diff --git a/README.md b/README.md
index d09b338..4da627d 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ Every time you run an experiment, your code will be auto-committed with metadata
 * Query your scientific log, e.g. `mthd query metrics.accuracy < 0.8`.
 
 ```python
-from mthd import commit
+from mthd import commit, Run
 from pydantic import BaseModel
 
 class Hypers(BaseModel):
@@ -39,15 +39,18 @@ class Metrics(BaseModel):
     accuracy: float
 
 
-@commit(hypers="hypers")
-def my_experiment(hypers: Hypers) -> Metrics:
+@commit
+def my_experiment(run: Run) -> Metrics:
     ...
-    # experiment
+
+    run.set_hyperparameters({ ... })
+
     ...
 
-    metrics = Metrics(...)
+    run.set_metrics({ ... })
 
-    return metrics
+if __name__ == "__main__":
+    my_experiment()
 ```
 
 Then run your experiment:
diff --git a/mthd/decorator.py b/mthd/decorator.py
index 7180e50..ba1fd1f 100644
--- a/mthd/decorator.py
+++ b/mthd/decorator.py
@@ -1,7 +1,8 @@
 import os
 
+from dataclasses import dataclass
 from functools import wraps
-from typing import Callable, Optional, cast
+from typing import Callable, Concatenate, Literal, Optional, ParamSpec, TypeVar, Union, cast, overload
 
 from pydantic import BaseModel
 from rich.console import Console
@@ -14,39 +15,110 @@
 from mthd.util.di import DI
 
 
+@dataclass
+class Run:
+    """Tracks experiment hyperparameters and metrics."""
+
+    _hypers: Optional[dict] = None
+    _metrics: Optional[dict] = None
+
+    def set_hyperparameters(self, hypers: dict) -> None:
+        """Set hyperparameters manually."""
+        self._hypers = hypers
+
+    def set_metrics(self, metrics: dict) -> None:
+        """Set metrics manually."""
+        self._metrics = metrics
+
+    @property
+    def hyperparameters(self) -> Optional[dict]:
+        return self._hypers
+
+    @property
+    def metrics(self) -> Optional[dict]:
+        return self._metrics
+
+
+P = ParamSpec("P")
+R = TypeVar("R")
+T = TypeVar("T")
+
+
+@overload
+def commit(
+    fn: None = None,
+    *,
+    hypers: str = "hypers",
+    template: str = "run {experiment}",
+    strategy: StageStrategy = StageStrategy.ALL,
+    implicit: Literal[False] = False,
+) -> Callable[[Callable[Concatenate[Run, P], R]], Callable[P, R]]: ...
+
+
+@overload
 def commit(
-    fn: Optional[Callable] = None,
+    fn: None = None,
     *,
     hypers: str = "hypers",
     template: str = "run {experiment}",
     strategy: StageStrategy = StageStrategy.ALL,
-) -> Callable:
+    implicit: Literal[True],
+) -> Callable[[Callable[P, R]], Callable[P, R]]: ...
+
+
+@overload
+def commit(
+    fn: Callable[P, R],
+) -> Callable[Concatenate[Run, P], R]: ...
+
+
+def commit(
+    fn: Optional[Callable[..., R]] = None,
+    *,
+    hypers: str = "hypers",
+    template: str = "run {experiment}",
+    strategy: StageStrategy = StageStrategy.ALL,
+    implicit: bool = False,
+) -> Union[Callable[[Callable[..., R]], Callable[..., R]], Callable[..., R]]:
     """Decorator to auto-commit experimental code with scientific metadata.
 
     Can be used as @commit or @commit(message="Custom message")
     """
 
-    def decorator(func: Callable) -> Callable:
+    def decorator(func: Callable[..., R]) -> Callable[..., R]:
         @wraps(func)
         def wrapper(*args, **kwargs):
             di = DI()
-            # @todo: handle this better (eg. positional args)
-            hyperparameters = cast(BaseModel, kwargs.get(hypers, None))
-            if not hyperparameters:
-                raise MthdError("Hyperparameters must be provided in the function call.")
             git_service = di[GitService]
-            # codebase_service = di[CodebaseService]
 
-            # Generate commit message
+            if not implicit:
+                context = Run()
+                args = [context] + list(args)
+                metrics = func(*args, **kwargs)
+
+                if context.hyperparameters is None:
+                    raise MthdError("When using context, hyperparameters must be set via the Context object")
+                if context.metrics is None:
+                    raise MthdError("When using context, metrics must be set via the Context object")
 
-            # Run experiment
-            metrics = func(*args, **kwargs)
+                hyper_dict = context.hyperparameters
+                metric_dict = context.metrics
+            else:
+                metrics = func(*args, **kwargs)
+
+                hyperparameters = cast(BaseModel, kwargs.get(hypers, None))
+                if not hyperparameters:
+                    raise MthdError("When not using context, hyperparameters must be provided as function arguments")
+                if not isinstance(metrics, BaseModel):
+                    raise MthdError("When not using context, metrics must be returned as a BaseModel")
+
+                hyper_dict = hyperparameters.model_dump()
+                metric_dict = metrics.model_dump()
 
             experiment = ExperimentRun(
                 experiment=func.__name__,
-                hyperparameters=hyperparameters.model_dump(),
-                metrics=metrics.model_dump(),
-                # annotations=codebase_service.get_all_annotations(),
+                hyperparameters=hyper_dict,
+                metrics=metric_dict,
             )
             message = experiment.as_commit_message(template=template)
 
@@ -82,9 +154,18 @@ class Metrics(BaseModel):
         b: float
         c: str
 
-    @commit(hypers="hypers", template="run {experiment} at {timestamp}")
-    def test(hypers: Hyperparameters):
-        print("\n<Experiment goes here>\n")
+    # Example using function arguments/return
+    @commit(hypers="hypers", implicit=True, template="run {experiment} at {timestamp}")
+    def test1(hypers: Hyperparameters):
+        print("\n<Experiment 1 goes here>\n")
         return Metrics(a=1, b=2.0, c="3")
 
-    test(hypers=Hyperparameters(a=1, b=2.0, c="3"))
+    # Example using Context object
+    @commit()
+    def test2(run: Run, foo: int):
+        print("\n<Experiment 2 goes here>\n")
+        run.set_hyperparameters({"a": 1, "b": 2.0, "c": "3"})
+        run.set_metrics({"a": 1, "b": 2.0, "c": "3"})
+
+    test1(hypers=Hyperparameters(a=1, b=2.0, c="3"))
+    test2(5)  # No need to pass context
diff --git a/tests/e2e/e2e_test.py b/tests/e2e/e2e_test.py
index bf6a688..9cd58bc 100644
--- a/tests/e2e/e2e_test.py
+++ b/tests/e2e/e2e_test.py
@@ -62,7 +62,7 @@ class Metrics(BaseModel):
     accuracy: float
     loss: float
 
-@commit(hypers="hypers")
+@commit(hypers="hypers", implicit=True)
 def train_model(hypers: Hyperparameters) -> Metrics:
     # Simulate training
     accuracy = 0.75 + ({iteration} * 0.05)  # Gradually improve accuracy
@@ -86,6 +86,39 @@ def train_model(hypers: Hyperparameters) -> Metrics:
         f.write(content)
 
 
+def create_run_experiment_file(temp_dir: Path, iteration: int) -> None:
+    """Create or update the experiment file using run-based API."""
+    content = f"""
+from mthd import commit
+from mthd.decorator import Run
+
+@commit
+def train_model(run: Run):
+    # Set hyperparameters
+    run.set_hyperparameters({{
+        "learning_rate": 0.001 * ({iteration} + 1),
+        "batch_size": 32 * ({iteration} + 1),
+        "epochs": 10 * ({iteration} + 1)
+    }})
+    
+    # Simulate training
+    accuracy = 0.75 + ({iteration} * 0.05)  # Gradually improve accuracy
+    loss = 0.5 - ({iteration} * 0.1)        # Gradually decrease loss
+    
+    # Set metrics
+    run.set_metrics({{
+        "accuracy": accuracy,
+        "loss": max(0.1, loss)
+    }})
+
+if __name__ == "__main__":
+    train_model()
+"""
+
+    with open(temp_dir / "experiment.py", "w") as f:
+        f.write(content)
+
+
 def test_multiple_experiments(temp_dir: Path):
     """Test running multiple experiments and creating commits."""
     # Get the path to the Python executable in the virtual environment
@@ -128,7 +161,72 @@ def test_multiple_experiments(temp_dir: Path):
         text=True,
         cwd=temp_dir,
     )
-    print(result.stdout)
+
+    assert result.returncode == 0
+
+    # Should find 2 commits (iterations 2 and 4 have accuracy > 0.8)
+    output_lines = result.stdout.strip().split("\n")
+    assert len(output_lines) > 0
+    assert "Found 2 commit(s)" in output_lines[0]
+
+    # Test querying for experiments with low loss
+    result = subprocess.run(
+        [str(mthd_path), "query", "metrics.loss < 0.5"],
+        capture_output=True,
+        text=True,
+        cwd=temp_dir,
+    )
+
+    assert result.returncode == 0
+
+    # Should find 3 commits (iterations 2, 3, and 4 have loss < 0.5)
+    output_lines = result.stdout.strip().split("\n")
+    assert len(output_lines) > 0
+    assert "Found 3 commit(s)" in output_lines[0]
+
+
+def test_multiple_run_experiments(temp_dir: Path):
+    """Test running multiple experiments using run-based API."""
+    # Get the path to the Python executable in the virtual environment
+    if os.name == "nt":  # Windows
+        python_path = temp_dir / ".venv" / "Scripts" / "python.exe"
+        mthd_path = temp_dir / ".venv" / "Scripts" / "mthd.exe"
+    else:  # Unix-like
+        python_path = temp_dir / ".venv" / "bin" / "python"
+        mthd_path = temp_dir / ".venv" / "bin" / "mthd"
+
+    # Run multiple iterations of the experiment
+    for i in range(4):
+        create_run_experiment_file(temp_dir, i)
+
+        # Run the experiment using the virtualenv python
+        subprocess.run(
+            [str(python_path), str(temp_dir / "experiment.py")],
+            check=True,
+        )
+
+    # Verify the commits
+    repo = git.Repo(temp_dir)
+    commits = list(repo.iter_commits())
+
+    # Should have 4 commits
+    assert len(commits) == 4
+
+    # All commits should be experiment commits
+    for commit in commits:
+        message = commit.message if isinstance(commit.message, str) else commit.message.decode("utf-8")
+
+        assert message.startswith("exp: ")
+        assert "metrics" in message
+        assert "hyperparameters" in message
+
+    # Test querying for experiments with high accuracy
+    result = subprocess.run(
+        [str(mthd_path), "query", "metrics.accuracy > 0.8"],
+        capture_output=True,
+        text=True,
+        cwd=temp_dir,
+    )
 
     assert result.returncode == 0