# Tessary traces

A trace is one unit in Tessary: the stored record of one agent turn. Traces live in Tessary's
substrate, the agent-native store every other part of the product reads from. The substrate has
three fixed levels: the session, the trace (one turn), and the span (one step, an LLM call or a tool
call). The levels match how agents actually run: a user session holds turns, and each turn holds the
steps the agent took to produce its answer.

Each level is keyed on your own ids, and a span carries the actual content of its step: the
payloads, tool calls, retrieved documents, and media. Spans can also carry tessary.call_site.id, a
plain span attribute that needs no SDK. It's what findings, baselines, and regressions bind to.

To send traces, point the OpenTelemetry exporter your agent already uses at Tessary over OTLP, or
use the SDK push source if your stack doesn't have one. PII redaction runs on the write path, before
anything is stored. Classifiers, cases, and root cause analysis all read this same stored record, so
every conclusion cites evidence you can open.

## Questions answered under this concept

- [Does Tessary read my Langfuse account?](https://tessary.ai/answers/tessary-traces/does-tessary-read-my-langfuse-account)
- [Does Tessary store images from my agent's traces?](https://tessary.ai/answers/tessary-traces/does-tessary-store-images-in-traces)
- [Is Tessary a trace explorer?](https://tessary.ai/answers/tessary-traces/is-tessary-a-trace-explorer)
- [What does a production span carry that a dataset row cannot?](https://tessary.ai/answers/tessary-traces/what-does-a-production-span-carry-that-a-dataset-row-cannot)
- [What is a trace?](https://tessary.ai/answers/tessary-traces/what-is-a-trace)
- [What structure does an ingested agent trace have?](https://tessary.ai/answers/tessary-traces/what-structure-does-an-ingested-trace-have)

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Source: https://tessary.ai/answers/tessary-traces
All concepts: https://tessary.ai/answers
From Tessary, agent reliability for AI agents in production: https://tessary.ai