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

# Security

> Privacy, integrity, and delivery guarantees

Capture is built around a single commitment to the partner: **what you submit gets delivered, privately, without modification.**

## Privacy

* Submitted transactions are **never broadcast to the public mempool**
* Routing uses nexroute's private partnerships exclusively
* No third party can observe or front-run a transaction submitted via Capture before it appears on-chain
* The dedicated per-partner endpoint is not visible from the public internet (see [Authentication](/capture/rpc/authentication))

## Delivery

Once nexroute responds with a transaction hash, the transaction has been accepted into the routing pipeline.

* Backrun construction failures, simulation errors, or wallet contention all fall through to **direct delivery**. The partner-signed transaction is forwarded without modification
* Internal transient errors (e.g., builder hiccups) are retried before being surfaced
* A non-error response means delivery is committed; there is no silent drop path

## Integrity

* The partner-signed transaction is forwarded **byte-for-byte**. nexroute does not re-sign, repackage, or modify the payload.
* Nonce, gas parameters, and signature originate from the partner's signing infrastructure
* When a backrun is appended, it is a separate transaction signed by nexroute's wallets and bundled atomically *behind* the partner transaction. The partner transaction always executes first within the bundle.

## Network

* Per-partner IP allowlist enforced at the network layer
* HTTPS and secure WebSocket (`wss://`) supported on the same endpoint
* TLS termination at the endpoint; in-flight encryption end-to-end from partner to nexroute