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Documentation Index

Fetch the complete documentation index at: https://arize-ax.mintlify.dev/docs/llms.txt

Use this file to discover all available pages before exploring further.

The spans functions are currently in ALPHA. The API may change without notice. A one-time warning is emitted on first use.

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List Spans

List spans for a given project. Supports time-window filtering, SQL-style filter expressions, and cursor-based pagination. 
import { listSpans } from "@arizeai/ax-client";

// By project ID
const { data: spans, pagination } = await listSpans({
  project: "your_project_id",
  limit: 50,
});

// By project name (requires space)
const { data: spans, pagination } = await listSpans({
  project: "My Project",
  space: "my-space",
  startTime: new Date("2026-03-01T00:00:00Z"),
  endTime: new Date("2026-03-08T00:00:00Z"),
  filter: "status_code = 'ERROR'",
  limit: 100,
});

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Parameters

ParameterTypeDescription
projectstringThe project name or ID.
spacestringThe space name or ID. Required when project is a name.
startTimeDateDefaults to 1 week ago.
endTimeDateDefaults to current time.
filterstringSQL-style filter expression (e.g. "status_code = 'ERROR'").
limitnumberMaximum number of spans to return.
cursorstringCursor for pagination.

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Span Fields

Each returned Span object includes:
FieldTypeDescription
namestringThe span name.
context.traceIdstringThe trace ID.
context.spanIdstringThe span ID.
kindstringThe span kind (e.g. "LLM", "CHAIN").
parentIdstring | nullParent span ID, if any.
startTimeDateWhen the span started.
endTimeDateWhen the span ended.
statusCodestring | nullStatus code (e.g. "OK", "ERROR").
statusMessagestring | nullStatus message, if any.
attributesobject | nullSpan attributes (e.g. LLM inputs/outputs).
annotationsAnnotation[]Human annotations attached to this span.
evaluationsEvaluation[]LLM-as-judge evaluations for this span.
eventsSpanEvent[]Events recorded during the span.

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Annotate Spans

Write human annotations to a batch of spans in a project. Annotations are upserted by annotation config name for each span; submitting the same name for the same span overwrites the previous value. Up to 1000 spans may be annotated per request. Spans are looked up within the specified time window (defaulting to the last 31 days). 
import { annotateSpans } from "@arizeai/ax-client";

await annotateSpans({
  project: "My Project",  // project name or ID
  space: "my-space",      // required when project is a name
  annotations: [
    {
      recordId: "your_span_id",
      values: [
        { name: "quality", score: 0.9 },
        { name: "topic", label: "science" },
      ],
    },
  ],
});

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Delete Spans

Permanently delete spans by their IDs. This operation is irreversible. Only spans within the supported lookback window (2 years) are considered. Maximum 5,000 span IDs per call. 
import { deleteSpans } from "@arizeai/ax-client";

await deleteSpans({
  project: "My Project",  // project name or ID
  space: "my-space",      // required when project is a name
  spanIds: ["a1b2c3d4e5f6a7b8", "f8e7d6c5b4a39281"],
});