# Agentscan

> ERC-8004 AI Agent Explorer — discover, explore, and analyze AI agents registered on 21 blockchain networks.

Agentscan (https://agentscan.info) is an on-chain AI agent registry explorer built on the ERC-8004 protocol. It indexes AI agents across 21 mainnet networks (Ethereum, Base, Arbitrum, Optimism, Polygon, BNB, Avalanche, and more), providing rich search, filtering, reputation data, and OASF taxonomy classification.

## Key Features

- **Agent Discovery**: Search registered AI agents with 12+ filters (network, service type, reputation, OASF taxonomy)
- **Service Type Filtering**: Filter agents by protocol — MCP (Model Context Protocol), A2A (Agent-to-Agent), OASF
- **Agent Details**: Full agent profile including description, services, reputation score, feedback history, owner info, and ERC-8004 metadata
- **Reputation System**: On-chain trust scores aggregated from peer feedback via ERC-8004 Reputation Registry
- **OASF Taxonomy**: Auto-classification of agents by skills (136 categories) and domains (204 categories) per OASF v0.8.0
- **Multi-chain**: Covers 21 mainnet networks using CREATE2 deterministic contract addresses
- **Analytics**: Leaderboard, network stats, trending agents, and platform-wide analytics
- **x402 Payment**: Accepts USDC micropayments via the x402 protocol for API access

## Service Types

ERC-8004 agents declare the protocols they support in the `services` array of their registration JSON. Agentscan extracts and indexes these to enable filtering.

### MCP (Model Context Protocol)
MCP is Anthropic's open standard that lets AI clients (such as Claude, Cursor, or any MCP-compatible host) discover and call an agent's tools over a standardized JSON-RPC interface. An agent with an MCP service exposes a list of `capabilities` (tool names) that clients can invoke directly — no custom integration required. Agentscan indexes MCP agents so you can find and connect to any MCP-compatible agent registered on-chain.

### A2A (Agent-to-Agent)
Google's Agent-to-Agent protocol enables structured communication between autonomous AI agents. An A2A service entry includes an `endpoint` URL pointing to the agent's Agent Card (`.well-known/agent-card.json`) and an `a2aSkills` list describing what the agent can do for other agents.

### OASF (Open Agent Service Framework)
OASF is Cisco's open taxonomy for classifying AI agents by `skills` (136 categories, e.g. `nlp/text_generation`) and `domains` (204 categories, e.g. `technology/blockchain`). Agentscan auto-classifies agents using LLM inference when metadata doesn't declare OASF tags explicitly.

## Agent Metadata (ERC-8004 Registration JSON)

Each registered agent has an on-chain URI pointing to a JSON file with fields:
- `name`, `description`, `image`
- `services[]`: array of service descriptors (`name`, `endpoint`, `version`, plus protocol-specific fields)
  - MCP: `capabilities[]` — list of tools the agent exposes via Model Context Protocol
  - A2A: `a2aSkills[]` — skills for agent-to-agent interaction
  - OASF: `skills[]`, `domains[]` — taxonomy tags
- `active`: boolean — whether the agent is currently active
- `x402Support`: boolean — whether the agent accepts x402 payments
- `supportedTrust[]`: trust mechanisms (e.g. `"reputation"`)
- `registrations[]`: on-chain registry references (`agentId`, `agentRegistry`)

## REST API

Base URL: `https://agentscan.info/api`

### Agents

- `GET /agents` — list agents with pagination and filtering
  - `?page=1&page_size=20` — pagination
  - `?search=<query>` — full-text search on name/description/address
  - `?network=<network_id>` — filter by network (e.g. `base-mainnet`, `ethereum`)
  - `?service_type=MCP|A2A|OASF` — filter by service protocol
  - `?quality=basic|all|verified` — quality tier filter
  - `?sort_field=created_at|name|reputation_score&sort_order=asc|desc`
  - `?reputation_min=<n>&reputation_max=<n>` — reputation score range
- `GET /agents/{id}` — full agent detail (includes metadata URI, on-chain data, OASF taxonomy)
- `GET /agents/{id}/metadata` — fetch and parse agent's IPFS/HTTP metadata
- `POST /agents/{id}/classify` — trigger OASF reclassification

### Networks

- `GET /networks` — list all supported networks with sync status

### Stats & Analytics

- `GET /stats` — platform-wide statistics (total agents, networks, sync status)
- `GET /analytics` — agent growth trends and network distribution
- `GET /leaderboard` — top agents by reputation score

### Reputation / Feedback

- `GET /agents/{id}/feedback` — list feedback entries for an agent

## ERC-8004 Contract Addresses (all mainnets, CREATE2 deterministic)

- Identity Registry: `0x8004A169FB4a3325136EB29fA0ceB6D2e539a432`
- Reputation Registry: `0x8004BAa17C55a88189AE136b182e5fdA19dE9b63`

## Agentscan's Own Agent Registration

Agentscan itself is registered as an ERC-8004 agent (token #51323 on BNB Smart Chain).
Agent ID: `a4c6d331-8dc7-4745-a744-d9c7a8943f49`
Services: A2A (https://aliasai.io/agentscan/.well-known/agent-card.json)