Contribution Guide

Run the repository’s pre-commit checks before opening a pull request. From the repository root:

pre-commit run --all-files

If a hook modifies files, review its changes and run the checks again.

Naming and lint checks

Use public names for classes, functions, methods, and attributes defined in sglang_omni/ and tests/. The leading-underscore lint hook checks every Python file under those directories, including new model packages and test suites. It flags class and function definitions, every attribute read or write, and string names passed to getattr. It ignores vendor copies, dunder names such as __init__, a lone _, and definitions inside functions.

A name inherited from an upstream object still fails the check. Keep that spelling, and mark the line:

session_request._omni_prompt_cache_key = adapter_request._omni_prompt_cache_key  # noqa: leading-underscore

When a local definition must keep a name because an external interface requires it, put # noqa: leading-underscore on that line and explain why:

class ExternalAdapter(ExternalBase):
    # ExternalBase calls this hook by its exact name.
    def _required_external_hook(self):  # noqa: leading-underscore
        return self.state

The exemption keeps the definition out of lint violations and automatic renames. Its references retain the same name. A comment such as # skip leading-underscore class and function names is not an exemption.

The pre-commit hook runs scripts/check_leading_underscore.py and only reports violations. It does not rewrite files. To rename violating class and function definitions and their references within the same file, run the fixer and review the diff:

python scripts/check_leading_underscore.py --fix

The fixer never renames attributes, and it does not update callers in other files, pytest fixture parameters, or string references such as monkeypatch.setattr(module, "_name", ...). Rename those by hand, preserve third-party API names, and update those references explicitly.

Every if checked under sglang_omni/ (excluding sglang_omni/vendor/) must have an else, or belong to an if/elif chain that ends in else. Returning, raising, or a one-line body does not exempt it. There is no # noqa exemption. Prefer an else branch that does real work. At least write else: pass.

The pre-commit hook runs scripts/check_if_else.py and only reports violations. It does not rewrite files. When the other branch truly does nothing, insert else: pass yourself, or run the fixer:

python scripts/check_if_else.py --fix

Write documentation

See the documentation README for writing conventions, local previews, and documentation checks.