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

# Supported Endpoints & Capabilities

> Which endpoints, providers, input types, and execution modes Portkey Guardrails support.

Guardrails run at the Gateway layer — provider-agnostic, between your app and any upstream LLM.

***

## Supported Endpoints

| Endpoint                             | Input | Output |
| :----------------------------------- | :---: | :----: |
| `/v1/chat/completions`               |   ✓   |    ✓   |
| `/v1/completions`                    |   ✓   |    ✓   |
| `/v1/embeddings`                     |   ✓   |    —   |
| `/v1/messages` (Anthropic)           |   ✓   |    ✓   |
| `/v1/responses`                      |   ✓   |    ✓   |
| `/v1/prompts/{promptId}/completions` |   ✓   |    ✓   |

<Note>
  Embeddings have no model-generated output to evaluate, so only `input_guardrails` apply. See [Guardrails for Embeddings](/product/guardrails/embedding-guardrails).
</Note>

***

## Endpoints That Don’t Support Guardrails

Guardrails are only evaluated on **LLM inference** endpoints where Portkey can extract a text input and/or text output.

The following Inference API endpoints **do not run guardrails**:

* **Assistants API (all endpoints)**: `/v1/assistants/*`, `/v1/threads/*`
* **Audio (all endpoints)**: `/v1/audio/*`
* **Images (all endpoints)**: `/v1/images/*`
* **Files (all endpoints)**: `/v1/files/*`
* **Batch (all endpoints)**: `/v1/batches/*`
* **Fine-tuning (all endpoints)**: `/v1/fine_tuning/*`
* **Moderations**: `/v1/moderations`
* **Models**: `/v1/models`
* **Prompt rendering (no model call)**: `/v1/prompts/{promptId}/render`
* **Response retrieval (no model call)**: `GET /v1/responses/*` (guardrails apply only to `POST /v1/responses`)

***

## Sync vs. Async

| Mode                | `async` | Behavior                                                                                                  | Latency                      |
| :------------------ | :------ | :-------------------------------------------------------------------------------------------------------- | :--------------------------- |
| **Async** (default) | `true`  | Runs in parallel with the LLM call. Results are logged only — no effect on the response.                  | None                         |
| **Sync**            | `false` | Runs before forwarding the request (input) or before returning the response (output). Can deny or modify. | Adds guardrail check latency |

Use async to observe and log without blocking. Use sync when the guardrail result must gate the request.

<Info>
  With `async=false`, Portkey returns `246` (failed, but allowed) or `446` (failed, denied) instead of the standard provider status codes. See [Guardrail behavior on the gateway](/product/guardrails#guardrail-behavior-on-the-gateway).
</Info>

***

## Streaming

| Guardrail Type      | Streaming                                                                                  |
| :------------------ | :----------------------------------------------------------------------------------------- |
| `input_guardrails`  | **Supported** — evaluated before the stream starts                                         |
| `output_guardrails` | **Supported** — evaluated on the full response after stream completes (informational only) |

With input guardrails on a streaming request: if the check passes, the stream proceeds normally. If it fails with `deny=true`, the stream is blocked with `446` before any tokens are sent.

With output guardrails on a streaming request: After the stream completes and the `[DONE]` chunk is sent, Portkey evaluates the full assembled response against your output guardrails. The results are delivered as an additional `hook_results` chunk. Output guardrail results on streaming are **informational only** — no fallback or retry actions are triggered.

To receive `hook_results` inside streaming chunks, set:

```
x-portkey-strict-open-ai-compliance: false
```

By default this header is `true`, and `hook_results` chunks will not be visible.

`hook_results` for input guardrails appear in the first chunk for `/chat/completions`, or as a separate `hook_results` event for `/messages`. Output guardrail results are sent as a chunk after `[DONE]`.

<Note>
  For Anthropic `/messages` streaming, `hook_results` aren't accessible via the Anthropic SDK. Use cURL or raw HTTP requests.
</Note>

See [Streaming Hook Results](/product/guardrails#streaming-responses) for SDK examples.

***

## What Gets Evaluated

### Text

Input guardrails evaluate the **last message** in the request. Output guardrails evaluate the **generated text** in the response.

### Images

Guardrails are text-only. Image inputs (base64 or URLs in multimodal messages) are **not evaluated**. Only the text portions of a message are passed to checks.

### Tool Calls

| Scenario                                  | Evaluated by                                |
| :---------------------------------------- | :------------------------------------------ |
| Model deciding to call a tool             | Output guardrails                           |
| Tool result sent back to the model        | Input guardrails (on the follow-up request) |
| Function definitions in the system prompt | Input guardrails                            |

Tool call arguments (JSON) are treated as text — checks like Regex Match, Contains, and LLM-based detectors (e.g., Prompt Injection) all process this content.

***

## Quick Reference

| Capability                        | Supported                                 |
| :-------------------------------- | :---------------------------------------- |
| `/chat/completions`               | ✓                                         |
| `/completions`                    | ✓                                         |
| `/embeddings`                     | ✓ (input only)                            |
| `/messages` (Anthropic)           | ✓                                         |
| `/responses`                      | ✓                                         |
| `/prompts/{promptId}/completions` | ✓                                         |
| All providers & models            | ✓                                         |
| Input guardrails                  | ✓                                         |
| Output guardrails                 | ✓                                         |
| Async execution                   | ✓ (default)                               |
| Sync execution                    | ✓                                         |
| Streaming — input                 | ✓                                         |
| Streaming — output                | ✓ (informational only, no fallback/retry) |
| Image inputs                      | ✗                                         |
| Text in multimodal messages       | ✓                                         |
| Tool call text                    | ✓                                         |

***

<CardGroup cols={2}>
  <Card title="Guardrails Overview" href="/product/guardrails">
    Create guardrails, configure actions, attach to requests
  </Card>

  <Card title="Guardrails for Embeddings" href="/product/guardrails/embedding-guardrails">
    Guardrails on embedding workflows
  </Card>

  <Card title="List of Guardrail Checks" href="/product/guardrails/list-of-guardrail-checks">
    All built-in and partner checks
  </Card>

  <Card title="Raw Guardrails in JSON" href="/product/guardrails/creating-raw-guardrails-in-json">
    Define guardrails directly in code
  </Card>
</CardGroup>