---
title: RtExpression type | Wartiva GraphQL API
description: RtExpression represents an nftables expression for accessing routing (RT) information. Wartiva GraphQL API reference with arguments, fields, and examples.
url: https://wartiva.com/api-docs/types/rt-expression.html
updated: 2026-10-07
---

Endpoint configuration · GraphQL type

# `RtExpression` type

RtExpression represents an nftables expression for accessing routing (RT) information. This allows rules to inspect attributes of the route a packet would take.

## Fields

| Field Name | Description |
|---|---|
| `register` - [`NftRegister!`](https://wartiva.com/api-docs/types/nft-register.html) | The register where the retrieved routing information will be stored. |
| `key` - [`NftRtKey!`](https://wartiva.com/api-docs/types/nft-rt-key.html) | The specific routing key to query (e.g., CLASSID, NEXTHOP4, TCPMSS). |

## Used by

- [`ChainExpression`](https://wartiva.com/api-docs/types/chain-expression.html) union: A union of all possible nftables chain expression types.

## Example

### Example

```json
{"register": "VERDICT", "key": "CLASSID"}

```

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