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# What is baml_client?

**baml\_client** is the code that gets generated from your BAML files that transforms your BAML prompts into the same equivalent function in your language, with validated type-safe outputs.

![](/_fern-img/6a5a6f26e4b20863fac7e1db990827ab71ebcdfcf34ecf1ecfed3fe02bcfbd8c.webp)

**`Python`**

```python Python
from baml_client import b
resume_info = b.ExtractResume("....some text...")
```

This has all the boilerplate to:

1. call the LLM endpoint with the right parameters,
2. parse the output,
3. fix broken JSON (if any)
4. return the result in a nice typed object.
5. handle errors

In Python, your BAML types get converted to Pydantic models. In Typescript, they get converted to TypeScript types, and so on. **BAML acts like a universal type system that can be used in any language**.

### Generating baml\_client

Refer to the **[Installation](/guide/installation-language/python)** guides for how to set this up for your language, and how to generate it.

But at a high-level, you just include a [generator block](/ref/baml/generator) in any of your BAML files.

**`Python`**

```baml Python
generator target {
    // Valid values: "python/pydantic", "typescript", "ruby/sorbet", "go"
    output_type "python/pydantic"

    // Where the generated code will be saved (relative to baml_src/)
    output_dir "../"

    // What interface you prefer to use for the generated code (sync/async)
    // Both are generated regardless of the choice, just modifies what is exported
    // at the top level
    default_client_mode "sync"

    // Version of runtime to generate code for (should match installed baml-py version)
    version "0.203.1"
}
```

**`TypeScript`**

```baml TypeScript
generator target {
    // Valid values: "python/pydantic", "typescript", "ruby/sorbet", "go"
    output_type "typescript"

    // Where the generated code will be saved (relative to baml_src/)
    output_dir "../"

    // What interface you prefer to use for the generated code (sync/async)
    // Both are generated regardless of the choice, just modifies what is exported
    // at the top level
    default_client_mode "async"

    // Version of runtime to generate code for (should match the package @boundaryml/baml version)
    version "0.203.1"
}
```

**`Go`**

```baml Go
generator target {
    // Valid values: "python/pydantic", "typescript", "ruby/sorbet", "go"
    output_type "go"

    // Where the generated code will be saved (relative to baml_src/)
    output_dir "../"

    // Version of runtime to generate code for (should match installed github.com/boundaryml/baml version)
    version "0.203.1"

    // Go module name for the generated client
    client_package_name "example.com/myproject"

    // Commands to run after code generation (mandatory as it cleans up the generated code)
    on_generate "gofmt -w . && goimports -w . && go mod tidy"
}
```

**`Ruby (beta)`**

```baml Ruby (beta)
generator target {
    // Valid values: "python/pydantic", "typescript", "ruby/sorbet", "go"
    output_type "ruby/sorbet"

    // Where the generated code will be saved (relative to baml_src/)
    output_dir "../"

    // Version of runtime to generate code for (should match installed `baml` package version)
    version "0.203.1"
}
```

**`OpenAPI`**

```baml OpenAPI
generator target {
    // Valid values: "python/pydantic", "typescript", "ruby/sorbet", "go", "rest/openapi"
    output_type "rest/openapi"

    // Where the generated code will be saved (relative to baml_src/)
    output_dir "../"

    // Version of runtime to generate code for (should match installed `baml` package version)
    version "0.203.1"

    // 'baml-cli generate' will run this after generating openapi.yaml, to generate your OpenAPI client
    // This command will be run from within $output_dir
    on_generate "npx @openapitools/openapi-generator-cli generate -i openapi.yaml -g OPENAPI_CLIENT_TYPE -o ."
}
```

The `baml_client` transforms a BAML function into the same equivalent function in your language,