API Reference

TSE (Technische Sicherheitseinrichtung)

Manage your fiskaly Cloud TSE integration. The TSE is the tamper-resistant security module required by German law (KassenSichV) to cryptographically sign every fiscal transaction.

Legal Requirement

TSE is legally required for all electronic cash register systems in Germany under KassenSichV. A daily self-test is mandated by §4 KassenSichV. Possfer runs this automatically, but you can also trigger it manually via the API.

Check TSE Status

Returns the current health status of the TSE and the result of the last self-test.

GET/api/tse/statusAdmin Only

Retrieve the current health and self-test status of the connected TSE.

Response

json

{
  __PH0__: true,
  __PH1__: {
    __PH2__: "PASSED",
    __PH4__: "2026-03-20T02:00:00Z",
    __PH6__: "2026-03-20T02:00:03Z"
  },
  __PH8__: null
}

Response Fields

Name	Type	Required	Description
`healthy`	`boolean`	Required	Whether the TSE is operational and responding correctly.
`last_self_test`	`object \| null`	Optional	Details of the most recent self-test, or null if no test has been run.
`last_self_test.state`	`string`	Required	Result of the self-test. Possible values: "PASSED", "FAILED", "RUNNING".
`last_self_test.started_at`	`string (ISO 8601)`	Required	Timestamp when the self-test started.
`last_self_test.finished_at`	`string (ISO 8601)`	Required	Timestamp when the self-test completed. Null if still running.
`last_self_test_error`	`string \| null`	Optional	Error message from the last self-test, if it failed.

Run Self-Test

Trigger a manual TSE self-test. Required daily by §4 KassenSichV. Possfer runs this automatically at 02:00 UTC, but you may trigger it manually at any time.

POST/api/tse/self-testAdmin Only

Initiate a manual self-test on the connected TSE. Returns immediately; the test runs asynchronously.

Response

json

{
  __PH0__: "RUNNING",
  __PH2__: "2026-03-20T14:32:10Z",
  __PH4__: null
}

Asynchronous Operation

The self-test runs asynchronously. Poll GET /api/tse/status to check the result. Typical duration is 2-5 seconds.

TSE Information

Retrieve detailed information about the connected TSE device, including serial number, public key, and certificate expiry.

GET/api/tse/infoAdmin Only

Return metadata and identity information for the connected fiskaly Cloud TSE.

Response

json

{
  __PH0__: "tse_abc123def456",
  __PH2__: "Possfer Cloud TSE - Mein Restaurant",
  __PH4__: "INITIALIZED",
  __PH6__: "a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2",
  __PH8__: "BHxGqt5gy...",
  __PH10__: "2028-12-31T23:59:59Z"
}

Response Fields

Name	Type	Required	Description
`_id`	`string`	Required	Unique identifier of the TSE in fiskaly.
`description`	`string`	Required	Human-readable label for this TSE instance.
`state`	`string`	Required	Current TSE state. Values: "INITIALIZED", "DISABLED", "DECOMMISSIONED".
`serial_number`	`string`	Required	Unique serial number of the TSE, printed on receipts.
`public_key`	`string`	Required	Public key for verifying TSE transaction signatures.
`certificate_expiry`	`string (ISO 8601)`	Required	Expiry date of the TSE certificate. Must be renewed before this date.

Certificate Expiry

Monitor the certificate_expiry field. Operating with an expired TSE certificate is a legal violation under KassenSichV. Plan renewal at least 30 days in advance.

List TSE Transactions

Retrieve a list of TSE-signed transactions within a date range. Useful for audit trails and DSFinV-K export verification.

GET/api/tse/transactionsAdmin Only

List TSE transactions filtered by date range.

Query Parameters

Name	Type	Required	Description
`from`	`string (ISO 8601)`	Required	Start of the date range (inclusive). Example: 2026-03-01T00:00:00Z
`to`	`string (ISO 8601)`	Required	End of the date range (inclusive). Example: 2026-03-20T23:59:59Z

Response

json

[
  {
    __PH0__: 1042,
    __PH1__: "FINISHED",
    __PH3__: "POS-001",
    __PH5__: "2026-03-20T11:05:22Z",
    __PH7__: "2026-03-20T11:05:23Z",
    __PH9__: 8847
  },
  {
    __PH10__: 1043,
    __PH11__: "FINISHED",
    __PH13__: "POS-001",
    __PH15__: "2026-03-20T11:12:45Z",
    __PH17__: "2026-03-20T11:12:46Z",
    __PH19__: 8848
  }
]

Response Fields (per transaction)

Name	Type	Required	Description
`number`	`integer`	Required	Sequential transaction number assigned by the TSE.
`state`	`string`	Required	Transaction state. Values: "ACTIVE", "FINISHED", "CANCELLED".
`client_id`	`string`	Required	Identifier of the POS client that initiated the transaction.
`time_start`	`string (ISO 8601)`	Required	When the TSE transaction was started.
`time_end`	`string (ISO 8601)`	Required	When the TSE transaction was finalized.
`signature_counter`	`integer`	Required	Monotonically increasing counter for tamper detection.