peer-to-peer messaging
109 |   and blogging.
110 | * [Delay tolerant networking](https://en.wikipedia.org/wiki/Delay-tolerant_networking)
111 | * Applications that require a high level of data-integrity or
112 |   auditing.
113 | * Delay-tolerant peer-to-peer social networks, games, file sharing
114 |   etc...
115 | * Time series data storage
116 | 
117 | # Software implementation ideas
118 | 
119 | * A messenger application
120 | * An IoT data logger
121 | * A newsgroup or [NNTP](https://en.wikipedia.org/wiki/Network_News_Transfer_Protocol) analog
122 | * A turn-based board game
123 | * A microblogging social network
124 | * An e-commerce application for P2P cryptocurrency users
125 | * A Secure Scuttlebutt import / export / gateway tool
126 | * A social mapping / point-of-interest sharing site
127 | * A Bluetooth file sharing application
128 | * A graphical database browser for developers that want to use the
129 |   protocol for log storage or as a time series database
130 | * A synchronization system over actual pigeons, possibly soliciting
131 |   help from the world-famous boxer and pigeon-racing enthusiast, Mike
132 |   Tyson
133 | 
134 | # Implementations
135 | 
136 | There is currently one working implementation available
137 | [here](https://github.com/PigeonProtocolConsortium/pigeon-cli-ruby).
138 | A long term goal is to support all major platforms and languages.
139 | 
140 | # How does the Pigeon protocol work?
141 | 
142 | Each node in a social network of peers has a local "log". The log is an
143 | append-only feed of messages written in an ASCII-based serialization
144 | format.
145 | 
146 | Messages are signed with a secret key to validate a message's
147 | integrity and to prevent tampering by malicious peers.
148 | 
149 | Nodes in the social network "follow" other logs from peers. Nodes replicate the
150 | logs of their peers and "gossip" information about peers across the
151 | social network.
152 | 
153 | Gossip information is packaged into "bundles" which contain backups of
154 | peer logs in a format that can be transmitted through sneakernet,
155 | direct serial connection, or any high-throughput medium, regardless of
156 | latency.
157 | 
158 | Log synchronization through Sneakernet is the main use case for Pigeon
159 | messages to be transmitted. SD Cards sent via postal mail offer an
160 | excellent medium for transmission of Pigeon messages, although any
161 | data transfer medium is possible.
162 | 
163 | ![](sync.png)
164 | 
165 | # What do Pigeon messages look like as data?
166 | 
167 | Pigeon messages use a custom ASCII-based encoding scheme, as seen in
168 | **Example 1** and **Example 2** below.
169 | 
170 | **Note**: Although the message encoding scheme is human-readable the
171 | messages should be parsed by third-party applications rather than
172 | written by hand.
173 | 
174 | **Example 1**:
175 | 
176 | ```
177 | author USER.R68Q26P1GEFC0SNVVQ9S29SWCVVRGCYRV7D96GAN3XVQE3F9AZJ0
178 | depth 0
179 | kind my_blog
180 | prev NONE
181 | 
182 | current_status:"Another great day. Nice weather, too!"
183 | 
184 | signature 2VMAG4SCX5RHVBKCB1RNZCB0AJN4WN6FEMS7W9FM1CVYSZXMX7CPQFCDPYEKCTGG91Y1YSGY4G5K8XAGQ67HEPDFRMRYQHWQBATAC2R
185 | 
186 | ```
187 | 
188 | **Example 2**:
189 | 
190 | ```
191 | author USER.R68Q26P1GEFC0SNVVQ9S29SWCVVRGCYRV7D96GAN3XVQE3F9AZJ0
192 | depth 1
193 | kind like
194 | prev TEXT.6CBA4J3756A5SNM1W1GHNCTT9EG95ZP3ZMAT5Z1EJP7TXMNNVZC0
195 | 
196 | liked_post_multihash:TEXT.6CBA4J3756A5SNM1W1GHNCTT9EG95ZP3ZMAT5Z1EJP7TXMNNVZC0
197 | 
198 | signature Y34Q47V0BY370RM5KWGRJRN9HFNGJN0C3DEYVB2V2476CW9RN5HD4XD7KMQ6T4T42N36R5P3XX6E3FYEWVZR25AVCF6KQPZHJP6EM10
199 | 
200 | ```
201 | 
202 | ![A hierarchy diagram showing how the message in example 2 points back to example 1, and how example 1 points back to NONE](diagram1.png)
203 | 
204 | For examples of how messages are handled, see the Ruby-implementation tutorial
205 | [here](https://github.com/PigeonProtocolConsortium/pigeon-cli-ruby/blob/main/ruby_tutorial.md)
206 | 
207 | # Constraints and Design Philosophy
208 | 
209 |  * Offline-first means offline-only. Never incorporate TCP or UDP
210 |    features. TCP- or UDP-related concerns must be handled by
211 |    higher-level protocols or by application developers. This is to
212 |    ensure the protocol is always an option for off-grid usage.
213 | 
214 |    <!-- I wasn't sure what the "do not make ... unless it would hurt portability" meant below -->
215 |  * Natural is better than simple. Convention over configuration. Do
216 |    not make plugins for common use cases unless it would hurt
217 |    portability.
218 | 
219 |  * Prefer a monolithic internal structure. Avoid external dependencies
220 |    except for limited use cases (Eg: crypto libs). Do not break things
221 |    into smaller pieces until there are at least three real-world
222 |    reasons to do so. Decoupling a library into a package for only 2
223 |    use cases is not acceptable.
224 | 
225 |  * Maintain ecosystem diversity by having a protocol that can be
226 |    easily and entirely ported to new languages and platforms.
227 | 
228 |  * No singletons. No signing authorities, no servers of any kind, even
229 |    locally, no differentiation between peers (eg: no "super peers").
230 | 
231 |  * Configuration is always a design compromise. We will allow a limit
232 |    of 10 configuration options for all eternity. These are simple
233 |    key/value pairs. No nesting, no namespacing, no dots, no dashes, no
234 |    nested config names, no arrays, none of that crap. Seriously, I'm
235 |    watching you.
236 | 
237 |  * Assume CPU and RAM are not plentiful.
238 | 
239 |  * Assume platform has no networking support. No servers. No hooks for
240 |    startup, shutdown, or reboot.
241 | 
242 |  * Assume block storage is plentiful when making resource allocation
243 |    trade-offs.
244 | 
245 |  * Files are better than sessions, but be filesystem
246 |    agnostic. Persistence mechanisms are implementation-specific.
247 | 
248 |  * Provide tamper resistance. Privacy features will be added later.
249 | 
250 |  * Enable "Free listening"
251 | 
252 |  * Have a formal specification (reference implementations are not OK).
253 | 
254 |  * Minimize conceptual overhead (If it's not needed at least 80% of
255 |    the time, don't add it).
256 | 
257 |  * Use a serialization format that is deterministic and easy to parse
258 |    on constrained devices.
259 | 
260 |  * Backwards compatibility. Numerous compromises have been made to
261 |    support legacy systems, such as devices that use FAT16 file systems or lack network support.
262 | 
263 | # What the Pigeon protocol is not trying to address
264 | 
265 | * Networking support: The protocol will make no mention of TCP, UDP,
266 |   SSH, HTTP, Etc..
267 | * Configurability: Configuration is the root of all evil. Instead of
268 |   trying to create something that serves every use case, focus on
269 |   over 80% use cases and allow edge cases to be handled by
270 |   application developers.
271 | * Anonymity: Though pseudonymity is possible via the use of multiple
272 |   identities, the concept of anonymity is not well suited to this
273 |   protocol. Every message is signed by a known identity, though
274 |   identities are easily created and can be backed by pseudonyms for
275 |   privacy.
276 | * OPEN TO DISCUSSION: Encryption. Like many internet protocols,
277 |   encryption concerns are offloaded to the transport layer. Consider
278 |   using an encrypted file system or encrypted compression application
279 |   to store data. If you have ideas on how we could support encryption,
280 |   please contact us. Please keep in mind that anonymity is not
281 |   necessarily a project goal.
282 | 
283 | # How the Pigeon protocol differs from Sneakernet
284 | 
285 | [Sneakernet](https://en.wikipedia.org/wiki/Sneakernet) is a protocol
286 | used by ancient civilizations to exchange files between computers with
287 | limited internet connectivity.
288 | 
289 | Although the Pigeon protocol messages can be exchanged over
290 | sneakernet, the Pigeon protocol is _not_ sneakernet. Sneakernet
291 | messages by themselves are not tamper-resistant, nor does it provide
292 | redundant backup using peers.
293 | 
294 | In contrast, a Pigeon protocol message is redundantly replicated
295 | _beyond_ its intended recipient to neighboring peers, "a friend of a
296 | friend", through gossip. Unlike sneakernet, the Pigeon protocol also
297 | uses cryptography to guarantee that a message's content has not been
298 | altered by a third party.
299 | 
300 | # How the Pigeon protocol differs From Secure Scuttlebutt
301 | 
302 | [Secure Scuttlebut](https://scuttlebutt.nz/) is a decentralized,
303 | peer-to-peer protocol that also works offline.
304 | 
305 | The Pigeon protocol does not rely on networking in the core
306 | library. Although Secure Scuttlebutt is able to support
307 | Sneakernet-only operation, it is difficult in practice due to reliance
308 | on UDP, TCP, and in the case of
309 | [pubs](https://github.com/ssbc/ssb-server/wiki/Pub-Servers), DNS.
310 | 
311 | The Pigeon protocol uses a custom key/value serialization format
312 | instead of JSON. This has two benefits:
313 | 
314 | * Serialization and signing is more simple, because indentation and
315 |   whitespace are less likely to cause verification problems.
316 | * Unlike JSON, pigeon messages do not allow nesting, which promotes
317 |   simplified message schemas.
318 | 
319 | The Pigeon protocol uses Crockford-flavored Base32 rather than URL
320 | safe Base64. This makes it easier to support old or low-powered
321 | systems and is easier to support FAT16 or embedded systems.
322 | 
323 | Unlike Secure Scuttlebutt, the Pigeon protocol was designed for
324 | portability and simplicity. It allows support for platforms that
325 | aren't limited to NodeJS.
326 | 
327 | Complicated features, such as network support, are ignored in favor of
328 | an easy-to-implement standard.
329 | 
330 | # Influences
331 | 
332 | Pigeon borrows many of the ideas set forth by the
333 | [Secure Scuttlebutt protocol](https://ssbc.github.io/scuttlebutt-protocol-guide/).
334 | It is our opinion that SSB is one of the most innovative protocols
335 | created in recent years. Without the research and efforts of the
336 | [Secure Scuttlebutt Consortium](https://github.com/ssbc)
337 | , this project would not be possible, so a big thanks goes out to all
338 | the people who make SSB possible.
339 | 
340 | We've also been inspired by the compactness and minimalism of
341 | [SQLite, which should serve as a role model for all of us](https://www.sqlite.org/talks/wroclaw-20090310.pdf).
342 | 
343 | In many ways, this protocol can be considered an amalgam of the best
344 | ideas from both SQLite and Secure Scuttlebutt.
345 | 
346 | # Getting involved with the Pigeon protocol development
347 | 
348 | **PIGEON PROTOCOL DEVELOPERS MAILING LIST:** Send an email with "subscribe" in the subject line to `pigeon_developers@vaporsoft.xyz`.
349 | 
350 | If you want to be involved with the Pigeon protocol development, there
351 | are areas we need help in currently:
352 | 
353 | * Documentation, editors, and feedback.
354 | * We need applications to be built using the protocol! We are happy to
355 |   assist you along the way.
356 | * We need a BNF grammar for Pigeon messages.
357 | 
358 | Your feedback really helps. Feel free to email us your opinions and
359 | ideas at `contact at vaporsoft.xyz`. We will reply to all messages.
360 | 
361 | # For more information
362 | 
363 | Check out the following links:
364 | 
365 | * [Message Format Specification](message_format.md)
366 | * [Bundle Format Specification](dev_docs.md)
367 | * [Frequently Asked Questions](faq.md)
368 | * [Roadmap](roadmap.md)
369 | * [Ideas and Features](ideas.md)
370 | 
371 | TODO:
372 | 
373 |  * Explain what forking is and why it is not supported.
374 |  * Explain how verification happens (Soapdog)
375 |  * Question: "How do apps find what they need in the Pigeon feeds and/or accumulate state forward? Is this the responsibility of the Pigeon libraries, or do apps do it themselves?"
376 | 


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/dev_docs.md:
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  1 | # Fundamental Concept: Free Listening
  2 | 
  3 | The concept of "Free Listening" is mentioned often when developing the protocol. The original concept is borrowed from the Secure Scuttlebutt protocol and is well summarized in [a 2018 work by Andre Staltz](https://staltz.com/reinvent-the-social-web.html):
  4 | 
  5 | ```
  6 | Pull is the opposite of push. Instead of realtime push notifications, you choose when you want to get updates about new content. Instead of free speech, as in the right to broadcast, we value free listening, which is the right not to be shouted at. Most social networks allow people to basically insert—push—themselves into a community. But Scuttlebutt invites are the other way around: someone in the community has to pull you in.
  7 | 
  8 | We are not proponents of total self-reliance. With full independence, you’d just be a lonely node in your social graph. The real value of the social graph is not the amount of nodes, it’s the amount of edges. They represent dependence on each other.
  9 | 
 10 | Your friend is your backup, literally. If you happen to lose all your data because your computer explodes, all you need is your crypto key pair, your identity, which is a small file. Then you can re-download everything you said and liked and did from a friend nearby. Nothing will be lost. This happened to someone in the community, and we were pleasantly surprised how well it worked.
 11 | ```
 12 | 
 13 | Pigeon has many of the same goals as Secure Scuttlebutt, including the user's right to Free Listening. Keep this in mind as you navigate the various design decisions and compromises of the protocol.
 14 | 
 15 | # Fundamental Concept: Content Addressing
 16 | 
 17 | Pigeon Protocol relies heavily on content addressing and the SHA-256 hashing algorithm. This means that instead of assigning arbitrary or user-generated names to resources (as is the case with web addresses), names are assigned using the SHA-256 hash algorithm.
 18 | 
 19 | Please watch [this video] if you are unfamiliar with hashing algorithms.
 20 | 
 21 | # Fundamental Concept: Digital Signatures
 22 | 
 23 | Pigeon uses [ED25519](https://ed25519.cr.yp.to/) to generate and verify message signatures. An understanding of digital signing algorithms is assumed. If you need help understanding this concept, please contact us on the mailing list. Due to time constraints, I will defer to existing resources that exist online.
 24 | 
 25 | # Messages: The Basic Building Block
 26 | 
 27 | The most important protocol concept is that of the "message".
 28 | In their most simple form, Pigeon protocol messages are just text documents. Text encoding is determined by the client, but UTF-8 is highly encouraged for maximum interoperability. They are human readable and can even be created by hand in a text editor, though most clients will provide better means of authoring messages.
 29 | 
 30 | Below is an example of such a message:
 31 | 
 32 | ```
 33 | author USER.4CZHSZAH8473YPHP1F1DR5ZVCRKEA4Q0BY18NMXYE14NZ0XV2PGG
 34 | depth 123
 35 | kind weather_report
 36 | prev TEXT.E90DY6RABDQ2CJPVQHYQDYH6N7Q46SZKQ0AQ76J6D684HYBRKE4G
 37 | 
 38 | temperature:"22.0C"
 39 | webcam_photo:FILE.FV0FJ0YZADY7C5JTTFYPKDBHTZJ5JVVP5TCKP0605WWXYJG4VMRG
 40 | weather_reported_by:USER.GGP2VX0ZN41EYXMN81YB0Q4AEKRCVZ5RD1F1PHPY3748HAZSHZC4
 41 | 
 42 | signature JSPJJQJRVBVGV52K2058AR2KFQCWSZ8M8W6Q6PB93R2T3SJ031AYX1X74KCW06HHVQ9Y6NDATGE6NH3W59QY35M58YDQC5WEA1ASW08
 43 | ```
 44 | 
 45 | The specifics of the message format are explained line-by-line [in the message format explanation document](message_format.md). **Please read the message format explanation document before continuing.**
 46 | 
 47 | # Bundles: The Transmission Medium
 48 | 
 49 | A message without a receiver is not very useful. Any peer in a Pigeon cluster has two things it needs to share with its peers:
 50 | 
 51 |  * Messages, created by the peer or forwarded on behalf of a "peer of a peer"
 52 |  * Files, in the form of blobs
 53 | 
 54 | Pigeon sends messages and files to peers through the use of "bundles". Bundles are a file directory arranged in a predictable layout that is specified by the protocol. Peers share bundles with each other through a variety of means. When a peer unpacks a bundle into their local database, the database contents are updated with new information from peers such as messages and blobs (files).
 55 | 
 56 | The directories are transmitted over any medium that supports file transfer (the protocol does not involve itself with such concerns).
 57 | 
 58 | Pigeon follows the philosophy of "offline-first means offline-only". Bundle files could theoretically be:
 59 | 
 60 |  * Transmitted over removable media such as USB drives or optical media (CD).
 61 |  * Compressed using zip compression to increase storage capacity.
 62 |  * Encrypted using tools like PGP
 63 |  * Hosted and dynamically updated on a web server for network retrieval.
 64 | 
 65 | The protocol does not place any restrictions on how bundles are handled, transported, compressed or encrypted. It does, however, dictate the internal layout of the bundle. Authors of protocol clients must pay special attention to how bundles are created to ensure security and interoperability between client implementations.
 66 | 
 67 | ## Where Do Messages Go in a Bundle?
 68 | 
 69 | A bundle's [message](message_format.md) payload (as opposed to its blob payload) is contained in a plaintext file at the root bundle directory. The file is named `messages.pgn`. Messages are joined together via carriage return (`\n`).
 70 | 
 71 | Typically, `messages.pgn` will contain messages created by the bundle's author, plus messages created by the author's peers.
 72 | 
 73 | Here is an example of  the contents of a `messages.pgn` file:
 74 | 
 75 | ```
 76 | author USER.R68Q26P1GEFC0SNVVQ9S29SWCVVRGCYRV7D96GAN3XVQE3F9AZJ0
 77 | depth 0
 78 | kind chat_message
 79 | prev NONE
 80 | 
 81 | content:"Hello, world!"
 82 | 
 83 | signature 2VMAG4SCX5RHVBKCB1RNZCB0AJN4WN6FEMS7W9FM1CVYSZXMX7CPQFCDPYEKCTGG91Y1YSGY4G5K8XAGQ67HEPDFRMRYQHWQBATAC2R
 84 | 
 85 | author USER.R68Q26P1GEFC0SNVVQ9S29SWCVVRGCYRV7D96GAN3XVQE3F9AZJ0
 86 | depth 1
 87 | kind chat_message
 88 | prev TEXT.6CBA4J3756A5SNM1W1GHNCTT9EG95ZP3ZMAT5Z1EJP7TXMNNVZC0
 89 | 
 90 | content:"Good morning!"
 91 | 
 92 | signature Y34Q47V0BY370RM5KWGRJRN9HFNGJN0C3DEYVB2V2476CW9RN5HD4XD7KMQ6T4T42N36R5P3XX6E3FYEWVZR25AVCF6KQPZHJP6EM10
 93 | 
 94 | author USER.0JZA9F3EQVX3NAG69D7VRYCGRVVCWS92S9QVVNS0CFEG1P62Q86R
 95 | depth 2
 96 | kind like
 97 | prev TEXT.GAP6NJ21K6N75RAEJQ10C2QHFXNRHVPMC54FMGVA77CDJ8AVZQB5
 98 | 
 99 | target:TEXT.5BQZVA8JDC77AVGMF45CMPVHRNXFHQ2C01QJEAR57N6K12JN6PAG
100 | 
101 | signature W68NWDQB2WTZ8T1RHP5BZA4N1STVKV16K0PXH10MZVR3XTF8HC7T8646X7SAKP5DFZ5K74QEKE3T2K6V0EST50YQQD7FD2PT0H8J62G
102 | ```
103 | 
104 | The example above is multiple pigeon messages joined together with a carriage return ("\n").
105 | **Notice that not all messages were created by the same author.**
106 | 
107 | A peer can use the file above to update their local database. It is important to note that **a client will always reject a message that it cannot verify**. Below is an example of a refused update:
108 | 
109 |  * Peer A has verified peer B's messages up to `depth 5`.
110 |  * Peer C sends Peer A a new bundle.
111 |  * The bundle contains messages authored by peer B, starting at `depth 8`.
112 |  * Since Peer A cannot verify message at `depth 8` until it receives `depth 7` and `depth 6`, the messages are rejected by peer A.
113 | 
114 |  * Clients always reject messages that cannot be verified. For example, if a `messages.pgn` file starts at `depth 6` for a peer `USER.ABC`, and the local client has only verified `USER.ABC`s feed up to `depth 3`, the messages in the bundle will be rejected by the local client because it does not have enough information available to verify the authenticity of the message.
115 |  * Messages must be ordered by `depth` for a particular author.
116 | 
117 | # Where Do Files Go in a Bundle?
118 | 
119 | Files ("blobs") are transferred alongside the `*.pgn` message bundle.
120 | It is the responsibility of the _receiver_ (not the sender) to calculate the multihash of an incoming file. The ensures that files are not misrepresented or tampered with.
121 | 
122 | Files added to a blob must follow these naming rules:
123 | 
124 |  * The [filename extension](https://en.wikipedia.org/wiki/Filename_extension) is located in the same directory as the `messages.pgn` file.
125 |  * The filename must follow [8.3 filename conventions](https://en.wikipedia.org/wiki/8.3_filename).
126 |   * The file extension must be `.blb`.
127 |   * The filename cannot be longer than 8 chars.
128 | 


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/diagram.md:
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 1 | Edit this diagram at https://mermaid-js.github.io/mermaid-live-editor/#/edit
 2 | ```mermaid
 3 | classDiagram
 4 | 	None <|-- Example1: None
 5 | 	Example1 <|-- Example2: TEXT.6CF2...A982
 6 | 
 7 |   class None{
 8 |     empty
 9 |   }
10 | 
11 | 	class Example1{
12 |     author USER.R68...ZJ0
13 |     depth 0
14 |     kind my_blog
15 |     prev NONE
16 | 
17 |     current_status:"Another great day. Nice weather, too!"
18 | 
19 |     signature 2VMAG...TAC2R
20 | 	}
21 | 
22 | 	class Example2{
23 |     author USER.R68...ZJ0
24 |     depth 1
25 |     kind like_a_post
26 |     prev TEXT.6CB...ZC0
27 | 
28 |     liked_post_multihash:TEXT.6CB...ZC0
29 | 
30 |     signature Y34Q47...6EM10
31 | 	}
32 | ```
33 | 


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/faq.md:
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 1 | # I Have Internet Access. Why Should I Care?
 2 | 
 3 |  * [Everything [in the cloud] is Amazing, But Nothing is Ours](https://alexdanco.com/2019/10/26/everything-is-amazing-but-nothing-is-ours/)
 4 |  * [Encryption is Not Preventing Law Enforcement from Investigating Crime](https://www.alec.org/article/encryption-is-not-preventing-law-enforcement-from-investigating-crime/)
 5 |  * [‘Nobody’s got to use the Internet’: A GOP lawmaker’s response to concerns about Web privacy](https://www.washingtonpost.com/news/powerpost/wp/2017/04/15/nobodys-got-to-use-the-internet-a-gop-lawmakers-response-to-concerns-about-web-privacy/)
 6 |  * [How Iran Turned Off the Internet](https://thewire.in/tech/how-iran-turned-off-the-internet)
 7 |  * [Google goes offline after fibre cables cut](https://www.bbc.com/news/technology-50851420)
 8 |  * [Building Internet-connected things seems obvious today, but what about when there’s no Internet?](https://back7.co/home/raspberry-pi-recovery-kit)
 9 |  * [The death of America's net neutrality and how it affects you](https://www.dw.com/en/the-death-of-americas-net-neutrality-and-how-it-affects-you/a-43934099)
10 |  * [YouTube and Facebook Are Removing Evidence of Atrocities, Jeopardizing Cases Against War Criminals](https://theintercept.com/2017/11/02/war-crimes-youtube-facebook-syria-rohingya/)
11 |  * [Iraq introduces nightly internet curfew](https://netblocks.org/reports/iraq-introduces-nightly-internet-curfew-JAp1DKBd)
12 |  * [Building a Low-Tech Internet](https://www.lowtechmagazine.com/2015/10/how-to-build-a-low-tech-internet.html)
13 |  * [Inside Cuba's massive, weekly, human-curated sneakernet](https://boingboing.net/2018/05/03/inside-cubas-massive-weekly.html)
14 |  * [CollapseOS](https://collapseos.org/)
15 |  * [Indian Internet shut down as protests rage against citizenship bill](https://edition.cnn.com/2019/12/12/asia/india-shutdown-citizenship-bill-intl-hnk/index.html)
16 |  * [Authoritarian Nations Are Turning the Internet Into a Weapon](https://onezero.medium.com/authoritarian-nations-are-turning-the-internet-into-a-weapon-10119d4e9992)
17 |  * [Russian Law Takes Effect that Gives Government Sweeping Power Over Internet](https://www.npr.org/2019/11/01/775366588/russian-law-takes-effect-that-gives-government-sweeping-power-over-internet)
18 | 
19 | # When is Pigeon the Wrong Choice?
20 | 
21 |  * When the application requires true deletion of data, ephemeral data or mutability of previously created data. Pigeon feeds are immutable, append-only and permanently replicated by peers.
22 |  * When the application requires realtime interactions or does not benefit from delay tolerance. Support for TCP or UDP sockets will never be added.
23 |  * Extremely "chatty" protocols. Pigeon was built with the assumption that data storage is cheap and data transfer is expensive and slow. Use cases with complex handshakes, pinging or timeouts may not be well suited to this protocol.
24 | 
25 | # Is This a Blockchain?
26 | 
27 | It's different than a block chain despite some similarity. A global blockchain is a singleton, and Pigeon has no singletons. Each Pigeon node maintains their own feed of messages rather than sharing a global feed. When you trust a peer, you agree to replicate their feed. You also replicate the feed of their peers. Unlike a blockchain, there are many feeds (rather than one) and they do not require consensus or coordination to coexist. Additionally, forking of feeds is not supported by Pigeon.
28 | 


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/ideas.md:
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1 | # Idea Bin
2 | 
3 | This is an ongoing list of ideas. Email me if you have ideas you would like to share.
4 | 
5 |  * Ephemeral key exchange
6 |  * Standardized general purpose message schemas (follow, unfollow, same_as, etc.)
7 | 


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/message_format.md:
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  1 | # Exploring the Pigeon Message Format
  2 | 
  3 | In the test that follows, we will explore a pigeon message line-by-line.
  4 | 
  5 | The example message is shown in its entirety below:
  6 | 
  7 | ```
  8 | author USER.4CZHSZAH8473YPHP1F1DR5ZVCRKEA4Q0BY18NMXYE14NZ0XV2PGG
  9 | depth 123
 10 | kind weather_report
 11 | prev TEXT.E90DY6RABDQ2CJPVQHYQDYH6N7Q46SZKQ0AQ76J6D684HYBRKE4G
 12 | 
 13 | temperature:"22.0C"
 14 | webcam_photo:FILE.FV0FJ0YZADY7C5JTTFYPKDBHTZJ5JVVP5TCKP0605WWXYJG4VMRG
 15 | weather_reported_by:USER.GGP2VX0ZN41EYXMN81YB0Q4AEKRCVZ5RD1F1PHPY3748HAZSHZC4
 16 | 
 17 | signature JSPJJQJRVBVGV52K2058AR2KFQCWSZ8M8W6Q6PB93R2T3SJ031AYX1X74KCW06HHVQ9Y6NDATGE6NH3W59QY35M58YDQC5WEA1ASW08
 18 | ```
 19 | 
 20 | ### Pigeon Multihashes and Data Types
 21 | 
 22 | Pigeon has 4 data types:
 23 | 
 24 |  * Blob multihash: Used to identify arbitrary binary files mentioned in a feed. Blob multihashes start with the word `FILE.`, followed by a Base32 hash (SHA256).
 25 |  * Message multihash: Used to reference a message in someone's feed. Starts with the word `TEXT.` followed by a Base32 SHA256 checksum.
 26 |  * User multihash: Used to reference a particular feed. Starts with the word `USER.` followed by a base32 encoded ED25519 public key.
 27 |  * String: Information shorter than 128 characters can be wrapped in "double quotes" and placed directly into messages. Larger strings must be converted to blobs. The byte length of a character is determined by the client's chosen text encoding scheme. Pigeon has no official text encoding, but UTF-8 is highly encouraged in scenarios where interoperability is important. One character always one character, even if it is multi-byte. Strings cannot contain whitespace characters (encoding dependent). The protocol does not implement character escaping (eg: `"\n"`). Please start a discussion on the mailing list if your application requires this feature.
 28 |  * None: The word "NONE" is used to indicate the absence of data, similarly to `null` or `nil` seen in some programming languages.
 29 | 
 30 | ### Parts of a Message
 31 | 
 32 | The three parts of a Pigeon message are:
 33 | 
 34 | 1. Header: Data that is used by the _protocol_
 35 | 2. Body: Data that is used by the _user or application_
 36 | 3. Footer: Cryptographic signature to prevent tampering or forgery.
 37 | 
 38 | **The parts of a message must follow the order specified in this document.** The order of headers is not user definable. The fact that headers are alphabetical is a coincidence and future versions of the protocol might not be alphabetized.
 39 | 
 40 | ### Parts of a Header
 41 | 
 42 | A header is the first part of a message and contains 5 subsections. Each of these sections will be explained in further detail in the sections that follow:
 43 | 
 44 |  1. `author`: A user multihash indicating the author of the message. The public key will be used to verify the signature (found in the footer)
 45 |  1. `depth`: The order number of the current message. Since feeds are append-only, this number will only increase. The `depth` field ensures unique message signatures, even for successive duplicate messages.
 46 |  1. `kind`: Used by applications to determine the intent or "shape" of a message.
 47 |  1. `prev`: The multihash of the previous message in the feed. Required for verifying the authenticity of a feed.
 48 | 
 49 | 
 50 | **Header entries must follow the order specified above.**
 51 | 
 52 | ### Line 1: `Author`
 53 | 
 54 | EXAMPLE:
 55 | 
 56 | ```
 57 | author USER.4CZHSZAH8473YPHP1F1DR5ZVCRKEA4Q0BY18NMXYE14NZ0XV2PGG
 58 | ```
 59 | 
 60 | The first line of a Pigeon message header is the `author` entry.
 61 | 
 62 | Every Pigeon database has an "identity". An identity is an ED25519 key pair that prevents tampering by parties other than the database owner. In the example above, the identity multihash was `USER.4CZHSZAH8473YPHP1F1DR5ZVCRKEA4Q0BY18NMXYE14NZ0XV2PGG`.
 63 | 
 64 | The steps to generate a valid identity are:
 65 | 
 66 | 1. Perform [Crockford Base32 encoding](https://www.crockford.com/base32.html) on an ED25519 public key.
 67 | 2. Concatenate the characters `USER.` to the beginning of the string from step 1.
 68 | 
 69 | ### Line 2: `Depth`
 70 | 
 71 | EXAMPLE:
 72 | 
 73 | ```
 74 | depth 3
 75 | ```
 76 | 
 77 | Pigeon messages exist in a linear sequence which only moves forward and never "forks", skips or moves backward.
 78 | Every message has a `depth` field to indicate its "place in line".
 79 | Because every message has an ever-increasing integer that never duplicates, every message in a Pigeon feed will have a unique hash. This is true even if messages have identical body content.
 80 | 
 81 | The `depth` count always starts at 0 and icreases by 1 every time a new message is added to the feeds. Feeds that assign `depth` values in a non-sequential order are invalid. Eg: No gaps, no skipping, etc..
 82 | 
 83 | ### Line 3: `Kind`
 84 | 
 85 | EXAMPLE:
 86 | 
 87 | ```
 88 | kind weather_report
 89 | ```
 90 | 
 91 | The second line of the header is the `kind` entry. This entry is user definable. The `kind` entry is used as a means of signalling intent to applications that will consume the message.
 92 | 
 93 | It must meet the following criteria:
 94 | 
 95 |  * Must be 1-90 characters in length
 96 |  * Cannot contain whitespace or control characters
 97 |  * May contain any of the following characters:
 98 |     * alphanumeric characters
 99 |     * dashes (`-`), underscores (`_`) and dots (`.`)
100 | 
101 | **For the first message of a feed, this value is set to `NONE`.**
102 | 
103 | Message multihashes are calculated as follows:
104 | 
105 | 1. Create a [Crockford base 32](https://www.crockford.com/base32.html) sha256 hash of the message's content.
106 | 2. Append the string `TEXT.` to the front of the checksum created in step 1.
107 | 
108 | ### Line 4: `Prev`
109 | 
110 | EXAMPLE:
111 | 
112 | ```
113 | prev TEXT.E90DY6RABDQ2CJPVQHYQDYH6N7Q46SZKQ0AQ76J6D684HYBRKE4G
114 | ```
115 | 
116 | A Pigeon message feed is a unidirectional chain of documents where the newest document points back to the document that came before it in the chain ([example diagram](diagram1.png)).
117 | 
118 | To create this chain, a Pigeon message uses the `prev` field. The `prev` field contains a message multihash. In this case, the multihash is `TEXT.E90DY6RABDQ2CJPVQHYQDYH6N7Q46SZKQ0AQ76J6D684HYBRKE4G`.
119 | 
120 | Messages are content addressed. This is in contrast to protocols such as HTTP which use names to identify resources. Because Pigeon messages are addressed by content rather than by name, changing a message's content, even by just one character, has the effect of completely changing the message's multihash.
121 | 
122 | 
123 | ### Line 5: Body Start (Empty Line)
124 | 
125 | Once all headers are added, a client must place an empty line (`\n`) after the header.
126 | The empty line signifies the start of the message body.
127 | 
128 | Some notes about body entries:
129 | 
130 |  * The body of a message starts and ends with an empty line (`\n`).
131 |  * Every body entry is a key value pair. Keys and values are separated by a `:` character (no spaces).
132 |  * A message may not exceed 128 key/value pairs.
133 |  * A key must be 1-90 characters in length.
134 |  * A key cannot contain whitespace or control characters
135 |  * A key only contains the following characters (`[A-Z|a-z|\-|\_|\.|0-9]{1,90}`):
136 |     * alphanumeric characters (a-z, A-Z, 0-9)
137 |     * dots (`.`)
138 |     * dashes (`-`)
139 |     * underscores (`_`)
140 |  * A value may be a:
141 |    * A string (128 characters or less)
142 |    * A multihash referencing an identity (`USER.`), a message (`TEXT.`) or a blob (`FILE.`).
143 | 
144 | ### Lines 6: Example Entry Containing a String
145 | 
146 | EXAMPLE:
147 | 
148 | ```
149 | temperature:"22.0C"
150 | ```
151 | 
152 | Body entries are defined by the user and contain key/value pairs of application-specific data.
153 | When a key/value pair represents something other than an identity, blob or message ID, a string is used.
154 | Strings can be used for any type of data that does not fit into the other three categories.
155 | Strings must be less than or equal to 128 characters in length.
156 | The example above is the most simple kind of body entry. It specifies an arbitrary string representing the current temperature.
157 | 
158 | The protocol does not dictate the format of strings (ie: there is no 1st class JSON support). The meaning and formatting of a string is the responsibility of the application.
159 | 
160 | ### Lines 7: Entry Referencing a Blob
161 | 
162 | EXAMPLE:
163 | 
164 | ```
165 | webcam_photo:FILE.FV0FJ0YZADY7C5JTTFYPKDBHTZJ5JVVP5TCKP0605WWXYJG4VMRG
166 | ```
167 | 
168 | Applications may attach files to messages in the form of blobs. Blobs are referenced using a blob multihash.
169 | 
170 | A blob is referenced in a message's key or value. A client will include a blob's content in a "bundle" (explained later). This ensures that a feed's peers get a copy of the file that a message references.
171 | 
172 | ### Lines 8: Entry Referencing a Peer's Identity
173 | 
174 | EXAMPLE:
175 | 
176 | ```
177 | weather_reported_by:USER.GGP2VX0ZN41EYXMN81YB0Q4AEKRCVZ5RD1F1PHPY3748HAZSHZC4
178 | ```
179 | 
180 | A message may reference other identities (or its own identity) by using an identity multihash either in the key or value portion of the entry.
181 | 
182 | This is analogous to "social tagging" seen in many social networks.
183 | 
184 | ### Lines 9: Empty Carriage Return (Footer Start)
185 | 
186 | The last part of a message is the footer. Like a message body, a message footer starts and ends with an empty line.
187 | The footer is essential for ensuring the tamper resistant properties of a Pigeon message.
188 | 
189 | ### Lines 10: Signature Line
190 | 
191 | EXAMPLE:
192 | 
193 | ```
194 | signature JSPJJQJRVBVGV52K2058AR2KFQCWSZ8M8W6Q6PB93R2T3SJ031AYX1X74KCW06HHVQ9Y6NDATGE6NH3W59QY35M58YDQC5WEA1ASW08
195 | ```
196 | 
197 | A signature starts with the word `signature` followed by a space.
198 | After that, the body and header (including the trailing `\n`) are signed using the author's ED25519 key.
199 | The signature is encoded with Crockford base 32.
200 | An empty carriage return is added after the signature line.
201 | 


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/roadmap.md:
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 1 | 
 2 | # Roadmap
 3 | 
 4 | ## Phase I: Build a Working Client
 5 | 
 6 | **Completed April 2020**
 7 | 
 8 | This is the brainstorming phase where the initial proof-of-concept clients will be written. The first protocol client will be slow and may not be suitable for embedded use within a larger application.
 9 | 
10 | This phase is complete when there is at least one functioning client implementation.
11 | 
12 | ## [Current] Phase II: Build a Working Application
13 | 
14 | Using the protocol client from phase I, build an application which uses Pigeon for simulated real-world conditions. This phase will allow for discovery of problems with the draft specification and the first client implementations.
15 | 
16 | Please see the "What's Possible" section for a list of applications that may be published.
17 | 
18 | This phase is complete when there are at least two applications (rather than libs or clients) that utilize the protocol.
19 | 
20 | ## Phase III: Client Improvements
21 | 
22 | Once a gauntlet of applications have been built and outstanding design problems have been addressed, re-write existing client libraries. Unlike the client built in Phase I, the clients built in this phase will have a focus on:
23 | 
24 |  * Production-scale performance
25 |  * Stability
26 |  * Portability to targets like WASM, embedded systems, Windows, etc..
27 |  * Ability to be embedded into existing applications.
28 | 
29 | This phase is complete when:
30 |  * There is a client library that is written in an embeddable language (C, Rust, etc..).
31 |  * There is a client library that can performantly serve a mesh of more than 15 peers in a real-world application.
32 | 
33 | Nice-to-haves for this phase: see the implementation of a WASM and bare metal (embedded) client.
34 | 
35 | ## Phase IV: Finalize v1 Spec
36 | 
37 | Once a production-grade client exists, the focus will then become documentation. Using the knowledge gained from phases I-III, we will re-write all documentation, possibly using Gitbook or similar services.
38 | 
39 | Version 1 of the protocol will be considered complete at this phase and the protocol will be considered "ready for production use".
40 | 
41 | This phase is complete when the "Pigeon Protocol Handbook" is authored. The handbook will be a guide less than 100 pages long, that can be read by a developer from start to finish (as opposed to being referenced) to help them start writing Pigeon applications.
42 | 
43 | ## Phase V: Stabilize, Maintain, Proliferate
44 | 
45 | With a finalized spec and a portable client library, the next goal is to promote the product to as many developers as possible and continue to author software that is well suited to the protocol.
46 | 
47 | This phase will be considered complete when there are three production-scale apps using the libraries authored. By this point, we've hopefully made a difference and helped people regain control of their data and find a new alternative to the current status-quo of "online only" computer applications.
48 | 
49 | After that, I might rename the project so that we are not tied to the legacy baggage of the prototype phase. It might be fun to apply to a grant for continued maintenance (or just lock down the feature set- it's too early to say).
50 | 


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