Channels, Feeds & Transactions Discussion group meeting 30th Sept 2021

[kriswest]

Group overview

There are currently 13 open issues in the FDC3 repository, under consideration for the 2.0 release, that relate to the existing concept of channels (both the 'system channels' used via the desktop agent API, and 'app channels' interacted with through the Channels API) and new concepts we've discussed introducing: transactions (a standardized way to make a request and receive a response back) and feeds (a standardized way to request a stream of data, such as a pricing stream).

Relevant issue tags

Current open issues that relate to the above concepts with the label:

Meeting Date

Thursday 30th Sept 2021 - 9am EDT / 2pm BST

WebEx info

• Meeting Link
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• Password: 4eZpzMTm7J6

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Meeting notices

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Agenda

• Convene & roll call, review meeting notices (5mins)
• Review action items from previous meeting (5mins)
  • Channels, Feeds & Transactions Discussion group meeting 9th Sept 2021 #452
  • New reviews needed:
    • Support raiseIntent without a context #361
      • Support raise Intent without a context #375
    • fdc3.joinChannel docs should explain expected behavior on joinChannel #418
      • Clarify existing behavior of joinChannel and addIntentListener when joining a channel #454
    • Documentation for raise intent only describes the case with a specified app #426
      • Improve the raiseIntent documentation #461
    • Clarify how apps should handle broadcast and receipt of multiple context types #434
      • Clarify broadcast of complex context types #464
    • Method.ts addContextListener signature was not updated for 1.2 and it overrides types for Desktop Agent #435
      • fix: update Methods addContextListener to support new signature #462
• Add the concept of a feed or stream to FDC3 to handle use-cases not covered by channels or intents #433 (35mins)
• Getting started on Allow intents to be targeted at specific instances of apps #450 (10mins)
• Next meeting agenda, AOB & Adjourn (5mins)

Minutes

#433

• Wherever possible we should reuse existing concepts
  • However, channels currently fall short
    • E.g. Not possible to do discovery, track subscriptions, know who you are exchanging messages with etc.
  • Identity
    • You'll definitely want controls over who can join, or who you are listening to when working with concepts like pricing
      • with channels, any app could spoof messages, or two apps could try and push pricing streams to the same channel
    • Should credential be a concept in FDC3?
      • The spec might not define the standard for credentials, but at least allow them to be passed in some way so another app could verify them
  • Concerns raised over discovery (and firms reporting over what else was running on the desktop)
    • To a certain extent this is already possible with findIntent...
  • Concerns raise over 1:1 comms or authentication/authorisation for comms being against the 'spirit' of FDC3
    • we're really talking about either 1:* comms or 1:1 - the main point that on one end there is guaranteed to be a single entity (feed owner)
    • we already doing 1:1 comms with intents - FDC3 enables it without prior coordination
    • channels are : comms
    • FDC3 comms is, at the moment, anonymous, does this proposal change that?
      • Not necessarily - we guaranteeing that one end of the communication is always the same entity
      • It's previously been commented that implementations of Desktop Agents could differentiate themselves with features such as security (in this case authentication) - the standard doesn't have to define how this is implemented, it only has to do the minimum necessary to enable it.
• Resolved to allow time for proposals to be considered further and revised at the next meeting

#450

• A quick overview was given of the following:
  • the previous attempt at dealing with app instances (App instance proposal + connect to app instance for intent results #287)
    • some find this proposal counterintuitive
  • straw-man proposals that introduce less new concepts than the previous attempt (and are compatible with favoured proposal to solve Make it possible to return data from a raised intent #432)
    • Proposal A
    • Proposal B
    • Supplementary proposal
• Some positive opinions of Proposal A were expressed
  • We should arrange things so that apps don't have to create their own AppMetadata/AppInstance objects, they should always be able to use one returned to them by another API call (allows for some diversity in implementations)
• Resolved to allow time for proposals to be considered further and revised at the next meeting

Action Items

• All Before next meeting, please review straw-man proposals already posted:
  • Feeds proposal
  • Instances Proposal A
  • Instances Proposal B
  • Instances Supplementary Proposal
• @kriswest Next meeting agenda:
  • Continue the discussion on:
    • Add the concept of a feed or stream to FDC3 to handle use-cases not covered by channels or intents #433
    • Allow intents to be targeted at specific instances of apps #450
• Rolled over from previous meetings:
  • @rikoe Raise an issue for adding TS generics to FDC3 APIs
  • @rikoe Split out separate issues for raiseIntent with data return type for other API extensions, and declaring return types in AppD intents
  • (needs PR author) Rename 'System Channels' 'User Channels' #430
  • @kriswest Make optional: fdc3.joinChannel and fdc3.leaveChannel #431 (Documentation only)
  • @kriswest / @thorsent Make it possible to return data from a raised intent #432 (Create PR for final proposal @thorsent posted)
  • (needs PR author) Improve spec and documentation of fdc3.addContentListener to mention joining channels #451
  • @pbaize All DesktopAgent and Channel APIs should be async #362
  • @kriswest @rikoe Discuss experimental features (stage 1/stage 2) in terms of spec rewrites with LF team

Untracked attendees

Full name	Affiliation	GitHub username

[kriswest]

🚀

[mattjamieson]

🤖

[Julia-Ritter]

Julia // FINOS

[openfin-gavin]

here

[agitana]

Aitana Myohl / FINOS

[thorsent]

Present

[pbaize]

Here

[jgavronsky]

Jane Gavronsky @ FINOS here