---
title: Hello World
description: >-
  Here is a simple example of how Thunder lets you compile and run PyTorch
  modules and functions:
canonical: 'https://lightning.ai/docs/thunder/stable/home/hello_world'
---
# Hello World {#hello-world}

Here is a simple example of how Thunder lets you compile and run PyTorch modules and functions:

```python
import torch
import thunder

def foo(a, b):
  return a + b

jitted_foo = thunder.jit(foo)

a = torch.full((2, 2), 1)
b = torch.full((2, 2), 3)

result = jitted_foo(a, b)

print(result)

# prints
# tensor(
#  [[4, 4],
#   [4, 4]])
```

The compiled function `jitted_foo` takes and returns PyTorch tensors, just like the original function, so modules and functions compiled by Thunder can be used as part of bigger PyTorch programs.

Thunder currently understands a subset of PyTorch operations, and a subset of Python. It's adding support quickly, however. Reach out on the Thunder repo and open an issue there to easily get help if an operator is currently not supported.

---

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- Parent: [Home](/docs/thunder/0.2.6/home.md)