AgentBadge — Agent Marketplace on Arc

Trust & settlement layer for agentic economic activity. Agents discover paid services, pay per-request in USDC via x402 on Arc Mainnet, receive NFT access passes, and earn publicly verifiable on-chain attestations.

Live: agentbadge.xyz · Article: We deployed AgentBadge to Arc Mainnet · Full feature docs: FEATURES.md

What is this?

AgentBadge is a marketplace where AI agents are the customers. Sellers (services, APIs, data feeds) publish priced endpoints; buyers (agents, bots, humans) pay per request in USDC — no accounts, no API keys, no subscription forms. Payment is the authorization: settle a USDC transfer on Arc and an NFT access pass is minted to your wallet.

Who it's for:

• Service/API owners — monetize endpoints for agent consumers in minutes; set a USDC price, get a ServicePass-gated route.
• Agent builders — pay per-request for market data, scans, and attestations without signup flows or credit cards.
• The agent economy — every interaction leaves an on-chain receipt: payments, reputation feedback, attestations.

How the marketplace works:

1. A client hits a paid endpoint → gets 402 Payment Required with payment requirements (amount, USDC asset, recipient, network eip155:5042).
2. The client signs an EIP-3009 transferWithAuthorization — gasless, signature only.
3. The server verifies and settles the authorization on Arc via the eip3009-client-broadcast scheme.
4. On settlement, a ServicePass NFT is minted (time-boxed access) and the request is served. Subsequent calls check hasAccess on-chain.
5. Readiness scans additionally write ERC-8004 reputation feedback + memo — a publicly verifiable attestation of what was scanned and scored.

Architecture

flowchart TD
    A[Client agent / human] -->|HTTPS| B[Hono server<br/>agentbadge.xyz]
    B --> C{bstock-freemium gate}
    C -->|free tier / valid pass| D[API resource]
    C -->|no access| E[402 + payment requirements]
    E -->|PAYMENT-SIGNATURE| F[Arc facilitator]
    F -->|verify + settle| G[Arc Mainnet<br/>USDC EIP-3009]
    F -->|on success| H[MarketplacePassNFT<br/>mintServicePass]
    H --> D
    D -->|scan results| I[ERC-8004<br/>reputation + memo]

Agent ↔ platform interaction

sequenceDiagram
    autonumber
    participant A as Agent
    participant S as Paid endpoint
    participant G as x402 gate
    participant F as Facilitator
    participant C as Arc Mainnet
    participant N as ServicePass NFT

    A->>S: Request (no payment)
    S->>G: Check free bucket / hasAccess
    G-->>A: 402 + requirements ($5 USDC, eip155:5042)
    A->>A: Sign EIP-3009 transferWithAuthorization
    A->>S: Retry + PAYMENT-SIGNATURE
    S->>F: verify + settle
    F->>C: Broadcast authorization (gasless)
    C-->>F: tx confirmed
    F->>N: mintServicePass(payer, serviceId, 30d)
    N-->>F: minted
    S-->>A: 200 + PAYMENT-RESPONSE + data
    Note over A,N: Next requests pass hasAccess —<br/>no payment until pass expires

Live on Arc Mainnet (chainId 5042)

Not a testnet demo — every link resolves on the live explorer.

Full transaction log: docs/arc-mainnet-links.md

Try it

# 1) Free scan — first request is free
curl -X POST https://agentbadge.xyz/api/attestations \
  -H "Content-Type: application/json" \
  -d '{"url":"https://your-agent-api.com"}'

# 2) Second request → HTTP 402 with PAYMENT-REQUIRED header
#    scheme: eip3009-client-broadcast, network: eip155:5042, asset: USDC

# 3) Pay: sign EIP-3009 transferWithAuthorization → retry with
#    PAYMENT-SIGNATURE header → 200 + PAYMENT-RESPONSE + attestation on-chain

Product surface

Repo layout

src/server/               ← Hono app: routes, middleware (bstock-freemium, x402 gate), SSR views
src/agent-readiness/      ← 138-rule agent-readiness scanner engine
src/mcp/                  ← MCP namespaces (/mcp/bstock, /mcp/*)
src/verifiers/            ← payment + attestation verifiers
docs/diagrams/            ← D2 → SVG animated diagrams
docs/arc-mainnet-links.md ← live mainnet tx links (deploys, payments, attestations)
public/                   ← static assets (icons, images, css)
tests/                    ← vitest unit + e2e

Related packages (published on npm as @agentbadge/*): circle-payments (x402 facilitator + EIP-3009 handle), bstock-tracker (market-data feed), agent-readiness-scanner (shared engine). Contracts (MarketplacePassNFT, AgentPassportNFT, AgentEventLog) live in the monorepo's contracts/ package.

Stack

Agent-first contract

Paid surfaces are declared machine-readably — agents never scrape docs:

• openapi/openapi.yaml — committed OpenAPI artifact (regenerate: bun run gen:openapi; CI fails on drift via bun run check:openapi). Carries the x402 contract components: X402PaymentRequired (the 402 body a buyer's validateAccepts checks — x402Version: 2, accepts[] with scheme/network/asset/amount/extra.decimals: 6), X402HonestRefusal (charged: false on every refusal).
• GET /api/v1/services — service catalog; input_schema per SKU is the same object gated routes declare in their bazaar extension (inputSchemaOf(sku) — single source, no drift).
• Payer-binding — self-settle rails require X-Wallet/X-Sig/X-Timestamp (EIP-191, agentbadge-pay:v1).

License

Apache-2.0 — see LICENSE.

Looking for the old full README (scanner rules, all 65 MCP tools, Hedera flows)? → FEATURES.md