> ## Documentation Index
> Fetch the complete documentation index at: https://docs.protectorplus.cloudsine.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# API Reference

> Inspect prompts and responses through Protector Plus over HTTP.

The Protector Plus Guardrail Service API exposes two inspection endpoints — one for prompts (`/input-check`) and one for responses (`/output-check`) — plus an unauthenticated health probe.

## Base URL

```
https://<your-protector-plus-host>
```

Your `<your-protector-plus-host>` depends on your deployment:

* **AWS Marketplace AMI** — the public IP or DNS of your EC2 instance.
* **Kubernetes / Helm** — the hostname exposed by your Ingress Controller.
* **On-prem** — the hostname inside your network.

## Authentication

All API calls require an API key passed in the `X-API-Key` header. See [Authentication](/api-reference/authentication).

## Content type

All endpoints accept `application/json`.

## Endpoints

| Endpoint                                    | Method | Purpose                                               |
| ------------------------------------------- | ------ | ----------------------------------------------------- |
| `/apikey/api/protectorplus/v1/input-check`  | POST   | Inspect a user prompt before forwarding to the LLM.   |
| `/apikey/api/protectorplus/v1/output-check` | POST   | Inspect an LLM response before returning to the user. |
| `/api/protectorplus/v1/health`              | GET    | Liveness probe — no authentication.                   |

## Where to start

<CardGroup cols={2}>
  <Card title="Authentication" icon="key" href="/api-reference/authentication">
    Generate and use your API key.
  </Card>

  <Card title="Integration pattern" icon="route" href="/api-reference/integration-pattern">
    Wire `input-check` + `output-check` into your LLM call path.
  </Card>

  <Card title="input-check" icon="arrow-right-to-bracket" href="/api-reference/input-check">
    Prompt inspection.
  </Card>

  <Card title="output-check" icon="arrow-right-from-bracket" href="/api-reference/output-check">
    Response inspection.
  </Card>
</CardGroup>

<Card title="Need an API key?" icon="key" href="https://www.cloudsine.tech/contact">
  Request a sandbox key for evaluation or a deeper technical conversation.
</Card>