A spending firewall for AI agents.

Hand an autonomous agent a funded wallet without the fear. A private model must approve every payment before the money can move — and the budget is a MetaMask delegation it physically cannot exceed. Two locks: whether, and how much. Neither trusted; both enforced on-chain.

Stack
A2A Capped sub-budgets via re-delegation (ERC-7710)
x402 Agents pay agents via HTTP 402 pay-per-call
1SHT Gasless settlement through 1Shot relayer
VNC Private reasoning via Venice zero-retention AI
Dwg: Delegation Tree — Authority Flow Live on Base
DWG: DELEGATION-TREE-01 SCALE: SCHEMATIC MAYOR — YOU City Treasury ERC-7715 grant <= 5.00 USDC 5.00 USDC MANAGER AGENT Re-Delegates sub-budgets <= 5.00 USDC 0.50 USDC ANALYST AGENT Analysis sub-delegation <= 0.50 USDC cap RESEARCH AGENT Research sub-delegation <= 0.50 USDC cap ■ ALL CAPS ENFORCED ON-CHAIN ■ OVERSPEND REVERTS BY CONSTRUCTION
7715 FIG. 1 — AGENT CITY · ELEVATION SCALE: SCHEMATIC

A full agent economy — bounded by cryptography

Every cap is on-chain. Not trust — math.

  1. A

    Fund the city

    You grant the city treasury a master budget via MetaMask Advanced Permissions (ERC-7715) — a scoped delegation with a hard USDC cap. The agents hold no keys.

  2. B

    Hire specialists

    The Manager re-delegates narrower sub-budgets to worker agents (ERC-7710). A worker can never access more than it was handed — the chain enforces it.

  3. C

    Agents pay agents

    Workers hit real HTTP 402 paywalled services. Each payment settles as a bounded ERC-7710 redemption, relayed gaslessly through 1Shot with gas paid in USDC.

  4. D

    Revoke the whole city

    Pull authority in one click. The Manager and every worker beneath it is cut off instantly — the next spend never clears, and nothing new settles on-chain.

On-Chain Proof — Transaction Log Proven on Base Sepolia & Base mainnet — not a mock
Best A2A Coordination — Sheet 01/04
Agents hire agents

A Manager re-delegates a narrower budget to a worker. The chain enforces the smaller cap — the transaction reverts if the worker tries to exceed it.

0x24af…ae27 ↗
Settled
A2A / ERC-7710 · Base Sepolia 0x24af…ae27
Best x402 + ERC-7710 — Sheet 02/04
Agents pay agents

A worker hits a real HTTP 402 paywalled service and settles the payment as a bounded ERC-7710 redemption. Resource unlocks only after chain confirmation.

0xbbce…450b ↗
Settled
x402 / ERC-7710 · Base Sepolia 0xbbce…450b
Best 1Shot Relayer — Sheet 03/04
Gasless settlement

Every payment redeems through 1Shot’s permissionless relayer. Gas paid in USDC — no ETH required. Proven on Base mainnet, not testnet.

0x0349…48bf ↗
Settled
1Shot Relayer · Base mainnet 0x0349…48bf
Best Venice AI — Sheet 04/04
Private reasoning

Every agent reasons with Venice’s zero-retention model. Reasoning traces appear live in the City UI — each worker shows exactly how it chose to spend.

Watch agents reason →
Venice AI · Zero-retention live in /app
The Thesis — Architecture
The budget is the leash

Autonomous AI spending is the unsolved part of agent coordination. Agent City solves it with on-chain caps — so autonomy never means unbounded financial risk.

See it move money →
ERC-7715 / ERC-7710 · Base on-chain caps
Best Agent — Bounded Autonomy
Bounded autonomy

Each agent runs a resumable planner — reason, propose, act — but only inside its cap. The approval step pauses before any value moves, keeping you in control.

Enter the city →
Best Agent · Agent City approve-first
SPC-01 / KEY-CUSTODY

No agent holds your keys

Agents sign nothing on your behalf beyond the scoped delegations you explicitly grant down the tree. Your wallet stays in your custody.

SPC-02 / CAP-ENFORCEMENT

Every cap is cryptographic

Budgets are on-chain caveats, not prompts. Exceed one and the transaction reverts — by construction, not by policy or agent goodwill.

SPC-03 / REVOCATION

Revoke the whole tree

Pull authority in one click — every worker beneath the Manager is cut off the instant you revoke; no further payment goes through.

Watch a city of agents transact under hard caps.

The live demo runs on Base: the Manager hires workers, they pay via x402, 1Shot settles on-chain — and you can revoke the whole city in one click.

Enter the city →