---
title: "Get system clock synchronization state"
method: GET
path: "/api/system/clock"
tags: ["System"]
---

# Get system clock synchronization state

`GET /api/system/clock`

Returns the current kernel time-discipline state as reported by
`ntp_adjtime(2)`. This includes the TAI-UTC offset, PLL status,
current offset being applied, and frequency adjustment — the same
information used by chrony, ntpd and systemd-timesyncd.

Useful for diagnosing flows that use `Realtime` or `Tai` pipeline
clocks, where the accuracy depends on how the OS clock is being
synchronized.

## Response `200`

System clock state

- SystemClockInfo — System clock synchronization information. Reads the kernel's `ntp_adjtime()` state (same information used by chrony, ntpd, systemd-timesyncd, etc.) and reports how the system clock is being disciplined. Relevant for flows using Realtime or TAI pipeline clocks.
  - `est_error_us` integer, required — Estimated error, in microseconds.
  - `frequency_ppm` number, double, required — Current frequency adjustment in parts-per-million.
  - `last_update` integer, nullable — Timestamp when this info was read (Unix seconds).
  - `max_error_us` integer, required — Maximum error estimate, in microseconds.
  - `offset_ns` integer, required — Current time offset being applied to the clock, in nanoseconds.
  - `pll_active` boolean, required — Whether PLL discipline is active (STA_PLL).
  - `state` string, required — High-level state from `ntp_adjtime()` return value. One of: `ok`, `ins` (leap insert pending), `del`, `oop`, `wait`, `error` (unsynced).
  - `synchronized` boolean, required — Whether the kernel considers the clock synchronized (STA_UNSYNC not set).
  - `tai_offset_sec` integer, required — TAI - UTC offset in seconds (typically 37 as of 2026). Set by the clock sync daemon so that `CLOCK_TAI` is correct.

## Other responses

- `500` — Failed to read system clock state

---

[API](https://skmtc.net/eyevinn/apis/strom-api.md) · [All operations](https://skmtc.net/eyevinn/apis/strom-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/eyevinn/strom-api/versions/c96558b86012/schema)