> ## Documentation Index
> Fetch the complete documentation index at: https://doc.featherhq.com/llms.txt
> Use this file to discover all available pages before exploring further.

# List the per-turn engineering-waterfall summaries for a v2 conversation

> Session-level engineering list, reconstructed from Langfuse (ENG-689 T3).

Replaces the retired self-hosted ``…/telemetry`` list. Same row contract as the old
``TurnTelemetryListItem`` so the frontend list is unchanged; the source is now Langfuse
observations rebuilt into the per-turn waterfall shape.



## OpenAPI

````yaml /api-reference/openapi.json get /v1/v2/conversations/{conversation_id}/engineering/turns
openapi: 3.1.0
info:
  title: Feather API
  description: >-
    Unified customer experience platform API. Manages identity, conversations,
    memory, agents, procedures, policies, model routing, knowledge bases,
    integrations, and runtime execution.
  version: 1.21.0
servers:
  - url: https://api-sandbox.featherhq.com
    description: Sandbox
  - url: http://localhost:8000
    description: Local dev
security: []
paths:
  /v1/v2/conversations/{conversation_id}/engineering/turns:
    get:
      tags:
        - runtime v2
      summary: List the per-turn engineering-waterfall summaries for a v2 conversation
      description: >-
        Session-level engineering list, reconstructed from Langfuse (ENG-689
        T3).


        Replaces the retired self-hosted ``…/telemetry`` list. Same row contract
        as the old

        ``TurnTelemetryListItem`` so the frontend list is unchanged; the source
        is now Langfuse

        observations rebuilt into the per-turn waterfall shape.
      operationId: listV2ConversationEngineeringTurns
      parameters:
        - name: conversation_id
          in: path
          required: true
          schema:
            type: string
            format: uuid
            title: Conversation Id
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/EngineeringTurnSummary'
                title: Response Listv2Conversationengineeringturns
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
      security:
        - APIKeyHeader: []
components:
  schemas:
    EngineeringTurnSummary:
      properties:
        turn_id:
          type: string
          format: uuid
          title: Turn Id
        conversation_id:
          type: string
          format: uuid
          title: Conversation Id
        schema_version:
          anyOf:
            - type: integer
            - type: 'null'
          title: Schema Version
        mode:
          anyOf:
            - type: string
            - type: 'null'
          title: Mode
        turn_ttft_ms:
          anyOf:
            - type: integer
            - type: 'null'
          title: Turn Ttft Ms
        perceived_ttft_ms:
          anyOf:
            - type: integer
            - type: 'null'
          title: Perceived Ttft Ms
        turn_duration_ms:
          anyOf:
            - type: integer
            - type: 'null'
          title: Turn Duration Ms
        tokens_out:
          anyOf:
            - type: integer
            - type: 'null'
          title: Tokens Out
        router_model:
          anyOf:
            - type: string
            - type: 'null'
          title: Router Model
        router_ttft_ms:
          anyOf:
            - type: integer
            - type: 'null'
          title: Router Ttft Ms
        router_duration_ms:
          anyOf:
            - type: integer
            - type: 'null'
          title: Router Duration Ms
        router_tokens_out:
          anyOf:
            - type: integer
            - type: 'null'
          title: Router Tokens Out
        router_target_id:
          anyOf:
            - type: string
            - type: 'null'
          title: Router Target Id
        router_intent:
          anyOf:
            - type: string
            - type: 'null'
          title: Router Intent
        router_fallback_applied:
          type: boolean
          title: Router Fallback Applied
          default: false
        speculation_savings_ms:
          anyOf:
            - type: integer
            - type: 'null'
          title: Speculation Savings Ms
        wasted_tokens:
          anyOf:
            - type: integer
            - type: 'null'
          title: Wasted Tokens
        flags:
          items:
            type: string
          type: array
          title: Flags
        created_at:
          type: string
          format: date-time
          title: Created At
      additionalProperties: false
      type: object
      required:
        - turn_id
        - conversation_id
        - created_at
      title: EngineeringTurnSummary
      description: >-
        Lightweight per-turn summary for the session-level engineering list
        (ENG-689 T3).


        Reconstructed from Langfuse observations (the inverse of the T1
        projector), this preserves the

        exact field set the retired ``TurnTelemetryListItem`` exposed so the
        frontend list contract is

        unchanged. ``created_at`` is the turn root's wall-clock start (the
        projector backdated every

        span to it), not a DB insertion time.
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError
  securitySchemes:
    APIKeyHeader:
      type: apiKey
      in: header
      name: x-api-key

````