# Posti (Finland) Tracking API & MCP

URL: https://docs.lastscanned.com/carriers/posti

Query live **Posti** (`posti`) item status and scan history in a single synchronous `GET` request or MCP tool call. `lastscanned` auto-detects UPU S10 numbers ending `FI` and returns a normalized `TrackingResult` JSON payload, without an OmaPosti login.

## Overview & Quick Facts

| Property | Value |
|---|---|
| **Carrier slug (`?carrier=`)** | `posti` |
| **Brand & service aliases** | Posti, Posti Finland, Itella, OmaPosti, Smartposti |
| **Category** | Finnish national post and parcel network |
| **Single-package REST endpoint** | `GET https://api.lastscanned.com/v1/track/{trackingNumber}` |
| **Batch REST endpoint** | `GET https://api.lastscanned.com/v1/track?numbers=CA291746308FI,...` |
| **MCP server (`https://mcp.lastscanned.com`)** | `track_package`, `track_packages`, `list_carriers` (`claude mcp add --transport http lastscanned https://mcp.lastscanned.com`) |
| **Authentication & pricing** | `Authorization: Bearer lsk_live_...` · **1 free keyless lookup/day per IP** · **Free tier** (5 unique numbers/day, $0) · **Pro** ($4.99/mo for 1,000 unique numbers, unlimited re-polls, $0.015/extra) · **HTTP 402 Stripe MPP** ($0.50 for 25-number `lsk_pack_` key or $0.02/number in USDC on Tempo) |

## Why developers use `lastscanned` for Posti

- **No OmaPosti account**: the posti.fi tracking page asks Posti's auth service for an anonymous session and then queries its GraphQL API. `lastscanned` does the same and returns JSON from one `fetch()`.
- **Package-level scans**: when a shipment holds several parcels, the scans of the parcel you asked for are returned.
- **Reasons kept**: when Posti gives a reason for an event (for example a failed delivery attempt), it is appended to the description.

## Tracking Number Formats & Auto-Detection (`matches` vs `?carrier=posti`)

| Pass | Rule / Regex | Check Digit | Examples |
|---|---|---|---|
| **Pass 1 (`matches`)** | `/^[A-Z]{2}\d{9}FI$/` with a valid UPU S10 check digit | S10 mod 11 | `CA291746308FI` |
| **Pass 2 (`mayMatch`)** | `/^JJFI\d{14}$/` (Posti parcel number) | — | `JJFI65000000000000` |
| **Explicit (`?carrier=posti`)** | Any other number Posti tracks | — | — |

### When is `?carrier=posti` optional vs required?

- **Optional (auto-detected)**: S10 numbers ending `FI` with a valid check digit (Pass 1) and `JJFI` + 14 digits when no other carrier claims them (Pass 2).
- **Required**: any other Posti number.

## Synchronous `GET` Request & Normalized JSON Response

### `curl`

```bash
curl -s "https://api.lastscanned.com/v1/track/CA291746308FI" \
  -H "Authorization: Bearer $LASTSCANNED_API_KEY"
```

### JavaScript / TypeScript (`fetch`)

```ts
const res = await fetch("https://api.lastscanned.com/v1/track/CA291746308FI", {
  headers: { Authorization: `Bearer ${process.env.LASTSCANNED_API_KEY}` },
});
const pkg = await res.json();
console.log(pkg.status, pkg.events[0]);
```

### MCP `track_package` tool call

```json
{
  "tool": "track_package",
  "arguments": {
    "tracking_number": "CA291746308FI"
  }
}
```

### Normalized `TrackingResult` JSON response

```json
{
  "carrier": "posti",
  "trackingNumber": "CA291746308FI",
  "status": "in_transit",
  "statusDescription": "Item is on its way to the destination country",
  "service": null,
  "deliveredAt": null,
  "deliveredAtLocal": null,
  "signedBy": null,
  "destination": null,
  "events": [
    {
      "timestamp": "2026-10-25T10:12:00Z",
      "localTime": "2026-10-25T10:12:00",
      "status": "in_transit",
      "description": "Item is on its way to the destination country",
      "location": "Vantaa",
      "code": null
    },
    {
      "timestamp": "2026-10-24T07:30:00Z",
      "localTime": "2026-10-24T07:30:00",
      "status": "in_transit",
      "description": "Item has been processed in the sorting centre",
      "location": "Helsinki",
      "code": null
    },
    {
      "timestamp": "2026-10-23T12:05:00Z",
      "localTime": "2026-10-23T12:05:00",
      "status": "in_transit",
      "description": "Item has been received by Posti",
      "location": "Helsinki",
      "code": null
    }
  ]
}
```

> **Times and codes**: Posti's events carry an ISO time and a city but no event code, so `code` is `null`. `timestamp` is set when the ISO time includes an offset. Descriptions are requested in English.
> **No record**: a number Posti has no record of returns `not_found`.

## Related Resources

- **Live browser lookup tool**: [Track a Posti package live on lastscanned.com/lookup/posti](https://lastscanned.com/lookup/posti)
- **Carrier hub**: [All supported carriers](/carriers)
- **Regex & check digits**: [Tracking number formats & auto-detection](/formats)
- **AI support workflows**: [WISMO AI agents & synchronous tracking](/wismo)