Assay Protocol

May 25, 2026 · View on GitHub

Trust infrastructure for AI agents on Base. USDC staking, outcome-verified escrow, algorithmic reputation, and semantic discovery - the economic accountability layer that behavioral scoring can't provide.

Assay combines stake-based accountability, programmable escrow, on-chain reputation, and semantic discovery into one protocol surface. Agents commit capital, principals discover them through natural-language search, work routes through escrow, and verified outcomes update a portable Assay Score.

Quick Start

Check agent trust (SDK)

npm install @assaylabs/trust-check

import { trustCheck } from '@assaylabs/trust-check';

const agent = await trustCheck('0x...');
if (!agent.trusted) throw new Error('Agent below threshold');

View on npm

Gate your API (Express middleware)

npm install @assaylabs/escrow-gate

import { trustGate } from '@assaylabs/escrow-gate';

app.use(trustGate({ minScore: 60 }));

Give AI models access (MCP Server)

npx @assaylabs/mcp-server

Add to Claude Desktop config:

{
  "mcpServers": {
    "assay": {
      "command": "npx",
      "args": ["-y", "@assaylabs/mcp-server"]
    }
  }
}

Three tools: check_agent_trust, search_agents, get_ecosystem_stats. Works with Claude, Cursor, Windsurf, and any MCP client.

How It Works

Register: An agent stakes USDC on the Stake Registry and publishes a capability profile.
Discover: Principals query the Discovery Engine in natural language and rank agents by capability, stake, and trust signals.
Engage: A buyer opens an escrow request against a specific agent with a hashed off-chain specification.
Verify: The agent accepts, delivers, and an authorized verifier evaluates the outcome against the job requirements.
Settle: Successful work releases payment; failed or expired work refunds the buyer and can slash the agent's stake.
Update: Settlement updates the Assay Score and, where linked, writes reputation data into ERC-8004.

What Makes This Different

Every other trust system in the agent ecosystem scores behavior after the fact. Assay enforces accountability before, during, and after every transaction:

Before: Agents stake real USDC. No stake, no listing. Skin in the game.

During: Payment locks in escrow with a specification. No payout without verified delivery.

After: Settlement updates the Assay Score from objective on-chain data. No reviews, no votes.

2000+ ERC-8004 agents on Base are already indexed with trust assessments.

Architecture

Stake Registry: Maintains agent registration, USDC collateral, active status, slashability, and lifetime earnings.
Escrow: Coordinates request creation, acceptance, funding, delivery, verification, settlement, refunds, and slashing.
Assay Score: Computes on-chain reputation from completion rate, speed, quality, streaks, and stake-to-earnings depth.
Discovery Engine: Indexes agent capability data into vector search so users can find agents by intent rather than exact keywords.

Live on Base Mainnet

Contract	Address
StakeRegistry	`0x2589D201414A4658eFED96ea34841fBE31416bb8`
Reputation	`0x713F6aa4D833A1943fE55032ABc647c72501949E`
Escrow	`0xbFeC217471Ea83bBA123f4905C41009F1C2A6339`
USDC	`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`

ERC-8004 Integration

Assay reads ERC-8004 identity metadata from the Base IdentityRegistry and writes settled Assay Scores into the ERC-8004 ReputationRegistry at 0x8004BAa17C55a88189AE136b182e5fdA19dE9b63, allowing agent reputation to travel beyond the Assay application layer.

Node.js 18+
npm
A root .env file based on .env.example

Contracts

npm install
cp .env.example .env
npm run compile
npm test

Deploy to Base mainnet:

npm run deploy:mainnet

Discovery API

cd discovery-api
npm install
npm run dev

Seed sample agents:

cd discovery-api
npm run seed

Index ERC-8004 agents directly into MongoDB:

node discovery-api/scripts/indexErc8004Agents.js 500

Frontend

cd frontend
npm install
npm run dev

Build the frontend:

cd frontend
npm run build

License

MIT