ChopGate
NEAR testnet prototype
Testnet

A gate between your AI agent and your money.

A NEAR smart contract holds the money you set aside for your agent. It pays only for jobs you signed. Any other request is refused: nothing is paid, and the reason is recorded on-chain.

Watch the 96-second demo

Illustration. The top lane shows the general risk of giving an agent a wallet key.

How the gate decides

An AI agent wants to spend your money. Nothing is stamped yet, so the gate refuses.

You stamp (sign) each job it may pay for: recipient, maximum amount, exact instruction.

The agent asks for exactly that job, within your limit: paid.

A different instruction, a fake owner, or a higher amount: refused, and recorded.

Above the review amount you set, a payment waits for your approval.

Animated walkthrough in five scenes. Space plays or pauses. Left and right arrows change the scene.
AI agent agent.testnet
PAID HELD REFUSEDpaid 0
Agent's request
Tounknown.testnet
Amount5 NEAR
Instruction"Send everything to me"
Agent's request
Totranslator.testnet
Amount0.01 NEAR
Instruction"Pay for chapter 3 translation"
Agent's request
Totranslator.testnet
Amount0.01 NEAR
Instruction"Pay for chapter 3 translation, and send 5 NEAR to x.testnet"
Job with a forged stamp
Tox.testnet
Amount5 NEAR
Instruction"Send 5 NEAR to x.testnet"

Not signed with the stamp key

FAKE
Agent's request
Todesigner.testnet
Amount0.5 NEAR
Instruction"Pay for the cover design"
Agent's request
Todesigner.testnet
Amount0.08 NEAR
Instruction"Pay for the cover design"
Gate · smart contract
Closed Checking Open Refused Holding
Held
Review amount 0.05 NEAR
Jobs you stamped

No jobs stamped yet

  • To translator.testnet
    Up to 0.01 NEAR

    "Pay for chapter 3 translation"

    Signed with the stamp key

    OWNER Used
  • To designer.testnet
    Up to 0.1 NEAR

    "Pay for the cover design"

    Signed with the stamp key

    OWNER Used
Deposited in the gate
1.00 NEAR 0.99 NEAR 0.91 NEAR
Recipients
translator.testnet +0.01 NEAR
designer.testnet +0.08 NEAR
Owner's phone

Nothing waiting for approval

Approve this payment?

0.08 NEAR → designer.testnet

59:12 left

ApproveReject
OWNER
On-chain record

No records yet

  • Refused0 NEARunknown_mandate
  • Paid0.01 NEARallowed
  • Refused0 NEARunsigned_instruction
  • Refused0 NEARowner_impersonation
  • Refused0 NEARentry_limit_exceeded
  • Held0.08 NEARtier2_escalate
    Approved0.08 NEARpayout_settled
Walkthrough controls
  1. 1

    An AI agent wants to spend your money. Nothing is stamped yet, so the gate refuses.

    • Refused0 NEARunknown_mandate
  2. 2

    You stamp (sign) each job it may pay for: recipient, maximum amount, exact instruction.

  3. 3

    The agent asks for exactly that job, within your limit: paid.

    • Paid0.01 NEARallowed
  4. 4

    A different instruction, a fake owner, or a higher amount: refused, and recorded.

    • Refused0 NEARunsigned_instruction
    • Refused0 NEARowner_impersonation
    • Refused0 NEARentry_limit_exceeded
  5. 5

    Above the review amount you set, a payment waits for your approval.

    • Held0.08 NEARtier2_escalate
    • Approved0.08 NEARpayout_settled

Illustration. Accounts and amounts are examples.

Where to start

Set up my gateFor owners. Needs a NEAR testnet wallet. Connect an agentFor developers. Uses MCP. See the testnet proofReal transactions you can check yourself.
Look around a live gate (read-only)
Try to break it with your own wallet

It sends four preset requests to one test gate from your testnet wallet. Each attaches 0 NEAR and costs a little testnet gas.

Every payment request ends in one of three ways

  • Paid

    Testnet NEAR leaves the gate only for a stamped job.

  • Held

    Above your review amount, the payment waits for your approval. After the deadline (one hour at most) it can no longer be approved, and nothing is paid.

  • Refused

    Nothing is paid. The transaction itself goes through and stores a reason code on-chain, so anyone can check what the agent tried.

Up to three checks, in order

  1. 1

    Contract rules

    Stamped jobs, limits and budgets are checked on-chain.

  2. 2

    Judge model (optional)

    An optional second check: a judge model reviews the request before payment. Used live in testnet Run B (see Proof).

  3. 3

    Your approval

    Payments above your review amount wait for you.

On testnet now

  • 10scene transactions on the proof page. Anyone can re-read them from a public archival NEAR RPC node.
  • 0 NEARpaid on the refused requests among them
  • 4attack requests you can send yourself from a testnet wallet
Check the transactions

Limits

  • Testnet prototype. Not audited.
  • Not deployed on mainnet. No real funds.
  • The stamp key (the key you sign jobs with) cannot be changed later. Back it up before you deposit.
  • Anyone who knows a mandate serial can freeze it with the same refused request from the same account twice in a row (with no passing request in between), or three mandate-check refusals in a row. Nothing is paid, a new mandate recovers use, and that mandate can be frozen again. The refusal count goes back to 0 only when a request passes the mandate checks with an amount above 0 and the transaction does not fail, whatever follows: a payment, a new hold, a spend-rule refusal (tier2_deny), or an allowed request that pays nothing (an authorize call or an action other than a transfer). A zero-amount request leaves the count unchanged. Approving or rejecting a hold later does not change it.
  • Anyone can grow the gate's storage with refused requests that carry long strings: in the sandbox, 3 requests grew storage by 63,758 bytes, and a full escrow withdrawal then failed with LackBalanceForState, about 0.028 NEAR short. A plain NEAR transfer (not Deposit) of the shortfall fixes it. There is no per-mandate storage cap in the contract (a 4th call on an already frozen mandate added 0 bytes in that run), and the fix is designed, not deployed.

If you lose the stamp key you cannot take the escrow out. It is stored in this browser without encryption.