Briefcase

Briefcase turns a single MetaMask permission into a working AI agent workforce. A user grants one ERC-7715 Advanced Permission (e.g. 10 USDC/day). A chief agent redelegates narrower budget slices to three specialists (Scout, Analyst, Designer) via ERC-7710 redelegation — true agent-to-agent coordination. Each specialist pays for premium data and Venice AI inference over x402, settling through the MetaMask facilitator. Payroll settles on Base mainnet through the 1Shot permissionless relayer: gas paid in USDC, the account bootstrapped via an EIP-7702 authorization, status streamed back over signed webhooks. The user can revoke at any moment — cancelling the run and the on-chain authority, so the agents physically cannot spend another cent.

✅ Best x402 + ERC-7710

Specialists pay an x402-gated API and Venice via ERC-7710 delegations

(@metamask/x402 x402Erc7710Client; seller uses x402ExactEvmErc7710ServerScheme).

✅ Best Agent

The entire product is an agent workforce driven by one 7715 grant; the

MetaMask Smart Accounts Kit is the main flow, not a side feature.

✅ Best A2A Coordination

The chief slices the grant into narrower redelegations per specialist

(createDelegation({ parentPermissionContext })).

✅ Best use of Venice AI

Venice powers all agent reasoning, on-chain reads, and the report cover

image; paid via x402 — the agent buys its own intelligence.

✅ Best 1Shot Relayer

Mainnet 7710 relay with an attached EIP-7702 authorization, gas paid in

USDC, Ed25519-signed webhooks drive the dashboard.

- x402 + ERC-7710 settlement: 0x67b6a6f1…0873c4 (Base Sepolia)

- 1Shot 7702 relay: 0xa6775d38…43d4da (Base Sepolia)

- Hosted production agent job, Scout's x402 purchase on-chain:

0x9e92445e…fb97f (Base Sepolia)

- 1Shot relayer settlement, real USDC, gas paid from a zero-ETH account:

0x535b7478…33276a (Base MAINNET)

https://basescan.org/tx/0x535b74786a4bff3be3fd8410521a5a6fdfce11761417df3b72fd1399a233276a

— Developer Experience Feedback (MetaMask Smart Accounts Kit · 1Shot · Venice) —

During integration we hit four behaviors that weren't documented in the official guides; each cost real debugging time and would help other builders.

1. The x402 facilitator silently requires the delegator to be a 7702-upgraded EOA. A counterfactual (undeployed) Implementation.Hybrid smart account is rejected at /verify with invalid_exact_evm_erc7710_account_not_delegated ("delegator EOA must complete an EIP-7702 upgrade … before ERC-7710 verify or settle"). The buyer-with-delegations guide's Hybrid example reads as if any smart account works. Suggestion: state explicitly that the x402+7710 buyer path requires an on-chain 7702-upgraded account, and cross-link the 1Shot relayer as the gas-free way to perform that upgrade.

2. 1Shot relayer fee units are inconsistent between two endpoints. relayer_getFeeData.minFee is a decimal string in human units ("0.01") with token.decimals provided, but relayer_estimate7710Transaction.requiredPaymentAmount is in base units ("10000"). Mixing them (e.g. BigInt("0.01")) throws. Suggestion: document the unit of each field in the OpenRPC spec, or normalize both to base units.

3. Venice SIWE nonces violate strict EIP-4361 parsers. The sign-in-with-x challenge nonce can contain "-" (e.g. vo-RtfnCZqxtx-g6ub8Ct), which spec-strict helpers (viem's createSiweMessage) reject — EIP-4361 requires alphanumeric nonces. Builders must hand-roll the message. Suggestion: issue alphanumeric nonces.

4. Venice SIWE credentials are single-use, and only some endpoints serve challenges. Reusing a signed header returns X402_SIGN_IN_NONCE_REUSED; inference endpoints (e.g. /chat/completions) return 402 without a sign-in-with-x extension. What actually works — self-generating a fresh nonce per request client-side — is undocumented. Suggestion: document the self-generated-nonce flow and the per-request single-use rule explicitly.

All four are handled in our codebase and recorded in docs/superpowers/spikes/.

Everything was built during the hackathon. We shipped the full stack: a MetaMask ERC-7715 grant flow on the dashboard, a chief agent that redelegates ERC-7710 budget slices to three specialists, x402-gated payments for premium data and Venice AI inference settling through the MetaMask facilitator, and mainnet payroll through the 1Shot permissionless relayer (gas paid in USDC, account bootstrapped via EIP-7702, status over Ed25519-signed webhooks). We verified a full end-to-end agent job on Base Sepolia and a real 1Shot settlement on Base mainnet, deployed the dashboard (Vercel) and API (Render), and hardened the hosted demo (concurrency and eviction caps, a code-grounded analyst that cannot fabricate on-chain data, and an abortable kill switch). 112 tests pass and the codebase went through multiple security and code reviews.

Independent hackathon project, not currently raising. Built and self-funded during the event. We would welcome grants or ecosystem support to develop the agent-payments and delegation infrastructure further.