Bringing Structured Outputs and Schema-Aligned Parsing to Golang, Java, PHP, Ruby, Rust, and More

With today's release of BAML 0.55.0, we're excited to announce that BAML now supports Golang, Java, PHP, Ruby, Rust, and any language which you might want to use. Check it out here!

What is BAML?

BAML is an open-source programming language that combines a great developer experience - live preview, IDE integration, first-class tests - with new techniques to make it easy to get structured output out of LLMs.

How do you support all languages?

For any BAML function you define, you can now

expose that function over an HTTP/RESTful interface, and
call it using an OpenAPI-generated client in the language of your choice.

And, of course, it's all 100% local, so you retain control over your prompts and data models.

Show me an example!

Developers define two key primitives in BAML: prompts and output schemas. For example, to define an ExtractReceipt function that asks GPT4o to extract a receipt from an image:

class Receipt {
  date string @description("ISO8601 formatted date")
  total int @description("The total amount of the receipt")
  items Item[] @description("The items on the receipt")
}

function ExtractReceipt(receipt: image) -> Receipt {
    client "openai/gpt-4o"
    prompt ...
}

You can now start a BAML server to expose this function over HTTP:

npx @boundaryml/baml dev --preview --from baml_src/

which you can curl to get a parsed Receipt:

$ curl -X POST localhost:2024/call/ExtractReceipt \
    -H 'content-type: application/json' \
    -d '{"receipt": {"url": "https://i.redd.it/adzt4bz4llfc1.jpeg"}}'
{
  "establishment_name": "Brasa Rotisserie",
  "date": "2024-01-27T20:50:00",
  "total": 24,
  "currency": "USD",
  "items": [
    {
      "name": "Roasted Pork & Over Easy Egg Bowl",
      "price": 15.25,
      "quantity": 1
    },
    {
      "name": "Indeed Mex Honey Lite",
      "price": 6.5,
      "quantity": 1
    }
  ]
}

If you've followed the quickstart guide, the development server will also automatically generate an OpenAPI client for you in the language of your choosing.

We've added example projects that demonstrate this for Golang, Java, PHP, Ruby, and Rust in our baml-examples repo, but to save you a click, we've also included snippets here:

Golang

imageUrl := "https://i.redd.it/adzt4bz4llfc1.jpeg"
req := baml.ExtractReceiptRequest{
  Receipt: baml.BamlImage{
    BamlImageUrl: &baml.BamlImageUrl{
      Url: imageUrl,
    },
  },
}
resp, _, err := b.ExtractReceipt(context.Background()).ExtractReceiptRequest(req).Execute()
if err != nil {
  log.Printf("Error when calling ExtractReceipt: %v\n", err)
} else {
  log.Printf("ExtractReceipt Response: %v\n", resp)
}

Java

var image = new BamlImage(new BamlImageUrl().url("https://i.redd.it/adzt4bz4llfc1.jpeg"));
var req = new ExtractReceiptRequest().receipt(image);
var resp = b.extractReceipt(req);
System.out.println(resp);

PHP

$image = new BamlImage();
$image->setUrl("https://i.redd.it/adzt4bz4llfc1.jpeg");
$req = new ExtractReceiptRequest();
$req->setReceipt($image);
$resp = $apiInstance->extractReceipt($req);
echo "<pre> ExtractReceipt: " . print_r($resp, true) . "</pre>";

Ruby

image = BamlClient::BamlImageUrl.new(url: 'https://i.redd.it/adzt4bz4llfc1.jpeg')
req = BamlClient::ExtractReceiptRequest.new(receipt: image)
resp = b.extract_receipt(req)
puts resp

Rust

let image = BamlImage::BamlImageUrl(BamlImageUrl {
    url: "https://i.redd.it/adzt4bz4llfc1.jpeg".to_string(),
    media_type: None,
});
let req = ExtractReceiptRequest { receipt: image };
let resp = b::extract_receipt(&config, req).await?;
dbg!(resp);

You can see the full list of client languages that OpenAPI supports here.

If this seems useful to you, visit the quickstart to try it out today!