# Install a Library or Service

Arguably TinyChain's most powerful feature is the ability to install a `Library` or `Service` at runtime without restarting. For example, TinyChain's linear algebra and machine learning services are distributed as part of the Python client (`math.linalg.LinearAlgebra`, `ml.NeuralNets`, and `ml.Optimizers`). Installing them is as easy as:

```python
import tinychain as tc

# the lead replica (can be a load balancer)
LEAD = tc.URI("http://your.tinychain.cluster")

host = tc.Host(LEAD)
host.install(tc.math.linalg.LinearAlgebra())

```

## Install your Service

Of course the built-in `Service`s aren't much use without being able to install your own! 

```python
# ...

class MyService(tc.service.Service):
    NS = "my_namespace"
    NAME = "my_service"
    VERSION = tc.Version("0.0.0")

    __uri__ = tc.service.service_uri(LEAD, NS, NAME, VERSION)

    @tc.get
    def hello(self, name: tc.String) -> tc.String:
        return tc.String("Hello, {{name}}!").render(name=name)


assert tc.URI(MyService).path() == "/service/my_namespace/my_service/0.0.0"

host.install(MyService())

assert host.get(tc.URI(MyService()).path() + "/hello", "World") == "Hello, World!"
```