I agree with Alex. Downstream projects are currently struggling to build proper parsers without standardization, and https://github.com/apache/polaris/pull/4236 is a good example.
+1 on the proposal. Best, Yufei On Sun, Sep 6, 2026 at 10:58 PM Eduard Tudenhöfner <[email protected]> wrote: > > I agree that this looks like a good addition, so +1 to the proposal. > > On Thu, Sep 3, 2026 at 1:04 AM Prashant Singh <[email protected]> > wrote: >> >> Thanks for starting the thread Rahul ! >> +1 to the proposal >> >> On Wed, Sep 2, 2026 at 3:37 PM Daniel Weeks <[email protected]> wrote: >>> >>> Hey Rahul, >>> >>> Thanks for the proposal. Minor comments on the spec, but overall looks >>> great. >>> >>> On Wed, Sep 2, 2026 at 3:01 PM Ryan Blue <[email protected]> wrote: >>>> >>>> This looks like a good proposal to me. Thanks, Rahul. >>>> >>>> On Wed, Sep 2, 2026 at 9:05 AM Alex Dutra <[email protected]> wrote: >>>>> >>>>> Hi Rahul, >>>>> >>>>> I really like your proposal. Some time ago, I attempted to identify >>>>> clients in Polaris by analyzing their User-Agent and X-Client-Version >>>>> headers, but I quickly discovered that this approach was far more >>>>> complicated and unreliable than I had expected [1]. I think the >>>>> standardization that you are proposing here will finally make it >>>>> doable. >>>>> >>>>> Thanks, >>>>> Alex >>>>> >>>>> [1]: https://github.com/apache/polaris/pull/4236 >>>>> >>>>> On Tue, Sep 1, 2026 at 6:26 PM rahul mahadev <[email protected]> >>>>> wrote: >>>>> > >>>>> > Hi all, >>>>> > >>>>> > I'd like to propose a recommended User-Agent format for REST catalog >>>>> > clients, so a client identifies itself to a catalog in a consistent, >>>>> > parseable way. >>>>> > >>>>> > Today it's inconsistent: >>>>> > - iceberg-java sends no User-Agent by default (it's opt-in via config). >>>>> > - pyiceberg sends "PyIceberg/<version>", iceberg-rust >>>>> > "iceberg-rs/<version>", >>>>> > iceberg-go "GoIceberg/<version>" basically all different naming. >>>>> > - X-Client-Version carries the library version in Java/Python but the >>>>> > REST >>>>> > spec version in Rust/Go. >>>>> > - None of this is described in the spec. >>>>> > >>>>> > That makes it hard for a catalog operator to tell what's actually >>>>> > calling, >>>>> > which matters for observability, debugging, and support. >>>>> > >>>>> > Proposal: use the standard User-Agent header (RFC 7231) i.e. whitespace- >>>>> > separated product/version tokens, most specific first (engine -> >>>>> > integration -> Iceberg library -> runtime), with an optional >>>>> > parenthesized >>>>> > comment for extra context. Example: >>>>> > >>>>> > Spark/4.0.0 iceberg-spark/1.9.0 iceberg-java/1.9.0 (scala/2.13.16) >>>>> > >>>>> > The Iceberg library token is the one piece every client can supply, so >>>>> > it >>>>> > should always be present. The header is optional and informational only: >>>>> > servers must not reject on it, must not use it for auth or trust >>>>> > decisions, >>>>> > and it is not a capability negotiation mechanism. >>>>> > >>>>> > Draft PR with the spec change: >>>>> > https://github.com/apache/iceberg/pull/17727 >>>>> > >>>>> > If the format looks right, the follow-ups would be conforming the client >>>>> > libraries (java / python / rust / go) to emit it. >>>>> > >>>>> > A few open questions: >>>>> > 1. Should we also reconcile X-Client-Version (library vs spec version >>>>> > across clients), or leave it and treat User-Agent as the canonical >>>>> > identity going forward? >>>>> > 2. Naming: keep the existing library names (PyIceberg, iceberg-rs, >>>>> > GoIceberg) or converge on one scheme (iceberg-<lang>)? >>>>> > 3. Is a separate environment token (e.g. prod/staging) useful, or does >>>>> > that belong in the comment? >>>>> > 4. Any other fields we want to capture ? >>>>> > >>>>> > Feedback welcome. >>>>> > >>>>> > Thanks, >>>>> > Rahul Mahadev (github: rahulsmahadev)
