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[MINUTES] W3C CCG Verifiable Credentials API Call - 2022-02-01

From: CCG Minutes Bot <minutes@w3c-ccg.org>
Date: Fri, 04 Feb 2022 00:06:33 +0000
Message-ID: <E1nFm7P-0006ur-1B@mimas.w3.org>
Thanks to Our Robot Overlords for scribing this week!

The transcript for the call is now available here:


Full text of the discussion follows for W3C archival purposes.
Audio of the meeting is available at the following location:


VC API Task Force Transcript for 2022-02-01

  1. Introductions and Community Updates
  2. Start Workflow - Presentation Availability Convergence
Action Items:
  1. Update Presentation Availability to 
    "/exchanges/initiate/{exchange-type-id}/{?exchange-uuid}" and you 
    have to POST data to the endpoints.
  2. Update POST body to accept a JSON object, where the 
    Traceability spec will further define exactly the type of object 
    they're looking for (a VPR?)
  Manu Sporny, Orie Steele, Markus Sabadello, Mike Varley, Mahmoud Alkhraishi
  Our Robot Overlords
  Mike Prorock, Manu Sporny, Mahmoud Alkhraishi, Markus Sabadello, 
  TallTed // Ted Thibodeau (he/him) (OpenLinkSw.com), Andy Miller, 
  Dmitri Zagidulin, Joe Andrieu, Juan Caballero, Kerri Lemoie, Phil 
  L (P1), PL (T3), Eric Schuh, Kaliya Young

Our Robot Overlords are scribing.
Manu Sporny:  All right welcome everyone to the February 1st 2022 
  verifiable credentials API call we have our agenda in the chat 
  Channel right now on the agenda today we have an agenda review 
  introductions relevant Community updates.
Manu Sporny:  We have a discussion on workflow so the the kind of 
  one of the goals of this call is to try and align two calls in 
  the VC API with what the traceability folks are doing and so 
  we're going to attempt the whole call today is going to be 
  focused on getting that kind of alignment so that has to do with 
  the start workflow and then the presentation availability.
Manu Sporny:  With either workflow interaction or the submit 
  presentation call so they're just two calls therefore calls now 
  we're going to try and boil them down into two calls if possible 
  or just get a plan together and how to do that there's also some 
  issue processing that we need to do Mike I think you raised the 
  concern about controller style and point the pattern that we're 
  using for the API and so maybe we want to change that and then 
  there's this.
Manu Sporny:  Flo IDs and names should they be in the URL or 
  should they be in the post body so those are the items that we 
  have for discussion today and then we'll do issue processing if 
  we have any time left over which I doubt we're going to have any 
  updates or changes to the agenda anything else folks want to 
  discuss today.
Manu Sporny:  Okay is there anyone new to the call or anyone that 
  would like to reintroduce themselves.

Topic: Introductions and Community Updates

Manu Sporny:  All right is there are there any Community updates 
  specifically relevant to be Capi.
Manu Sporny:  I do think it's probably relevant mentioning the 
<manu_sporny> VC APIs "out of scope": 
Manu Sporny:  Disagreements that are happening right now for 
  those of you that are not aware BC apis there's a suggestion by 
  Microsoft that any kind of protocol work any kind of API work in 
  the VC 2.
Manu Sporny:   Co-working.
<pl_(t3)> Why is MS saying that?
Manu Sporny:  Escape completely don't want to talk about 
  protocols none of that stuff there are a couple of us that are 
  engaging in that thread we would appreciate others chiming in one 
  of the concerns here is that we want to.
Manu Sporny:  One of the concerns there is that we want to 
  publish a note around the work that we're doing in this group 
  just to set it up so that we can take it standards track during 
  the next recharter which would be in 2 years or whenever the work 
  you know when of the working group finishes its work there.
Manu Sporny:  Yourself seems to be pushing back pretty hard on 
  that Phil you asked why currently Microsoft is trying to get open 
  IDC the protocol in as the protocol to move mobile driver's 
  licenses around there has been a decent bit of pushback on mdl as 
  it's currently formed because it doesn't take into account 
  verifiable credentials and verifiable presentations.
Manu Sporny:  And this is just my opinion my expectation is 
  Microsoft would like to see that happen over open I DC connect 
  and having another protocol out there that moves verifiable 
  credentials around places that approach into question.
Manu Sporny:  I will pause and other people that you know other 
  people may want to speak to that as well anyone want to put 
  themselves on the Queue to speak to that.
<juancaballero> or at least, into competition :)
<pl_(t3)> Understood. The revenue impact is now getting clearer 
Mike Prorock:  Yeah and II think that there's definitely some 
  folks working pretty hard on going down like you know open ID can 
  act as a path for exchanging credentials right and I don't think 
  that's going to change right when we look at the way you know 
  who's involved Etc I do think that there is a potential path 
  forward to do so and in fact I opened a PR for it man oh I don't 
  know if you saw that all.
Mike Prorock:  I think 66 all lengths.
Mike Prorock: https://github.com/w3c/vc-wg-charter/pull/66
Mike Prorock:  But basically this a look let's go ahead and very 
  explicitly in the non-normative side of things from a developer 
  you know be able to give developer documentation guidance 
  etcetera put up possibly as an extension or set of extensions on 
  top of the existing implementation guide for a rest API 
  definition such as we're talking about here but also not to rule 
  out guidance on how to handle you know if you're going to 
  exchange credentials via open it.
Mike Prorock:   Eid connect we should be able as working group to 
  discuss that.
Mike Prorock:  His well basically right because I don't it's 
  gonna take a little while to get to some consensus on that and I 
  think the danger that I see is that if we try to push back hard 
  on open ID connect or push back hard on something else that they 
  you know we may see what more resistance to saying look any 
  protocols you know for exchanger discussion of that even in a non 
  normative ways out the.
Mike Prorock:   Window and that's that's.
Mike Prorock:  More dangerous I think from an adoption 
Mike Prorock: +1 Be able to discuss REST APIs
Manu Sporny:  Sure and in the suggestion isn't to say you can't 
  do open ID connect it's it's yeah absolutely if you want to do 
  open ID connect and move these around on it that's great we 
  should be able to talk about that in the group and if the folks 
  in this group want to see the VC API as a part of that discussion 
  we need to put it in scope so the concern here is that if we 
  don't put the document we're working on right now squarely in.
Manu Sporny:  From a non-normative standpoint there will be.
Manu Sporny:  About it right so that is that is the concern that 
  I have is that if we do not make it very clear that we can talk 
  about VC API and publish it as node and all that kind of stuff 
  there will be objections to doing that once the working group 
  starts up go ahead Joe your.
Joe Andrieu:  I think you mean stop talking about it in that 
  working group which is not the context we're talking about that 
  now so it still wouldn't prevent us from continuing the ccg work 
  on it or charger in another working group to actually standardize 
  it all right.
<mprorock> we will move on from it and not dedicate resources if 
  it is not in the WG
Manu Sporny:  That is partially correct remember this is now 
  somewhat of a race in open ID has its own foundation and you know 
  these participants are active there in all they have to do is 
  stamp something as a standard of they're done it's a it's a 
  global standard and then all of a sudden the VC API is a why do 
  we need that when we already have this other standard out there 
  right so.
Manu Sporny:   From a strategic.
Manu Sporny:  They think it's a bit concerning if we just 
  continue to work on this as a community group and it continues to 
  be referred to as a yeah but that's just some random group of 
  people on the Internet working on it rather than it being 
  actually discussed the spec itself in published as a note in the 
  verifiable credential working group so that we can take it 
  standards track.
Manu Sporny:  I'm sorry I think I jumped the cute and I might go 
  ahead apologies.
Mike Prorock:  Yeah I think I was going to say some of what you 
  were saying there but I will clarify like for instance just 
  because of limited resources and having to pick our battles like 
  if honestly like if some kind of a rest API and I think putting a 
  reference in directly to the VC API as it stands today is not the 
  worst idea but it you know if that's not as part of that working 
  group honestly we're going to probably.
Mike Prorock:  Have to move on.
Mike Prorock:  Try we just have limited resources to go dedicate 
  to it especially if there's a clear path to like an open ID 
  connect path right so that's the that's the difficulty I see I 
  vastly prefer arrest for all of these interactions right so 
  that's part of the reason I'm making the effort here and you know 
  opening PRS I and you know discussing on the issues over on the 
  work group you know Charter discussion because I think it's 
  important to have a clear restful.
Mike Prorock:   Path to exchange this kind of the.
Manu Sporny:  All right thanks for that Mike no one else is on 
  the Queue will move on we've just you know this was just 
  highlight that that conversation is happening there.
Manu Sporny:  Okay happy to do that.
Mike Prorock:  Yeah let's think I was going to say Manu if if you 
  want to suggest on that PR you know like a such as and then a 
  link to the VC API or something I'm happy to I think that'd be a 
  good way to at least get the conversation going in one place on 
  that yeah cool thanks.

Topic: Start Workflow - Presentation Availability Convergence

Manu Sporny:  All right so let's go ahead and move into our first 
  topic then which is the start workflow presentation availability 
  convergence discussion so let me go ahead and share my screen 
  here one second.
Manu Sporny:  There are currently two calls in the VC API that 
  effectively do the same thing one of them has been in there for a 
  while and that is the presentation availability availability and 
  point in the purpose of this endpoint please correct me if I'm 
  wrong here Mike is to basically kind of.
Manu Sporny:   Say that you.
Manu Sporny:  Have some presentations available to the server so 
  you're the client and you're contacting the server and you're 
  like I've got some stuff that I'd like to send you the server 
  then responds with potentially be PRI VPR a verifiable 
  presentation request and it's like okay well if you want to send 
  those things to me here's some here's some instructions on how 
  you do it the start workflow.
<mprorock> yep, Query By example, Challenge, etc
Manu Sporny:  As opposed to end point in when you post data to it 
  the workflows kind of encoded as a in the URL and it says okay if 
  you want to start that workflow with me here's a verifiable 
  presentation request so the only thing that differs between these 
  two endpoints is the data that you post to it the start workflow 
  call just takes any object it's just like just send me it's.
Manu Sporny:   It's not very specific.
Manu Sporny:  In the expectation here is that the server once it 
  receives the object will understand oh you want to do that kind 
  of workflow with me and you gave me the data to kind of kick it 
  off and here's your presentation request and then you go back and 
  forth on that the presentation availability and point is a little 
  more specific in that you actually I think Mike you send it a VPR 
  but it's effectively an.
Manu Sporny:   Checked you send it an object and it responds back 
  with a.
Manu Sporny:  Want to send me that information here the things 
  that you need to hear the things you really need to send me and 
  the thing that's usually returned in both cases is like a domain 
  and a nonce and a challenge and they like that kind of stuff like 
  the credentials it wants to see that sort of thing so there was a 
  lot of effort put into this to try and make this call to start 
  workflow call a superset of the presentation availability.
Manu Sporny:   All so you.
Manu Sporny:  Do both with with start workflow.
Manu Sporny:  So the I think the proposal here is can we merge 
  these both down into one thing the suggestion is can we do the 
  start workflow one and then the trace folks specify in the 
  traceability spec that they want this object to be a VPR.
Manu Sporny:   So let me let me start.
Manu Sporny:  And see Mike if you have any questions concerns 
  Mahmud or anyone else that would like to comment on this should 
  these be merged under what circumstances that kind of thing go 
  ahead Mike Europe.
Mike Prorock:  I'll defer to Joe first so.
Manu Sporny:  Go ahead Joe.
Joe Andrieu:  Okay yeah I'd like to see the merge in part because 
  I think the semantics of presentations available is that the 
  wrong layer like I think it's data is available or claims 
  available the presentation isn't created until the nonce is sent 
  right so I think there's just a little bit of impedance mismatch 
  there and I think we can clean that up with a start workflow as 
  an alternative.
Manu Sporny:  Okay thanks Jill Mike Europe.
Mike Prorock:  Yeah I have a little bit of some similar to 
  concern to what Joe just said in the sense that the presentation 
  is not created yet obviously because what you're saying is hey 
  give me the stuff I need in order to you know create a 
  presentation and send it to you where I the the only way were 
  exchanging data on the supply chain side is via presentations 
  right it's a presentation with an array.
Mike Prorock:  Credentials in it.
Mike Prorock:  The concerns I have is that there's a bit of 
  overloading of the term workflow right so from a supply chain 
  context and especially from like a USC Customs Border Protection 
  context when we use the term workflow we're referring to a very 
  explicit like import workflow or you know set of regulatory rules 
  and stages and inspections and things that actually have to 
Mike Prorock:   To a physical good so.
Mike Prorock:  The same you know we have the same term applying 
  you know being used in it you know supply chain context as 
  opposed to kind of more of like a broader digital context so that 
  is one concern I have a bit over the notion of saying yep we're 
  going to have you know an endpoint that just arbitrary workflow I 
  think it might work I'm not sure I would love Mike moods thoughts 
  on this but that's a little that kind of overloading their I 
  could see cause.
Mike Prorock:   And confusion for some folks.
Manu Sporny:  Go ahead and Mahmud if you've got some thoughts.
Mahmoud Alkhraishi:  So one of the things that Mike and Joe both 
  mentioned that really resonates is the idea that presentation 
  isn't actually available when you say position available I think 
  everybody's on board with that that makes you know all the sense 
  in the world to at least semantically change what we're saying 
Mahmoud Alkhraishi:  I think the two flows makes a lot of sense 
  to me but the word workflow is like ridiculous that overloaded 
  now I know you've mentioned that this is a working title and then 
  we're going to change that and I'm happy to you know do that 
  change so I'm going to only talk about it from a conceptual level 
  for getting the word workflow right let's just talk about it from 
  a concept of can I merge the two different.
Mahmoud Alkhraishi:   Calls that we're going to do.
<joe_andrieu> perhaps "initiateExchange"?
Mike Prorock: +1 Joe - something like that might work
Mahmoud Alkhraishi:  And to me the answer to that is yes as long 
  as I have a way of saying I need one two three credentials from 
  you please provide it to me in a presentation and.
Mahmoud Alkhraishi:  That's like a hard requirement for me I 
  think everything else just you know as long as we're able to do 
  that it makes sense.
Manu Sporny:  Got it all right so I'm on the Queue I think the 
  respond to both of those things so yeah makes total sense 
  speaking to the workflow term I just I just used that term like 
  he was just like a placeholder right so if we want to call it 
  Sally or you know snowboard or whatever like we should totally 
  buy shed it and call it 11 potential there is just to call it 
<mprorock> or notify
Manu Sporny:  And flow or something like that but I feel like we 
  can bike shed that later Mike the way that you use the word 
  workflow though when you specify traceability is exactly what I 
  was thinking it with respect to the word workflow so a workflow 
  is a predetermined kind of set of steps that you want to execute 
  and in some cases when you enter a workflow you don't necessarily 
  know what steps.
Manu Sporny:   Soooo 34.
Manu Sporny:  And seven are going to be you know that you're 
  going to start with something but then the server might ask you 
  for something different depending on this the type of you know 
  when you start a workflow the server is going to ask you the same 
  thing in return I need to see X y&z from you but that verifiable 
  presentation request that that it asks for me so this is speaking 
  to what you said Mahmood that that VPR that you get back that's 
  like I want to see items one two and three that can.
Manu Sporny:   Have some optional things in it and based on what 
  you give back to the server.
Manu Sporny:  Oh oh now I need these other things from you right 
  so there's the ability to kind of float fork in a workflow and do 
  that kind of thing but the the semantics of the word workflow 
  Mike was exactly what you described that's what I what I meant 
  but at the same time I completely understand if it's overloaded 
  and people don't feel comfortable with it that's fine we can 
  rename it I think the key thing here is.
Manu Sporny:  You in can the trace folks continue to do what 
  they're currently doing I think the answer to that's yes so let 
  me stop there and see if any one kind of wants to react to that 
  oh sorry go ahead Joe I think you're back in the queue.
Joe Andrieu:  Yeah I know we can buy said this later I agree with 
  that I had proposed initiate Exchange in the chat and just wanted 
  a bubble that up that may offer the same affordances without the 
  overloading of the term workflow.
<mprorock> or presentation/notify
Manu Sporny:  Cool plus one of that go ahead mama.
Mahmoud Alkhraishi:  So one of the things that I want to surface 
  up is that on the traceability side we've been talking about 
  workflows as an amalgamation of multiple different actors doing 
  different things in a long-term process right so what Mike was 
  saying with import is includes the person who is growing the 
  product the person who is transporting the products the person 
  who's filling out the input declaration etcetera etcetera.
<mprorock> it won't happen all in one api call or set of calls 
  back and forth even
Mahmoud Alkhraishi:  I'm hearing from you about the word workflow 
  is more about I am talking to a single server and I am initiate 
  and I'm doing an exchange of VCS once I give you to VCS you come 
  back to me and you say hey can you give me a third VC that's a 
  little bit different right so to me you're talking about an 
  exchange with a single party whereas what Mike is talking about 
  and what we can talk about disability side.
<mprorock> two weeks later a workflow gets picked up and 
<mprorock> etc
Mahmoud Alkhraishi:  Multiple instances of that exchange with 
  multiple different parties that need to be all relatable to each 
  other I hope I made that clear yeah.
Manu Sporny:  Got it yeah I don't know that's crystal clear so 
  conceptually the way at least I'm looking at that is that your 
  multi-party workflows are just a bunch of mini workflows chained 
  together is that a wrong way to look at it so like you know there 
  can be the the whole workflow like the total end and multi-party 
  workflow with Bunches of people you know.
Manu Sporny:   Sending and receiving.
Manu Sporny:  Kind of stuff but each one of those individual 
  actors in the traceability whole workflow is is doing their own 
  mini workflow they're just providing their bit of their 
  particular workflow that point in time thoughts on that go ahead 
Mike Prorock:  Yeah I think that's not a terrible way of thinking 
  of it but you can't always guarantee that you're going to have 
  clean segmentation so like in the egg case like in a layout just 
  like a physical example because sometimes it's easier to think 
  about right so you'll have a credential comes come in that 
  represents the Harvest data right so such was harvested packaged 
  up in a box at the actual Farm itself right cool.
Mike Prorock:   Oh great one actor.
Mike Prorock:  Yep that was my part of it and I moved it to Cold 
  Storage great there was my second part right so then though you 
  might or might not have someone that picks up part of that and 
  goes down a different path that's like a may go down a certain 
  path branching case right that may not have been Divine defined 
  to begin with right so there's just not really clear segmentation 
  as far as which actors are taking part in which aspects of the 
  workflow or.
Mike Prorock:   Even segments of that workflow and.
Mike Prorock:  Us it's a lot easier to just say look I've got 
  this arbitrary async batch of data ready go ahead and you know 
  let me know when you're ready to receive it and I'll start 
  sending it over because that stuff's coming very very 
  intermittently and in you know not necessarily predictably and we 
  are linking that stuff very actively via use of like a 
  correlation ID between presentations right this.
Mike Prorock:   Presentation has credentials.
Mike Prorock:  Linked up to this particular workflow or 
  potentially this credential is linked to another one via 
  correlation ID and we're looking at ways of associating an IED to 
  associate a specific like regulatory workflow that that 
  correlation ID applies to as an instance of but that's still 
  being hashed out so it's does that does that help give a little 
  Clarity there because it's not like it's going to be oh I start a 
Mike Prorock:  Done with even my portion of the workflow that may 
  change day-to-day or instance to instance even within the same 
  product leaving the same location going to the same destination 
  for the same importer.
Manu Sporny:  Yeah so let me check the queue yes that makes sense 
  I think we're still talking about bit past each other but that's 
  okay the workflows here at least the definition that I was 
  thinking of don't need to be synchronous and they don't need to 
  be known because it before ahead of time and they can change from 
  day to day and I think all of that meets matches what you just 
Manu Sporny:  But I'll note that like I don't want us to get like 
  caught up on the word workflow I think success here is like going 
  oh we can merge these two because they're effectively the same 
  thing and we you know go with Joe suggestion of like this is 
  really about initiating a presentation and kind of go from there.
Manu Sporny:   Go ahead mama.
Mahmoud Alkhraishi:  To me when we're talking I think we are 
  talking past each other and that's very valid I think in general 
  I'm on board with saying we need a way to merge the two apis into 
  something that's essentially an exchange API the mechanics of 
  which we can easily hash out over a PR where we go oh actually I 
  need to Define X first I first that's straightforward to me what 
  I want to make.
<mprorock> presentation/initiate or something
Mahmoud Alkhraishi:  Super clear is that there is a necessity to 
  link multiple exchanges to each other and that's something that 
  we've defined on the trade side as a workflow now we can call 
  that an end-to-end flow whatever you want to call it but the 
  point is I need to be able to point to separate instances of 
  exchange and say these exchanges are all.
<mprorock> and to link subsets or incomplete groups as well as 
  the end to end
Mahmoud Alkhraishi:  In some way and I need to be able to point 
  to what are these exchanges were made by me or by some other 
  party right it doesn't need to be like I shouldn't only need to 
  point to an exchange of that I made with a server I could point 
  to an exchange that somebody else made with you know a different 
  server and say these are.
Manu Sporny:  We do have this bit around so workflows have IDs 
  the around workflow interactions so that might have to do with 
  that might speak to your ability to link these things together 
  that is certainly contemplated here in the workflow interaction.
<mprorock> it is more a UUID to represent a type of workflow, and 
  another UUID for the specific instance of that type of workflow
Manu Sporny:  But I'm wondering if that's where we should take 
  the conversation because one thing we could just ask is like if 
  we renamed presentation availability to something like start 
  interaction or something like that and we made this thing more 
  generic so it doesn't have to be a VPR it can be any Json object.
<mprorock> but, yes
<mprorock> bc i would like to use this for cred refresh as well
Manu Sporny:  That I think just those two things would allow us 
  to merge the two together and then that would allow us to 
  initiate like credential refresh using this kind of unified API 
  and it should allow the trace folks to just continue doing what 
  they're doing with like a small renamed of the endpoint.
Mahmoud Alkhraishi:  So I've been simplifying how we use work 
  clothes a little bit just for the sake of you know making it 
  clear but what Mike put in chat is absolutely important to the 
  Limit right and that's basically when we talk about end-to-end 
  flows we're talking about a process and we have to separate 
  identifiers that were associating with those bosses right one is 
  an identifier.
Mahmoud Alkhraishi:   That says this is the it.
Mahmoud Alkhraishi:  Pace of what are the possible paths that 
  this process can take which were using as a way to define hey I 
  can do X Y or Z separate actions and all of these actions will 
  generate a VC or won't generate a VC or whatever but it this is 
  the whole problem space so to speak right the second identifier 
  is an identified were using for an instance of a workflow now.
Mahmoud Alkhraishi:   If I'm able.
Mahmoud Alkhraishi:  To link multiple exchanges to a single 
  instance of an end-to-end flow via the ID that you pointed out 
  then that would be a very reasonable solution in my money right.
Manu Sporny:  Could you could you repeat that again my mood 
  because I almost got it but but didn't so you're saying if we 
Manu Sporny:  Link this ID.
Manu Sporny:  To the information that you're talking about okay.
Mahmoud Alkhraishi:  Heidi I'm going to call an exchange ID right 
  this exchange ID I want to link it to three other exchanges that 
  have occurred all by pointing to a end-to-end flow ID right so I 
  want to say this end-to-end flow ID is associated with 
  interactions XY and z and this end-to-end flow ID is of type.
Mahmoud Alkhraishi:  Or avocados to you.
<identitywoman> isn't this what DIDComm does?
Mahmoud Alkhraishi:  All right and so if we satisfy that 
  requirement then I think we're happy on the trade side.
Mahmoud Alkhraishi:  I'm saying as long as we have that ability 
Manu Sporny:  Yeah I mean I eat that shouldn't I use that that 
  should be possible with this are you saying you wanted to find in 
  the VC API like doing that like oh yeah I mean you certainly have 
  that ability right because well I guess the question is where 
  where are where the trace folks doing that today like how how you 
  doing that link today in the traceability APA.
Mike Prorock:  Yeah so we we actually defined a credential that 
  represents like a traceable presentation right or a type that 
  represents a traceable presentation so that we can have in the 
  message body itself right here there's two uuids at play one is a 
  uuid representing the actual type of workflow itself what is this 
  end-to-end workflow which is all possible maybe some review no 
  required items you know.
Mike Prorock:  Nigel's I could be looking at tote right then 
  there's the uid that represents the actual instance of that 
  workflow that we're talking about here and we're so as long as we 
  have the ability to refer to both at like if we're thinking about 
  this from a restful standpoint ideally we would like to be able 
  to in any of these flows you know even if it's a post with like a 
  you know containing a presentation.
Mike Prorock:  If it's referencing you know both the workflow ID 
  name in this case right so the actual type of workflow that is 
  plus the ID of the you know the actual instance that it's 
  applying to I think that gets a lot of it right there and I will 
  note because I think you said something important man in which is 
  we also have a credential refresh you know flow that I think 
  mirrors very closely to yours that we would like to.
Mike Prorock:   To be able to.
Mike Prorock:  You use the same you know set of end points for 
  right so I think it's worth it's a little bit painful because we 
  have to you know kind of a line on terms Etc but it's I think it 
  feel like this is heading the right direction.
Manu Sporny:  Okay I mean you should be able to do that with this 
  this API I mean they both do the same thing after the first.
<mahmoud_alkhraishi> yeah im not hearing any real blockers
Mike Prorock:  Yeah after that kick off right and.
Mike Prorock:  The now a question for you would you ever be 
  exchanging data outside of a presentation like crossing a trust 
  boundary outside of a verifiable presentation for some reason.
Manu Sporny:  You mean in this start workflow thing it's possible 
  in the future but I don't think we should even like go there 
  until there's like the solid use case yeah.
Mike Prorock:  Yeah it just feels like an out of scope thing 
  because I'm almost wondering if we just have because like if we 
  just do some naming adjustments right because like instead of 
  saying like you know presentation you know available because the 
  presentation isn't ready yet do something like presentation 
  initiate and then presentation exchange and as long as the rest 
  URI allows us to specify both a workflow ID of some kind 
  preferably you know in our case.
Mike Prorock:  At least you know probably a uid.
Mike Prorock:  An instance ID in the path I think it's fine like.
Manu Sporny:  So you want to put that in the path like it's here.
Mike Prorock:  Yeah to be typically from a risk standpoint you 
  want to try to get both right you would like workflow the type of 
  the workflow then the ID if it exists if not then it doesn't 
  create on it right and returns back the new idea I mean that's 
  just kind of like a rest best practice thing because you have 
  that cross check between the payload and the URI itself.
Manu Sporny:  Yeah got it okay that's that's interesting.
Mike Prorock:  That good rolls back to that controller comment 
  earlier right that's part of the reason so much like that they've 
  clarified so much about that because so many issues have Arisen 
  from that not being clear early on when rest was you know people 
  not reading the paper basically right just going off the web.
Manu Sporny:  Yeah and I think that that was largely pushed by 
  Ori I think right so let me let me try and rattle off a list of 
  changes to either one of these that I think would bring alignment 
  so one of them is rename this from availability to something 
<mprorock> @Joe - is this making sense and seeming sane?
Manu Sporny:  The other one would be adding something into the 
  URL that allows you to give it an ID of some kind so it's 
  something here / in ID / maybe something or maybe nothing so it's 
  either presentation / in a presentation you know exchange numbers 
  or something like that that's a uid and you post to it.
Manu Sporny:   I think that's what my.
<mprorock> +1, and maybe a few types as examples
Manu Sporny:  Or and I would be totally on board with that and 
  then the only other difference here is replacing this with the 
  ability to just post an arbitrary Json object because for the 
  credential refresh case we don't need post a VPR and in fact 
  there's some other use cases we have where we do want to post 
  some different type of Jason it doesn't it's not a VPR it's 
  something else.
Manu Sporny:   And you know if the server.
<mprorock> i like json
<mprorock> or a refresh, etc
Manu Sporny:  And that it can just replace pain back with the 
  like I don't know what you're talking about like you know you 
  sent me something to initiate a presentation exchange that I 
  don't know what it is so you know error so the changes would be 
  widened this the acceptable thing here to just be a Json object 
  and in traceability you guys can in your specs say no it needs to 
  be a VPR or whatever you want to make it and then add an ID.
Manu Sporny:   D up here and then rename.
Manu Sporny:  Initiate or something.
Manu Sporny:  Is that go ahead like you're on the Queue and then 
  my mood.
Mahmoud Alkhraishi:  One quick question on that you're basically 
  saying each server would Define on that end point the kind of 
  Json that it would understand and if it gets something that it 
  does understand it or respond with sorry I have no idea what this 
  is please provide it please provide XYZ is that roughly what 
  you're saying.
<mprorock> close
<mprorock> more that our profile can specify what that type of 
  JSON is
Manu Sporny:  Roughly I except for the last little bit that you 
  said the server I mean it works like any kind of HTTP server 
  right I mean you send it garbage and it's like I don't know what 
  you're talking about error right 400 works malformed right but 
  for the things that it does understand it can basically be like 
  oh you're starting to you're trying to initiate a trace thing 
  with me like a traceability API.
Manu Sporny:   I thing with me I know what that means here you 
Manu Sporny:  Here's a.
Manu Sporny:  PR I want to see these things from you.
Manu Sporny:  That makes sense.
Manu Sporny:  Okay and then I think Mike you're on the queue.
Mike Prorock:  Yeah I thought I'd let my food go first so the 
  clarification there my mood is we can specify and this is exactly 
  the way I've been looking at like the trace profile versus the VC 
  API is that the trace profile is going in and saying yep we've 
  got this kind of broad common set of capabilities you know like 
  your bare minimum common MVP capabilities so to speak in the VC 
  API we can go in and say hey if you're going to support the new 
<mahmoud_alkhraishi> yeah im on board
Mike Prorock:  Y'see method we only in that trace it you know if 
  you're complying with the trace profile you would have to accept 
  like a you know VP request for sending a presentation right or 
  you would have to accept a credential refresh right you know so 
  we can specify exactly what data must be accepted or it could 
  only be accepted right we have that flexibility there especially 
  if it's defined broadly.
Mike Prorock:   Only to say that the endpoint is.
Mike Prorock:  At the VC API level is yep its way to initiate or 
  exchange presentations there's some additional parameters that 
  you can leverage and oh by the way it can be just Json right 
  that's that's the way I'm kind of reading it manner because that 
  gives us both kind of the flexibility to say yep we've got these 
  specific you know like credential refresh type scenarios that 
  apply to like citizenship use cases or credential refresh that I 
  think overlap right for like an AG inspection and.
Mike Prorock:   By the way this is also a way that you can 
  initiate a.
Mike Prorock:  Presentation of data.
Manu Sporny:  Yep I think we're I think we're on the same page 
  there Mahmud what are your thoughts on putting an ID in this URL 
  so well hold on let's go by these one by one I think we all agree 
  that we're going to rename and availability to be like something 
  else like presentation initiation is there agreement on that.
Mahmoud Alkhraishi:  Yeah on my own.
Manu Sporny:  Okay alright I'm hearing anyone.
Mike Prorock:  My mood if we if you we do that I'm putting you on 
  the spot to open the pr to change it all on our side I got your 
  back but.

PROPOSAL:  Rename "Presentation Availability" to something else, 
  the current proposal is "Initiate Presentation".

Joe Andrieu:  I think presentation also has semantic issues that 
  several people chimed in.
Manu Sporny:  Well here let's put it down as a proposal renamed 
  presentation availability to something else the current proposal 
  is initiate presentation how does that work for folks just okay 
  what would you like.
Joe Andrieu:  It suggested initiate exchange that seem to have 
  some residence.
Manu Sporny:  I should exchange okay all right so.
Mahmoud Alkhraishi:  Sorry man I think this is probably something 
  that's almost definitely better when you see it in the pr and 
  it's a lot harder to resolve it over phone.
<mprorock> presentation/initiate ?
<mprorock> or exchange/initiate
Manu Sporny:  So let me just put some actions down then so 
  renamed presentation availability to Joe you said initiate 
Manu Sporny: ACTIONS: Rename "Presentation Availability" to 
  "Initiate Exchange".
Joe Andrieu:  As a candidate like I don't know that we need to 
  buy set of now but.
Manu Sporny:  Okay I'll just you know I can I can do a PR for 
  that okay the second one Mike you said that you would be okay 
  with having an ID here so I don't know what is this become / 
Manu Sporny:   Let's go.
Manu Sporny:  Run with it and say it's / exchange is update and 
  Tatian availability to / present or sorry exchange it is / uid 
  well I'll just I'll just put identifier.
<mprorock> /exchanges/{TYPE_ID}/{INSTANCE_ID}
Manu Sporny:  You have you have to post.
Manu Sporny:  By the instance ID could you clarify what type ID 
  and instance ideas like.
<joe_andrieu> I had forgot the noun/verb pattern begs for nouns.
Mike Prorock:  Yeah so the more and I missed a thing in there but 
  it would be like exchanges initiate and then an exchange of a 
  specific type right so you know or a specific workflow by uuid 
  depending on how it's being used and then the instance ID if it's 
  available would be if the if you already have a known you know 
  uuid for correlation right between presentations.
Manu Sporny:  Okay so then you have to post data to those 
Manu Sporny:  So we're keeping the post post to the endpoints we 
  do use case where we need to get.

ACTION: Update Presentation Availability to 
  "/exchanges/initiate/{exchange-type-id}/{?exchange-uuid}" and you 
  have to POST data to the endpoints.

<mprorock> POST 
Manu Sporny:  I think we can talk about that later like people we 
  have to submit we have to support post and maybe only a couple 
  people support kit but I don't want to complicate the discussion 
  while we're making progress okay and then the last and final 
  thing is generalized the post body to accept any Json object 
  where trace of the trace folks will specify that they require a 
  VPR for certain types of things.
Manu Sporny:  Update post body to accept a Json object where the 
  traceability spec will further Define exactly the type of object 
  object here looking for it's a VPR right now isn't it.

ACTION: Update POST body to accept a JSON object, where the 
  Traceability spec will further define exactly the type of object 
  they're looking for (a VPR?)

<mprorock> or POST/GET/PUT 
Manu Sporny:  Is that right okay alright okay so and that's the 
  final one and if we do that then I think we are aligned we can 
  merge these into one and then we can bike shed bit more Mike I'm 
  expecting or E2 object to structure of the URL I don't know if 
  you're expecting the same thing.
Mike Prorock:  I am we need to get the stuff more in line with 
  the way things are done broadly so I'm willing to kind of argue 
  that one out in and by the way if we go this route of like oh 
  it's a presentations / exchange / like a uuid to the type of 
  exchange to the instance itself or something similar to that then 
  your post get put you know delete Etc all works right you we can 
  Define this stuff very cleanly.
Mike Prorock:  Rest and point because we're not abstract to get.
Mahmoud Alkhraishi: +1
Mike Prorock:  Who like we're doing rest properly right we're 
  letting the actual HTTP method call Define the type of operation 
  going on my mood I expect full arguments from you with my favor 
  on this again story.
Mahmoud Alkhraishi:  Yeah definitely it's going to be a fun 
Manu Sporny:  Okay okay great so you two are aligned on that 
  there's a huge plus one from digital bizarre as well we always 
  wanted to take this path we just you know it seemed like 
  everybody else wanted to go the different a different route so 
  totally agree with both of you well we would rather see the API 
  structured in that way and follow good restful design principles.
Manu Sporny:  That is a bigger discussion that was actually one 
  of the issues towards the end that we had but I think this is we 
  should declare Victory and move on because from my reading that's 
  alignment my mom would do you guys disagree like does it seem 
  like we just align the two.
Mahmoud Alkhraishi:  I think it makes the most sense to me.
Mike Prorock:  Yeah it gives us a really clean path forward it 
  doesn't mean that it's set in stone and of the day everything 
  right that's kind of the beauty what we have here but it gives us 
  a way to put something out test it and see how it works right.
Manu Sporny:  Beautiful okay awesome okay that's that's the first 
  item and that was not as difficult as I thought it was going to 
  be so that's great okay so the second one is workflow interaction 
  this is very much this is very much kind of see the submit 
  presentation thing the difference between these two endpoints is 
  with the workflow interaction thing.
Manu Sporny:  MIT a you're expected to submit a presentation here 
  and the only difference is that in this submit presentation 
  they're all kinds of things that are returned back like payment 
  required is a is a potential here in the presentation didn't 
  contain a proof and all that kind of stuff in what we needed at 
  least for the refresh you.
Manu Sporny:   Has case is the ability.
<mprorock> PUT or POST right?
<mprorock> if we are gonna due this right
Manu Sporny:  To respond back with another VPR right so I think 
  the way the tray stuff is defined right now it's just like a you 
  know you start the exchange and then and then you send the 
  presentation and that's it you can do anything more than that in 
  what at least we'd like on the the refresh side of it is the 
  ability to like say well thank you for that presentation you 
<mprorock> upsert or create
<mprorock> and possibly defined by a correlation id
Manu Sporny:  I need this other thing from you and so what you 
  get back is a VPR and so I think a lot of this alignment has to 
  do with making it so that it is possible to respond back with a v 
  p so the first one was having an ID to post to that's an active 
  kind of ID where you're in process and it's got an ID on the 
  server and then the second part of it is being able to respond 
  back with.
Manu Sporny:  Got your presentation that's the traceability use 
  case but for the credential refresh one we'd like to be ability 
  to be able to be like actually we need more information from you 
  and here's another VPR or well yeah you here's another VPR 
  thoughts on that.
Mahmoud Alkhraishi:  I think the idea of sorry that my trunk.
Mike Prorock:  Beat you to the formal Q I think if we change this 
  to put or post right depending on whether or not you're creating 
  or observing and we say presentations and then it's an IED of you 
  know potentially write that kind of a thing then we're getting 
  this a little bit more in line and then allows potential 
  responses that say yep I'm not accepting this here's why and 
  here's this.
Mike Prorock:  Response that says I need more information.
Mike Prorock:  Something else I think the way Direction you're 
  heading that at least that's kind of how kind of feeling about it 
  I'm in submission I'm a little bit okay with right it just feels 
  a little bit weird but I mean obviously we've got it in there 
  that way now but.
Mike Prorock:  But I think that notion of being able to specify 
  like it's a presentation with an ID potentially with like abroad 
  you know like a tighter group of presentations right you know so 
  you know like a type of like overthink it relate it back to the 
  workflow side it's very very similar very very related the trick 
  is are we defining and giving ourself enough flexibility in the 
  response or the method call right.
Mike Prorock:   Is that is that.
Mike Prorock:  Struggle is plus the ability to you know specify 
  ID and or put right as opposed to post.
Mike Prorock:  Yeah presentations The Exchange initiate bright.
Manu Sporny:  Yeah I think the the first so if we had to get a 
  list of changes here it's insert an ID in here just like we 
  agreed to for whatever we were calling this thing initiate 
  something or another yep yep yep and so so put put an ID in the 
  URL and then we can have a debate about post versus put in what 
  that means but the.
Manu Sporny:   So that's item one.
Manu Sporny:  In the URL item 2 is allow us to respond back with.
Manu Sporny:  CPR meaning like either like cool everything looks 
  great presentation accepted or you know we can also do malformed 
  and didn't contain proof in that kind of time think we're okay 
  with that but we need to be able to respond back with a VPR to 
Mike Prorock:  Potentially could you just request a reject it 
  though and indicate that they need to request an exchange if you 
  need a.
Mike Prorock:  You know an actual like VPR.
Manu Sporny:  Yep that's right yeah you can you know because the 
  way VP are structured you can respond back with like a now go 
  back to go back and start over right or go to this other URL and 
  continue the workflow they're like you're done here but you need 
  to go over there now.
Manu Sporny:  Abilities if we enable a VPR to beerus sent back so 
  when they posted this endpoint we're able to send the VP are back 
  that's like you you're not done yet all right.
Mike Prorock:  Yeah and I'm not sure that a 400 is the right 
  error for that but it would be something like that right where 
  you're throwing a response code back along with the message that 
  happens to be like either you know a VP are back or some Json 
  object in response right.
<mahmoud_alkhraishi> 418 im a teapot is always the correct 
Manu Sporny:  Yeah I'm less concerned about the response codes 
  than I am with the ability to respond back with a VPR as like a 
  continuation of you know the the flow yep exactly.
Mike Prorock:  Go into go do this next.
<manu> haha HTTP 418
Mike Prorock:  Question because right now what is the is it does 
  it allow you to give an error message back or what's the.
Mike Prorock:  Don't.
Manu Sporny:  We should probably also allow that as well I don't 
  think that's allowed is either.
Mike Prorock:  Yeah yeah because I think that's some of the issue 
  is that we need to specify and honestly we should consider 
  specifying if the accept type is application Json right that it 
  should return Json back period so then that use case is covered 
  plus proper are handlings covered right.
Manu Sporny:  Yep yep yep yep yeah I think is so right now we 
  don't support oh yeah so here's what we support like accepting 
  like everything's cool we support sending back a verifiable 
  presentation we do not support sending back a VPR and we don't 
  support sending back an error message.
Manu Sporny:   So we should.
Mike Prorock:  Oh yeah so if we just change 400 and that if 
  accept Json is in the headers that you can send back a saint to 
  whoever posted we've solved the problem right and that's the 
  right way in quotes to do it from a rest standpoint anyways.
<mahmoud_alkhraishi> i think we're there
Manu Sporny:  Yep yep yep yeah I think I think that that works I 
  mean I think the only all the implementers of just implemented 
  application Chase and I don't think well I shouldn't say that 
  okay so I don't think we have complete resolution yet but would 
  my mood you know or Mike would either of you object if I put 
  together PR that like suggests the other return types that should 
  I want to try and get this done in one go and.
Manu Sporny:  Didn't what.
Manu Sporny:  Maybe that's maybe that's asking too much.
Mahmoud Alkhraishi:  I think there were at is next up is 
  absolutely waiting up there because there's just no way to like 
  we're going to get lost in the weeds unless we actually get a PR 
  where we get to go into the weeds and figure out how to solve it 
  so yes absolutely and I think if you can get it with responsible 
  that would be perfect.
<mprorock> yep, PR or openAPI is good
Manu Sporny:  Okay alright let me do them one at a time so I'll 
  try and collapse start workflow in presentation availability in 
  one PR and then I'll try and collapse workflow interaction and 
  submit presentation in one go I just wanted to make sure that 
  before I did that PR that both of you weren't like immediate I'm 
  going to immediately subject to it I'm hearing that both of you 
  are willing to have a discussion around a PR and it seems like 
Manu Sporny:   Converging so that's good.
Manu Sporny:  Did I misread any of that.
Mike Prorock:  No I think where you could potentially see 
  objections from some folks in and I'm not saying I would have 
  ejected to it is if you try to make it to specific like if you 
  keep it General and just say ah yeah if a method has an error and 
  you're following the right rules and sending the server back text 
  or Json depending on what they asked for you could send back 
  anything conformant with that right because a VPR is just Json so 
  that way we're not painting ourselves into a corner there and 
  then we're still giving.
Mike Prorock:  The ability for a profile to say oh it could only 
  be a.
Mike Prorock:  Are or an X in this case right you know so.
<mahmoud_alkhraishi> thank you all
<mprorock> rock on
Manu Sporny:  Yep okay I've got enough direction to put together 
  some PR's that I'm fairly certain won't get immediate objections 
  all right this was a very productive call thank you everyone for 
  participating thank you Mike and my mood for engaging I'm feeling 
  upbeat about where this is going all right that's it for the call 
  today thanks everyone we will meet again next week ciao.
Received on Friday, 4 February 2022 22:28:02 UTC

This archive was generated by hypermail 2.4.0 : Thursday, 24 March 2022 20:25:28 UTC