pay2play

Meter anything on Arc. HTTP, MCP, stream, or pixel — settled gaslessly in USDC.

An agnostic nanopayment infrastructure built on Circle's Arc L1. Submission for the Agentic Economy on Arc hackathon (Apr 2026).

Honest framing

pay2play is a thin composition over:

• @circle-fin/x402-batching · Circle's Gateway-backed x402 middleware (BatchFacilitatorClient + GatewayClient)
• @x402/mcp · Vercel/Coinbase's paidTool + withPayment for MCP
• @modelcontextprotocol/sdk · streamable-HTTP MCP transport (required for x402 headers)
• viem · arcTestnet chain already exported

What we add:

• Unified UsageSignal meter — one price function covers every metering axis
• Voucher Session — client accumulates, server flushes, clean for streaming
• Per-angle modular components (C1–C9 on Arc) — 4 tracks + 5 bonus components
• Honest observability — distinguishes signed vouchers from settled on-chain batches

Coverage matrix

Dimension	Modes
Transport	HTTP · MCP (streamable-HTTP) · SSE · viewport (browser)
Metering axis	request · tokens · frames · bytes · rows · dwell · seconds
Settlement	Circle Gateway batched (default) · thirdweb · Coinbase public · Algorand AVM
Actor modes	human↔agent · agent↔agent · agent↔API · machine↔machine
Cross-chain	USDC bridge (CCTP V2) · EURC swap (FxEscrow) · same-chain send
Agent identity	ERC-8004 register + reputation · ERC-8183 job escrow lifecycle
Smart contracts	Vyper — pay2play-grown (PaymentChannel, AgentEscrow, SpendingLimiter, SubscriptionManager) + vendored from vyperlang/vyper-agentic-payments (PaymentSplitter, Vault)
Languages	TypeScript (primary) · Python (GatewayClient + Titanoboa + FastAPI)

Components

#	Component	Track / Bonus	Price	Status
C1	api-meter	Track 1: Per-API Monetization	$0.001/request	live + tested ✓
C2	agent-loop	Track 2: Agent-to-Agent	$0.0005/ask	live + tested ✓
C3	llm-stream · WOW	Track 3: Usage-Based Compute	$0.00005/token	live SSE ✓
C4	dwell-reader	Track 4: Real-Time Micro-Commerce	$0.0001/paragraph	live + tested ✓
C5	mcp-tool	bonus — MCP paid tools	$0.001/call	scaffolded
C6	frame-classifier	bonus — M2M	$0.0005/frame	live + tested ✓
C7	row-meter	bonus — data	$0.0001/row	live + tested ✓
C8	bridge	bonus — Stablecoin FX / Cross-chain	$0.001/op	live + tested ✓
C9	agent-identity	bonus — Agentic Economy (ERC-8004/8183)	$0.002/call	live + tested ✓
—	pay2play-algo	Algorand counterpart — separate repo	1000 µALGO/call	github.com/AgenticPlace/pay2play-algo

Full specs: docs/07-components.md

Why Arc? (margin analysis)

Chain	$0.001 call margin	Verdict
Ethereum L1	–49,900%	❌
Optimism	–200% to –400%	❌
Base L2	–400% to +70%	⚠️ marginal
Arbitrum One	–300% to +80%	⚠️ marginal
Arc direct	–200%	❌
Arc + Gateway (batched)	+97%	✅

Full analysis with break-even formulas: docs/08-margin-analysis.md

Quick start

git clone <repo>
cd pay2play
pnpm install
pnpm --filter @pay2play/core build
pnpm --filter @pay2play/server build
pnpm --filter @pay2play/client build
pnpm --filter @pay2play/bridge build

cp .env.example .env
# Edit .env: set SELLER_ADDRESS + BUYER_PRIVATE_KEY (via scripts/generate-wallets.ts)
# Fund buyer at https://faucet.circle.com/ → Arc Testnet → 20 USDC

# Run the WOW demo:
pnpm --filter c3-llm-stream start       # → http://localhost:4023/

# Original components:
pnpm --filter c1-api-meter dev          # :4021  paid weather/geocode
pnpm --filter c2-agent-loop server      # :4022  paid agent-to-agent
pnpm --filter c4-dwell-reader start     # :4024  dwell-based article paywall
pnpm --filter c6-frame-classifier start # :4026  paid frame classification
pnpm --filter c7-row-meter start        # :4027  paid data rows

# New components:
pnpm --filter c8-bridge start           # :3008  cross-chain bridge (CCTP V2)
pnpm --filter c9-agent-identity start   # :3009  ERC-8004 register + ERC-8183 jobs
# Algorand: see https://github.com/AgenticPlace/pay2play-algo (separate repo)

# Agent identity flows:
pnpm tsx scripts/register-agent.ts --dry-run
pnpm tsx scripts/create-job.ts --dry-run

# AgenticPlace gateway smoke test (start C9 first):
pnpm tsx scripts/test-agenticplace.ts        # 6 checks vs http://localhost:3009

# Gateway setup (run once per buyer wallet):
pnpm tsx scripts/gateway-deposit.ts 1   # deposit 1 USDC into Circle Gateway
pnpm tsx scripts/gateway-balance.ts     # check gateway + wallet balances

# Integration smoke tests:
bash tests/smoke-test.sh
pnpm tsx scripts/test-c6.ts
pnpm tsx scripts/test-c7.ts
pnpm tsx scripts/test-c9.ts

Architecture

┌──────── @pay2play/core ─────────────────────────┐
│  meter · session · arc (15 contracts) · types    │
│  AgentIdentity · JobState · ABIs                │
└──────┬────────────────────────────────┬──────────┘
       │                                │
 ┌─────▼──────┐  ┌───────────────┐  ┌──▼───────────┐
 │@p2p/server │  │ @p2p/client   │  │ @p2p/bridge  │
 │ http/sse   │  │ fetch/openai  │  │ Bridge/Swap   │
 │ mcp        │  │ mcp/viewport  │  │ Send (CCTP)   │
 │ facilitators│  └───────┬───────┘  └──────┬────────┘
 │ circle/3web│          │                   │
 └──────┬─────┘          │                   │
        └────────┬────────┘                   │
                 ▼                            ▼
   ┌─────────────────────────┐  ┌─────────────────────┐
   │  components/ (C1..C9)   │  │  components/c8-bridge│
   └──────────┬──────────────┘  └──────────────────────┘
              │
    ┌─────────▼──────────────────────────┐
    │  Arc Testnet · Algorand Testnet    │
    │  USDC-gas + Gateway + CCTP V2      │
    │  ERC-8004/8183 (Arc, this repo)    │
    └────────────────────────────────────┘

Research index

In ./docs/:

• 01-hackathon-rules.md — rules, prizes, judging
• 02-arc-network.md — Arc testnet config (chain 5042002) + all 15 contracts
• 03-circle-nanopayments.md — Gateway SDK, App Kit bridge, thirdweb, Python SDK
• 04-x402-protocol.md — v2 spec + header format + 3 facilitators + Python
• 05-repos-to-clone.md — reference repos
• 06-architecture.md — 5-layer ladder (L0–L4) + how mindX & AgenticPlace fit
• 07-components.md — C1–C9 Arc components + governance-layer Vyper primitives
• 08-margin-analysis.md — chain economics
• 09-competitive-intel.md — prior-winners analysis
• 10-circle-feedback.md — Circle Product Feedback draft
• 11-tool-map.md — comprehensive tool/SDK/contract reference map
• fees.md — precision-correct fee math, default fees per component, PPMT projections, three layers of fee setting (env / admin / on-chain)

Sister repos

• pay2play-algo — Algorand counterpart (vendored agnostic core, AVM atomic-group settlement)

Hackathon metadata

• Primary track: Per-API Monetization Engine (C1)
• Coverage: all 4 tracks via C1/C2/C3/C4 + 6 bonus components
• Circle products used: Nanopayments · Gateway (batched settlement) · x402 (on Arc) · Arc testnet · Circle Faucet · App Kit Bridge · CCTP V2 · ERC-8004/8183 identities · Circle Titanoboa SDK (Python)
• Hard rules met:
  • ≤$0.01/action ✓ (range: $0.00005 to $0.002)
  • ≥50 on-chain txs ✓ (63+ settlements confirmed — see tests/)
  • Margin analysis ✓ (docs/08-margin-analysis.md)
  • Public GitHub + MIT ✓
  • Circle Product Feedback draft ✓ (docs/10-circle-feedback.md)
• Integration tested: C1/C2/C3/C4/C6/C7/C8/C9 live on Arc testnet (see tests/integration-results-2026-04-24.md)

Testnet facts (from _refs/arc-nanopayments)

Chain ID	5042002
CAIP-2	eip155:5042002
RPC	https://rpc.testnet.arc.network
Explorer	https://testnet.arcscan.app
Faucet	https://faucet.circle.com
USDC	0x3600000000000000000000000000000000000000
GatewayWallet	0x0077777d7EBA4688BDeF3E311b846F25870A19B9
GatewayMinter	0x0022222ABE238Cc2C7Bb1f21003F0a260052475B
Scheme extra.name	GatewayWalletBatched

License

MIT — see LICENSE.

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Testnet-only. Arc mainnet is not yet live as of April 2026. "Arc" here = Circle's stablecoin-native L1, NOT Algorand ARC standards.