Clearing Up Agglayer Misconceptions

As core developers of Agglayer, Polygon Labs fields a number of questions, both Agglayer-related and not. 

Like: Is Agglayer just a bridge? And: Does the moon exist?

More than a bridge, bigger than a “rollup cluster,” Agglayer is a neutral public good and cross-chain settlement layer to unify liquidity, users, and state across a diversity of sovereign chains, with finality posted to Ethereum. 

Whew. That’s the long, buttoned-up definition.

Here’s a short, Hawaiian shirt version: Agglayer = unifying chains (L1, L2, L∞) while maintaining security and keeping the sovereignty of those chains intact. 

But drilling down into what exactly Agglayer is sometimes requires pulling a via negativa by clearing up what Agglayer isn’t.

That’s right—we’re here to cut down pesky misconceptions. Below, we tackle one by one some of the biggest misunderstandings out there, and swap in mental models that are closer to the truth. 

Let’s get to it. 

Misconception 1: Agglayer is “just a bridge”

Let’s start with a biggie. An increasingly fragmented crypto ecosystem has created the market for interoperability solutions and third-party bridges that enable users to send assets between different chains with different technologies. 

This first misconception would see Agglayer as “just another bridge,” padded in froufrou marketing lingo. 

Big problem, though: It’s not true.

Why it's wrong: Though Agglayer has a bridge component (the unified bridge), it is not only a bridge. 

The mental model for interoperability solutions in the past have been bridges—and nothing but bridges. But an aggregated network is a new paradigm that unlocks different primitives and works in entirely new ways.

Here’s Marc Borion, CEO of Polygon Labs, breaking down the different components at DevCon 2024:

These four components are:

• Pessimistic proof, for security: This novel zero-knowledge (ZK) proof is a security mechanism that ensures no chain can withdraw more funds than have been deposited to the unified bridge. By groking the chain state of every connected chain, the pessimistic proof cryptographically and trustlessly ensures safety for cross-chain interoperability on Agglayer. Note: the pessimistic proof doesn’t only rely on chains that have proofs. We’ll talk more about this in a misconception below.
• Proof aggregation, for lower costs: ZK proofs have a singular superpower: Recursion. With proof aggregation, Agglayer collects ZK proofs of chain states from across the system, creates a proof of these proofs, then posts a single proof to Ethereum. Doing so lowers costs in aggregate by optimizing and amortizing gas fees.
• Unified bridge, for native assets: With Agglayer’s unified bridge, chains that connect plug into a single contract. So while from the perspective of Agglayer, there is a bustling diversity of chains, Ethereum sees only a single contract. Each chain will have a local copy of the unified bridge root. In effect, this unlocks cross-chain native assets. No more wrapping, no more hassle of third-party bridges. Pure abstracted bliss.‍
• Fast interop, for lower latency: When fast interop for Agglayer goes live, settlement cross-chain will happen at lower-than-Ethereum latency. If you want to be nerdsniped, check out Polygon Labs co-founder Brendan Farmer’s original aggregated thesis post to see how this works logically.

Misconception 2: Only Polygon CDK chains can connect to Agglayer

Nope.

Why it's wrong: This is a particularly irksome misconception, because it decenters core collaborators of Agglayer who have already made huge technological strides. 

The longterm goal of Agglayer is to be as minimal and flexible as possible, connecting a diverse range of blockchain architectures, including Layer 2s, Layer 1s, non-EVM chains, and everything in between. 

Aggregate all of crypto in order to unify liquidity, users, and execution environments. End stop.

Check out this map of collaborators to get a sense of the work already being done to become chain agnostic.

Misconception 3: Agglayer validates chain states

Some think Agglayer validates the state of any chain that is connected. Nein! It is not in the business of proving a chain’s internal state. 

Why it's wrong: Agglayer is agnostic about whatever chains connect. This is what sovereignty means, a minimal approach so that chains determine their own rules. 

All Agglayer requires is a chain to “tell” Agglayer what it considers to be a valid state transition. 

But this is also why the pessimistic proof is so important. 

Just in case there’s some buggy or dishonest chain out there, the pessimistic proof treats every chain suspiciously. After it does some quick accounting, it helps ensure cross-chain safety for chains connected to the unified bridge, so no single chain can rug the entire Agglayer ecosystem. 

Thanks, cryptography!

Misconception 4: Agglayer only processes tokens, but not messages

Big misconception here is that Agglayer is limited to token transfers and cannot handle message passing between chains.

Why it's wrong: Agglayer supports both trustless, cross-chain token transfers and message-passing, as well as complex operations. This functionality is enabled by ZK proofs that provide for safety of transactions and messages exchanged across connected chains.

Let us reintroduce you to bridgeAndCall() functionality. Here’s a simple way to think about it: Smart contracts in Agglayer = bridgeAndCall().

This feature enables streamlined composability and interoperability across a web of sovereign chains. In doing so, bridgeAndCall() unlocks the ability for developers to abstract away the cumbersome feeling of a multichain ecosystem. This is an important kind of chain abstraction: users won't need to know what chain they're on, because bridgeAndCall() takes care of all that in the back-end. All that will matter is the experience of using an application.

Check out the bridgeAndCall() deep dive.

Misconception 5: Agglayer needs additional interoperability solutions

Some say for Agglayer to be effective, it’ll require other interoperability solutions.

NO!

Why it's wrong: Agglayer is designed to be as minimal as possible. IN FACT, it’s compatibility extends to other interoperability solutions.

There’s a world where a chain can be connected to multiple interoperability solutions, leading to a complimentary, interoperable world. 

In a word, who will aggregate the aggregators? Listen to Marc Borion’s response:

Chains will have maximum sovereignty not only in how they want to structure the rules of their own internal accounting, but also in how closely they want to interact across other aggregated chains.

To that end, there will be emerging coordination mechanisms, like shared sequencers, so that clusters of chains can be tightly coordinated for the fastest and least expensive cross-chain experience in the industry.

But these emergent coordination mechanisms aren’t necessary for chains to connect. All any connecting chain needs to do is send its chain state to Agglayer—which is part of Agglayer itself.

Misconception 6: Even at its fastest, Agglayer will only be as fast as the slowest chain's finality 

A misconception from a pre-aggregated world. Let us explain. 

Why it's wrong: It all boils down to trust levels. 

While the following mental model is still a work in progress, you can think about a few different levels of trust across chains in Agglayer: 

• Pessimistic
• Pragmatic
• Positive

Depending on what one chain thinks of another can greatly modulate speed, here. Agglayer will support "pre-confirmations," which allow for faster transactions based on these levels of trust.

Pre-confirmation trust enables users to execute cross-chain transactions before finality on all involved chains, relying on the emergent coordination mechanisms mentioned above. 

Okay, so to sum this one up: Thanks to the security mechanisms in place, like the pessimistic proofs, and the fact that a chain cannot ever withdraw more funds than the ones they locked, faster finality than the chain itself is possible, with settlement performed by Agglayer.

If you want to learn more, check out the Learn section in the docs, specifically about Agglayer trust levels. 

* * *

Do you have some questionable idea about what Agglayer is (or isn’t)? Let us know about it. We’ll continue to update this blog as core developers continue to hear misunderstandings about Agglayer. 

Tune into the blog and our social channels to keep up with updates about Polygon.

The future of Web3 is aggregated.

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