> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lytix.co/llms.txt
> Use this file to discover all available pages before exploring further.
# Custom LLM Tracing Setup
> How to setup custom LLM tracing in your project
**Prerequisite** Please see [here](/api-key-setup) to get and set your API Key
environment variable.
# Install the lytix SDK
```sh Python
pip3 install lytix-py
```
```sh Typescript
npm install @lytix/client
```
#### (Reccomended) Set you API key via the environment variable
```sh
export LX_API_KEY=
```
#### Set your API key in the code
```py Python
from optimodel import LytixCreds
LytixCreds.setAPIKey('')
```
```ts Typescript
import { LytixCred } from "@lytix/client";
LytixCreds.setAPIKey("sk-1234");
```
# Capture Model Trace
Capture custom model IO events outside of any SDK or client
```py Python
import asyncio
from lytix_py import lytix
userInput = "Whats the capital of France?"
"""
The function to be traced
"""
@lytix.trace(modelName="testModelName")
async def getResponse(logger):
modelOutput = "Paris is the capital of france"
# Set our defined params however we want
lytix.setMessage(userInput, "user")
# Set a system message
lytix.setMessage("You are a helpful assistant", "system")
# Set the output
lytix.setMessage("Ouput of model", "assistant")
# Optional values
lytix.setUserIdentifier("testUser")
lytix.setSessionId("testSession")
return modelOutput
async def main():
response = await getResponse("What is the capital of France?")
print(response)
if __name__ == "__main__":
asyncio.run(main())
```
```ts Typescript
import { MetricCollector } from "@lytix/client";
await MetricCollector.captureModelIO({
modelName: "testModelName",
systemPrompt: "You area helpful assistant",
userPrompt: "Some user input",
assistantMessage: "Some model output",
/**
* Optional fields
*/
metricMetadata: {
/**
* Optional extra data
*/
env: "prod",
}
userIdentifier?: string;
sessionId?: string;
);
```
You'll now see the model IO trace in the Lytix platform [here](https://lab.lytix.co/home/logs).
