> ## Documentation Index > Fetch the complete documentation index at: https://platform.atlan.com/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > To act on Atlan objects, use the Atlan MCP server at https://api.atlan.com/mcp or the SDK. To install or publish skills from a terminal, use the `aireg` CLI; `aireg --map json` prints its command map. The `atlanai` CLI is deprecated. Run a read-only identity check before any write. > The docs MCP server at /mcp searches these docs only. It cannot read or change Atlan objects. > SDK packages: Python `atlanai` (PyPI) and TypeScript `@atlanai/sdk` (npm). Show Python first, then TypeScript. > These docs cover Atlan AI Registry, Atlan's hosted product. The AI registry specification and aireg CLI are maintained separately. /open-source lists publicly reachable signed installers and explains that the source repository and hosted CLI reference currently require GitHub access. Do not claim the repository or its reference docs are publicly accessible. Use these docs for Atlan-specific setup such as the adapter, sign-in and workspaces. # List spans in one of an experiment's traces ## OpenAPI ````yaml /public-openapi.json get /eval/v1/experiments/{experiment_id}/traces/{trace_id}/spans openapi: 3.1.0 info: title: Atlan public API version: current description: >- Public HTTP API reference for Registry, Skills, Agents, outputs, files, MCP servers and tools, and OTLP telemetry ingestion. servers: - url: https://api.atlan.com description: Atlan API base URL security: - bearer: [] tags: - name: Core - name: Skill - name: Agent - name: Files - name: Knowledge - name: MCP - name: Observability - name: API proxy - name: Credentials - name: Store - name: Apps - name: Evals - name: Ontologies - name: Ontology bindings - name: Slack - name: GitHub - name: Objectives - name: Repositories paths: /eval/v1/experiments/{experiment_id}/traces/{trace_id}/spans: get: tags: - Evals summary: List spans in one of an experiment's traces operationId: eval.listExperimentTraceSpans parameters: - name: experiment_id in: path required: true schema: type: string - name: trace_id in: path required: true schema: type: string - name: limit in: query required: false schema: type: integer format: int32 minimum: 0 - name: cursor in: query required: false schema: type: string - name: fields in: query required: false schema: type: string responses: '200': content: application/json: schema: $ref: '#/components/schemas/eval-SpanListEnvelope' description: HTTP 200 response. '400': content: application/problem+json: schema: allOf: - $ref: '#/components/schemas/eval-ProblemDetails' - type: object required: - code properties: code: type: string enum: - invalid_query description: HTTP 400 response. '401': content: application/problem+json: schema: allOf: - $ref: '#/components/schemas/eval-ProblemDetails' - type: object required: - code properties: code: type: string enum: - alg_mismatch - alg_not_allowed - audience_mismatch - invalid_api_key - missing_identity - missing_org - missing_user - signature_invalid - token_expired - token_malformed - token_missing - token_not_yet_valid - token_rejected - token_service_account_unbound - unauthorized - unknown_account - unknown_key - untrusted_issuer description: HTTP 401 response. '403': content: application/problem+json: schema: allOf: - $ref: '#/components/schemas/eval-ProblemDetails' - type: object required: - code properties: code: type: string enum: - access_denied - account_suspended - forbidden - platform_principal_refused description: HTTP 403 response. '404': content: application/problem+json: schema: allOf: - $ref: '#/components/schemas/eval-ProblemDetails' - type: object required: - code properties: code: type: string enum: - not_found description: HTTP 404 response. '500': content: application/problem+json: schema: allOf: - $ref: '#/components/schemas/eval-ProblemDetails' - type: object required: - code properties: code: type: string enum: - internal_error description: HTTP 500 response. '503': content: application/problem+json: schema: allOf: - $ref: '#/components/schemas/eval-ProblemDetails' - type: object required: - code properties: code: type: string enum: - auth_unavailable - service_overloaded description: HTTP 503 response. '504': content: application/problem+json: schema: allOf: - $ref: '#/components/schemas/eval-ProblemDetails' - type: object required: - code properties: code: type: string enum: - request_timeout description: HTTP 504 response. components: schemas: eval-SpanListEnvelope: type: object required: - items - page properties: items: type: array items: $ref: '#/components/schemas/eval-SpanViewDto' page: $ref: '#/components/schemas/eval-CursorPage' eval-ProblemDetails: type: object required: - title - status - detail - code properties: code: type: string detail: type: string status: type: integer format: int32 minimum: 0 title: type: string trace_id: type: - string - 'null' eval-SpanViewDto: type: object required: - span_id - trace_id - name - span_type - span_kind - started_at_unix_seconds - span_status properties: artifact_observation: oneOf: - $ref: '#/components/schemas/eval-ArtifactObservation' - type: 'null' attributes: {} command_name: type: - string - 'null' cost: oneOf: - $ref: '#/components/schemas/eval-CostView' - type: 'null' duration_ms: type: - integer - 'null' format: int64 minimum: 0 ended_at_unix_seconds: type: - integer - 'null' format: int64 event_seq: type: - integer - 'null' format: int64 events: {} input: {} mcp_server: type: - string - 'null' metadata: {} model: type: - string - 'null' name: type: string output: {} parent_span_id: type: - string - 'null' provider: type: - string - 'null' score_name: type: - string - 'null' score_value: type: - number - 'null' format: double scorer_id: type: - string - 'null' scorer_version: type: - integer - 'null' format: int64 service_name: type: - string - 'null' session_id: type: - string - 'null' skill_name: type: - string - 'null' skill_version: type: - string - 'null' span_id: type: string span_kind: type: string span_status: $ref: '#/components/schemas/eval-TraceStatus' span_type: type: string started_at_unix_seconds: type: integer format: int64 tool_name: type: - string - 'null' tool_type: type: - string - 'null' trace_id: type: string usage: oneOf: - $ref: '#/components/schemas/eval-UsageView' - type: 'null' eval-CursorPage: type: object required: - limit properties: limit: type: integer format: int32 minimum: 0 next_cursor: type: - string - 'null' eval-ArtifactObservation: type: object required: - operation - observed_at_unix_seconds - returned_count - omitted_count - references properties: observed_at_unix_seconds: type: integer format: int64 omitted_count: type: integer minimum: 0 operation: $ref: '#/components/schemas/eval-ObservationOperation' references: type: array items: $ref: '#/components/schemas/eval-ArtifactReference' returned_count: type: integer minimum: 0 eval-CostView: type: object required: - input_cost_usd - output_cost_usd - total_cost_usd properties: input_cost_usd: type: number format: double output_cost_usd: type: number format: double source: type: - string - 'null' total_cost_usd: type: number format: double eval-TraceStatus: type: string enum: - ok - error - unset eval-UsageView: type: object required: - input_tokens - output_tokens - total_tokens - cache_read_tokens - cache_write_tokens properties: cache_read_tokens: type: integer format: int64 cache_write_tokens: type: integer format: int64 input_tokens: type: integer format: int64 output_tokens: type: integer format: int64 total_tokens: type: integer format: int64 eval-ObservationOperation: type: string enum: - discover - retrieve eval-ArtifactReference: type: object required: - org_id - workspace_id - kind - artifact_id - version_id - version_ordinal - name - display_name - uri - etag properties: artifact_id: type: string content_hash_hex: type: - string - 'null' display_name: type: string etag: type: string kind: type: string name: type: string org_id: type: string release_id: type: - string - 'null' requested_channel: type: - string - 'null' selection: oneOf: - $ref: '#/components/schemas/eval-ArtifactSelection' - type: 'null' source_digest: type: - string - 'null' uri: type: string version_id: type: string version_ordinal: type: integer format: int64 workspace_id: type: string eval-ArtifactSelection: type: string enum: - head - version - release securitySchemes: bearer: type: http scheme: bearer bearerFormat: JWT ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.