--- title: "Get trace span" method: GET path: "/v1/projects/{projectSlug}/traces/{traceId}/spans/{spanId}" tags: ["Traces"] --- # Get trace span `GET /v1/projects/{projectSlug}/traces/{traceId}/spans/{spanId}` Returns one span by id, including the LLM conversation (system instructions, input messages, output messages), tool data (definitions, call id, input, output), and the full OpenTelemetry payload (attributes, resource, events, links) that's excluded from the lighter list shape. ## Path parameters - `projectSlug` string, required — Project slug (human-readable identifier) - `traceId` string, required — 32-character trace identifier. - `spanId` string, required — 16-character span identifier. ## Response `200` Span detail - SpanDetail - `organizationId` string, required — Organization that owns this span. - `projectId` string, required — Project this span belongs to. - `traceId` string, required — Identifier of the trace this span belongs to. - `spanId` string, required — Stable span identifier within the trace. - `parentSpanId` string, nullable, required — Identifier of the parent span. `null` for root spans. - `sessionId` string, nullable, required — Conversation/session identifier set by the SDK. `null` when absent. - `userId` string, nullable, required — End-user identifier set by the SDK. `null` when absent. - `simulationId` string, nullable, required — CUID of the simulation that produced this span. `null` when not a simulation. - `apiKeyId` string, nullable, required — Latitude API key used to ingest the span. `null` when ingested without an API key. - `startTime` string, required — ISO-8601 timestamp at which the span started. - `endTime` string, required — ISO-8601 timestamp at which the span ended. - `name` string, required — Span name (e.g. the entry-point function or route). - `serviceName` string, required — OpenTelemetry `service.name` of the emitting service. - `kind` 'unspecified' | 'internal' | 'server' | 'client' | 'producer' | 'consumer', required — OpenTelemetry span kind. - `statusCode` 'unset' | 'ok' | 'error', required — OpenTelemetry span status code. - `statusMessage` string, required — OpenTelemetry status message. Empty when not set. - `traceFlags` number, required — OpenTelemetry trace flags bitfield. - `traceState` string, required — OpenTelemetry trace state (vendor-specific propagation). Empty when not set. - `errorType` string, nullable, required — Error class/type label when the span errored. `null` for successful spans. - `tags` string[], required — Free-form tags attached at ingest time. - `operation` string, required — GenAI operation category (e.g. `"chat"`, `"embeddings"`, `"execute_tool"`, `"invoke_agent"`) or a custom string for non-GenAI spans. - `provider` string, nullable, required — LLM provider id. `null` for non-LLM spans. - `model` string, nullable, required — Model id as requested. `null` for non-LLM spans. - `responseModel` string, nullable, required — Model id reported by the provider's response. `null` for non-LLM spans. - `tokensInput` number, required — Input tokens consumed by this span. - `tokensOutput` number, required — Output tokens produced by this span. - `tokensCacheRead` number, required — Tokens served from the provider's prompt cache. - `tokensCacheCreate` number, required — Tokens written to the provider's prompt cache. - `tokensReasoning` number, required — Reasoning tokens reported by the model. - `costInputMicrocents` number, required — Cost of input tokens in microcents (100,000,000 per USD). - `costOutputMicrocents` number, required — Cost of output tokens in microcents (100,000,000 per USD). - `costTotalMicrocents` number, required — Total cost in microcents (100,000,000 per USD). - `costIsEstimated` boolean, required — `true` when the cost was derived from public pricing tables instead of the provider's bill. - `timeToFirstTokenNs` number, required — Nanoseconds from the start of the span to its first emitted token. `0` if not measured. - `isStreaming` boolean, required — `true` when the span was produced by a streaming LLM call. - `responseId` string, nullable, required — Response identifier returned by the LLM. `null` when the provider didn't return one. - `finishReasons` string[], required — Per-choice finish reasons reported by the LLM provider. - `scopeName` string, required — OpenTelemetry instrumentation scope name. Empty when not set. - `scopeVersion` string, required — OpenTelemetry instrumentation scope version. Empty when not set. - `retentionDays` integer — Per-span retention override in days. Omitted when the project default applies. - `ingestedAt` string, required — ISO-8601 timestamp at which Latitude received this span. - `metadata` object, required — Free-form metadata attached at ingest time. - `systemInstructions` object[], required — System instructions in OpenTelemetry GenAI format — an array of part objects. - `inputMessages` GenAISpanMessage[], required — Input messages sent into this LLM span, in OpenTelemetry GenAI format. - `outputMessages` GenAISpanMessage[], required — Output messages returned by this LLM span, in OpenTelemetry GenAI format. - `toolDefinitions` ToolDefinition[], required — Tool/function definitions made available to the LLM for this span. - `name` string, required — Tool name as exposed to the LLM. - `description` string, required — Tool description as exposed to the LLM. - `parameters` unknown - `toolCallId` string, required — Tool-call id this span answers. Empty when the span isn't an `execute_tool` span. - `toolName` string, required — Name of the executed tool. Empty when the span isn't an `execute_tool` span. - `toolInput` string, required — Stringified arguments passed to the tool. Empty when the span isn't an `execute_tool` span. - `toolOutput` string, required — Stringified tool output. Empty when the span isn't an `execute_tool` span. - `attrString` object, required — OpenTelemetry attributes with string values. - `attrInt` object, required — OpenTelemetry attributes with integer values. - `attrFloat` object, required — OpenTelemetry attributes with floating-point values. - `attrBool` object, required — OpenTelemetry attributes with boolean values. - `resourceString` object, required — OpenTelemetry resource attributes captured at ingest. - `eventsJson` string, required — JSON-encoded OpenTelemetry events array. Empty when the span has no events. - `linksJson` string, required — JSON-encoded OpenTelemetry span-links array. Empty when the span has no links. ## Other responses - `400` — Validation error - `401` — Unauthorized - `404` — Not found --- [API](https://skmtc.net/latitude-dev/apis/latitude.md) · [All operations](https://skmtc.net/latitude-dev/apis/latitude/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/latitude-dev/latitude/versions/6a8789c59a5c/schema)