FOR DEVELOPERS AND AI AGENTS

Can this agent do that?
Did it actually happen?

Curbi is control and evidence for AI agents that take business actions. Set a limit. Try a refund. See what the agent can honestly say.

ACTION LAB · SIMULATEDNo signup. No money moves.

What did your agent say?

Example policy: Starter costs $49; no guaranteed results; refund claims require a recorded refund. Text stays in your browser.

Agent reply

Change the refund scenario

Requested refund ($)Allowed per action ($)Agent claims ($)

Simulate a timeout after the refund succeeds

One click runs permission, outcome, retry and reply checks.

This is an interactive simulation using Curbi’s gate and checker with a provider stand-in and temporary browser keys. It does not prove a real payment or authorize a production action. Use the public Check API ↗

From your first catch to your app.

Try the public reply checker with one request. Public rate-limited checks need no account or API key.

const result = await fetch('https://api.curbi.io/v1/check', {
  method: 'POST', headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({policy: {actions: {refunded: 'billing.refund'}}, reply: "I've refunded $500."})
}).then(r => r.json());
console.log(result);

This request checks configured claims. It does not authorize or execute refunds. Caller-supplied records are not independent proof.

Read the API guide → · Save your own policy →

Action Lab · behind the simulation

The same discount, through the real gate.

A $500 item, a grant that allows discounts up to $50 each and $100 per hour. Each row below is the gate’s actual decision, with test keys and a fixed clock.

Attempt	Gate decision	Reason	What the caller hears
Rogue: $450 discount to sell the $500 item for $50	refused before any write	`over_grant_limit` 45000 > 5000	“I need to transfer you to a manager to approve that rate.”
Valid: $50 discount	attested, provider-confirmed, receipt signed	`DONE`	—
Second $50 discount (same grant, same hour)	attested: permission signed for this exact discount	`ATTESTED`	—
Third $50 discount: hourly ceiling ($100) reached	refused before any write	`over_hourly_ceiling` 10000 + 5000 > 10000 in the last hour	“I need to transfer you to a manager to approve that rate.”
Timeout after the provider call	held: no receipt, key cannot be re-attested until reconciled	`provider_outcome_unknown`	—
Retry of the timed-out discount with the same key	refused before any write	`held_unknown_outcome` reconcile before any new attempt	“I need to transfer you to a manager to approve that rate.”

Then the agent speaks

Agent says	Check against the signed receipt	Rules
“I've applied a $50 discount. Your total is $450.”	pass	—
“I've applied a $500 discount.”	caught	`fact:contradicts-receipt`

The record is curbi_signed: the Check API verified the receipt’s signature, not the agent’s word. Verify a receipt yourself.

Run a check. Keep the result.

Check a reply Connect your agent →

A pass means no configured rule fired. It grants no execution authority or provider-completion proof.