Channels, Feeds & Transactions Discussion group meeting 15 July 2021

[kriswest]

Group overview

There are currently 11 10 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 15 July 2021 - 9am EST / 2pm GMT

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Agenda

• Convene & roll call, review meeting notices (5mins)
• Review action items from previous meeting (5mins)
• Application Interop use-cases (& whether they are all served by current FDC3 API features) (40mins)
  • Related issues:
    • Refine the description of App and System channels in the spec to clarify intended use #376
    • Data Driven Intents #201
    • Add Request/Response - Remote Procedure call style interaction #203
    • Application channel discovery #220
• AOB & Adjourn (5mins)

Minutes

@kriswest presented notes on interop use-cases:

1. User-controlled Context linking (system channels)

• Predefined colour channels with display metadata - currently called 'System channels'
  • Confusing name, not well defined in docs, only in spec
• Any member of a channel can post or listen for (typed) context
  • No way to determine sender of messages
• Currently supported
  • However, you can 'join' any channel with the API, which was probably not intended. Should we enforce only joining system channels?
• Use-cases:
  • Use Case 1: Equity sell side trader:
    https://fdc3.finos.org/docs/use-cases/uc-1 (workflows 4 & 5)
  • Use Case 15: Sales Floor Base Workflow
    https://fdc3.finos.org/docs/use-cases/uc-15
  • Use Case 17: Fine-tuning InterOp with Channels
    https://fdc3.finos.org/docs/use-cases/uc-17

2. Developer-controlled Context linking (app channels)

• Arbitrary named channels - currently called 'App channels'
• Any member of a channel can post or listen for (typed) context
  • No way to determine sender
• Currently supported via bus-style communication (with typed last value cache) on channels
• Use-cases:
  • Use Case 9: Call Transcription to CRM
    https://fdc3.finos.org/docs/use-cases/uc-9
  • Use Case 10: Real-Time voice trades -> trade ticket population
    https://fdc3.finos.org/docs/use-cases/uc-10
  • Use Case 15: Sales Floor Base Workflow
    https://fdc3.finos.org/docs/use-cases/uc-15
  • Use Case 17: Fine-tuning InterOp with Channels
    https://fdc3.finos.org/docs/use-cases/uc-17

3. Requesting an action (Raising an intent)

• Fire and forget - metadata is returned on what app resolved the intent, but no response data
• Supported with a context or without (fd3.nothing type, coming soon)
• Currently supported
• Use-cases:
  • Use Case 1: Equity sell side trader
    https://fdc3.finos.org/docs/use-cases/uc-1 (workflows 1-3)
  • Use Case 2: Buy side Portfolio Manager
    https://fdc3.finos.org/docs/use-cases/uc-2 (workflows 3-6)
  • Use Case 9: Call Transcription to CRM
    https://fdc3.finos.org/docs/use-cases/uc-9
  • Use Case 10: Real-Time voice trades -> trade ticket population
    https://fdc3.finos.org/docs/use-cases/uc-10
  • Use Case 15: Sales Floor Base Workflow
    https://fdc3.finos.org/docs/use-cases/uc-15

4. Open an application (optionally with context)

• Currently supported (fdc3.open)
  • Although not possible to get a list of available applications through API
  • It IS possible to get a list of apps that can resolve an intent however...
• Use-cases:
  • Use Case 3: In-house Cross-Platform Launcher
    https://fdc3.finos.org/docs/use-cases/uc-3
  • Use Case 13: User launches multiple apps from a single container
    https://fdc3.finos.org/docs/use-cases/uc-13

5. Requesting a response (a Transaction or intent that returns data)

• Raising an intent and receive a single response back with data
  • Part of the original idea for intents, but not fulfilled correctly
• Not currently supported!
• Fairly simple proposal to resolve
  https://docs.google.com/document/d/1OTODXIbOifsBSWboAofTtUGRyxiFapcisCf8a65Ex8w/edit?ts=60db4746#heading=h.3tcfym35ggnx
  • Proposal to be posted on issue
  • How long should you wait? Does proposal need to incorporate an optional timeout?
• Use-cases:
  • Use Case 4: Client-side FX Trader Credit Check
    https://fdc3.finos.org/docs/use-cases/uc-4
  • Use Case 9: Call Transcription to CRM
    https://fdc3.finos.org/docs/use-cases/uc-9
  • Use Case 15: Sales Floor Base Workflow
    https://fdc3.finos.org/docs/use-cases/uc-15
  • Riko’s OSSF talk from 2020 describes a real-world use case in which an intent that returns data is useful:
    https://www.youtube.com/watch?v=sTyEphOHPKw
    Intent: ExecuteTrade
    Context: TradeRequest (requestId, instrument, side, price, quantity etc.)
    Return context: TradeResponse (requestId, tradeId, success/failure, timestamp etc.)

6. Requesting or sending a (private?) stream of data (a Feed or Stream)

• A more specific and more restricted channel for communicating with/receiving messages from a specific application on a specific topic
  • Messages to be delivered to a particular entity, NOT shared with other apps
  • Source of messages to be identifiable
  • Multiple responses at regular or irregular intervals
• A context may be required to characterize the request (e.g. request pricing for specified security)
  Stream likely to NOT exist before request (It's impractical to stream prices for every security) and may need to be cleaned up when no longer needed.
  • Track subscription/unsubscription
  • Need to be sure all responses come from the same entity (other apps should not be able to publish messages)
  • Not currently supported!
  • Use-cases:
    • Use Case 5: Buy side Treasurer - client rates across providers
      https://fdc3.finos.org/docs/use-cases/uc-5
    • Request a feed from a particular application that provides Pricing (type of feed) of specific security (context).
    • RFQs (type) for a particular market sector, client or security (context)
      Notifications feed
    • Any use-case where the sender must be known / it is imperative that other apps NOT be able to send their own messages.
    • Working with the container/Dekstop Agent itself, where the feeds are created and used by the desktop agent/container to implement functionality that interacts with the desktop, rather than a specific application.
      • Feeds might be used to implement functions such as:
        a. Workspace state saving
        b. Notification
        c. Federated search
        d. Authentication
        e. Lifecycle management (startup dependencies, graceful shutdowns)
        f. User preferences
      • Although FDC3 is not intended to provide an API for an application container, shared facilities like these are common parts of a multi-vendor Desktop and are not easy to implement with FDC3's channels and intents alone. The ability to integrate apps into a common platform is a key aspect of them working together

@lspiro-Tick42 also raised the streams feature in plexus as something we should review in a future meeting.

(Minutes still WIP)

Action Items

• Raise an issue to change the name of 'system channels' to 'user channels' and update documentation to be clear on what actions can only be performed on a user channel.
  • Rename 'System Channels' 'User Channels' #430
• Raise an issue to consider deprecating fdc3.joinChannel as this is intended to be provided by the desktop agent as UI.
  • Make optional: fdc3.joinChannel and fdc3.leaveChannel #431
• Raise an issue for the transactions proposal (intents that return data)
  • Make it possible to return data from a raised intent #432
• Raise an issue to add a stream or feed concept to FDC3 with a summary of the requirements agreed during the meeting. Proposals can then be added to that issue
  • Add the concept of a feed or stream to FDC3 to handle use-cases not covered by channels or intents #433

Untracked attendees

Full name	Affiliation	GitHub username

[kriswest]

🚀

[ggeorgievx]

Present ✅

[openfin-gavin]

here

[thorsent]

Present

[lspiro-Tick42]

Here

[rikoe]

hi

[agitana]

Aitana Myohl / FINOS

[jgavronsky]

Jane@FINOS

[Julia-Ritter]

Julia Ritter / FINOS

[Julia-Ritter]

Untracked attendees:

• David Jones / ipushpull
• Terry Thorsen / Cosiac
• Yin Phyu / IHS Markit