---
metadata:
  - name: generator
    content: Diplodoc Platform v5.50.6
alternate:
  - https://ydb.tech/docs/en/reference/observability/tracing/external-traces.md?version=main
  - https://ydb.tech/docs/ru/reference/observability/tracing/external-traces.md?version=main
sourcePath: en/core/reference/observability/tracing/external-traces.md
---
> **Documentation Index:** Fetch the complete configuration index at https://ydb.tech/docs/en/llms.txt

# Passing external trace-id to YDB

## gRPC API

YDB supports passing external trace-id to build a complete operation trace. The trace-id is passed according to the [trace context specification](https://w3c.github.io/trace-context/#traceparent-header) — a string of the form `00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01` must be passed through the `traceparent` header of the gRPC request. It consists of 4 parts separated by the `-` character:

1. Version – at the time of writing, the specification defines only version 00.
2. Trace id – the identifier of the trace that the request is part of.
3. Parent id – the identifier of the parent span.
4. Flags – a set of recommendations for handling the data passed in the header.

Only version 00 is supported; flags are ignored. If the header does not conform to the specification, it is ignored. All traces obtained this way have [detail level](https://ydb.tech/docs/en/reference/observability/tracing/setup.md?version=main#tracing-levels) 13 (all components are traced at level `Detailed`).

{% note warning %}

If the [`external_throttling`](https://ydb.tech/docs/en/reference/observability/tracing/setup.md?version=main#external-throttling) section is present and the request flow exceeds the set limits, not all requests may be traced. If the [`external_throttling`](https://ydb.tech/docs/en/reference/observability/tracing/setup.md?version=main#external-throttling) section is absent, the `traceparent` header is **ignored** and no external traces are continued.

{% endnote %}

## SDK support

Some SDKs support trace-id passing; you can find their list and usage examples on the [Tracing with OpenTelemetry](https://ydb.tech/docs/en/reference/ydb-sdk/observability/tracing/opentelemetry.md?version=main) page.