Developers

Build your experience on Hamiltonn.

Documented REST APIs, signed webhooks, scoped keys and a sandbox that behaves like production. The platform your product runs on should feel like it was built by engineers — because it was.

Request sandbox access Headless architecture
Full documentation at docs.cloud.hamiltonn.net — coming with general availability
POST /v1/customersAPI
POST /v1/customers
Authorization: Bearer sk_sandbox_…

{
  "type": "business",
  "name": "ABC Limited",
  "email": "ops@abclimited.co.uk"
}

# 201 Created
{
  "id": "cus_9f2K4Lq",
  "type": "business",
  "status": "active",
  "created_at": "2026-08-08T10:24:08Z"
}

API design

Predictable by principle.

Resource-oriented

Customers, accounts, transactions, projects, agents — nouns you expect, verbs that behave.

Versioned

Breaking changes only behind explicit version bumps. Your integration keeps working.

Consistent errors

Structured error objects with type, message and a request id for support.

Cursor pagination

Stable pagination on every list endpoint. No page-number lies.

Authentication

Scoped keys per environment.

  • Bearer keys — sandbox and production keys are visibly distinct.
  • Scopes — grant a key only the resources it needs.
  • Rotation — rotate keys without downtime.
  • Server-side policy — approval rules apply to API calls too; a key cannot bypass your controls.
AuthenticationKeys
# keys are environment-prefixed
sk_sandbox_Xh29kQ…   # sandbox — safe to experiment
sk_live_9One4Lm…     # production — scoped + rotatable

curl https://api.sandbox.hamiltonn.cloud/v1/me \
  -H "Authorization: Bearer sk_sandbox_Xh29kQ…"

Webhooks

Everything that happens, streamed to you.

Signed events with delivery retries. Verify the signature, act on the event, replay from the log if you ever miss one.

  • Signatures — verify authenticity on every delivery.
  • Retries — failed deliveries retry with backoff.
  • Event log — inspect and replay past events.
webhook: transaction.settledEvent
{
  "id": "evt_2Kq8Zw",
  "event": "transaction.settled",
  "created_at": "2026-08-08T10:26:41Z",
  "data": {
    "transaction": "txn_51Qa",
    "account": "acc_7Hw2Rt",
    "amount": "12400.00",
    "currency": "GBP"
  }
}

Sandbox

Break things where it doesn’t matter.

Production-shaped

The sandbox mirrors production behaviour, workflows and webhooks.

Test data

Seeded customers, accounts and projects to integrate against immediately.

Simulators

Trigger settlement, approval and failure scenarios on demand.

Integration guides

Step-by-step guides — first request, webhooks, going live — ship with sandbox access today and move to docs.cloud.hamiltonn.net at general availability. Platform status will be published at status.cloud.hamiltonn.net.

Get sandbox keys.

Tell us what you are building and we will provision sandbox access with a technical walkthrough.

Request access Headless architecture