Developers

Integrate in an afternoon

Tell Interlink Wallet when your data changes. It works out which passes are affected, what they should now say, and how to deliver the update to every device, safely and exactly once.

Request sandbox access Jump to the Events API

Events API

POST /v1/events

Send the current values for one holder. You do not need to know which passes exist or which platforms they are on; we handle that.

holder_ref: your own identifier for the person, up to 128 characters.
template: the pass template to update, by its short name.
type: a label for your own records, such as commission.cleared.
data: the values your field map reads, as a JSON object.

RequestHTTP

POST /v1/events HTTP/1.1
Host: wallet.interlink.digital
Authorization: Bearer iw_live_...
Idempotency-Key: booking-88213-v3
Content-Type: application/json

{
  "holder_ref": "client-5521",
  "template": "appointment",
  "type": "booking.rescheduled",
  "data": {
    "pet": "Biscuit",
    "starts_at": "2026-10-02T09:30:00Z"
  }
}

Responses

Predictable, retry-friendly results

Errors follow RFC 9457 problem details, and every response carries a request ID you can quote to us.

Status	Meaning	What to do
202 Accepted	Event stored and queued; passes update within seconds	Nothing
200 OK	Same Idempotency-Key seen before; the original event is returned	Nothing, this is safe
400 / 415	Missing Idempotency-Key, invalid JSON or wrong content type	Fix the request
401	Missing, revoked or wrong-environment key, or missing scope	Check the key and its scopes
413	Event larger than 256 KB	Send only the fields your passes use
422	The event failed validation; the detail explains why	Fix the data
429	Rate limit reached; Retry-After says when to try again	Back off and retry

Field maps

Configuration, never code

A field map says where each value comes from and how to format it. It is plain JSON with a closed set of formats, so it can be validated, versioned and previewed, and it can never run arbitrary code.

Format	Example output
currency	£1,234.50 · 1.234,50 € · $0.99
integer / decimal	12,480 · 4.50
date / datetime	1 Aug 2026 · 1 Aug 2026, 14:30
relative_date	Today · Tomorrow, 10:30
text / enum	M365-NC21 · Gold tier

Field mapJSON

{
  "header": {
    "label": "Earned",
    "path": "$.earned_pence",
    "format": "currency", "currency": "GBP",
    "notify": { "on": "increase",
                "message": "Commission cleared: {delta}" }
  },
  "fields": [
    { "id": "pending", "label": "Pending",
      "path": "$.pending_pence",
      "format": "currency", "currency": "GBP" }
  ]
}

Keys and limits

Secure defaults

Scoped API keys

Separate test and live keys, each limited to the scopes it needs. Keys are shown once, stored only as hashes and can be revoked instantly.

Idempotency

Every event needs an Idempotency-Key of 8 to 128 characters. Reusing a key returns the original result instead of creating a duplicate.

Rate limits

Generous per-organisation limits with standard Retry-After headers. Contact us before a large backfill and we will plan it with you.

Coming next

On the developer roadmap

Full REST API

Passes, holders, templates and brands.

Signed webhooks

Installed, removed, scanned and redeemed.

SDKs

PHP and TypeScript first, Python next.

Developer portal

Interactive docs, quickstarts and sandbox keys.

Build with us

Request a sandbox tenant and a test key, and we will help you ship your first live pass.

Request sandbox access