ERC-8004's Identity Registry on Ethereum mainnet now shows 50,727 registered agents (checked 2026-09-07). That's not a claim from a deck — it's a number you can read off the chain yourself at [satohub.ai/resources/erc-8004](https://satohub.ai/resources/erc-8004). Fifty thousand agents choosing a portable, checkable identity over "trust the API key" is the kind of thing that used to be a thought experiment. It isn't anymore.
The library, by the numbers
Sato Hub is now tracking 374 pieces of the onchain agent stack — the frameworks, MCPs, tools, wallets, and rails builders actually reach for. The mix tells you where the energy is:
- ▸MCP — 134 (36% of everything tracked). If you're building an agent that needs to *do* something onchain instead of just talk about it, odds are you're reaching for an MCP server first.
- ▸API / SDK — 45, Agent Framework — 29, Skill Repo — 27, Trading Tool — 27, Wallet Infrastructure — 26.
- ▸Smaller but real: Data Tool — 23, Developer Tool — 20, DeFi Tool — 14, Security Tool — 10, Onchain Agent — 6 (curated, and deliberately few — that's the agent itself, not something you build with), Agent Marketplace — 5, Agent Launchpad — 3.
MCP's lead isn't close. The protocol has become the default handshake between an agent and the tools it needs, and the library reflects it.
On chains: Multichain — 136, Base — 122, Ethereum — 103, Solana — 92, Arbitrum — 54, Polygon — 47, BNB Chain — 39 (39 more listings didn't specify). Base and Ethereum lead the single-chain count, but the biggest bucket is tooling that doesn't pick a side at all — the stack is consolidating around chain-agnostic building blocks, not one execution layer.
Identity onchain: the ERC-8004 count keeps climbing
The headline number — 50,727 agents registered in ERC-8004's Identity Registry on Ethereum mainnet — is read directly from the registry contract, not self-reported by any project. That's the whole point of the standard: an agent's identity becomes something *other* agents can check without asking a platform to vouch for it. Worth restating so it doesn't get lost in the count: registration proves an agent *exists* with an onchain identity. It says nothing about whether that agent is safe or good at its job — that's a separate, harder problem, and ERC-8004's own Reputation and Validation registries are the ones built to eventually address it.
Sato Score leaders this week
A reminder before the list: the Sato Score measures how open, active, and verifiable a listing is — maintenance signals, code transparency, docs, provenance. It is explicitly not a safety, quality, or returns grade, and non-product listings don't get scored at all. With that framing: this week's High-tier leaders are Raydium (95), BlockRun MCP (89), Coinbase AgentKit (88), TradingAgents (88), ElizaOS (87), and GOAT SDK (87). All six show up as maintained, documented, and checkable — which is what the score is actually measuring, full stop.
Notable moves this week
- ▸Three new listings landed: TermiX (Agent Marketplace) and Q402 (Quack AI) (Wallet Infrastructure) on 2026-09-02, plus SingularityNET (Agent Marketplace) and Ocean Protocol (Data Tool) on 2026-08-30. A marketplace and a data-availability layer showing up in the same week is a decent snapshot of what "agent economy infrastructure" now spans.
- ▸agentnode-sdk shipped v0.24.1, and Subsquid's portal-mcp-server pushed two releases (v0.8.4, v0.8.5) in quick succession — the kind of routine version churn that's easy to skip past but is exactly what the Sato Score's maintenance component is built to notice.
- ▸The odd one out: [CoinDesk reported](https://www.coindesk.com/markets/2026/09/07/once-hyped-ethereum-rival-harmony-wants-to-shut-its-blockchain-over-ai-threats) that Harmony, a once-hyped Ethereum rival, wants to shut down its own blockchain over AI-related security threats. We're not in a position to verify Harmony's threat assessment — but it's a useful counterweight to a week full of registration and release numbers: not every chain is confident it can survive agents transacting on it. Worth remembering while you're picking rails.
What to watch
MCP's share of the library isn't slowing down, and the ERC-8004 count has nowhere to go but up as more agents look for a way to prove they exist without a middleman. The gap to watch is the one between those two numbers: 374 things you can build with, and 50,727 agents that have registered an identity — most of which weren't built with anything we're currently tracking. That gap is the market.
If you're building one of them: describe the agent, and Sato maps the stack — skills, MCPs, wallets, and rails, scored and query-able over MCP. [Start at satohub.ai/build](https://satohub.ai/build).