> ## Documentation Index > Fetch the complete documentation index at: https://dsrs.herumbshandilya.com/llms.txt > Use this file to discover all available pages before exploring further. # dspy_rs::trace > Execution trace capture (RFC 0001). Generated from rustdoc JSON at `dspy-rs v0.7.3` (commit `b5da857`). Do not edit by hand; regenerate with `python3 docs/scripts/gen_api.py` (see the script header for the rustdoc commands). Item links lead to full signatures and method docs on docs.rs. Execution trace capture (RFC 0001). ## Re-exports | Item | Description | | ------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------- | | `capture::*` | Glob re-export. | | `export::*` | Glob re-export. | | [`is_replaying`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/fn.is_replaying.html) | Re-export of `replay::is_replaying`. | | [`replay`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/fn.replay.html) | Re-export of `replay::replay`. | | [`ReplayError`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/enum.ReplayError.html) | Re-export of `replay::ReplayError`. | | [`ReplayMode`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/enum.ReplayMode.html) | Re-export of `replay::ReplayMode`. | | [`ReplayReport`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/struct.ReplayReport.html) | Re-export of `replay::ReplayReport`. | | `span::*` | Glob re-export. | | [`TRACE_FORMAT_VERSION`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/serialize/constant.TRACE_FORMAT_VERSION.html) | Re-export of `serialize::TRACE_FORMAT_VERSION`. | ## Modules | Item | Description | | -------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- | | [`capture`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/index.html) | Task-local capture scope for the unified trace format. | | [`export`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/index.html) | Exports: projections of the trace format onto external training and observability conventions (RFC 0001 §4f/§4g). | | [`replay`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/index.html) | Replay scope: serve `Predict` calls from a recorded `Trace` (RFC 0001 §4d/§4e). | | [`serialize`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/serialize/index.html) | JSONL wire format for `Trace`: header line, span lines, optional footer. | | [`span`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/index.html) | The unified trace format (RFC 0001): one `Span` per `Predict` invocation, one `Trace` per rollout. | ## `trace::capture` Task-local capture scope for the unified trace format. ### Structs | Item | Description | | --------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [`SpanGuard`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/struct.SpanGuard.html) | Owns a `SpanId` — event/close attribution travels with the guard, never through "innermost open span" lookups, so interleaved `Predict`s on one task (`futures::join!`) cannot cross... | | [`SpanOutcome`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/struct.SpanOutcome.html) | Everything recorded lazily at span close. | | [`SpanRequest`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/struct.SpanRequest.html) | Everything recorded eagerly at span open. | | [`TraceSink`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/struct.TraceSink.html) | Shared handle to an in-progress trace. | ### Functions | Item | Description | | ----------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | | [`begin_span`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/fn.begin_span.html) | Opens a span in the active capture scope. Returns `None` when no scope is active — the caller does nothing else in that case (zero-overhead path). | | [`capture_with_meta`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/fn.capture_with_meta.html) | `capture` with caller-provided rollout metadata (input, candidate hash, tags). Missing `trace_id`/`started_at_us` are minted at scope start. | | [`capture`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/fn.capture.html) | Runs `f` while recording every `Predict` call on this task into a `Trace`. | | [`is_capturing`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/capture/fn.is_capturing.html) | Returns `true` if the current task is inside a `capture` scope. | ## `trace::export` Exports: projections of the trace format onto external training and observability conventions (RFC 0001 §4f/§4g). ### Re-exports | Item | Description | | --------------------------------------------------------------------------------------------------- | ---------------------------------- | | [`OtelEvent`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelEvent.html) | Re-export of `otel::OtelEvent`. | | [`OtelKeyValue`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelKeyValue.html) | Re-export of `otel::OtelKeyValue`. | | [`OtelSpan`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelSpan.html) | Re-export of `otel::OtelSpan`. | | [`OtelStatus`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelStatus.html) | Re-export of `otel::OtelStatus`. | | [`OtelValue`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/enum.OtelValue.html) | Re-export of `otel::OtelValue`. | | [`RlRollout`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/rl/struct.RlRollout.html) | Re-export of `rl::RlRollout`. | | [`RlTransition`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/rl/struct.RlTransition.html) | Re-export of `rl::RlTransition`. | ## `trace::export::otel` OTel export (RFC 0001 §4g): one-way batch mapping of a finished `Trace` onto OpenTelemetry GenAI semantic conventions — as plain serializable structs in the OTLP/JSON wire shape, w\... ### Structs | Item | Description | | --------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | | [`OtelEvent`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelEvent.html) | OTLP span `Event`. | | [`OtelKeyValue`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelKeyValue.html) | OTLP `KeyValue`. | | [`OtelSpan`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelSpan.html) | One span in the OTLP/JSON wire shape (proto3 JSON mapping: camelCase keys, 64-bit integers as decimal strings, ids as lowercase hex). | | [`OtelStatus`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/struct.OtelStatus.html) | OTLP span `Status`. | ### Enums | Item | Description | | ------------------------------------------------------------------------------------------- | --------------------------------------------------- | | [`OtelValue`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/enum.OtelValue.html) | OTLP `AnyValue` (the oneof arms this export emits). | ### Constants | Item | Description | | ----------------------------------------------------------------------------------------------------------------- | -------------------------- | | [`SPAN_KIND_CLIENT`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/constant.SPAN_KIND_CLIENT.html) | OTLP `SPAN_KIND_CLIENT`. | | [`SPAN_KIND_INTERNAL`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/constant.SPAN_KIND_INTERNAL.html) | OTLP `SPAN_KIND_INTERNAL`. | | [`STATUS_CODE_ERROR`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/otel/constant.STATUS_CODE_ERROR.html) | OTLP `STATUS_CODE_ERROR`. | ## `trace::export::rl` RL rollout export (RFC 0001 §4f): the Agent Lightning / verifiers span convention — one rollout as message lists + reward + per-subcall transitions. ### Structs | Item | Description | | ------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- | | [`RlRollout`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/rl/struct.RlRollout.html) | One rollout: reward plus per-subcall transitions. Serializes to a single JSON object — the JSONL record RL trainers consume. | | [`RlTransition`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/export/rl/struct.RlTransition.html) | One policy subcall — a `Predict` invocation as (prompt messages, emitted completion) with its span metadata. | ## `trace::replay` Replay scope: serve `Predict` calls from a recorded `Trace` (RFC 0001 §4d/§4e). ### Structs | Item | Description | | ---------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------- | | [`ReplayReport`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/struct.ReplayReport.html) | What a replay scope did, returned by `replay` alongside the closure's result. | ### Enums | Item | Description | | ------------------------------------------------------------------------------------------ | ------------------------------------------------------------------- | | [`ReplayError`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/enum.ReplayError.html) | Why a call could not be served from the recording. | | [`ReplayMode`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/enum.ReplayMode.html) | How a replay scope treats a call that does not match its recording. | ### Functions | Item | Description | | ------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [`is_replaying`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/fn.is_replaying.html) | Returns `true` if the current task is inside a `replay` scope. | | [`replay`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/replay/fn.replay.html) | Runs `f` with `trace` as the canned-response source for every `Predict` call on this task. Returns the closure's result and a `ReplayReport` of what was served versus live. | ## `trace::serialize` JSONL wire format for `Trace`: header line, span lines, optional footer. ### Constants | Item | Description | | ------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------- | | [`TRACE_FORMAT_VERSION`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/serialize/constant.TRACE_FORMAT_VERSION.html) | Highest format version this reader understands. | ## `trace::span` The unified trace format (RFC 0001): one `Span` per `Predict` invocation, one `Trace` per rollout. ### Structs | Item | Description | | -------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [`CompId`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.CompId.html) | Per-trace interned component index. The component *name* is the same string the params system addresses: an fx slot name (`"drafter"`) or a facet dotted path (`"pipeline.rater"`). | | [`Eval`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.Eval.html) | The metric result type: one score, optional textual feedback. | | [`ModelEntry`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.ModelEntry.html) | Interned model configuration: `LMConfig` minus live state, minus secrets. | | [`ModelId`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.ModelId.html) | Per-trace interned model configuration. | | [`PrefixEntry`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.PrefixEntry.html) | | | [`PrefixId`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.PrefixId.html) | Per-trace interned prompt prefix (system message + demo turns). One entry per distinct (component, candidate) configuration — demos serialize once per trace, not once per span. | | [`Span`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.Span.html) | One `Predict` invocation: one rendered prompt in, one parsed output out, with the tool loop's inner structure as ordered events. | | [`SpanError`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.SpanError.html) | | | [`SpanId`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.SpanId.html) | Index of a span within its trace. Dense, assigned in insertion order. | | [`Trace`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.Trace.html) | One rollout: ordered spans plus per-trace intern tables. | | [`TraceMeta`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.TraceMeta.html) | | | [`TraceOutcome`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/struct.TraceOutcome.html) | | ### Enums | Item | Description | | -------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------- | | [`SpanErrorKind`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/enum.SpanErrorKind.html) | | | [`SpanEvent`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/enum.SpanEvent.html) | Ordered events inside a span. Tagged; readers skip unknown tags — this is the streaming seam (RFC 0001 §6). | ### Type aliases | Item | Description | | -------------------------------------------------------------------------------- | ----------- | | [`JsonMap`](https://docs.rs/dspy-rs/latest/dspy_rs/trace/span/type.JsonMap.html) | |