> For the complete documentation index, see [llms.txt](https://nexanetwork.gitbook.io/nexa/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nexanetwork.gitbook.io/nexa/why-bridge-agnostic.md).

# Why Bridge-Agnostic?

The Chain-Agnostic Token (CAT) standard enables tokens and NFTs to be native and fungible across multiple blockchains, without third party custody risk:

1. **Native** contracts on each chain that inherit the characteristics of the underlying blockchain.
2. **Trustless** — contracts are project-owned, with no funds escrowed by third parties.
3. **Compatible** — tokens can be seamlessly transferred between blockchains

Moreover, the CAT standard is **compatible with any message passing protocol**. This grants the token issuer complete ownership and flexibility in defining validation methods and ensuring secure message transmission between token contracts across different blockchains.

## Compatible with any message passing protocol

The growing adoption of the multi-chain ecosystem has led to the increase of different interoperability solutions. These solutions are typically referred to as **’bridges'** or **‘message passing’** protocols, and their purpose is transfer data securely between blockchains. Similarly to blockchains, different message passing protocols has their own unique architecture and possess distinct strengths and weaknesses.

The Chain-Agnostic Token standard is designed for maximum compatibility across all message passing protocols with the use of **Message Router** contracts. This implementation ensures flexibility for token issuers to select and determine the priority order of message passing protocols used, and avoids any vendor lock-in.

Here's why this approach is not just preferable but essential:

1. **Guarding Against Single Points of Failure:**

   Relying solely on a single messaging protocol could lead to a single point of failure. If the protocol experiences issues, faces security vulnerabilities, or becomes compromised, the token transfer process may fail.
2. **Continuous Operation and Reliability:**

   If one message passing protocol encounters issues, the Message Router contract can seamlessly pivot to an alternative, minimising disruptions and enhancing system robustness.
3. **Interoperability and Future-proofing:**

   New message passing solutions emerge regularly. Staying vendor-agnostic allows token contracts to remains interoperable with future advancements in cross-chain technology.
4. **Avoiding Vendor Lock-In Costs:**

   Vendor lock-in can be costly for both integration and operations. A single-vendor solution may need signification reconfiguration if situations chain. The Chain-Agnostic Token standard mitigates these costs by maintaining the freedom to switch between protocols seamlessly.
5. **Community and Developer Preference:**

   Developers and users can choose the priority order of message passing protocols that align best with their requirements and security considerations.

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Want more information on how it works? Read[TECHNICAL ARCHITECTURE](/nexa/technical-architecture/key-components.md)
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