Hi Adam, thanks for chiming in! I’m okay with either polaris (main) or polaris-tools. The POC currently lives in the main repo, but it’s a standalone JAR, it neither depends on other modules nor has modules depending on it. Another option is to consider it as a client. We could put it along with the CLI client under "/client". These are all minor points. I will move it to the tool repo if people feel strongly about it.
It's a good idea to have an Iceberg MCP server. We might think of it as a separate effort. It's a POC, we will definitely add more context. And context engineering isn't just a one-time effort. It's a continuing project. I'm still trying to figure out a better way to do so, a better way means not too much also not too less and more accurate. With that said, a remote MCP server is probably a better option, as the context update would be centralized. For availability and rolling upgrades, it’s fine that the MCP server is local for now. We can address those concerns when we build out the remote MCP server. Yufei On Thu, Oct 30, 2025 at 7:44 AM Adam Christian < [email protected]> wrote: > This is fantastic, Yufei! I love this idea and the demo is wonderful. > > A few thoughts: > > 1. I agree with your assessment that an MCP Server would complement > Polaris' other interfaces - REST, the python client, & the future UI. > This > adds to the growing Polaris ecosystem and I know people will find this > helpful. > 2. I agree with your approach of building an MCP Server rather than > using some sort of RAG approach (adding it to the chat context). It's a > seamless sort of integration that we see other vendors leveraging as > well. > 3. I am unsure of whether this work should be integrated into the > Polaris repository or the Polaris-Tools repository. I don't know how we > as > a community make the distinction. I know that the UI is going to be put > into the Polaris-Tools repository. Here's my understanding so far, but > I'd > love to chat about it: > 1. Polaris-Tools Pros: > 1. We don't want any hard dependencies between the core Polaris > codebase and the MCP Server. You have done a phenomenal job > at doing this > by making the MCP Server be a shim between the REST API and the AI > Application (Claude Desktop, 5ire, etc). > 2. This work might not be applicable for core use cases, so it > would be an additional series of packages that would be > unused by users and > cause overhead for building and maintaining. > 2. Polaris Pros: > 1. It can leverage common infra (Gradle, etc). > 2. It'll be faster to develop. > 3. It'll be easier to keep in sync with the REST APIs (although > that applies to the UI as well). > 4. I'm wondering if we should create an Iceberg Catalog MCP Server > and a Polaris MCP Server. A lot of the tools that you created would > benefit > the wider Iceberg Catalog ecosystem and are not Polaris-specific. For > example, the polaris-namespace-request and the polaris-table-request are > just Iceberg Catalog operations. What are your thoughts there? > 5. For some of the issues that you have observed with setting > privileges, I believe that we might be able to improve the accuracy by > updating the tools' descriptions. You & I can chat about this offline, > but > from my analysis of the code, we can make those descriptions much richer > and that'll increase accuracy without too much additional work. I've > seen > this in other MCP Servers that I've built. But, we can handle this after > we've released the first version. It's a small change. > 6. I know this is early days, but have you thought about what sort of > availability you would want with the MCP Server? Like, Polaris tries to > support rolling upgrades [1]. Is that your intention here? > > Thanks for doing all this work. I'm excited about where this is going! > > [1] - https://polaris.apache.org/in-dev/unreleased/evolution/ > > Cheers, > > Adam > > On Tue, Oct 28, 2025 at 4:30 PM Yufei Gu <[email protected]> wrote: > > > Hi all, > > > > I’d like to propose the Polaris MCP Server, which lets users and AI > agents > > interact with Polaris using natural language instead of REST or CLI. > > Example: “Show me all tables in prod.sales updated in the last 7 days.” > > > > It runs locally, connects to Polaris via REST, and requires no backend > > change. Privileges are limited to the authenticated Polaris user. > Supports > > OAuth2 client credentials and direct bearer tokens. > > > > This bridges Polaris with LLM-based tools like Claude and Cursor, laying > > the groundwork for agentic catalog operations. > > > > Design Doc: > > > > > https://docs.google.com/document/d/1yA_d3netDzgicn0z5HEGZIIOHcCgTJC1eKx_DTZPXps/edit?usp=sharing > > A Java-based, working POC: https://github.com/apache/polaris/pull/2803. > I > > demoed it at this event https://luma.com/pxikwty3. > > Yufei > > >
