Robert, I think Yufei and Russell explained above that we can either:
* Continue doing what we are doing today - IRC clients see (and ignore) endpoints they will not action upon. OR * Separate it out into two different getConfig APIs - one for Polaris, one for IRC. In this case, the Polaris getConfig would be a strict superset of the IRC API - and the Polaris-specific clients would use the Polaris getConfig API. My understanding of why Russell brought up the point regarding "Can non-IRC endpoints be added to the IRC config response without breaking clients?" is: There is clearly a use case for Polaris clients using the getConfig API - so the real question, in my opinion, is what is the benefit of creating two `getConfig` APIs versus continuing our current approach which reduces code paths and complexity? Does Polaris gain anything from separating these two getConfig APIs other than establishing a strict, principled stance on our interpretation of the IRC spec text? Best, Adnan Hemani On Tue, Jun 23, 2026 at 9:50 AM Robert Stupp <[email protected]> wrote: > Hi all, > > I think we should separate two questions: > > 1. Can non-IRC endpoints be added to the IRC config response without > breaking clients? > 2. What can a normal Iceberg REST client actually do with that information? > > The first question only tells us whether the behavior is tolerated. > It does not establish that the IRC config response is the right contract > for Polaris-wide capability discovery. > > For a normal IRC client, I do not see a concrete use case for OpenLineage, > OSI, generic-table, or policy endpoints in that response. > A Polaris-aware client may need discovery, but that sounds like Polaris > capability discovery, not IRC capability discovery. > > So what is the concrete use case for exposing those endpoints to normal IRC > clients? > > Best, > Robert > > On Tue, Jun 23, 2026 at 3:26 PM Dmitri Bourlatchkov < > [email protected]> wrote: > > > Hi Yufei, > > > > > The community has already decided to reuse the IRC config endpoint for > > capability discovery > > > > Could you give a link to that decision? > > > > Thanks, > > Dmitri. > > > > On Mon, Jun 22, 2026 at 9:45 PM Yufei Gu <[email protected]> wrote: > > > > > > Yet, no one answered my second question from the initial email. That > > is: > > > why do we need to expose non-IRC endpoints in the IRC config response > in > > > the first place? > > > > > > Apologies if I didn't explain this clearly in my earlier email. > > > > > > With Polaris, you can use a pure IRC client, or you can use a Polaris > > > client that leverages Polaris specific capabilities such as generic > > tables > > > and policies in addition to IRC functionality. The community has > already > > > decided to reuse the IRC config endpoint for capability discovery. I > > shared > > > an example from the Polaris Spark client previously, but I'll repeat it > > > here because it illustrates the point well. Note that the client > supports > > > both Iceberg tables and generic tables: > > > > > > public List<TableIdentifier> listGenericTables(Namespace ns) { > > > Endpoint.check(endpoints, PolarisEndpoints.V1_LIST_GENERIC_TABLES); > > > } > > > > > > In this model, the config endpoint acts as a capability discovery > > > mechanism. Standard IRC clients can simply ignore endpoints they do not > > > recognize, while Polaris aware clients can use the additional > information > > > to enable Polaris specific functionality. > > > > > > I also think Adam made a good point. The /api/catalog/v1/config > endpoint > > > returns both IRC and Polaris capabilities. Otherwise, we need to > > introduce > > > a separate Polaris-specific discovery endpoint, requiring clients to > > query > > > and manage two different capability sources. > > > > > > Yufei > > > > > > > > > On Mon, Jun 22, 2026 at 5:28 PM Adnan Hemani via dev < > > > [email protected]> > > > wrote: > > > > > > > Ah yes, my mistake. But I think a similar point exists: Does the > > service > > > > need to know about all new endpoint information? Can we not make it > > dumb > > > > and gate on a server-wide feature flag or something similar? > > > > > > > > -Adnan > > > > > > > > On Mon, Jun 22, 2026 at 5:02 PM Dmitri Bourlatchkov < > [email protected]> > > > > wrote: > > > > > > > > > Hi Adnan, > > > > > > > > > > You might have misinterpreted my message. My point was about the > > server > > > > > (service) side, not client side. > > > > > > > > > > Cheers, > > > > > Dmitri. > > > > > > > > > > On Mon, Jun 22, 2026 at 7:58 PM Adnan Hemani via dev < > > > > > [email protected]> > > > > > wrote: > > > > > > > > > > > > For example, if we are to expose Open Lineage or OSI endpoints > in > > > IRC > > > > > > config, the IRC service code will have to be aware of OL / OSI > > > modules. > > > > > > > > > > > > I don't agree with this statement; the IRC client is always free > to > > > > > > disregard any of these endpoints/modules. Returning this > > information > > > > does > > > > > > not force a client to take any action based on this extra > endpoint > > > > > > information. > > > > > > > > > > > > I do agree that if this forced the IRC client to be fundamentally > > > > altered > > > > > > because of these additional endpoints, then that would be a > > > significant > > > > > > issue. But as Russell stated above, "what would actually break if > > > > someone > > > > > > interpreted the spec this way?" > > > > > > > > > > > > Best, > > > > > > Adnan Hemani > > > > > > > > > > > > On Mon, Jun 22, 2026 at 3:30 PM Dmitri Bourlatchkov < > > > [email protected]> > > > > > > wrote: > > > > > > > > > > > > > Hi Russell, > > > > > > > > > > > > > > Your points sound reasonable to me. > > > > > > > > > > > > > > Yet, noone answered my second question from my initial email. > > That > > > > is: > > > > > > why > > > > > > > do we need to expose non-IRC endpoints in the IRC config > response > > > in > > > > > the > > > > > > > first place? > > > > > > > > > > > > > > Regarding the maintainability aspect, I see this becoming a > more > > > > > > > substantial concern if it evolves into a self-sustaining > pattern. > > > > > > > > > > > > > > For example, if we are to expose Open Lineage or OSI endpoints > in > > > IRC > > > > > > > config, the IRC service code will have to be aware of OL / OSI > > > > > modules. I > > > > > > > think this dependency is conceptually incorrect. > > > > > > > > > > > > > > I do not so much mind existing non-IRC endpoints in the IRC > > config, > > > > but > > > > > > > extending this to new APIs feels like an anti-pattern to me. > > > > > > > > > > > > > > Cheers, > > > > > > > Dmitri. > > > > > > > > > > > > > > On Mon, Jun 22, 2026 at 5:46 PM Russell Spitzer < > > > > > > [email protected] > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > From a very pragmatic point of view, I'm not sure what we'd > > gain > > > > from > > > > > > > > separate > > > > > > > > configuration mechanisms. We already have one and it's worked > > > well > > > > so > > > > > > > far, > > > > > > > > do we have a compelling reason to swap right now? > > > > > > > > > > > > > > > > As best I can tell, the worst case is that the IRC spec later > > > > > tightens > > > > > > > the > > > > > > > > semantics > > > > > > > > of the endpoints field, making our extra entries > non-compliant. > > > In > > > > > that > > > > > > > > situation > > > > > > > > we'd have to change our response, add a Polaris-specific > > > > > > config/discovery > > > > > > > > endpoint, and > > > > > > > > have our clients move over to it. But that's exactly the work > > > this > > > > > > > proposal > > > > > > > > is asking us to do today > > > > > > > > so we would be taking same burden now instead of potentially > > > never. > > > > > I'd > > > > > > > > rather defer > > > > > > > > it until something concrete forces our hand. > > > > > > > > > > > > > > > > The one counter I can see is that decoupling gets harder as > > more > > > > > > clients > > > > > > > > adopt it. But > > > > > > > > since the Polaris endpoints are already namespaced > > > (/polaris/...), > > > > > > > lifting > > > > > > > > them into a separate endpoint > > > > > > > > later stays mechanical, so I don't think we're meaningfully > > > > cheaper > > > > > > > doing > > > > > > > > it now. > > > > > > > > > > > > > > > > > > > > > > > > I'd like to gently point out that it doesn't feel especially > > > > > important > > > > > > > > whether the exact wording > > > > > > > > or original intent of the spec supports what we're doing. The > > > > > > discussion > > > > > > > is > > > > > > > > starting to feel > > > > > > > > like a legalistic reading of the spec rather than a focus on > > > > concrete > > > > > > > > impact. I'd suggest we focus > > > > > > > > on arguments like "what would actually break if someone > > > interpreted > > > > > the > > > > > > > > spec this way?" > > > > > > > > rather than "what was the original intent of the text?" > > > > > > > > > > > > > > > > On Mon, Jun 22, 2026 at 3:23 PM Adnan Hemani via dev < > > > > > > > > [email protected]> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > Hi Dmitri, > > > > > > > > > > > > > > > > > > I think you and I view the same statement very differently > - > > I > > > > > > > definitely > > > > > > > > > don't think it's "pretty clear that the scope of the data > > > > returned > > > > > > > under > > > > > > > > > that type is limited to the API defined by the spec". I see > > it > > > > this > > > > > > > way: > > > > > > > > if > > > > > > > > > this statement truly meant ONLY IRC endpoints, the spec > would > > > > > > > explicitly > > > > > > > > > use the words "IRC spec endpoints". The absence of > > > clarification > > > > in > > > > > > any > > > > > > > > > specification rarely means you should > > "read-between-the-lines" > > > to > > > > > > > assume > > > > > > > > > the writer's "intent". > > > > > > > > > > > > > > > > > > I will look into Iceberg mailing list threads and PRs for > > > > > background > > > > > > > > > information to clarify things. > > > > > > > > > > > > > > > > > > Best, > > > > > > > > > Adnan Hemani > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Jun 22, 2026 at 12:27 PM Dmitri Bourlatchkov < > > > > > > [email protected] > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > HI Adnan, > > > > > > > > > > > > > > > > > > > > The IRC spec defines a "type" for the config response. A > > > > property > > > > > > of > > > > > > > > that > > > > > > > > > > "type" is a list of "endpoints supported by the server". > > > There > > > > is > > > > > > no > > > > > > > > > > statement about generalizing those endpoints to non-IRC > > APIs. > > > > > > > > > > > > > > > > > > > > Therefore, I think it is pretty clear that the scope of > the > > > > data > > > > > > > > returned > > > > > > > > > > under that type is limited to the API defined by the > spec, > > > > which > > > > > is > > > > > > > > IRC. > > > > > > > > > > > > > > > > > > > > Let's expand this discussion a bit. > > > > > > > > > > > > > > > > > > > > What is the rationale for returning non-IRC endpoints in > > the > > > > IRC > > > > > > > config > > > > > > > > > > response? > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > Dmitri. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Jun 22, 2026 at 3:21 PM Adnan Hemani via dev < > > > > > > > > > > [email protected]> wrote: > > > > > > > > > > > > > > > > > > > >> Hi Dmitri, > > > > > > > > > >> > > > > > > > > > >> I'm not sure where you are assuming that "endpoints" > only > > > > refers > > > > > > to > > > > > > > > > >> Iceberg > > > > > > > > > >> endpoints in the IRC spec. Do you have any thing you can > > > point > > > > > us > > > > > > to > > > > > > > > > >> regarding this? > > > > > > > > > >> > > > > > > > > > >> Best, > > > > > > > > > >> Adnan Hemani > > > > > > > > > >> > > > > > > > > > >> On Mon, Jun 22, 2026 at 12:18 PM Dmitri Bourlatchkov < > > > > > > > > [email protected]> > > > > > > > > > >> wrote: > > > > > > > > > >> > > > > > > > > > >> > Hi Adam, > > > > > > > > > >> > > > > > > > > > > >> > > #1 - Is GET ' > > > > > > > > > >> > > > > > http://localhost:8181/api/catalog/v1/config?warehouse=polaris > > > > > ' > > > > > > > only > > > > > > > > > >> > an Iceberg Catalog concept? > > > > > > > > > >> > > > > > > > > > > >> > My interpretation is YES, because the payload of that > > > > response > > > > > > is > > > > > > > > > >> defined > > > > > > > > > >> > by the IRC API spec [1]. > > > > > > > > > >> > > > > > > > > > > >> > I believe one can reasonably assume that the statement > > > > > > "endpoints > > > > > > > > > >> supported > > > > > > > > > >> > by the server" is scoped only to the IRC API itself. > > > There's > > > > > no > > > > > > > > > >> provision > > > > > > > > > >> > in that spec about covering all possible APIs. > > > > > > > > > >> > > > > > > > > > > >> > That said, I'd be happy to discuss how clients can > > > discover > > > > > > > Polaris > > > > > > > > > >> > features in general without overloading existing > > > > > specifications. > > > > > > > > > >> > > > > > > > > > > >> > [1] > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://github.com/apache/iceberg/blob/apache-iceberg-1.11.0/open-api/rest-catalog-open-api.yaml#L105 > > > > > > > > > >> > > > > > > > > > > >> > On Mon, Jun 22, 2026 at 2:52 PM Adam Christian < > > > > > > > > > >> > [email protected]> wrote: > > > > > > > > > >> > > > > > > > > > > >> > > I agree with both Yufei & Dmitri: > > > > > > > > > >> > > > > > > > > > > > >> > > #1 - It seems like improper coupling for an Iceberg > > REST > > > > > > Catalog > > > > > > > > > >> config > > > > > > > > > >> > to > > > > > > > > > >> > > return a configuration unrelated to Iceberg. > > > > > > > > > >> > > #2 - Polaris is a superset of an Iceberg REST > Catalog. > > > > > > > > > >> > > > > > > > > > > > >> > > So, in my opinion, the question is more aptly framed > > as > > > > two > > > > > > > > > questions: > > > > > > > > > >> > > > > > > > > > > > >> > > #1 - Is GET ' > > > > > > > > > >> > > > > > http://localhost:8181/api/catalog/v1/config?warehouse=polaris > > > > > > > > > >> > > ' > > > > > > > > > >> > > only an Iceberg Catalog concept? > > > > > > > > > >> > > #2 - Should GET ' > > > > > > > > > >> > > > > > > > http://localhost:8181/api/catalog/v1/config?warehouse=polaris > > > > > > ' > > > > > > > > > return > > > > > > > > > >> > > additional endpoints? > > > > > > > > > >> > > > > > > > > > > > >> > > I believe that the answer to #1 is no, but that > > requires > > > > > > changes > > > > > > > > to > > > > > > > > > >> the > > > > > > > > > >> > > codebase. I believe the answer to #2 is yes. > > > > > > > > > >> > > > > > > > > > > > >> > > Based on the codebase, we are exposing several > > endpoints > > > > in > > > > > > this > > > > > > > > > >> > > configuration API which are not Iceberg endpoints. > For > > > > > > example, > > > > > > > in > > > > > > > > > the > > > > > > > > > >> > > Generic Tables case, it is explicitly not Iceberg. > In > > my > > > > > > > opinion, > > > > > > > > > >> this is > > > > > > > > > >> > > alright because our API specification only says > > > > > "Configuration > > > > > > > > API," > > > > > > > > > >> not > > > > > > > > > >> > > "Iceberg Configuration API." Yes, it is > > > > Iceberg-compatible, > > > > > > but > > > > > > > it > > > > > > > > > is > > > > > > > > > >> not > > > > > > > > > >> > > Iceberg-centric. This retrieves the configuration > for > > > the > > > > > > > Catalog; > > > > > > > > > >> > > regardless of whether it is an Iceberg Catalog. Now, > > if > > > > this > > > > > > is > > > > > > > > > truly > > > > > > > > > >> a > > > > > > > > > >> > > superset, it implies that IcebergCatalogHandler.java > > > > should > > > > > > not > > > > > > > > > handle > > > > > > > > > >> > > returning the configuration. Additionally, we need > to > > > > > return a > > > > > > > > > >> superset > > > > > > > > > >> > of > > > > > > > > > >> > > the ConfigResponse (an Iceberg-core concept) for the > > > REST > > > > > API > > > > > > > > > >> response. > > > > > > > > > >> > > > > > > > > > > > >> > > Now, if the answer to #1 is yes, that means we > should > > > > > probably > > > > > > > > have > > > > > > > > > a > > > > > > > > > >> > > separate API for configuration. > > > > > > > > > >> > > > > > > > > > > > >> > > What do y'all think? > > > > > > > > > >> > > > > > > > > > > > >> > > Go community, > > > > > > > > > >> > > > > > > > > > > > >> > > Adam > > > > > > > > > >> > > > > > > > > > > > >> > > On Mon, Jun 22, 2026 at 1:55 PM Yufei Gu < > > > > > > [email protected]> > > > > > > > > > >> wrote: > > > > > > > > > >> > > > > > > > > > > > >> > > > I think a Polaris client is also an IRC client, > just > > > > with > > > > > > > > > additional > > > > > > > > > >> > > > capabilities. In that sense, Polaris can be viewed > > as > > > a > > > > > > > superset > > > > > > > > > of > > > > > > > > > >> > IRC. > > > > > > > > > >> > > If > > > > > > > > > >> > > > the config endpoint is intended for capability > > > > discovery, > > > > > > > > > returning > > > > > > > > > >> > > Polaris > > > > > > > > > >> > > > specific endpoints seems reasonable. Standard IRC > > > > clients > > > > > > can > > > > > > > > > simply > > > > > > > > > >> > > ignore > > > > > > > > > >> > > > endpoints they don't recognize. > > > > > > > > > >> > > > > > > > > > > > > >> > > > A concrete example is the Polaris Spark client, > > which > > > > > checks > > > > > > > > > server > > > > > > > > > >> > > > capabilities before using Polaris specific > > > > functionality: > > > > > > > > > >> > > > > > > > > > > > > >> > > > public List<TableIdentifier> > > > listGenericTables(Namespace > > > > > > ns) { > > > > > > > > > >> > > > Endpoint.check(endpoints, > > > > > > > > > >> PolarisEndpoints.V1_LIST_GENERIC_TABLES); > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > Yufei > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > On Fri, Jun 19, 2026 at 7:43 AM Dmitri > Bourlatchkov > > < > > > > > > > > > >> [email protected]> > > > > > > > > > >> > > > wrote: > > > > > > > > > >> > > > > > > > > > > > > >> > > > > Hi All, > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > During my review of [4816] I realized [1] that > > > Polaris > > > > > > > returns > > > > > > > > > >> some > > > > > > > > > >> > > > non-IRC > > > > > > > > > >> > > > > endpoints in the IRC config responses. > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > For example: > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > GET ' > > > > > > > > > >> > > > http://localhost:8181/api/catalog/v1/config?warehouse=polaris > > > > ' > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > Result: > > > > > > > > > >> > > > > [...] > > > > > > > > > >> > > > > "endpoints": [ > > > > > > > > > >> > > > > "GET /v1/{prefix}/namespaces", > > > > > > > > > >> > > > > "GET /v1/{prefix}/namespaces/{namespace}", > > > > > > > > > >> > > > > "HEAD /v1/{prefix}/namespaces/{namespace}", > > > > > > > > > >> > > > > [...] > > > > > > > > > >> > > > > "DELETE > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > polaris/v1/{prefix}/namespaces/{namespace}/generic-tables/{generic-table}", > > > > > > > > > >> > > > > "GET > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > polaris/v1/{prefix}/namespaces/{namespace}/generic-tables/{generic-table}", > > > > > > > > > >> > > > > "GET > > > > > > > > /polaris/v1/{prefix}/namespaces/{namespace}/policies", > > > > > > > > > >> > > > > "POST > > > > > > > > /polaris/v1/{prefix}/namespaces/{namespace}/policies", > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > The latter group of endpoints is not related to > > the > > > > > > Iceberg > > > > > > > > REST > > > > > > > > > >> > > Catalog > > > > > > > > > >> > > > > API. > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > I wonder what the rationale might be for > returning > > > > them > > > > > in > > > > > > > the > > > > > > > > > IRC > > > > > > > > > >> > > config > > > > > > > > > >> > > > > response. > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > From my POV, returning them in the IRC config > > > response > > > > > is > > > > > > > > > >> incorrect > > > > > > > > > >> > > > because > > > > > > > > > >> > > > > these endpoints form APIs that follow a > different > > > > > > > > specification > > > > > > > > > >> and > > > > > > > > > >> > > > clients > > > > > > > > > >> > > > > using the IRC API do not need that information > to > > > > > properly > > > > > > > use > > > > > > > > > the > > > > > > > > > >> > IRC > > > > > > > > > >> > > > API. > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > WDYT? > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > [1] > > > > > > > > > >> > > > > > > > > > > https://github.com/apache/polaris/pull/4816#discussion_r3438945230 > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > [4816] > > https://github.com/apache/polaris/pull/4816 > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > Thanks, > > > > > > > > > >> > > > > Dmitri. > > > > > > > > > >> > > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > Dmitri Bourlatchkov > > Senior Staff Software Engineer, Dremio > > Dremio.com > > < > > > https://www.dremio.com/?utm_medium=email&utm_source=signature&utm_term=na&utm_content=email-signature&utm_campaign=email-signature > > > > > / > > Follow Us on LinkedIn <https://www.linkedin.com/company/dremio> / Get > > Started <https://www.dremio.com/get-started/> > > > > > > The Agentic Lakehouse > > The only lakehouse built for agents, managed by agents > > >
