[ Kontor / Developers ]
An API for engineers who have run a ledger before.
Kontor exposes the same primitives our own agents use: products, accounts, ledger events, decisions and cases. There's one REST API with typed SDKs for TypeScript and Python.
Money
Integer minor units, always
Amounts are integers in minor units with an ISO 4217 currency. Rounding happens once, in the ledger, under the product's declared rule.
Writes
Idempotent by key
Every write accepts an idempotency key. Retries return the original result, so a timeout never creates a second loan or a duplicate payment.
Reads
As-of on everything
Any balance or schedule can be queried with effective_at and known_at, which is how you reconcile, answer complaints and rebuild a past statement.
Events
Ordered, signed webhooks
Webhooks are signed with HMAC, ordered per account and replayable from a cursor. If an endpoint goes down you replay from the cursor; nothing is lost.
[ Webhooks ]
Every ledger event and agent decision, as it happens.
| ledger.* | posting.created, interest.accrued, allocation.applied, interest.restated |
| card.* | authorised, declined, cleared, reversed, hold.expired |
| loan.* | opened, schedule.amended, settlement.quoted, settled |
| agent.* | action.taken, proposal.created, proposal.approved, escalated |
| case.* | dispute.opened, s75.decided, complaint.opened, final_response.sent |
agent.proposal.created
POST /webhooks/kontor kontor-signature: t=1759484400,v1=9f2c…{ "id": "evt_01JB7Q…", "type": "agent.proposal.created", "account": "LN-20481", "sequence": 1182, "effective_at": "2026-03-01", "recorded_at": "2026-03-05T14:02:11Z", "data": { "agent": "arrears", "action": "plan.reduced_payment", "policy": "pol_conc7_v12#4.2", "requires": "approval", "rationale_url": "https://console.kontor.dev/r/…" }}Documentation
Full API reference and sandbox access.
The API reference, product config schema and a sandbox with synthetic portfolios are available to teams evaluating Kontor. Public docs, a status page and a changelog are on the way.
Run your credit book on Kontor.
Bring a product spec or a portfolio extract. We'll show you how the ledger, decisions and agents would run it, and what your regulator would see.