Your first policy

You now have an agent that flows through Klent but has no rules to enforce — every action is allowed by default. Let us change that.

A realistic scenario

Suppose your billing agent has a transfer_funds tool. It should never be allowed to move more than $10,000 in a single call. Everything else is fine.

The policy:

• Tool: transfer_funds
• Condition: input.amount > 10000
• Effect: deny

Create the policy

In the dashboard

Go to Policies → New policy and fill in:

Save. The rule is live immediately.

Via the API

curl -X POST https://api.klent.dev/v1/policies \
  -H "Authorization: Bearer $KLENT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Block high-value transfers",
    "enabled": true,
    "effect": "deny",
    "conditions": [
      { "field": "input.amount", "operator": "greater_than", "value": 10000 }
    ]
  }'

Watch it fire

Call evaluateAction with an amount over the limit:

const decision = await klent.evaluateAction({
  execution_id: execution.id,
  tool: 'transfer_funds',
  input: { to_account: 'BR-9921', amount: 50_000, currency: 'USD' },
});

console.log(decision);
// {
//   decision: 'deny',
//   matched_policy_id: 'pol_…',
//   modifications: null,
//   reason: 'Matched policy "Block high-value transfers"'
// }

And with one under the limit:

const decision = await klent.evaluateAction({
  execution_id: execution.id,
  tool: 'transfer_funds',
  input: { to_account: 'BR-9921', amount: 5_000, currency: 'USD' },
});

console.log(decision.decision); // → 'allow'

What just happened

• Klent compiled your policy once (in memory, per project).
• On each evaluation it walked your enabled policies in creation order, checked the condition against the action payload, and returned on the first match.
• The decision was recorded as an event on the execution timeline. Denials become action_blocked events; allows become decision events.

Combine conditions

All conditions in a single policy are AND-ed together. To block only transfers above $10k made in USD, add a second condition:

{
  "name": "Block high-value USD transfers",
  "effect": "deny",
  "conditions": [
    { "field": "input.amount", "operator": "greater_than", "value": 10000 },
    { "field": "input.currency", "operator": "equals", "value": "USD" }
  ]
}

For OR semantics, create two policies with the same effect.

Next

• Read the policy engine reference — all operators, the five effects (allow / deny / modify / approve / steer), evaluation order, field resolution, shadow / dry-run mode.
• Use auto-instrumentation so you don't have to call evaluateAction and logEvent by hand.
• Set up alerts in the dashboard (Alerts → New alert) so you hear about denials, errors, or pending approvals without having to watch the timeline live. Email and webhook delivery, with retries.