> ## Documentation Index
> Fetch the complete documentation index at: https://docs.truthsystems.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Introduction to Gateway
> Real-time hallucination detection for LLM outputs.
Gateway fact-checks LLM-generated text against your source documents. You provide a claim and sources, and Gateway tells you whether the claim is supported, refuted, or lacks sufficient evidence.
```python theme={null}
from gateway import TextSource
from gateway.aws import AwsClient
client = AwsClient.from_sfn_arn("arn:aws:states:us-east-1:123456789:stateMachine:gateway")
ruling = client.judge(
claim="The Eiffel Tower is in Paris and was built in 1889.",
sources=[
TextSource(id="doc1", text="The Eiffel Tower is located in Paris, France."),
TextSource(id="doc2", text="It was completed in 1889."),
],
)
print(ruling.verdict) # Verdict.SUPPORTS
```
```python theme={null}
import asyncio
from gateway import TextSource
from gateway.azure import AzureClient
client = AzureClient.from_function_app_url(
"https://yourprefix-func.azurewebsites.net",
api_key="your-function-key",
)
ruling = asyncio.run(client.judge(
claim="The Eiffel Tower is in Paris and was built in 1889.",
sources=[
TextSource(id="doc1", text="The Eiffel Tower is located in Paris, France."),
TextSource(id="doc2", text="It was completed in 1889."),
],
))
print(ruling.verdict) # Verdict.SUPPORTS
```
## How it works
1. **Claim decomposition** - Gateway breaks your claim into individual statements
2. **Evidence retrieval** - Each statement is matched against relevant passages in your sources
3. **Verdict classification** - We determine whether each statement is supported, refuted, or lacks evidence
## Supported clouds
Gateway deploys to your cloud account. We currently support **AWS** and **Azure**.
During onboarding, we provide the SDK and Terraform configuration for your cloud via SFTP.
## Next steps