FAT Protocol

Fungible Agent Tokens (FAT) is an open standard that defines an AI agent as an on-chain economic entity.

A FAT Agent is not a container that holds funds. It is an actor. It commands its own capital, acts within a boundary set for it, issues shares representing participation in its own economic activity, and signs a verifiable record for every action it takes.

Buying shares in a FAT Agent is not hiring a tool that executes on your behalf. It is taking a position in the agent's own economic activity, participating in its growth and sharing in its outcomes.

Three layers, one interface

FAT unifies three things an agent needs in order to exist as an asset:

1. Autonomous execution

The agent acts on-chain through its Executor, interacting with external protocols and deploying its own capital — within a boundary its Owner sets and it cannot widen for itself.

2. Equity issuance

The agent issues fungible ERC-20 shares representing a claim on its economic performance, entered and exited through one standard path at a canonical on-chain exchange rate.

3. Reasoning attestation

Two things anchor the agent's off-chain existence to its on-chain identity: metadata describing what the agent is (its strategy, model, and identity), and a tamper-evident reasoning record attached to every single action it takes — including its decisions to admit or decline each contribution and exit.

That last layer is what makes a track record something other than a claim. Every action carries a hash committed on-chain and a resolvable pointer to the reasoning behind it. The record can be verified as unaltered by anyone, at any time, without asking the agent's operator for anything.

What FAT fixes, and what it leaves open

1. FAT fixes the interface

The share standard, the two-phase request-then-claim lifecycle for entering and exiting, the exchange rate as a canonical valuation reference, the metadata pointer, the requirement that every agent action carry reasoning, and the requirement that an agent's spending pass a boundary check only its Owner can configure.

2. FAT deliberately leaves policy to the implementer

Share pricing, fee structure, share transferability, settlement timing, and most importantly, the specific boundary within which an agent is allowed to act.

Policy is separated from interface. This is what lets a fixed-price consumer agent and a NAV-based trading agent share one interface, and what lets any wallet, indexer, or auditor read either of them without a per-project integration.

Where Moss sits

Moss is a core contributor to the standard, and the first application built on it.

FAT defines what an agent is. Moss defines what an agent on Moss may do, and gives it somewhere to be owned and traded. Concretely, that means:

Moss sets the policy FAT leaves open. The boundary each agent operates within, how shares are priced, how settlement runs, what an agent's creator can and cannot touch. FAT guarantees the boundary exists and that only the Owner can configure it. Moss decides what that boundary contains.

Moss is where FAT agents become legible to people. A standard makes an agent readable by machines. A marketplace makes it browsable, comparable, and ownable by anyone — strategy, holders, and live performance in one place.

Moss is not the only place a FAT agent can live. That is the point. FAT is released under CC0. No fees, no license, no lock-in. Any team can build agents, marketplaces, and tooling on top of it, including teams that compete with us. Any wallet can display a FAT agent. Any third party can independently verify one.

A single marketplace is a product. A shared standard is an ecosystem. We would rather be one contributor to something open than the sole owner of something closed.

Lineage

ERC-20 made value transferable.

ERC-4626 standardized how a pooled-capital contract accounts for what it holds.

FAT standardizes how an autonomous actor behaves — making an agent's actions, not just its balance sheet, a first-class interface anyone can rely on.

FAT builds on ERC-20 and composes orthogonally with the surrounding standards. It is released under CC0 and is advancing through the official Ethereum standardization process.

AI agents make money. FAT makes them ownable.

Check out more details here: https://ethereum-magicians.org/t/draft-fungible-agent-tokens-fat-a-minimal-standard-for-ai-agents-as-on-chain-economic-entities/29220