Settled on Robinhood ChainChain ID 4663

The payment rail for
autonomous AI agents.

One API. Any protocol. Every transaction on-chain. Grand Protocol abstracts x402 and MPP behind a single developer interface, settles every payment on Robinhood Chain, and makes each one verifiable in real time.

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Block time
100ms
Per transaction
< $0.01
Protocols
x402 + MPP
Protocol fee
0%
Mission control
grandprotocol.org/dashboard
Grand Protocol dashboard showing agent wallets and live settlements
  • research-agent-v2x402api.dune.com0.0020 USDG0x7a3f4c…91b2settled
  • crawler-07mppfal.ai0.0120 USDG0x19be02…c4d7settled
  • orchestratorx402research-agent0.5000 USDG0xe4a1d9…0f63settled
  • browser-agentx402api.browserbase.com0.0045 USDG0x3c77aa…b8e1settled
  • quant-desk-3mppmodal.com0.0300 USDG0x90f2c1…7a5dsettled
  • summarisermppapi.openai.com0.0008 USDG0x5be6d0…22c9settled
  • research-agent-v2x402api.dune.com0.0020 USDG0xa17c3e…d044settled
  • ops-monitorx402api.service.com0.0010 USDG0x6d0b9f…31eesettled

01 / The problem

Two protocols.
One rail.

Two machine payment protocols emerged in 2025 and 2026. Neither is going away. Services are choosing one, the other, or both, and every agent developer inherits the fragmentation.

  • Protocol lock-in: an agent built for x402 cannot pay MPP-gated services without rewriting payment logic.
  • No unified wallet: separate credential management per protocol.
  • Settlement opacity: off-chain rails offer no transparent transaction record.
  • No spend controls: budget caps, allowlists, and per-agent limits are left to the developer.
  • No multi-agent accounting: when Agent A hires Agent B, the payment chain is untracked.

These are infrastructure problems. Grand Protocol solves them at the infrastructure level: it detects the protocol, negotiates the scheme, enforces your spend policy, and settles on Robinhood Chain. You call one method. Nothing else changes.

research-agentorchestratorcrawler-07x402MPPROBINHOODCHAIN
x402Coinbase

A lightweight HTTP-native standard that embeds the payment handshake in the request cycle using the long-dormant HTTP 402 status code.

  • Blockchain-native, USDG settled
  • EIP-712 signed payloads
  • Zero protocol fees

Supported natively

MPPStripe + Tempo

A purpose-built agent payment protocol submitted to the IETF as a Standards Track draft, with native sessions and multiple rails.

  • Stablecoins, cards, and Lightning
  • Native session support
  • Integrated by OpenAI, Anthropic, Google Gemini, and 50+ services

Supported natively

02 / Systems

Six systems. One gateway.

Grand Protocol does not build agents and does not choose your protocol. It is infrastructure: fast, transparent, and out of the way.

01

Agent wallets

Each agent or agent team gets a Robinhood Chain smart contract wallet, deployed deterministically from its ID and provisioned via SDK in one line.

02

Spend policies

Daily budgets, per-call limits, domain allowlists, and rate limits, enforced at the gateway before any funds move. Violations are logged on-chain.

03

Universal router

One method handles x402, MPP, and the protocols still to come. Detection, scheme negotiation, and signing all happen inside the gateway.

04

On-chain transparency

Every payment lands on Robinhood Chain with a public transaction hash. The blockchain is the ledger. There is no separate database of record.

05

Multi-agent payments

When an orchestrator hires sub-agents, each payment carries a parent transaction reference. The full chain is traceable end to end.

06

Dashboard

A live feed of every settlement, spend per agent, protocol split, and policy events, read directly from chain state.

03 / Wallets

Agent wallets, out of the box.

Every agent provisioned through Grand Protocol receives a Robinhood Chain smart contract wallet, deployed deterministically from its ID on first initialization. It holds USDG and is the settlement source for every payment the agent makes.

  • Deterministic deployment per agentId
  • USDG settlement by default
  • Fund by transfer, card top-up, or your own wallet
  • Non-custodial by design
Agent walletProvisioned

Address

0x7A3f9c1E4b8D2a6F0c5B7e9A1d3C8f2B4e6D0b1A2

Balance

42.50USDG

Spent today

3.18 USDG

32% of daily budget

Agent
research-agent-v2
Network
Robinhood Chain · 4663
Token
USDG (ERC-20)
Custody
Non-custodial

Spend policy

  • Daily budget100.00 USDG
  • Per call1.00 USDG
  • Rate limit500 / 1h

04 / Router

One call. Any protocol.

A single call handles both x402 and MPP. The gateway reads the 402 response, detects the protocol, negotiates the scheme, enforces your policy, and signs the payload. If a service supports both, x402 is chosen by default for lower overhead and full on-chain settlement. This is configurable.

  • Automatic protocol detection
  • x402 and MPP handlers
  • MPP session reuse across calls
  • Transaction hash on every response
import { GrandProtocol } from "@grandprotocol/sdk";

const grand = new GrandProtocol({
  agentId: "research-agent-v2",
  apiKey: process.env.GRAND_API_KEY,
});

// Protocol detected automatically: x402 or MPP.
const result = await grand.pay({
  endpoint: "https://api.dune.com/v1/query/1234/results",
});

result.protocol;    // "mpp"
result.amountPaid;  // { usdg: 0.002 }
result.txHash;      // Robinhood Chain transaction hash

05 / Constellations

Every agent chain, on-chain.

When an orchestrating agent delegates to sub-agents and those sub-agents incur costs, each payment is recorded with a parent transaction hash. The full hierarchy is traceable on Robinhood Chain without a separate accounting layer.

  • Budget caps per sub-agent run
  • Parent transaction reference on every hop
  • Queryable via API or Robinhood Chain RPC
  • Works with any agent framework
orchestrator0xe4a1…0f63research-agent0.50 USDG · 0x7a3f…91b2crawler-070.12 USDG · 0x19be…c4d7summariser0.08 USDG · 0x5be6…22c9api.dune.comfal.aiapi.browserbase.comapi.openai.comPARENT TX0xe4a1…0f63
ID 4663 · ARBITRUM NITRO · ETH SECURED

06 / Settlement layer

Built on Robinhood Chain.

Every transaction processed by Grand Protocol, whether the underlying protocol is x402 or MPP, is recorded on Robinhood Chain. Agent payments confirm in a fraction of a second at a fraction of a cent while inheriting Ethereum security. Existing x402 tooling, wallets, and indexers work without modification.

Architecture
Ethereum Layer 2 on the Arbitrum stack (Orbit + Nitro)
Block time
100ms
Security
Settles to Ethereum
Compatibility
Fully EVM-compatible
Gas token
ETH
Settlement token
USDG (ERC-20)
Chain ID
4663 mainnet, 46630 testnet
Mainnet launch
July 1, 2026. Public testnet since February 10, 2026

GrandProtocol.sol handles

  • Agent wallet registry, one smart contract wallet per agentId, deployed deterministically
  • Transaction ledger with protocol, amount, counterparty, and timestamp
  • On-chain budget checks for high-value transactions
  • Multi-agent payment routing with parent transaction links
  • USDG balance management

08 / Launch

Add payment infrastructure to your agents.
Deploy to production the same day.

Free up to $1,000 USDG in monthly volume. No percentage take on transactions. No gas markup. The infrastructure should be boring. The agent work should be interesting.

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