---
title: "List the per-turn engineering-waterfall summaries for a v2 conversation"
method: GET
path: "/v1/v2/conversations/{conversation_id}/engineering/turns"
tags: ["runtime v2"]
---

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

`GET /v1/v2/conversations/{conversation_id}/engineering/turns`

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.

## Path parameters

- `conversation_id` string, uuid, required

## Response `200`

Successful Response

- EngineeringTurnSummary[]
  - `turn_id` string, uuid, required
  - `conversation_id` string, uuid, required
  - `schema_version` integer, nullable
  - `mode` string, nullable
  - `turn_ttft_ms` integer, nullable
  - `perceived_ttft_ms` integer, nullable
  - `turn_duration_ms` integer, nullable
  - `tokens_out` integer, nullable
  - `router_model` string, nullable
  - `router_ttft_ms` integer, nullable
  - `router_duration_ms` integer, nullable
  - `router_tokens_out` integer, nullable
  - `router_target_id` string, nullable
  - `router_intent` string, nullable
  - `router_fallback_applied` boolean
  - `speculation_savings_ms` integer, nullable
  - `wasted_tokens` integer, nullable
  - `flags` string[]
  - `created_at` string, date-time, required

## Other responses

- `422` — Validation Error

---

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