03NESTED TRACES

Spans, tools & chains

Real LLM apps aren't one call — they're retrievers, tool calls, and chains of model steps. Currai nests spans inside a trace so you get the full tree of a request and can pinpoint exactly which step was slow or wrong.

Arbitrary nesting: spans inside spans inside the root trace.
Mix generations, retriever spans, and plain function spans freely.
Each node carries its own input, output, timing, and metadata.
Works with agent loops, RAG pipelines, and multi-model chains.

↗Follow a trace

Nest a RAG trace 🌳

trace = currai.trace(name="rag-answer")

retrieval = trace.span(name="retrieve-docs", input={"query": question})
docs = vector_store.search(question, k=4)
retrieval.end(output={"doc_ids": [d.id for d in docs]})

gen = trace.generation(name="answer", model="gpt-4o", input=prompt(docs))
gen.end(output=answer)

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