alt Hacker NewsPOML: Prompt Orchestration Markup Language
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I'm the sole code contributor of POML, maybe except for Codex and cc. I think I've found where all that GitHub stars suddenly came from. :)
I'm from a small group under Microsoft Research. POML originally came from a research idea that Prompt should have a view layer like the traditional MVC architecture in the frontend system. The view layer should take care of the data, the styles and rendering logic, so that the user no longer needs to care how some table needs to be rendered, how to present few-shot examples, how to reformat the whole prompt with another syntax (e.g., from markdown to XML).
I have to admit that I spent so much time on making POML work well with VSCode, building all the auto completion, preview, hover stuff. The time is long enough that the codebase is almost becoming a monster for an individual developer to handle. The outside environment is also changing drastically. The rise of Agentic AI, tool calls, response format. The models today are no longer sensitive to small changes in prompt format as they used to. AI-aided programming can simply give you code to read in PDFs, Excels and render them in any style you want. With all that in mind, I used to feel hopeless about POML.
Nevertheless, after several months of working on another projects, I recently noticed that the view layer can be more of just a view layer. With proper user interface (e.g., a VSCode live preview), it can deliver a very smooth experience in prompt debugging, especially in a multi-prompt agent workflow. I also noticed that the "orchestration" idea can go beyond a XML-like code. I'll share more details when I had a tutorial / screenshot to share.
Going through this thread, I saw a lot of thoughts that once went through my mind. We love markdowns. We love template engines like jinja. We need those response formats. I'm thinking what is the missing piece here. I've spend so much time writing prompts and building agents in the past few months. What's my biggest pain points?
I'm quite surprised that the news hit me first before I'm ready to hit the news. If you have tried POML, please send me feedbacks. I'll see what I can do; or maybe we end up not needing a prompt language at all.
You may also want to check out BAML https://github.com/BoundaryML/baml - a DSL for prompt templates that are literally treated like functions.
the prompt.yaml format (which this project uses) suffers from the fact that it doesn't address the structured outputs problem. Writing schemas in yaml/xml is insanely painful. But BAML just feels like writing typescript types.
I'm one of the developers!
There is already the .prompt.yaml format (https://docs.github.com/en/github-models/use-github-models/s...) from github, which is also Microsoft. Would be great to see some standard evolving.
<let name="objVar" type="object" value="{{ { key: 'value' } }}"/>
<item for="item in ['apple', 'banana', 'cherry']">{{item}}</item>
<p if="isVisible">This paragraph is visible.</p>
it is concerning that Microsoft didn't provide SDK for its own C#/.Net regarding this new technology, only nodejs and python, which says alot!
this looks like a straight rip off of SignalWire’s Prompt Object Model (POM) (from q1-2 2025)
Idk, looks like IP squatting
Do you have to install poml via the node or python or is the vscode plugin enough?
How’s this different from xml?
This is interesting but not sure why it needs to be a library
I'll keep using markdown.
SGML is so back!
With all these languages for writing better prompts, are we going to end up coming full circle?
Does anybody find it mildly ironic that LLM prompts, which are intended to be plain informal text, accumulate more and more structure around them, including a markup language in question?
This is not unlike the way the language of legal documents is highly formulaic, structured, and codified. When precise meaning is desirable, firmer structures tend to arise. With a bit more time, proper code languages may start to appear, to help tell LLMs exactly what we mean or want.